Merge pull request #23 from rfc1437/feat/user-templates

Feat/user templates

.claude/settings.local.json

@@ -13,7 +13,9 @@
       "WebFetch(domain:www.copilotkit.ai)",
       "Bash(grep -l \"A2UIRenderer\\\\|useA2UISurface\\\\|a2ui-surface\" /Users/gb/Projects/bDS/src/renderer/components/**/*.tsx)",
       "Bash(npm test)",
-      "Bash(ls -la /Users/gb/Projects/bDS/*.md)"
+      "Bash(ls -la /Users/gb/Projects/bDS/*.md)",
+      "Bash(grep -n \"templateSlug\\\\|postTemplateSlug\" /Users/gb/Projects/bDS/src/main/engine/*.ts)",
+      "Bash(npm test -- tests/renderer/i18nLocaleCompleteness.test.ts)"
     ]
   }
 }

API.md

@@ -1,6 +1,6 @@
 # API Documentation
 
-Contract version: 1.7.0
+Contract version: 1.9.0
 
 This reference documents all Python runtime API calls available through `bds_api` in embedded Pyodide.
 
@@ -21,6 +21,7 @@ project = await bds.meta.get_project_metadata()
 - [posts](#posts)
 - [media](#media)
 - [scripts](#scripts)
+- [templates](#templates)
 - [tasks](#tasks)
 - [app](#app)
 - [meta](#meta)
@@ -1949,6 +1950,300 @@ None
 
 [↑ Back to Table of contents](#table-of-contents)
 
+## templates
+
+**Module APIs**
+
+- [templates.create](#templatescreate)
+- [templates.update](#templatesupdate)
+- [templates.delete](#templatesdelete)
+- [templates.get](#templatesget)
+- [templates.getAll](#templatesgetall)
+- [templates.getEnabledByKind](#templatesgetenabledbykind)
+- [templates.validate](#templatesvalidate)
+- [templates.rebuildFromFiles](#templatesrebuildfromfiles)
+
+### templates.create
+
+Create template. data must include: title (str), kind ("post"|"list"|"not-found"|"partial"), content (str). Optional: slug (str), enabled (bool).
+
+**Parameters**
+
+- data (dict, required)
+
+**Response specification**
+
+- Return type: `TemplateData`
+- Data structures: `TemplateData`
+
+**Example call**
+
+```python
+from bds_api import bds
+result = await bds.templates.create(data={})
+```
+
+**Example response**
+
+```python
+{
+    'id': 'value',
+    'projectId': 'value',
+    'slug': 'value',
+    'title': 'value',
+    'kind': 'post',
+    'enabled': False,
+    'version': 0,
+    'filePath': 'value',
+    'content': 'value',
+    'createdAt': 'value',
+    'updatedAt': 'value'
+}
+```
+
+### templates.update
+
+Update template by id. data may include any of: title, kind, content, slug, enabled.
+
+**Parameters**
+
+- id (str, required)
+- data (dict, required)
+
+**Response specification**
+
+- Return type: `TemplateData | null`
+- Nullability: Returns `None` when no matching value exists.
+- Data structures: `TemplateData`
+
+**Example call**
+
+```python
+from bds_api import bds
+result = await bds.templates.update(id='id-1', data={})
+```
+
+**Example response**
+
+```python
+None  # or
+{
+    'id': 'value',
+    'projectId': 'value',
+    'slug': 'value',
+    'title': 'value',
+    'kind': 'post',
+    'enabled': False,
+    'version': 0,
+    'filePath': 'value',
+    'content': 'value',
+    'createdAt': 'value',
+    'updatedAt': 'value'
+}
+```
+
+### templates.delete
+
+Delete template by id. Without options, returns references if the template is in use. Pass options={"force": True} to clear references and delete.
+
+**Parameters**
+
+- id (str, required)
+- options (dict, optional)
+
+**Response specification**
+
+- Return type: `TemplateDeleteResult`
+- Data structures: `TemplateDeleteResult`
+
+**Example call**
+
+```python
+from bds_api import bds
+result = await bds.templates.delete(id='id-1')
+```
+
+**Example response**
+
+```python
+{
+    'deleted': False,
+    'references': 'value'
+}
+```
+
+### templates.get
+
+Fetch template by id.
+
+**Parameters**
+
+- id (str, required)
+
+**Response specification**
+
+- Return type: `TemplateData | null`
+- Nullability: Returns `None` when no matching value exists.
+- Data structures: `TemplateData`
+
+**Example call**
+
+```python
+from bds_api import bds
+result = await bds.templates.get(id='id-1')
+```
+
+**Example response**
+
+```python
+None  # or
+{
+    'id': 'value',
+    'projectId': 'value',
+    'slug': 'value',
+    'title': 'value',
+    'kind': 'post',
+    'enabled': False,
+    'version': 0,
+    'filePath': 'value',
+    'content': 'value',
+    'createdAt': 'value',
+    'updatedAt': 'value'
+}
+```
+
+### templates.getAll
+
+Fetch all templates.
+
+**Parameters**
+
+- None
+
+**Response specification**
+
+- Return type: `TemplateData[]`
+- Data structures: `TemplateData`
+
+**Example call**
+
+```python
+from bds_api import bds
+result = await bds.templates.get_all()
+```
+
+**Example response**
+
+```python
+[
+{
+    'id': 'value',
+    'projectId': 'value',
+    'slug': 'value',
+    'title': 'value',
+    'kind': 'post',
+    'enabled': False,
+    'version': 0,
+    'filePath': 'value',
+    'content': 'value',
+    'createdAt': 'value',
+    'updatedAt': 'value'
+}
+]
+```
+
+### templates.getEnabledByKind
+
+Fetch enabled templates filtered by kind.
+
+**Parameters**
+
+- kind (str, required)
+
+**Response specification**
+
+- Return type: `TemplateData[]`
+- Data structures: `TemplateData`
+
+**Example call**
+
+```python
+from bds_api import bds
+result = await bds.templates.get_enabled_by_kind(kind='kind')
+```
+
+**Example response**
+
+```python
+[
+{
+    'id': 'value',
+    'projectId': 'value',
+    'slug': 'value',
+    'title': 'value',
+    'kind': 'post',
+    'enabled': False,
+    'version': 0,
+    'filePath': 'value',
+    'content': 'value',
+    'createdAt': 'value',
+    'updatedAt': 'value'
+}
+]
+```
+
+### templates.validate
+
+Validate Liquid template syntax.
+
+**Parameters**
+
+- content (str, required)
+
+**Response specification**
+
+- Return type: `{ valid: boolean; errors: string[] }`
+
+**Example call**
+
+```python
+from bds_api import bds
+result = await bds.templates.validate(content='content')
+```
+
+**Example response**
+
+```python
+{}
+```
+
+### templates.rebuildFromFiles
+
+Rebuild templates from files.
+
+**Parameters**
+
+- None
+
+**Response specification**
+
+- Return type: `void`
+
+**Example call**
+
+```python
+from bds_api import bds
+result = await bds.templates.rebuild_from_files()
+```
+
+**Example response**
+
+```python
+None
+```
+
+[↑ Back to Table of contents](#table-of-contents)
+
 ## tasks
 
 **Module APIs**
@@ -3579,6 +3874,37 @@ Script definition for Python macros, utilities, and transforms.
 
 [↑ Back to Table of contents](#table-of-contents)
 
+### TemplateData
+
+Liquid template definition for posts, lists, not-found pages, and partials.
+
+**Fields**
+
+- id (`string`, required): Unique template identifier.
+- projectId (`string`, required): Owning project id.
+- slug (`string`, required): Stable template slug.
+- title (`string`, required): Human-readable template title.
+- kind (`'post' | 'list' | 'not-found' | 'partial'`, required): Template category.
+- enabled (`boolean`, required): Whether template is enabled.
+- version (`number`, required): Incrementing template version.
+- filePath (`string`, required): Filesystem path to template file.
+- content (`string`, required): Liquid template source code.
+- createdAt (`string`, required): Creation timestamp (ISO string).
+- updatedAt (`string`, required): Last update timestamp (ISO string).
+
+[↑ Back to Table of contents](#table-of-contents)
+
+### TemplateDeleteResult
+
+Result of a template delete operation. If the template is referenced by posts or tags, deleted is false and references lists the referencing IDs.
+
+**Fields**
+
+- deleted (`boolean`, required): Whether the template was deleted.
+- references (`{ postIds: string[]; tagIds: string[] }`, optional): Post and tag IDs referencing this template (present when deleted is false and references exist).
+
+[↑ Back to Table of contents](#table-of-contents)
+
 ### TaskProgress
 
 Task queue status object for long-running operations.

TODO.md

@@ -6,7 +6,7 @@ independently.
 
 ---
 
-## 1. Template Editor & Per-Entity Template Selection
+## ~~1. Template Editor & Per-Entity Template Selection~~ ✅ Done
 
 ### Goal
 

drizzle/0006_yummy_scorpion.sql

@@ -0,0 +1,16 @@
+CREATE TABLE `templates` (
+	`id` text PRIMARY KEY NOT NULL,
+	`project_id` text NOT NULL,
+	`slug` text NOT NULL,
+	`title` text NOT NULL,
+	`kind` text DEFAULT 'post' NOT NULL,
+	`enabled` integer DEFAULT true NOT NULL,
+	`version` integer DEFAULT 1 NOT NULL,
+	`file_path` text NOT NULL,
+	`created_at` integer NOT NULL,
+	`updated_at` integer NOT NULL
+);
+--> statement-breakpoint
+CREATE UNIQUE INDEX `templates_project_slug_idx` ON `templates` (`project_id`,`slug`);--> statement-breakpoint
+ALTER TABLE `posts` ADD `template_slug` text;--> statement-breakpoint
+ALTER TABLE `tags` ADD `post_template_slug` text;

drizzle/meta/_journal.json

@@ -43,6 +43,13 @@
       "when": 1771792324840,
       "tag": "0005_short_sally_floyd",
       "breakpoints": true
+    },
+    {
+      "idx": 6,
+      "version": "6",
+      "when": 1772213213016,
+      "tag": "0006_yummy_scorpion",
+      "breakpoints": true
     }
   ]
 }

src/main/database/schema.ts

@@ -33,6 +33,7 @@ export const posts = sqliteTable('posts', {
   checksum: text('checksum'),
   tags: text('tags'), // JSON array stored as text
   categories: text('categories'), // JSON array stored as text
+  templateSlug: text('template_slug'), // Optional user template override for this post
   // Legacy columns (kept for migration compatibility, no longer written)
   publishedTitle: text('published_title'),
   publishedContent: text('published_content'),
@@ -111,6 +112,7 @@ export const tags = sqliteTable('tags', {
   projectId: text('project_id').notNull(),
   name: text('name').notNull(),
   color: text('color'), // Optional hex color like #ff0000
+  postTemplateSlug: text('post_template_slug'), // Optional user template override for posts with this tag
   createdAt: integer('created_at', { mode: 'timestamp' }).notNull(),
   updatedAt: integer('updated_at', { mode: 'timestamp' }).notNull(),
 }, (table) => ({
@@ -169,6 +171,23 @@ export const scripts = sqliteTable('scripts', {
   projectSlugIdx: uniqueIndex('scripts_project_slug_idx').on(table.projectId, table.slug),
 }));
 
+// Templates table - stores metadata for Liquid templates persisted in templates/*.liquid
+export const templates = sqliteTable('templates', {
+  id: text('id').primaryKey(),
+  projectId: text('project_id').notNull(),
+  slug: text('slug').notNull(),
+  title: text('title').notNull(),
+  kind: text('kind', { enum: ['post', 'list', 'not-found', 'partial'] }).notNull().default('post'),
+  enabled: integer('enabled', { mode: 'boolean' }).notNull().default(true),
+  version: integer('version').notNull().default(1),
+  filePath: text('file_path').notNull(),
+  createdAt: integer('created_at', { mode: 'timestamp' }).notNull(),
+  updatedAt: integer('updated_at', { mode: 'timestamp' }).notNull(),
+}, (table) => ({
+  // Composite unique index: slug must be unique within each project
+  projectSlugIdx: uniqueIndex('templates_project_slug_idx').on(table.projectId, table.slug),
+}));
+
 // Types for TypeScript
 export type Project = typeof projects.$inferSelect;
 export type NewProject = typeof projects.$inferInsert;
@@ -194,3 +213,5 @@ export type ImportDefinition = typeof importDefinitions.$inferSelect;
 export type NewImportDefinition = typeof importDefinitions.$inferInsert;
 export type Script = typeof scripts.$inferSelect;
 export type NewScript = typeof scripts.$inferInsert;
+export type Template = typeof templates.$inferSelect;
+export type NewTemplate = typeof templates.$inferInsert;

src/main/engine/GenerationRouteRendererFactory.ts

@@ -1,3 +1,4 @@
+import path from 'node:path';
 import type { CategoryRenderSettings } from './PageRenderer';
 import { buildCanonicalPostPath } from './PageRenderer';
 import type { MenuDocument } from './MenuEngine';
@@ -210,6 +211,7 @@ export function createPreviewBackedGenerationRouteRenderer(params: {
       getMenu: async () => menu,
     },
     getActiveProjectContext: async () => projectContext,
+    userTemplatesDir: path.join(params.options.dataDir, 'templates'),
   });
 
   const htmlRewriteContextPromise: Promise<{ canonicalPostPathBySlug: Map<string, string>; canonicalMediaPathBySourcePath: Map<string, string> }> = (async () => {

src/main/engine/GitEngine.ts

@@ -3,6 +3,7 @@ import * as fsPromises from 'fs/promises';
 import * as path from 'path';
 import { execFile } from 'node:child_process';
 import type { GitScriptFileChange, GitScriptFileChangeStatus } from './ScriptEngine';
+import type { GitTemplateFileChange, GitTemplateFileChangeStatus } from './TemplateEngine';
 
 export interface GitAvailability {
   gitFound: boolean;
@@ -142,6 +143,7 @@ export interface GitPostFileChange {
 }
 
 export type { GitScriptFileChange, GitScriptFileChangeStatus };
+export type { GitTemplateFileChange, GitTemplateFileChangeStatus };
 
 type GitProvider = 'unknown' | 'github' | 'gitlab' | 'gitea-forgejo';
 
@@ -534,6 +536,11 @@ export class GitEngine {
     return normalized.startsWith('scripts/') && path.extname(normalized).toLowerCase() === '.py';
   }
 
+  private isTemplatesLiquidPath(value: string): boolean {
+    const normalized = this.normalizeRepoRelativePath(value);
+    return normalized.startsWith('templates/') && path.extname(normalized).toLowerCase() === '.liquid';
+  }
+
   private parseNameStatusOutput(raw: string, pathMatcher: (value: string) => boolean): GitPostFileChange[] {
     const tokens = raw.split('\0').filter((token) => token.length > 0);
     const changes: GitPostFileChange[] = [];
@@ -1388,6 +1395,33 @@ export class GitEngine {
     }
   }
 
+  async getChangedTemplateFilesBetween(projectPath: string, fromCommit: string, toCommit: string): Promise<GitTemplateFileChange[]> {
+    const fromRef = fromCommit.trim();
+    const toRef = toCommit.trim();
+    if (!fromRef || !toRef || fromRef === toRef) {
+      return [];
+    }
+
+    const git = this.createNonInteractiveGit(projectPath);
+    const args = ['diff', '--name-status', '--find-renames', '-z', `${fromRef}..${toRef}`, '--', 'templates'];
+
+    try {
+      const output = await git.raw(args);
+      return this.parseNameStatusOutput(output, (value) => this.isTemplatesLiquidPath(value));
+    } catch (error) {
+      const message = error instanceof Error ? error.message : String(error ?? '');
+      if (this.isSpawnBadFileDescriptorError(message)) {
+        try {
+          const output = await this.runGitCli(projectPath, args);
+          return this.parseNameStatusOutput(output, (value) => this.isTemplatesLiquidPath(value));
+        } catch {
+          return [];
+        }
+      }
+      return [];
+    }
+  }
+
   async pull(projectPath: string): Promise<GitActionResult> {
     const git = this.createNonInteractiveGit(projectPath);
     try {

src/main/engine/MetaEngine.ts

@@ -33,6 +33,8 @@ export interface ProjectMetadata {
 export interface CategoryRenderSettings {
   renderInLists: boolean;
   showTitle: boolean;
+  postTemplateSlug?: string;
+  listTemplateSlug?: string;
 }
 
 /**
@@ -167,6 +169,8 @@ function normalizeCategoryMetadata(value: unknown): Record<string, CategoryMetad
       renderInLists: settings.renderInLists !== false,
       showTitle: settings.showTitle !== false,
       title: sanitizeCategoryTitle(settings.title, category),
+      postTemplateSlug: typeof (settings as any).postTemplateSlug === 'string' ? (settings as any).postTemplateSlug : undefined,
+      listTemplateSlug: typeof (settings as any).listTemplateSlug === 'string' ? (settings as any).listTemplateSlug : undefined,
     };
   }
 
@@ -178,7 +182,12 @@ function normalizeCategorySettings(value: unknown): Record<string, CategoryRende
   return Object.fromEntries(
     Object.entries(metadata).map(([category, data]) => [
       category,
-      { renderInLists: data.renderInLists, showTitle: data.showTitle },
+      {
+        renderInLists: data.renderInLists,
+        showTitle: data.showTitle,
+        postTemplateSlug: data.postTemplateSlug,
+        listTemplateSlug: data.listTemplateSlug,
+      },
     ]),
   );
 }

src/main/engine/PageRenderer.ts

@@ -47,6 +47,8 @@ export interface TemplatePostEntry {
 export interface CategoryRenderSettings {
   renderInLists: boolean;
   showTitle: boolean;
+  postTemplateSlug?: string;
+  listTemplateSlug?: string;
 }
 
 export interface DayBlockContext {
@@ -1021,6 +1023,7 @@ export function resolvePageRendererTemplateRoots(options?: {
   moduleDir?: string;
   cwd?: string;
   resourcesPath?: string;
+  userTemplatesDir?: string;
 }): string[] {
   const moduleDir = options?.moduleDir ?? __dirname;
   const cwd = options?.cwd ?? process.cwd();
@@ -1036,9 +1039,67 @@ export function resolvePageRendererTemplateRoots(options?: {
     roots.unshift(path.resolve(resourcesPath, 'templates'));
   }
 
+  // User templates directory takes highest priority so user templates override built-ins
+  if (options?.userTemplatesDir) {
+    roots.unshift(options.userTemplatesDir);
+  }
+
   return Array.from(new Set(roots));
 }
 
+/**
+ * Resolve which template to use for rendering a single post.
+ * Priority: post.templateSlug -> first matching tag.postTemplateSlug -> category.postTemplateSlug -> default.
+ */
+export function resolvePostTemplateName(
+  post: { templateSlug?: string | null; tags?: string[]; categories?: string[] },
+  tagSettings?: Record<string, { postTemplateSlug?: string | null }>,
+  categorySettings?: Record<string, { postTemplateSlug?: string | null }>,
+): string {
+  if (post.templateSlug) {
+    return post.templateSlug;
+  }
+
+  if (tagSettings && post.tags) {
+    for (const tag of post.tags) {
+      const normalizedTag = tag.toLowerCase().trim();
+      const setting = tagSettings[normalizedTag] || tagSettings[tag];
+      if (setting?.postTemplateSlug) {
+        return setting.postTemplateSlug;
+      }
+    }
+  }
+
+  if (categorySettings && post.categories) {
+    for (const category of post.categories) {
+      const setting = categorySettings[category];
+      if (setting?.postTemplateSlug) {
+        return setting.postTemplateSlug;
+      }
+    }
+  }
+
+  return 'single-post';
+}
+
+/**
+ * Resolve which template to use for rendering a post list.
+ * Priority: category.listTemplateSlug -> default.
+ */
+export function resolveListTemplateName(
+  routeCategory?: string,
+  categorySettings?: Record<string, { listTemplateSlug?: string | null }>,
+): string {
+  if (routeCategory && categorySettings) {
+    const setting = categorySettings[routeCategory];
+    if (setting?.listTemplateSlug) {
+      return setting.listTemplateSlug;
+    }
+  }
+
+  return 'post-list';
+}
+
 export class PageRenderer {
   private readonly mediaEngine: MediaEngineContract;
   private readonly postMediaEngine: PostMediaEngineContract;
@@ -1051,13 +1112,14 @@ export class PageRenderer {
     postMediaEngine: PostMediaEngineContract,
     postEngineForMacros?: PostEngineContract,
     pythonMacroRenderer?: PythonMacroRendererContract,
+    userTemplatesDir?: string,
   ) {
     this.mediaEngine = mediaEngine;
     this.postMediaEngine = postMediaEngine;
     this.postEngineForMacros = postEngineForMacros;
     this.pythonMacroRenderer = pythonMacroRenderer;
 
-    const templateRoots = resolvePageRendererTemplateRoots();
+    const templateRoots = resolvePageRendererTemplateRoots({ userTemplatesDir });
 
     this.liquid = new Liquid({
       root: templateRoots,
@@ -1355,13 +1417,27 @@ export class PageRenderer {
       options,
     );
 
-    return this.liquid.renderFile('post-list', templateContext);
+    const routeCategory = options.archiveContext?.kind === 'category' ? options.archiveContext.name : undefined;
+    const listTemplateName = resolveListTemplateName(
+      routeCategory ?? undefined,
+      options.categorySettings as Record<string, { listTemplateSlug?: string | null }> | undefined,
+    );
+    return this.liquid.renderFile(listTemplateName, templateContext);
   }
 
   async renderSinglePost(
     post: PostData,
     rewriteContext: HtmlRewriteContext,
-    pageContext: { page_title: string; language: string; menu_items?: TemplateMenuItem[]; pico_stylesheet_href?: string; html_theme_attribute?: string; tag_color_by_name?: Record<string, string> },
+    pageContext: {
+      page_title: string;
+      language: string;
+      menu_items?: TemplateMenuItem[];
+      pico_stylesheet_href?: string;
+      html_theme_attribute?: string;
+      tag_color_by_name?: Record<string, string>;
+      tagSettings?: Record<string, { postTemplateSlug?: string | null }>;
+      categorySettings?: Record<string, { postTemplateSlug?: string | null }>;
+    },
     postEngine?: PostEngineContract,
   ): Promise<string> {
     const renderablePost = postEngine
@@ -1397,7 +1473,12 @@ export class PageRenderer {
       },
     };
 
-    return this.liquid.renderFile('single-post', context);
+    const postTemplateName = resolvePostTemplateName(
+      renderablePost as { templateSlug?: string | null; tags?: string[]; categories?: string[] },
+      pageContext.tagSettings,
+      pageContext.categorySettings,
+    );
+    return this.liquid.renderFile(postTemplateName, context);
   }
 
   async renderNotFound(context: NotFoundTemplateContext): Promise<string> {

src/main/engine/PreviewServer.ts

@@ -22,6 +22,7 @@ import {
   type PythonMacroRendererContract,
 } from './PageRenderer';
 import { getScriptEngine } from './ScriptEngine';
+import { getTemplateEngine } from './TemplateEngine';
 import { getPythonMacroWorkerRuntime } from './PythonMacroWorkerRuntime';
 import { getPicoStylesheetHref, sanitizePicoTheme, sanitizePicoThemeMode } from '../shared/picoThemes';
 import { renderRouteWithSharedContext } from './SharedRouteRenderer';
@@ -69,6 +70,7 @@ interface PreviewServerDependencies {
   settingsEngine: MetaEngineContract;
   menuEngine: MenuEngineContract;
   getActiveProjectContext: () => Promise<ActiveProjectContext>;
+  userTemplatesDir?: string;
 }
 
 interface SerializedTag {
@@ -106,7 +108,13 @@ export class PreviewServer {
         projectDescription: activeProject?.description ?? undefined,
       };
     });
-    this.pageRenderer = new PageRenderer(this.mediaEngine, this.postMediaEngine, this.postEngine, buildPythonMacroRenderer());
+    this.pageRenderer = new PageRenderer(
+      this.mediaEngine,
+      this.postMediaEngine,
+      this.postEngine,
+      buildPythonMacroRenderer(),
+      dependencies?.userTemplatesDir ?? getTemplateEngine().getTemplatesDirectory(),
+    );
   }
 
   async start(preferredPort = 0): Promise<number> {
@@ -197,6 +205,7 @@ export class PreviewServer {
       resolveListExcludedCategories: (settings) => this.resolveListExcludedCategories(settings),
       buildHtmlRewriteContext: () => this.buildHtmlRewriteContext(),
       resolveTagColorByName: (projectContext) => this.resolveTagColorByName(projectContext),
+      resolveTagTemplateSettings: (projectContext) => this.resolveTagTemplateSettings(projectContext),
       pageRenderer: this.pageRenderer,
       postEngineForMacros: this.postEngine,
       loadPublishedSnapshotsPage: (filter, pagination) => loadPublishedSnapshotsPage(this.postEngine, filter, pagination),
@@ -432,6 +441,39 @@ export class PreviewServer {
     }
   }
 
+  private async resolveTagTemplateSettings(projectContext: ActiveProjectContext): Promise<Record<string, { postTemplateSlug?: string | null }>> {
+    if (!projectContext.dataDir) {
+      return {};
+    }
+
+    const tagsPath = path.join(projectContext.dataDir, 'meta', 'tags.json');
+
+    try {
+      const source = await readFile(tagsPath, 'utf-8');
+      const parsed = JSON.parse(source);
+      if (!Array.isArray(parsed)) {
+        return {};
+      }
+
+      const settings: Record<string, { postTemplateSlug?: string | null }> = {};
+      for (const rawEntry of parsed as SerializedTag[]) {
+        const name = typeof rawEntry?.name === 'string' ? rawEntry.name.trim() : '';
+        const postTemplateSlug = typeof (rawEntry as Record<string, unknown>)?.postTemplateSlug === 'string'
+          ? ((rawEntry as Record<string, unknown>).postTemplateSlug as string).trim()
+          : undefined;
+        if (!name || !postTemplateSlug) {
+          continue;
+        }
+
+        settings[name] = { postTemplateSlug };
+      }
+
+      return settings;
+    } catch {
+      return {};
+    }
+  }
+
   private async resolveAsset(pathname: string): Promise<{ contentType: string; body: Buffer } | null> {
     const match = pathname.match(/^\/assets\/([^/]+)$/);
     if (!match) return null;
@@ -592,6 +634,8 @@ export class PreviewServer {
       mergedSettings[category] = {
         renderInLists: value.renderInLists,
         showTitle: value.showTitle,
+        postTemplateSlug: value.postTemplateSlug,
+        listTemplateSlug: value.listTemplateSlug,
       };
     }
     return mergedSettings;

src/main/engine/ProjectEngine.ts

@@ -81,12 +81,73 @@ export class ProjectEngine extends EventEmitter {
     // - If custom dataPath is provided, all project data lives there (allows cloud storage backup)
     // - If no dataPath (default project), use internal userData storage
     const dataDir = this.getDataDir(projectId, dataPath);
-    
+
     // Create all project directories in the data directory
     await fs.mkdir(path.join(dataDir, 'posts'), { recursive: true });
     await fs.mkdir(path.join(dataDir, 'media'), { recursive: true });
     await fs.mkdir(path.join(dataDir, 'meta'), { recursive: true });
     await fs.mkdir(path.join(dataDir, 'thumbnails'), { recursive: true });
+    await fs.mkdir(path.join(dataDir, 'templates'), { recursive: true });
+  }
+
+  private async copyStarterTemplates(projectId: string, dataPath?: string | null): Promise<void> {
+    const dataDir = this.getDataDir(projectId, dataPath);
+    const destDir = path.join(dataDir, 'templates');
+
+    // Resolve the bundled templates directory
+    const bundledRoots = [
+      path.resolve(__dirname, 'templates'),
+      path.resolve(process.cwd(), 'dist', 'main', 'engine', 'templates'),
+      path.resolve(process.cwd(), 'src', 'main', 'engine', 'templates'),
+    ];
+
+    if (typeof process.resourcesPath === 'string' && process.resourcesPath.length > 0) {
+      bundledRoots.unshift(path.resolve(process.resourcesPath, 'templates'));
+    }
+
+    let sourceDir: string | null = null;
+    for (const root of bundledRoots) {
+      try {
+        const stat = await fs.stat(root);
+        if (stat.isDirectory()) {
+          sourceDir = root;
+          break;
+        }
+      } catch {
+        // Directory doesn't exist, try next
+      }
+    }
+
+    if (!sourceDir) {
+      return;
+    }
+
+    try {
+      await this.copyDirectoryRecursive(sourceDir, destDir);
+    } catch (error) {
+      console.error('[ProjectEngine] Failed to copy starter templates:', error);
+    }
+  }
+
+  private async copyDirectoryRecursive(src: string, dest: string): Promise<void> {
+    await fs.mkdir(dest, { recursive: true });
+    const entries = await fs.readdir(src, { withFileTypes: true });
+
+    for (const entry of entries) {
+      const srcPath = path.join(src, entry.name);
+      const destPath = path.join(dest, entry.name);
+
+      if (entry.isDirectory()) {
+        await this.copyDirectoryRecursive(srcPath, destPath);
+      } else if (entry.name.endsWith('.liquid')) {
+        try {
+          await fs.access(destPath);
+          // File already exists, skip
+        } catch {
+          await fs.copyFile(srcPath, destPath);
+        }
+      }
+    }
   }
 
   async createProject(data: { name: string; description?: string; slug?: string; dataPath?: string }): Promise<ProjectData> {
@@ -119,6 +180,9 @@ export class ProjectEngine extends EventEmitter {
     // Create directories using project ID (not slug)
     await this.ensureProjectDirectories(id, data.dataPath);
 
+    // Copy bundled templates as starter templates
+    await this.copyStarterTemplates(id, data.dataPath);
+
     // Insert into database
     const dbProject: NewProject = {
       id: project.id,

src/main/engine/SharedRouteRenderer.ts

@@ -59,6 +59,7 @@ export interface SharedRouteRenderServices<TCategoryMetadata> {
   resolveListExcludedCategories: (settings: Record<string, CategoryRenderSettings>) => string[];
   buildHtmlRewriteContext: () => Promise<HtmlRewriteContext>;
   resolveTagColorByName: (projectContext: SharedActiveProjectContext) => Promise<Record<string, string>>;
+  resolveTagTemplateSettings?: (projectContext: SharedActiveProjectContext) => Promise<Record<string, { postTemplateSlug?: string | null }>>;
   pageRenderer: Pick<PageRenderer, 'renderPostList' | 'renderSinglePost'>;
   postEngineForMacros?: PostEngineContract;
   loadPublishedSnapshotsPage: (
@@ -96,6 +97,7 @@ async function resolveRouteWithSharedServices(
   categorySettings: Record<string, CategoryRenderSettings>,
   categoryMetadata: Record<string, CategoryMetadata>,
   tagColorByName: Record<string, string>,
+  tagTemplateSettings: Record<string, { postTemplateSlug?: string | null }>,
   listExcludedCategories: string[],
   services: SharedRouteRenderServices<CategoryMetadata>,
   allowEmptyArchiveRender: boolean,
@@ -187,6 +189,8 @@ async function resolveRouteWithSharedServices(
       pico_stylesheet_href: pageContext.picoStylesheetHref,
       html_theme_attribute: pageContext.htmlThemeAttribute,
       tag_color_by_name: tagColorByName,
+      tagSettings: tagTemplateSettings,
+      categorySettings: categorySettings as Record<string, { postTemplateSlug?: string | null }>,
     }, services.postEngineForMacros);
   }
 
@@ -270,6 +274,8 @@ async function resolveRouteWithSharedServices(
       pico_stylesheet_href: pageContext.picoStylesheetHref,
       html_theme_attribute: pageContext.htmlThemeAttribute,
       tag_color_by_name: tagColorByName,
+      tagSettings: tagTemplateSettings,
+      categorySettings: categorySettings as Record<string, { postTemplateSlug?: string | null }>,
     }, services.postEngineForMacros);
   }
 
@@ -310,6 +316,7 @@ export async function renderRouteWithSharedContext<TCategoryMetadata>(
   const picoStylesheetHref = getPicoStylesheetHref(appliedTheme);
   const htmlRewriteContext = options.htmlRewriteContext ?? await services.buildHtmlRewriteContext();
   const tagColorByName = await services.resolveTagColorByName(options.projectContext);
+  const tagTemplateSettings = await services.resolveTagTemplateSettings?.(options.projectContext) ?? {};
   const normalizedPathname = decodeURIComponent(pathname.replace(/\/+$/, '') || '/');
 
   return resolveRouteWithSharedServices(normalizedPathname, maxPostsPerPage, htmlRewriteContext, {
@@ -318,5 +325,5 @@ export async function renderRouteWithSharedContext<TCategoryMetadata>(
     menuItems,
     picoStylesheetHref,
     htmlThemeAttribute: options.htmlThemeAttribute,
-  }, categorySettings, categoryMetadata as Record<string, CategoryMetadata>, tagColorByName, listExcludedCategories, services as SharedRouteRenderServices<CategoryMetadata>, options.allowEmptyArchiveRender === true, options.singlePostOptions);
+  }, categorySettings, categoryMetadata as Record<string, CategoryMetadata>, tagColorByName, tagTemplateSettings, listExcludedCategories, services as SharedRouteRenderServices<CategoryMetadata>, options.allowEmptyArchiveRender === true, options.singlePostOptions);
 }

src/main/engine/TagEngine.ts

@@ -18,6 +18,7 @@ export interface TagData {
   projectId: string;
   name: string;
   color?: string;
+  postTemplateSlug?: string;
   createdAt: Date;
   updatedAt: Date;
 }
@@ -45,6 +46,7 @@ export interface CreateTagInput {
 export interface UpdateTagInput {
   name?: string;
   color?: string | null;
+  postTemplateSlug?: string | null;
 }
 
 /**
@@ -110,6 +112,7 @@ function isValidHexColor(color: string): boolean {
 interface SerializedTag {
   name: string;
   color?: string;
+  postTemplateSlug?: string;
 }
 
 /**
@@ -400,19 +403,27 @@ export class TagEngine extends EventEmitter {
       throw new Error('Invalid color format. Use hex format like #ff0000 or #f00');
     }
 
-    if (input.color === undefined) {
+    const hasColorUpdate = input.color !== undefined;
+    const hasTemplateUpdate = input.postTemplateSlug !== undefined;
+
+    if (!hasColorUpdate && !hasTemplateUpdate) {
       // No updates
       return this.rowToTagData(row);
     }
 
     const now = new Date();
 
+    const setFields: Record<string, unknown> = { updatedAt: now };
+    if (hasColorUpdate) {
+      setFields.color = input.color;
+    }
+    if (hasTemplateUpdate) {
+      setFields.postTemplateSlug = input.postTemplateSlug;
+    }
+
     await db
       .update(tags)
-      .set({
-        color: input.color,
-        updatedAt: now,
-      })
+      .set(setFields)
       .where(and(
         eq(tags.id, id),
         eq(tags.projectId, this.currentProjectId)
@@ -422,7 +433,8 @@ export class TagEngine extends EventEmitter {
       id: row.id,
       projectId: row.projectId,
       name: row.name,
-      color: input.color !== undefined ? input.color || undefined : row.color || undefined,
+      color: hasColorUpdate ? input.color || undefined : row.color || undefined,
+      postTemplateSlug: hasTemplateUpdate ? input.postTemplateSlug || undefined : row.postTemplateSlug || undefined,
       createdAt: row.createdAt,
       updatedAt: now,
     };
@@ -817,6 +829,7 @@ export class TagEngine extends EventEmitter {
       projectId: row.projectId,
       name: row.name,
       color: row.color || undefined,
+      postTemplateSlug: row.postTemplateSlug || undefined,
       createdAt: row.createdAt,
       updatedAt: row.updatedAt,
     };
@@ -838,6 +851,9 @@ export class TagEngine extends EventEmitter {
         if (tag.color) {
           entry.color = tag.color;
         }
+        if (tag.postTemplateSlug) {
+          entry.postTemplateSlug = tag.postTemplateSlug;
+        }
         return entry;
       });
 
@@ -867,6 +883,7 @@ export class TagEngine extends EventEmitter {
         if (!name) continue;
 
         const color = tag.color || null;
+        const postTemplateSlug = typeof tag.postTemplateSlug === 'string' ? tag.postTemplateSlug : null;
 
         // Check if tag with this name already exists
         const existing = await db
@@ -884,17 +901,22 @@ export class TagEngine extends EventEmitter {
             projectId: this.currentProjectId,
             name,
             color,
+            postTemplateSlug,
             createdAt: now,
             updatedAt: now,
           });
-        } else if (color) {
-          // Update color if provided and tag exists
+        } else if (color || postTemplateSlug) {
+          // Update color/postTemplateSlug if provided and tag exists
+          const setFields: Record<string, unknown> = { updatedAt: now };
+          if (color) {
+            setFields.color = color;
+          }
+          if (postTemplateSlug) {
+            setFields.postTemplateSlug = postTemplateSlug;
+          }
           await db
             .update(tags)
-            .set({
-              color,
-              updatedAt: now,
-            })
+            .set(setFields)
             .where(and(
               eq(tags.projectId, this.currentProjectId),
               sql`LOWER(${tags.name}) = LOWER(${name})`

src/main/engine/TemplateEngine.ts

@@ -0,0 +1,836 @@
+import { EventEmitter } from 'events';
+import { v4 as uuidv4 } from 'uuid';
+import * as fs from 'fs/promises';
+import * as path from 'path';
+import { app } from 'electron';
+import { and, desc, eq } from 'drizzle-orm';
+import { Liquid } from 'liquidjs';
+import { getDatabase } from '../database';
+import { posts, tags, templates, type NewTemplate, type Template } from '../database/schema';
+
+export type TemplateKind = 'post' | 'list' | 'not-found' | 'partial';
+
+export interface TemplateData {
+  id: string;
+  projectId: string;
+  slug: string;
+  title: string;
+  kind: TemplateKind;
+  enabled: boolean;
+  version: number;
+  filePath: string;
+  content: string;
+  createdAt: Date;
+  updatedAt: Date;
+}
+
+export interface CreateTemplateInput {
+  title: string;
+  kind: TemplateKind;
+  content: string;
+  slug?: string;
+  enabled?: boolean;
+}
+
+export interface UpdateTemplateInput {
+  title?: string;
+  kind?: TemplateKind;
+  content?: string;
+  slug?: string;
+  enabled?: boolean;
+}
+
+export type GitTemplateFileChangeStatus = 'added' | 'modified' | 'deleted' | 'renamed';
+
+export interface GitTemplateFileChange {
+  status: GitTemplateFileChangeStatus;
+  path: string;
+  previousPath?: string;
+}
+
+export interface TemplateReconcileResult {
+  created: number;
+  updated: number;
+  deleted: number;
+  processedFiles: number;
+}
+
+export interface TemplateValidationResult {
+  valid: boolean;
+  errors: string[];
+}
+
+export interface TemplateDeleteResult {
+  deleted: boolean;
+  references?: { postIds: string[]; tagIds: string[] };
+}
+
+interface ParsedTemplateFile {
+  metadata: {
+    id?: string;
+    projectId?: string;
+    slug?: string;
+    title?: string;
+    kind?: string;
+    enabled?: boolean;
+    version?: number;
+    createdAt?: string;
+    updatedAt?: string;
+  };
+  body: string;
+}
+
+export class TemplateEngine extends EventEmitter {
+  private currentProjectId = 'default';
+  private dataDir: string | null = null;
+
+  setProjectContext(projectId: string, dataDir?: string): void {
+    this.currentProjectId = projectId;
+    this.dataDir = dataDir || null;
+  }
+
+  getProjectContext(): string {
+    return this.currentProjectId;
+  }
+
+  getTemplatesDirectory(): string {
+    return this.getTemplatesDir();
+  }
+
+  async createTemplate(input: CreateTemplateInput): Promise<TemplateData> {
+    const now = new Date();
+    const allTemplates = await this.getAllTemplateRows();
+    const desiredSlug = this.normalizeSlug(input.slug || input.title || 'template');
+    const uniqueSlug = this.ensureUniqueSlug(desiredSlug, allTemplates);
+    const templateId = uuidv4();
+    const filePath = this.getTemplateFilePath(uniqueSlug);
+
+    const row: NewTemplate = {
+      id: templateId,
+      projectId: this.currentProjectId,
+      slug: uniqueSlug,
+      title: input.title,
+      kind: input.kind,
+      enabled: input.enabled ?? true,
+      version: 1,
+      filePath,
+      createdAt: now,
+      updatedAt: now,
+    };
+
+    await fs.mkdir(this.getTemplatesDir(), { recursive: true });
+    await fs.writeFile(filePath, this.serializeTemplateFile(row as Template, input.content), 'utf-8');
+
+    await getDatabase().getLocal().insert(templates).values(row);
+
+    const created = await this.toTemplateData(row as Template);
+    this.emit('templateCreated', created);
+    return created;
+  }
+
+  async updateTemplate(id: string, updates: UpdateTemplateInput): Promise<TemplateData | null> {
+    const existing = await this.getTemplateRow(id);
+    if (!existing) {
+      return null;
+    }
+
+    const allTemplates = await this.getAllTemplateRows();
+    const desiredSlug = typeof updates.slug === 'string'
+      ? this.normalizeSlug(updates.slug)
+      : typeof updates.title === 'string'
+        ? this.normalizeSlug(updates.title)
+        : existing.slug;
+    const nextSlug = this.ensureUniqueSlug(desiredSlug, allTemplates, existing.id);
+    const nextFilePath = this.getTemplateFilePath(nextSlug);
+    const now = new Date();
+
+    const nextTitle = updates.title ?? existing.title;
+    const nextKind = updates.kind ?? existing.kind;
+    const nextEnabled = updates.enabled ?? existing.enabled;
+    const nextVersion = existing.version + 1;
+    const nextContent = typeof updates.content === 'string'
+      ? updates.content
+      : await this.readTemplateBody(existing.filePath);
+
+    const nextRow = {
+      ...existing,
+      title: nextTitle,
+      slug: nextSlug,
+      kind: nextKind,
+      enabled: nextEnabled,
+      filePath: nextFilePath,
+      version: nextVersion,
+      updatedAt: now,
+    };
+
+    const dbUpdates = {
+      title: nextTitle,
+      slug: nextSlug,
+      kind: nextKind,
+      enabled: nextEnabled,
+      filePath: nextFilePath,
+      version: nextVersion,
+      updatedAt: now,
+    };
+
+    // DB-first: update the database row before touching the filesystem
+    await getDatabase().getLocal()
+      .update(templates)
+      .set(dbUpdates)
+      .where(and(eq(templates.id, existing.id), eq(templates.projectId, this.currentProjectId)));
+
+    try {
+      if (existing.filePath !== nextFilePath) {
+        await fs.mkdir(this.getTemplatesDir(), { recursive: true });
+        await fs.rename(existing.filePath, nextFilePath);
+      }
+
+      await fs.writeFile(nextFilePath, this.serializeTemplateFile(nextRow, nextContent), 'utf-8');
+    } catch (fileError) {
+      // Roll back the DB row to previous values on file operation failure
+      await getDatabase().getLocal()
+        .update(templates)
+        .set({
+          title: existing.title,
+          slug: existing.slug,
+          kind: existing.kind,
+          enabled: existing.enabled,
+          filePath: existing.filePath,
+          version: existing.version,
+          updatedAt: existing.updatedAt,
+        })
+        .where(and(eq(templates.id, existing.id), eq(templates.projectId, this.currentProjectId)));
+      throw fileError;
+    }
+
+    // Cascade slug updates to referencing posts and tags
+    if (existing.slug !== nextSlug) {
+      await getDatabase().getLocal()
+        .update(posts)
+        .set({ templateSlug: nextSlug })
+        .where(and(eq(posts.templateSlug, existing.slug), eq(posts.projectId, this.currentProjectId)));
+      await getDatabase().getLocal()
+        .update(tags)
+        .set({ postTemplateSlug: nextSlug })
+        .where(and(eq(tags.postTemplateSlug, existing.slug), eq(tags.projectId, this.currentProjectId)));
+    }
+
+    const updatedRow = await this.getTemplateRow(existing.id);
+    if (!updatedRow) {
+      return null;
+    }
+
+    const updated = await this.toTemplateData(updatedRow);
+    this.emit('templateUpdated', updated);
+    return updated;
+  }
+
+  async getTemplateReferences(slug: string): Promise<{ postIds: string[]; tagIds: string[] }> {
+    const db = getDatabase().getLocal();
+    const referencingPosts = await db
+      .select({ id: posts.id })
+      .from(posts)
+      .where(and(eq(posts.templateSlug, slug), eq(posts.projectId, this.currentProjectId)))
+      .all();
+    const referencingTags = await db
+      .select({ id: tags.id })
+      .from(tags)
+      .where(and(eq(tags.postTemplateSlug, slug), eq(tags.projectId, this.currentProjectId)))
+      .all();
+    return {
+      postIds: referencingPosts.map((row) => row.id),
+      tagIds: referencingTags.map((row) => row.id),
+    };
+  }
+
+  async deleteTemplate(id: string, options?: { force?: boolean }): Promise<TemplateDeleteResult> {
+    const existing = await this.getTemplateRow(id);
+    if (!existing) {
+      return { deleted: false };
+    }
+
+    const refs = await this.getTemplateReferences(existing.slug);
+    const hasReferences = refs.postIds.length > 0 || refs.tagIds.length > 0;
+
+    if (hasReferences && !options?.force) {
+      return { deleted: false, references: refs };
+    }
+
+    if (hasReferences && options?.force) {
+      const db = getDatabase().getLocal();
+      await db
+        .update(posts)
+        .set({ templateSlug: null })
+        .where(and(eq(posts.templateSlug, existing.slug), eq(posts.projectId, this.currentProjectId)));
+      await db
+        .update(tags)
+        .set({ postTemplateSlug: null })
+        .where(and(eq(tags.postTemplateSlug, existing.slug), eq(tags.projectId, this.currentProjectId)));
+    }
+
+    await getDatabase().getLocal()
+      .delete(templates)
+      .where(and(eq(templates.id, existing.id), eq(templates.projectId, this.currentProjectId)));
+
+    try {
+      await fs.unlink(existing.filePath);
+    } catch (error) {
+      const fsError = error as NodeJS.ErrnoException;
+      if (fsError.code !== 'ENOENT') {
+        throw error;
+      }
+    }
+
+    this.emit('templateDeleted', id);
+    return { deleted: true };
+  }
+
+  async getTemplate(id: string): Promise<TemplateData | null> {
+    const row = await this.getTemplateRow(id);
+    if (!row) {
+      return null;
+    }
+    return this.toTemplateData(row);
+  }
+
+  async getAllTemplates(): Promise<TemplateData[]> {
+    const rows = await this.getAllTemplateRows();
+    return Promise.all(rows.map((item) => this.toTemplateData(item)));
+  }
+
+  async getEnabledTemplatesByKind(kind: TemplateKind): Promise<TemplateData[]> {
+    const rows = await this.getAllTemplateRows();
+    const kindRows = rows.filter((row) => row.kind === kind && row.enabled);
+    return Promise.all(kindRows.map((item) => this.toTemplateData(item)));
+  }
+
+  async getTemplateBySlug(slug: string): Promise<TemplateData | null> {
+    const normalizedSlug = slug.toLowerCase();
+    const rows = await this.getAllTemplateRows();
+    const match = rows.find(
+      (row) => row.enabled && row.slug.toLowerCase() === normalizedSlug,
+    );
+    if (!match) {
+      return null;
+    }
+    return this.toTemplateData(match);
+  }
+
+  async validateTemplate(content: string): Promise<TemplateValidationResult> {
+    try {
+      const liquid = new Liquid({ strictVariables: false, strictFilters: false });
+      await liquid.parse(content);
+      return { valid: true, errors: [] };
+    } catch (error) {
+      const message = error instanceof Error ? error.message : String(error);
+      return { valid: false, errors: [message] };
+    }
+  }
+
+  async rebuildDatabaseFromFiles(): Promise<void> {
+    const db = getDatabase().getLocal();
+    const templatesDir = this.getTemplatesDir();
+
+    await db.delete(templates).where(eq(templates.projectId, this.currentProjectId));
+
+    const liquidFiles = await this.scanTemplateFiles(templatesDir);
+    if (liquidFiles.length === 0) {
+      this.emit('templatesRebuilt');
+      return;
+    }
+
+    const usedIds = new Set<string>();
+    const insertedRows: Template[] = [];
+
+    for (const filePath of liquidFiles) {
+      const parsed = await this.readTemplateFileWithMetadata(filePath);
+      if (!parsed) {
+        continue;
+      }
+
+      const desiredSlug = this.normalizeSlug(parsed.metadata.slug || path.basename(filePath, '.liquid'));
+      const slug = this.ensureUniqueSlug(desiredSlug, insertedRows);
+
+      const desiredId = typeof parsed.metadata.id === 'string' && parsed.metadata.id.trim().length > 0
+        ? parsed.metadata.id.trim()
+        : uuidv4();
+      const id = usedIds.has(desiredId) ? uuidv4() : desiredId;
+
+      const now = new Date();
+      const row: NewTemplate = {
+        id,
+        projectId: this.currentProjectId,
+        slug,
+        title: this.normalizeTitle(parsed.metadata.title, slug),
+        kind: this.normalizeKind(parsed.metadata.kind),
+        enabled: this.normalizeEnabled(parsed.metadata.enabled),
+        version: this.normalizeVersion(parsed.metadata.version),
+        filePath,
+        createdAt: this.normalizeDate(parsed.metadata.createdAt, now),
+        updatedAt: this.normalizeDate(parsed.metadata.updatedAt, now),
+      };
+
+      await db.insert(templates).values(row);
+      insertedRows.push(row as Template);
+      usedIds.add(id);
+    }
+
+    this.emit('templatesRebuilt');
+  }
+
+  async reconcileTemplatesFromGitChanges(projectPath: string, changes: GitTemplateFileChange[]): Promise<TemplateReconcileResult> {
+    const db = getDatabase().getLocal();
+    const normalizedProjectPath = path.resolve(projectPath);
+
+    const relevantChanges = changes.filter((change) => {
+      if (!this.isLiquidTemplatePath(change.path)) {
+        return false;
+      }
+      if (change.status === 'renamed' && change.previousPath && !this.isLiquidTemplatePath(change.previousPath) && !this.isLiquidTemplatePath(change.path)) {
+        return false;
+      }
+      return true;
+    });
+
+    if (relevantChanges.length === 0) {
+      return { created: 0, updated: 0, deleted: 0, processedFiles: 0 };
+    }
+
+    const templateRows = await this.getAllTemplateRows();
+    const templatesByPath = new Map<string, Template>();
+    for (const row of templateRows) {
+      templatesByPath.set(this.normalizePathForCompare(row.filePath), row);
+    }
+
+    let created = 0;
+    let updated = 0;
+    let deleted = 0;
+    let processedFiles = 0;
+
+    for (const change of relevantChanges) {
+      const absolutePath = this.normalizePathForCompare(path.resolve(normalizedProjectPath, change.path));
+      const previousAbsolutePath = change.previousPath
+        ? this.normalizePathForCompare(path.resolve(normalizedProjectPath, change.previousPath))
+        : null;
+
+      if (change.status === 'deleted') {
+        const existing = templatesByPath.get(absolutePath);
+        if (!existing) {
+          continue;
+        }
+
+        await db.delete(templates).where(and(eq(templates.id, existing.id), eq(templates.projectId, this.currentProjectId)));
+        templatesByPath.delete(absolutePath);
+        this.emit('templateDeleted', existing.id);
+        deleted += 1;
+        processedFiles += 1;
+        continue;
+      }
+
+      let existing = previousAbsolutePath
+        ? (templatesByPath.get(previousAbsolutePath) || templatesByPath.get(absolutePath))
+        : templatesByPath.get(absolutePath);
+
+      const parsed = await this.readTemplateFileWithMetadata(absolutePath);
+      if (!parsed) {
+        continue;
+      }
+
+      const allRows = await this.getAllTemplateRows();
+      const parsedId = typeof parsed.metadata.id === 'string' ? parsed.metadata.id.trim() : '';
+      if (!existing && parsedId.length > 0) {
+        const byId = allRows.find((row) => row.id === parsedId);
+        if (byId) {
+          existing = byId;
+        }
+      }
+      const desiredSlug = this.normalizeSlug(parsed.metadata.slug || path.basename(absolutePath, '.liquid'));
+      const slug = this.ensureUniqueSlug(desiredSlug, allRows, existing?.id);
+
+      if (existing) {
+        const updateNow = new Date();
+        const nextRow = {
+          title: this.normalizeTitle(parsed.metadata.title, slug, existing.title),
+          slug,
+          kind: this.normalizeKind(parsed.metadata.kind, existing.kind),
+          enabled: this.normalizeEnabled(parsed.metadata.enabled, existing.enabled),
+          version: this.normalizeVersion(parsed.metadata.version, existing.version),
+          filePath: absolutePath,
+          createdAt: this.normalizeDate(parsed.metadata.createdAt, existing.createdAt),
+          updatedAt: this.normalizeDate(parsed.metadata.updatedAt, updateNow),
+        };
+
+        await db.update(templates)
+          .set(nextRow)
+          .where(and(eq(templates.id, existing.id), eq(templates.projectId, this.currentProjectId)));
+
+        const updatedRow = await this.getTemplateRow(existing.id);
+        if (updatedRow) {
+          const updatedTemplate = await this.toTemplateData(updatedRow);
+          this.emit('templateUpdated', updatedTemplate);
+        }
+
+        if (previousAbsolutePath) {
+          templatesByPath.delete(previousAbsolutePath);
+        }
+        templatesByPath.set(absolutePath, {
+          ...existing,
+          ...nextRow,
+        });
+        updated += 1;
+        processedFiles += 1;
+        continue;
+      }
+
+      const desiredId = typeof parsed.metadata.id === 'string' && parsed.metadata.id.trim().length > 0
+        ? parsed.metadata.id.trim()
+        : uuidv4();
+      const idExists = allRows.some((row) => row.id === desiredId);
+      const rowId = idExists ? uuidv4() : desiredId;
+      const now = new Date();
+
+      const newRow: NewTemplate = {
+        id: rowId,
+        projectId: this.currentProjectId,
+        slug,
+        title: this.normalizeTitle(parsed.metadata.title, slug),
+        kind: this.normalizeKind(parsed.metadata.kind),
+        enabled: this.normalizeEnabled(parsed.metadata.enabled),
+        version: this.normalizeVersion(parsed.metadata.version),
+        filePath: absolutePath,
+        createdAt: this.normalizeDate(parsed.metadata.createdAt, now),
+        updatedAt: this.normalizeDate(parsed.metadata.updatedAt, now),
+      };
+
+      await db.insert(templates).values(newRow);
+
+      const createdRow = await this.getTemplateRow(newRow.id);
+      if (createdRow) {
+        const createdTemplate = await this.toTemplateData(createdRow);
+        this.emit('templateCreated', createdTemplate);
+      }
+
+      templatesByPath.set(absolutePath, newRow as Template);
+      created += 1;
+      processedFiles += 1;
+    }
+
+    return {
+      created,
+      updated,
+      deleted,
+      processedFiles,
+    };
+  }
+
+  private async getTemplateRow(id: string): Promise<Template | null> {
+    const rows = await this.getAllTemplateRows();
+    return rows.find((item) => item.id === id) || null;
+  }
+
+  private async getAllTemplateRows(): Promise<Template[]> {
+    return getDatabase().getLocal()
+      .select()
+      .from(templates)
+      .where(eq(templates.projectId, this.currentProjectId))
+      .orderBy(desc(templates.updatedAt))
+      .all();
+  }
+
+  private async toTemplateData(row: Template): Promise<TemplateData> {
+    const content = await this.readTemplateBody(row.filePath);
+
+    return {
+      id: row.id,
+      projectId: row.projectId,
+      slug: row.slug,
+      title: row.title,
+      kind: row.kind,
+      enabled: row.enabled,
+      version: row.version,
+      filePath: row.filePath,
+      content,
+      createdAt: row.createdAt,
+      updatedAt: row.updatedAt,
+    };
+  }
+
+  private getDataDir(): string {
+    if (this.dataDir) {
+      return this.dataDir;
+    }
+
+    return path.join(app.getPath('userData'), 'projects', this.currentProjectId);
+  }
+
+  private getTemplatesDir(): string {
+    return path.join(this.getDataDir(), 'templates');
+  }
+
+  private getTemplateFilePath(slug: string): string {
+    return path.join(this.getTemplatesDir(), `${slug}.liquid`);
+  }
+
+  private normalizePathForCompare(filePath: string): string {
+    return path.resolve(filePath).replace(/\\/g, '/');
+  }
+
+  private isLiquidTemplatePath(value: string): boolean {
+    const normalized = value.replace(/\\/g, '/').replace(/^\.\//, '');
+    return normalized.startsWith('templates/') && path.extname(normalized).toLowerCase() === '.liquid';
+  }
+
+  private normalizeSlug(value: string): string {
+    const normalized = value
+      .toLowerCase()
+      .replace(/[^a-z0-9]+/g, '_')
+      .replace(/^_+|_+$/g, '');
+    return normalized || 'template';
+  }
+
+  private ensureUniqueSlug(slug: string, rows: Template[], excludeId?: string): string {
+    const baseSlug = slug;
+    const taken = new Set(
+      rows
+        .filter((item) => item.id !== excludeId)
+        .map((item) => item.slug)
+    );
+
+    if (!taken.has(baseSlug)) {
+      return baseSlug;
+    }
+
+    let suffix = 2;
+    while (taken.has(`${baseSlug}_${suffix}`)) {
+      suffix += 1;
+    }
+
+    return `${baseSlug}_${suffix}`;
+  }
+
+  private serializeTemplateFile(row: Pick<Template, 'id' | 'projectId' | 'slug' | 'title' | 'kind' | 'enabled' | 'version' | 'createdAt' | 'updatedAt'>, content: string): string {
+    const lines = [
+      '---',
+      `id: ${this.toYamlString(row.id)}`,
+      `projectId: ${this.toYamlString(row.projectId)}`,
+      `slug: ${this.toYamlString(row.slug)}`,
+      `title: ${this.toYamlString(row.title)}`,
+      `kind: ${this.toYamlString(row.kind)}`,
+      `enabled: ${row.enabled ? 'true' : 'false'}`,
+      `version: ${row.version}`,
+      `createdAt: ${this.toYamlString(row.createdAt.toISOString())}`,
+      `updatedAt: ${this.toYamlString(row.updatedAt.toISOString())}`,
+      '---',
+      content,
+    ];
+
+    return lines.join('\n');
+  }
+
+  private toYamlString(value: string): string {
+    const escaped = value
+      .replace(/\\/g, '\\\\')
+      .replace(/"/g, '\\"');
+    return `"${escaped}"`;
+  }
+
+  private parseTemplateBody(rawContent: string): string {
+    const frontmatterPattern = /^---\r?\n[\s\S]*?\r?\n---\r?\n?/;
+    if (!frontmatterPattern.test(rawContent)) {
+      return rawContent;
+    }
+
+    return rawContent.replace(frontmatterPattern, '');
+  }
+
+  private parseTemplateFile(rawContent: string): ParsedTemplateFile {
+    const frontmatterPattern = /^---\r?\n([\s\S]*?)\r?\n---\r?\n?/;
+    const match = rawContent.match(frontmatterPattern);
+    if (!match) {
+      return {
+        metadata: {},
+        body: rawContent,
+      };
+    }
+
+    const metadataLines = (match[1] || '').split(/\r?\n/);
+    const metadata: ParsedTemplateFile['metadata'] = {};
+
+    for (const rawLine of metadataLines) {
+      const line = rawLine.trim();
+      if (!line || line.startsWith('#')) {
+        continue;
+      }
+
+      const separatorIndex = line.indexOf(':');
+      if (separatorIndex <= 0) {
+        continue;
+      }
+
+      const key = line.slice(0, separatorIndex).trim();
+      const valueRaw = line.slice(separatorIndex + 1).trim();
+      const value = this.parseYamlScalar(valueRaw);
+
+      if (key === 'enabled') {
+        if (typeof value === 'boolean') {
+          metadata.enabled = value;
+        }
+        continue;
+      }
+
+      if (key === 'version') {
+        const parsed = Number(value);
+        if (Number.isFinite(parsed)) {
+          metadata.version = parsed;
+        }
+        continue;
+      }
+
+      if (
+        key === 'id' ||
+        key === 'projectId' ||
+        key === 'slug' ||
+        key === 'title' ||
+        key === 'kind' ||
+        key === 'createdAt' ||
+        key === 'updatedAt'
+      ) {
+        if (typeof value === 'string') {
+          metadata[key] = value;
+        }
+      }
+    }
+
+    return {
+      metadata,
+      body: rawContent.replace(frontmatterPattern, ''),
+    };
+  }
+
+  private parseYamlScalar(valueRaw: string): string | number | boolean {
+    if ((valueRaw.startsWith('"') && valueRaw.endsWith('"')) || (valueRaw.startsWith("'") && valueRaw.endsWith("'"))) {
+      return valueRaw.slice(1, -1)
+        .replace(/\\"/g, '"')
+        .replace(/\\\\/g, '\\');
+    }
+
+    if (valueRaw === 'true') {
+      return true;
+    }
+
+    if (valueRaw === 'false') {
+      return false;
+    }
+
+    const numeric = Number(valueRaw);
+    if (!Number.isNaN(numeric)) {
+      return numeric;
+    }
+
+    return valueRaw;
+  }
+
+  private normalizeKind(kind: string | undefined, fallback: TemplateKind = 'post'): TemplateKind {
+    if (kind === 'post' || kind === 'list' || kind === 'not-found' || kind === 'partial') {
+      return kind;
+    }
+    return fallback;
+  }
+
+  private normalizeEnabled(enabled: boolean | undefined, fallback = true): boolean {
+    if (typeof enabled === 'boolean') {
+      return enabled;
+    }
+    return fallback;
+  }
+
+  private normalizeVersion(version: number | undefined, fallback = 1): number {
+    if (typeof version === 'number' && Number.isFinite(version) && version > 0) {
+      return Math.floor(version);
+    }
+    return fallback;
+  }
+
+  private normalizeDate(value: string | undefined, fallback: Date): Date {
+    if (typeof value === 'string') {
+      const parsed = new Date(value);
+      if (!Number.isNaN(parsed.getTime())) {
+        return parsed;
+      }
+    }
+    return fallback;
+  }
+
+  private normalizeTitle(title: string | undefined, slug: string, fallback?: string): string {
+    if (typeof title === 'string' && title.trim().length > 0) {
+      return title.trim();
+    }
+    if (typeof fallback === 'string' && fallback.trim().length > 0) {
+      return fallback.trim();
+    }
+    return slug;
+  }
+
+  private async scanTemplateFiles(dir: string): Promise<string[]> {
+    const results: string[] = [];
+
+    const scan = async (currentDir: string): Promise<void> => {
+      let entries: Array<{ name: string; isDirectory(): boolean; isFile(): boolean }> = [];
+      try {
+        entries = await fs.readdir(currentDir, { withFileTypes: true }) as Array<{ name: string; isDirectory(): boolean; isFile(): boolean }>;
+      } catch {
+        return;
+      }
+
+      for (const entry of entries) {
+        const fullPath = path.join(currentDir, entry.name);
+        if (entry.isDirectory()) {
+          await scan(fullPath);
+          continue;
+        }
+
+        if (entry.isFile() && path.extname(entry.name).toLowerCase() === '.liquid') {
+          results.push(fullPath);
+        }
+      }
+    };
+
+    await scan(dir);
+    return results;
+  }
+
+  private async readTemplateFileWithMetadata(filePath: string): Promise<ParsedTemplateFile | null> {
+    try {
+      const rawContent = await fs.readFile(filePath, 'utf-8');
+      return this.parseTemplateFile(rawContent);
+    } catch (error) {
+      const fsError = error as NodeJS.ErrnoException;
+      if (fsError.code !== 'ENOENT') {
+        throw error;
+      }
+      return null;
+    }
+  }
+
+  private async readTemplateBody(filePath: string): Promise<string> {
+    try {
+      const rawContent = await fs.readFile(filePath, 'utf-8');
+      return this.parseTemplateBody(rawContent);
+    } catch (error) {
+      const fsError = error as NodeJS.ErrnoException;
+      if (fsError.code !== 'ENOENT') {
+        throw error;
+      }
+      return '';
+    }
+  }
+}
+
+let templateEngineInstance: TemplateEngine | null = null;
+
+export function getTemplateEngine(): TemplateEngine {
+  if (!templateEngineInstance) {
+    templateEngineInstance = new TemplateEngine();
+  }
+  return templateEngineInstance;
+}

src/main/engine/mainProcessPythonApiInvoker.ts

@@ -90,6 +90,10 @@ export const ENGINE_MAP: Record<string, EngineGetter> = {
     const { getScriptEngine } = require('../engine/ScriptEngine');
     return getScriptEngine();
   },
+  templates: () => {
+    const { getTemplateEngine } = require('../engine/TemplateEngine');
+    return getTemplateEngine();
+  },
   tasks: () => {
     const { taskManager } = require('../engine/TaskManager');
     return taskManager;
@@ -190,6 +194,14 @@ const METHOD_NAME_MAP: Record<string, string> = {
   'scripts.get': 'getScript',
   'scripts.getAll': 'getAllScripts',
   'scripts.rebuildFromFiles': 'rebuildDatabaseFromFiles',
+  'templates.create': 'createTemplate',
+  'templates.update': 'updateTemplate',
+  'templates.delete': 'deleteTemplate',
+  'templates.get': 'getTemplate',
+  'templates.getAll': 'getAllTemplates',
+  'templates.getEnabledByKind': 'getEnabledTemplatesByKind',
+  'templates.validate': 'validateTemplate',
+  'templates.rebuildFromFiles': 'rebuildDatabaseFromFiles',
   'tasks.getAll': 'getAllTasks',
   'tasks.getRunning': 'getRunningTasks',
   'tasks.cancel': 'cancelTask',

src/main/ipc/handlers.ts

@@ -10,6 +10,7 @@ import { getMenuEngine, type MenuDocument } from '../engine/MenuEngine';
 import { getTagEngine } from '../engine/TagEngine';
 import { getPostMediaEngine } from '../engine/PostMediaEngine';
 import { getScriptEngine, type CreateScriptInput, type UpdateScriptInput } from '../engine/ScriptEngine';
+import { getTemplateEngine, type CreateTemplateInput, type UpdateTemplateInput } from '../engine/TemplateEngine';
 import { getGitEngine } from '../engine/GitEngine';
 import { getGitApiAdapter } from '../engine/GitApiAdapter';
 import { taskManager, TaskProgress } from '../engine/TaskManager';
@@ -191,11 +192,12 @@ export function registerIpcHandlers(): void {
       return pullResult;
     }
 
-    const [changedPostFiles, changedScriptFiles] = await Promise.all([
+    const [changedPostFiles, changedScriptFiles, changedTemplateFiles] = await Promise.all([
       engine.getChangedPostFilesBetween(projectPath, beforeHead, afterHead),
       engine.getChangedScriptFilesBetween(projectPath, beforeHead, afterHead),
+      engine.getChangedTemplateFilesBetween(projectPath, beforeHead, afterHead),
     ]);
-    if (changedPostFiles.length === 0 && changedScriptFiles.length === 0) {
+    if (changedPostFiles.length === 0 && changedScriptFiles.length === 0 && changedTemplateFiles.length === 0) {
       return pullResult;
     }
 
@@ -204,11 +206,13 @@ export function registerIpcHandlers(): void {
       const project = await projectEngine.getActiveProject();
       const postEngine = getPostEngine();
       const scriptEngine = getScriptEngine();
+      const templateEngine = getTemplateEngine();
 
       if (project) {
         const dataDir = projectEngine.getDataDir(project.id, project.dataPath);
         postEngine.setProjectContext(project.id, dataDir);
         scriptEngine.setProjectContext(project.id, dataDir);
+        templateEngine.setProjectContext(project.id, dataDir);
       }
 
       await Promise.all([
@@ -218,9 +222,12 @@ export function registerIpcHandlers(): void {
         changedScriptFiles.length > 0
           ? scriptEngine.reconcileScriptsFromGitChanges(projectPath, changedScriptFiles)
           : Promise.resolve(),
+        changedTemplateFiles.length > 0
+          ? templateEngine.reconcileTemplatesFromGitChanges(projectPath, changedTemplateFiles)
+          : Promise.resolve(),
       ]);
     } catch (error) {
-      console.error('Failed to reconcile published posts/scripts after git pull:', error);
+      console.error('Failed to reconcile published posts/scripts/templates after git pull:', error);
     }
 
     return pullResult;
@@ -304,12 +311,14 @@ export function registerIpcHandlers(): void {
       const menuEngine = getMenuEngine();
       const tagEngine = getTagEngine();
       const scriptEngine = getScriptEngine();
+      const templateEngine = getTemplateEngine();
       postEngine.setProjectContext(project.id, dataDir);
       mediaEngine.setProjectContext(project.id, dataDir, dataDir);
       metaEngine.setProjectContext(project.id, dataDir);
       menuEngine.setProjectContext(project.id, dataDir);
       tagEngine.setProjectContext(project.id, dataDir);
       scriptEngine.setProjectContext(project.id, dataDir);
+      templateEngine.setProjectContext(project.id, dataDir);
       const postMediaEngine = getPostMediaEngine();
       postMediaEngine.setProjectContext(project.id);
 
@@ -344,12 +353,14 @@ export function registerIpcHandlers(): void {
       const menuEngine = getMenuEngine();
       const tagEngine = getTagEngine();
       const scriptEngine = getScriptEngine();
+      const templateEngine = getTemplateEngine();
       postEngine.setProjectContext(project.id, dataDir);
       mediaEngine.setProjectContext(project.id, dataDir, dataDir);
       metaEngine.setProjectContext(project.id, dataDir);
       menuEngine.setProjectContext(project.id, dataDir);
       tagEngine.setProjectContext(project.id, dataDir);
       scriptEngine.setProjectContext(project.id, dataDir);
+      templateEngine.setProjectContext(project.id, dataDir);
       const postMediaEngine = getPostMediaEngine();
       postMediaEngine.setProjectContext(project.id);
 
@@ -794,6 +805,55 @@ export function registerIpcHandlers(): void {
     return true;
   });
 
+  // ============ Template Handlers ============
+
+  safeHandle('templates:create', async (_, data: CreateTemplateInput) => {
+    const engine = getTemplateEngine();
+    return engine.createTemplate(data);
+  });
+
+  safeHandle('templates:update', async (_, id: string, data: UpdateTemplateInput) => {
+    const engine = getTemplateEngine();
+    return engine.updateTemplate(id, data);
+  });
+
+  safeHandle('templates:delete', async (_, id: string, options?: { force?: boolean }) => {
+    const engine = getTemplateEngine();
+    return engine.deleteTemplate(id, options);
+  });
+
+  safeHandle('templates:get', async (_, id: string) => {
+    const engine = getTemplateEngine();
+    return engine.getTemplate(id);
+  });
+
+  safeHandle('templates:getAll', async () => {
+    const engine = getTemplateEngine();
+    return engine.getAllTemplates();
+  });
+
+  safeHandle('templates:getEnabledByKind', async (_, kind: string) => {
+    const engine = getTemplateEngine();
+    return engine.getEnabledTemplatesByKind(kind as 'post' | 'list' | 'not-found' | 'partial');
+  });
+
+  safeHandle('templates:validate', async (_, content: string) => {
+    const engine = getTemplateEngine();
+    return engine.validateTemplate(content);
+  });
+
+  safeHandle('templates:rebuildFromFiles', async () => {
+    const projectEngine = getProjectEngine();
+    const project = await projectEngine.getActiveProject();
+    const engine = getTemplateEngine();
+    if (project) {
+      const dataDir = projectEngine.getDataDir(project.id, project.dataPath);
+      engine.setProjectContext(project.id, dataDir);
+    }
+    await engine.rebuildDatabaseFromFiles();
+    return true;
+  });
+
   // ============ Task Handlers ============
 
   safeHandle('tasks:getAll', async () => {
@@ -1135,7 +1195,7 @@ export function registerIpcHandlers(): void {
     return engine.createTag(data);
   });
 
-  safeHandle('tags:update', async (_, id: string, data: { name?: string; color?: string | null }) => {
+  safeHandle('tags:update', async (_, id: string, data: { name?: string; color?: string | null; postTemplateSlug?: string | null }) => {
     const engine = getTagEngine();
     return engine.updateTag(id, data);
   });
@@ -1566,4 +1626,10 @@ export function registerIpcHandlers(): void {
   scriptEngine.on('scriptUpdated', forwardEvent('script:updated'));
   scriptEngine.on('scriptDeleted', forwardEvent('script:deleted'));
   scriptEngine.on('scriptsRebuilt', forwardEvent('scripts:rebuilt'));
+
+  const templateEngine = getTemplateEngine();
+  templateEngine.on('templateCreated', forwardEvent('template:created'));
+  templateEngine.on('templateUpdated', forwardEvent('template:updated'));
+  templateEngine.on('templateDeleted', forwardEvent('template:deleted'));
+  templateEngine.on('templatesRebuilt', forwardEvent('templates:rebuilt'));
 }

src/main/main.ts

@@ -8,6 +8,7 @@ import { eq } from 'drizzle-orm';
 import { getMediaEngine } from './engine/MediaEngine';
 import { getPostEngine } from './engine/PostEngine';
 import { getMetaEngine } from './engine/MetaEngine';
+import { getTemplateEngine } from './engine/TemplateEngine';
 import { getBlogmarkTransformService } from './engine/BlogmarkTransformService';
 import { PreviewServer } from './engine/PreviewServer';
 import { APP_MENU_ACTION_EVENT_MAP, APP_MENU_GROUPS, APP_MENU_ITEM_IDS, type AppMenuAction, type AppMenuItemDefinition } from './shared/menuCommands';
@@ -496,6 +497,11 @@ async function initializeActiveProjectContext(): Promise<void> {
     mediaEngine.setProjectContext?.(project.id, dataDir, dataDir);
     metaEngine.setProjectContext?.(project.id, dataDir);
 
+    const templateEngine = getTemplateEngine() as {
+      setProjectContext?: (projectId: string, dataDir?: string) => void;
+    };
+    templateEngine.setProjectContext?.(project.id, dataDir);
+
     await metaEngine.syncOnStartup?.();
 
     const metadata = await metaEngine.getProjectMetadata?.();

src/main/preload.ts

@@ -112,6 +112,18 @@ export const electronAPI: ElectronAPI = {
     rebuildFromFiles: () => ipcRenderer.invoke('scripts:rebuildFromFiles'),
   },
 
+  // Templates
+  templates: {
+    create: (data: { title: string; kind: import('./shared/electronApi').TemplateKind; content: string; slug?: string; enabled?: boolean }) => ipcRenderer.invoke('templates:create', data),
+    update: (id: string, data: { title?: string; kind?: import('./shared/electronApi').TemplateKind; content?: string; slug?: string; enabled?: boolean }) => ipcRenderer.invoke('templates:update', id, data),
+    delete: (id: string, options?: { force?: boolean }) => ipcRenderer.invoke('templates:delete', id, options),
+    get: (id: string) => ipcRenderer.invoke('templates:get', id),
+    getAll: () => ipcRenderer.invoke('templates:getAll'),
+    getEnabledByKind: (kind: import('./shared/electronApi').TemplateKind) => ipcRenderer.invoke('templates:getEnabledByKind', kind),
+    validate: (content: string) => ipcRenderer.invoke('templates:validate', content),
+    rebuildFromFiles: () => ipcRenderer.invoke('templates:rebuildFromFiles'),
+  },
+
   // Post-Media Links
   postMedia: {
     link: (postId: string, mediaId: string) => ipcRenderer.invoke('postMedia:link', postId, mediaId),
@@ -189,7 +201,7 @@ export const electronAPI: ElectronAPI = {
     get: (id: string) => ipcRenderer.invoke('tags:get', id),
     getByName: (name: string) => ipcRenderer.invoke('tags:getByName', name),
     create: (data: { name: string; color?: string }) => ipcRenderer.invoke('tags:create', data),
-    update: (id: string, data: { name?: string; color?: string | null }) => ipcRenderer.invoke('tags:update', id, data),
+    update: (id: string, data: { name?: string; color?: string | null; postTemplateSlug?: string | null }) => ipcRenderer.invoke('tags:update', id, data),
     delete: (id: string) => ipcRenderer.invoke('tags:delete', id),
     merge: (sourceTagIds: string[], targetTagId: string) => ipcRenderer.invoke('tags:merge', sourceTagIds, targetTagId),
     rename: (id: string, newName: string) => ipcRenderer.invoke('tags:rename', id, newName),

src/main/shared/electronApi.ts

@@ -52,6 +52,8 @@ export interface ProjectMetadata {
 export interface CategoryRenderSettings {
   renderInLists: boolean;
   showTitle: boolean;
+  postTemplateSlug?: string;
+  listTemplateSlug?: string;
 }
 
 export interface CategoryMetadata extends CategoryRenderSettings {
@@ -90,6 +92,7 @@ export interface PostData {
   publishedAt?: string;
   tags: string[];
   categories: string[];
+  templateSlug?: string;
 }
 
 export interface PostFilter {
@@ -158,6 +161,27 @@ export interface ScriptData {
   updatedAt: string;
 }
 
+export type TemplateKind = 'post' | 'list' | 'not-found' | 'partial';
+
+export interface TemplateData {
+  id: string;
+  projectId: string;
+  slug: string;
+  title: string;
+  kind: TemplateKind;
+  enabled: boolean;
+  version: number;
+  filePath: string;
+  content: string;
+  createdAt: string;
+  updatedAt: string;
+}
+
+export interface TemplateDeleteResult {
+  deleted: boolean;
+  references?: { postIds: string[]; tagIds: string[] };
+}
+
 export interface TaskProgress {
   taskId: string;
   name: string;
@@ -200,6 +224,7 @@ export interface TagData {
   projectId: string;
   name: string;
   color?: string;
+  postTemplateSlug?: string;
   createdAt: string;
   updatedAt: string;
 }
@@ -588,6 +613,28 @@ export interface ElectronAPI {
     getEnabledMacroSlugs: () => Promise<string[]>;
     rebuildFromFiles: () => Promise<void>;
   };
+  templates: {
+    create: (data: {
+      title: string;
+      kind: TemplateKind;
+      content: string;
+      slug?: string;
+      enabled?: boolean;
+    }) => Promise<TemplateData>;
+    update: (id: string, data: {
+      title?: string;
+      kind?: TemplateKind;
+      content?: string;
+      slug?: string;
+      enabled?: boolean;
+    }) => Promise<TemplateData | null>;
+    delete: (id: string, options?: { force?: boolean }) => Promise<TemplateDeleteResult>;
+    get: (id: string) => Promise<TemplateData | null>;
+    getAll: () => Promise<TemplateData[]>;
+    getEnabledByKind: (kind: TemplateKind) => Promise<TemplateData[]>;
+    validate: (content: string) => Promise<{ valid: boolean; errors: string[] }>;
+    rebuildFromFiles: () => Promise<void>;
+  };
   postMedia: {
     link: (postId: string, mediaId: string) => Promise<MediaLinkData>;
     unlink: (postId: string, mediaId: string) => Promise<void>;
@@ -654,7 +701,7 @@ export interface ElectronAPI {
     get: (id: string) => Promise<TagData | null>;
     getByName: (name: string) => Promise<TagData | null>;
     create: (data: { name: string; color?: string }) => Promise<TagData>;
-    update: (id: string, data: { name?: string; color?: string | null }) => Promise<TagData | null>;
+    update: (id: string, data: { name?: string; color?: string | null; postTemplateSlug?: string | null }) => Promise<TagData | null>;
     delete: (id: string) => Promise<DeleteTagResult>;
     merge: (sourceTagIds: string[], targetTagId: string) => Promise<MergeTagsResult>;
     rename: (id: string, newName: string) => Promise<RenameTagResult>;

src/main/shared/pythonApiContractV1.ts

@@ -129,6 +129,15 @@ const METHODS_V1: PythonApiMethodContractV1[] = [
   method('scripts.getAll', 'Fetch all scripts.', [], 'ScriptData[]'),
   method('scripts.rebuildFromFiles', 'Rebuild scripts from files.', [], 'void'),
 
+  method('templates.create', 'Create template. data must include: title (str), kind ("post"|"list"|"not-found"|"partial"), content (str). Optional: slug (str), enabled (bool).', [requiredObject('data')], 'TemplateData'),
+  method('templates.update', 'Update template by id. data may include any of: title, kind, content, slug, enabled.', [requiredString('id'), requiredObject('data')], 'TemplateData | null'),
+  method('templates.delete', 'Delete template by id. Without options, returns references if the template is in use. Pass options={"force": True} to clear references and delete.', [requiredString('id'), optionalObject('options')], 'TemplateDeleteResult'),
+  method('templates.get', 'Fetch template by id.', [requiredString('id')], 'TemplateData | null'),
+  method('templates.getAll', 'Fetch all templates.', [], 'TemplateData[]'),
+  method('templates.getEnabledByKind', 'Fetch enabled templates filtered by kind.', [requiredString('kind')], 'TemplateData[]'),
+  method('templates.validate', 'Validate Liquid template syntax.', [requiredString('content')], '{ valid: boolean; errors: string[] }'),
+  method('templates.rebuildFromFiles', 'Rebuild templates from files.', [], 'void'),
+
   method('tasks.getAll', 'Fetch all tasks.', [], 'TaskProgress[]'),
   method('tasks.getRunning', 'Fetch running tasks.', [], 'TaskProgress[]'),
   method('tasks.cancel', 'Cancel task by id.', [requiredString('taskId')], 'boolean'),
@@ -276,6 +285,31 @@ const DATA_STRUCTURES_V1: PythonApiDataStructureContractV1[] = [
       { name: 'updatedAt', type: 'string', required: true, description: 'Last update timestamp (ISO string).' },
     ],
   },
+  {
+    name: 'TemplateData',
+    description: 'Liquid template definition for posts, lists, not-found pages, and partials.',
+    fields: [
+      { name: 'id', type: 'string', required: true, description: 'Unique template identifier.' },
+      { name: 'projectId', type: 'string', required: true, description: 'Owning project id.' },
+      { name: 'slug', type: 'string', required: true, description: 'Stable template slug.' },
+      { name: 'title', type: 'string', required: true, description: 'Human-readable template title.' },
+      { name: 'kind', type: "'post' | 'list' | 'not-found' | 'partial'", required: true, description: 'Template category.' },
+      { name: 'enabled', type: 'boolean', required: true, description: 'Whether template is enabled.' },
+      { name: 'version', type: 'number', required: true, description: 'Incrementing template version.' },
+      { name: 'filePath', type: 'string', required: true, description: 'Filesystem path to template file.' },
+      { name: 'content', type: 'string', required: true, description: 'Liquid template source code.' },
+      { name: 'createdAt', type: 'string', required: true, description: 'Creation timestamp (ISO string).' },
+      { name: 'updatedAt', type: 'string', required: true, description: 'Last update timestamp (ISO string).' },
+    ],
+  },
+  {
+    name: 'TemplateDeleteResult',
+    description: 'Result of a template delete operation. If the template is referenced by posts or tags, deleted is false and references lists the referencing IDs.',
+    fields: [
+      { name: 'deleted', type: 'boolean', required: true, description: 'Whether the template was deleted.' },
+      { name: 'references', type: '{ postIds: string[]; tagIds: string[] }', required: false, description: 'Post and tag IDs referencing this template (present when deleted is false and references exist).' },
+    ],
+  },
   {
     name: 'TaskProgress',
     description: 'Task queue status object for long-running operations.',
@@ -370,7 +404,7 @@ const DATA_STRUCTURES_V1: PythonApiDataStructureContractV1[] = [
 ];
 
 export const BDS_PYTHON_API_CONTRACT_V1: PythonApiContractV1 = {
-  version: '1.7.0',
+  version: '1.9.0',
   generatedAt: '2026-02-27T00:00:00.000Z',
   methods: METHODS_V1,
   dataStructures: DATA_STRUCTURES_V1,

src/renderer/components/ActivityBar/ActivityBar.tsx

@@ -36,6 +36,12 @@ const ScriptsIcon = () => (
   </svg>
 );
 
+const TemplatesIcon = () => (
+  <svg width="24" height="24" viewBox="0 0 24 24" fill="currentColor">
+    <path d="M4 4h7v7H4V4zm9 0h7v7h-7V4zM4 13h7v7H4v-7zm9 0h7v7h-7v-7zM5.5 5.5v4h4v-4h-4zm9 0v4h4v-4h-4zm-9 9v4h4v-4h-4zm9 0v4h4v-4h-4z"/>
+  </svg>
+);
+
 const SettingsIcon = () => (
   <svg width="24" height="24" viewBox="0 0 24 24" fill="currentColor">
     <path d="M19.14 12.94c.04-.31.06-.63.06-.94 0-.31-.02-.63-.06-.94l2.03-1.58c.18-.14.23-.41.12-.61l-1.92-3.32c-.12-.22-.37-.29-.59-.22l-2.39.96c-.5-.38-1.03-.7-1.62-.94l-.36-2.54c-.04-.24-.24-.41-.48-.41h-3.84c-.24 0-.43.17-.47.41l-.36 2.54c-.59.24-1.13.57-1.62.94l-2.39-.96c-.22-.08-.47 0-.59.22L2.74 8.87c-.12.21-.08.47.12.61l2.03 1.58c-.04.31-.06.63-.06.94s.02.63.06.94l-2.03 1.58c-.18.14-.23.41-.12.61l1.92 3.32c.12.22.37.29.59.22l2.39-.96c.5.38 1.03.7 1.62.94l.36 2.54c.05.24.24.41.48.41h3.84c.24 0 .44-.17.47-.41l.36-2.54c.59-.24 1.13-.56 1.62-.94l2.39.96c.22.08.47 0 .59-.22l1.92-3.32c.12-.22.07-.47-.12-.61l-2.01-1.58zM12 15.6c-1.98 0-3.6-1.62-3.6-3.6s1.62-3.6 3.6-3.6 3.6 1.62 3.6 3.6-1.62 3.6-3.6 3.6z"/>
@@ -183,6 +189,13 @@ export const ActivityBar: React.FC = () => {
         >
           <ScriptsIcon />
         </button>
+        <button
+          className={`activity-bar-item ${isActivityActive(snapshot, 'templates') ? 'active' : ''}`}
+          onClick={() => executeActivityClick('templates')}
+          title={getTitle('templates')}
+        >
+          <TemplatesIcon />
+        </button>
         <button
           className={`activity-bar-item ${isActivityActive(snapshot, 'tags') ? 'active' : ''}`}
           onClick={() => executeActivityClick('tags')}

src/renderer/components/Editor/Editor.tsx

@@ -20,6 +20,7 @@ import { GitDiffView } from '../GitDiffView/GitDiffView';
 import { DocumentationView } from '../DocumentationView/DocumentationView';
 import { SiteValidationView } from '../SiteValidationView';
 import { ScriptsView } from '../ScriptsView/ScriptsView';
+import { TemplatesView } from '../TemplatesView/TemplatesView';
 import { AutoSaveManager, getContrastColor, loadTagColorMap } from '../../utils';
 import { InsertModal } from '../InsertModal';
 import { AISuggestionsModal, AISuggestions } from '../AISuggestionsModal/AISuggestionsModal';
@@ -71,6 +72,9 @@ const autoSaveManager = new AutoSaveManager({
     if ('categories' in changes) {
       update.categories = changes.categories as string[];
     }
+    if ('templateSlug' in changes) {
+      (update as Record<string, unknown>).templateSlug = changes.templateSlug as string || null;
+    }
 
     const updated = await window.electronAPI?.posts.update(id, update);
     if (updated) {
@@ -191,6 +195,8 @@ export const PostEditor: React.FC<PostEditorProps> = ({ postId }) => {
   const [author, setAuthor] = useState('');
   const [tags, setTags] = useState<string[]>([]);
   const [selectedCategories, setSelectedCategories] = useState<string[]>(['article']);
+  const [templateSlug, setTemplateSlug] = useState('');
+  const [availablePostTemplates, setAvailablePostTemplates] = useState<Array<{ slug: string; title: string }>>([]);
   const [isSaving, setIsSaving] = useState(false);
   const [hasPublishedVersion, setHasPublishedVersion] = useState(false);
   const [editorMode, setEditorMode] = useState<EditorMode>(preferredEditorMode);
@@ -319,10 +325,15 @@ export const PostEditor: React.FC<PostEditorProps> = ({ postId }) => {
       setAuthor(post.author || '');
       setTags(post.tags);
       setSelectedCategories(post.categories.length > 0 ? post.categories : ['article']);
+      setTemplateSlug((post as PostData & { templateSlug?: string }).templateSlug || '');
       setMetadataExpanded(post.title === '');
       markClean(postId);
       // Mark as initialized AFTER setting local state
       setIsInitialized(true);
+      // Load available post templates for the dropdown
+      window.electronAPI?.templates.getEnabledByKind('post').then((templates) => {
+        setAvailablePostTemplates((templates ?? []).map((tmpl) => ({ slug: tmpl.slug, title: tmpl.title })));
+      });
     }
   }, [post, postId, markClean, isInitialized]);
 
@@ -335,7 +346,8 @@ export const PostEditor: React.FC<PostEditorProps> = ({ postId }) => {
     const contentChanged = content !== post.content;
     const titleChanged = title !== post.title;
     const authorChanged = author !== (post.author || '');
-    const hasChanges = contentChanged || titleChanged || authorChanged ||
+    const templateSlugChanged = templateSlug !== ((post as PostData & { templateSlug?: string }).templateSlug || '');
+    const hasChanges = contentChanged || titleChanged || authorChanged || templateSlugChanged ||
       JSON.stringify(tags.slice().sort()) !== JSON.stringify(post.tags.slice().sort()) ||
       JSON.stringify(selectedCategories.slice().sort()) !== JSON.stringify(post.categories.slice().sort());
 
@@ -349,11 +361,12 @@ export const PostEditor: React.FC<PostEditorProps> = ({ postId }) => {
         author,
         tags: tags.join(', '),
         categories: selectedCategories,
+        templateSlug: templateSlug || undefined,
       });
     } else {
       markClean(postId);
     }
-  }, [title, content, author, tags, selectedCategories, post, postId, isInitialized, isDirty, markDirty, markClean]);
+  }, [title, content, author, tags, selectedCategories, templateSlug, post, postId, isInitialized, isDirty, markDirty, markClean]);
 
   // Handle editor mode change and persist preference
   const handleEditorModeChange = (mode: EditorMode) => {
@@ -375,7 +388,8 @@ export const PostEditor: React.FC<PostEditorProps> = ({ postId }) => {
         author: author || undefined,
         tags,
         categories: selectedCategories.length > 0 ? selectedCategories : ['article'],
-      });
+        templateSlug: templateSlug || null,
+      } as Parameters<typeof window.electronAPI.posts.update>[1]);
       
       if (updated) {
         updatePost(postId, updated as Partial<PostData>);
@@ -799,6 +813,20 @@ export const PostEditor: React.FC<PostEditorProps> = ({ postId }) => {
                 />
               </div>
             </div>
+            {availablePostTemplates.length > 0 && (
+              <div className="editor-field">
+                <label>{tr('editor.field.template')}</label>
+                <select
+                  value={templateSlug}
+                  onChange={(e) => setTemplateSlug(e.target.value)}
+                >
+                  <option value="">{tr('editor.field.templateDefault')}</option>
+                  {availablePostTemplates.map((tmpl) => (
+                    <option key={tmpl.slug} value={tmpl.slug}>{tmpl.title}</option>
+                  ))}
+                </select>
+              </div>
+            )}
 
             <PostLinks
               postId={postId}
@@ -1836,6 +1864,7 @@ export const Editor: React.FC = () => {
     ),
     'site-validation': () => <SiteValidationView />,
     scripts: () => <ScriptsView scriptId={editorRoute.tabId} />,
+    templates: () => <TemplatesView templateId={editorRoute.tabId} />,
     post: () => (editorRoute.tabId ? <PostEditor key={editorRoute.tabId} postId={editorRoute.tabId} /> : <Dashboard />),
     media: () => (editorRoute.tabId ? <MediaEditor key={editorRoute.tabId} mediaId={editorRoute.tabId} /> : <Dashboard />),
     dashboard: () => <Dashboard />,

src/renderer/components/SettingsView/SettingsView.tsx

@@ -34,6 +34,8 @@ interface CategoryMetadata {
   renderInLists: boolean;
   showTitle: boolean;
   title: string;
+  postTemplateSlug?: string;
+  listTemplateSlug?: string;
 }
 
 const RENDER_LANGUAGE_LABEL_KEY: Record<SupportedLanguage, string> = {
@@ -151,6 +153,10 @@ export const SettingsView: React.FC = () => {
   const [categoryMetadata, setCategoryMetadata] = useState<Record<string, CategoryMetadata>>(DEFAULT_CATEGORY_METADATA);
   const [newCategoryInput, setNewCategoryInput] = useState('');
 
+  // Available templates for category dropdowns
+  const [postTemplates, setPostTemplates] = useState<Array<{ slug: string; title: string }>>([]);
+  const [listTemplates, setListTemplates] = useState<Array<{ slug: string; title: string }>>([]);
+
   // AI Assistant settings
   const [aiSystemPrompt, setAiSystemPrompt] = useState('');
   const [aiSystemPromptModified, setAiSystemPromptModified] = useState(false);
@@ -221,6 +227,8 @@ export const SettingsView: React.FC = () => {
                 title: typeof (settings as any)?.title === 'string' && (settings as any).title.trim().length > 0
                   ? (settings as any).title.trim()
                   : category,
+                postTemplateSlug: typeof (settings as any)?.postTemplateSlug === 'string' ? (settings as any).postTemplateSlug : undefined,
+                listTemplateSlug: typeof (settings as any)?.listTemplateSlug === 'string' ? (settings as any).listTemplateSlug : undefined,
               };
             }
           }
@@ -230,6 +238,18 @@ export const SettingsView: React.FC = () => {
     }
   }, [activeProject]);
 
+  // Load available templates for category dropdowns
+  useEffect(() => {
+    if (activeProject) {
+      window.electronAPI?.templates.getEnabledByKind('post').then((templates) => {
+        setPostTemplates(templates.map((t) => ({ slug: t.slug, title: t.title })));
+      });
+      window.electronAPI?.templates.getEnabledByKind('list').then((templates) => {
+        setListTemplates(templates.map((t) => ({ slug: t.slug, title: t.title })));
+      });
+    }
+  }, [activeProject]);
+
   // Load saved credentials and categories
   useEffect(() => {
     const loadSettings = async () => {
@@ -771,6 +791,29 @@ export const SettingsView: React.FC = () => {
     }
   };
 
+  const handleCategoryTemplateChange = async (
+    category: string,
+    field: 'postTemplateSlug' | 'listTemplateSlug',
+    value: string,
+  ) => {
+    const nextCategoryMetadata: Record<string, CategoryMetadata> = {
+      ...categoryMetadata,
+      [category]: {
+        ...(categoryMetadata[category] || { renderInLists: true, showTitle: true, title: category }),
+        [field]: value || undefined,
+      },
+    };
+
+    setCategoryMetadata(nextCategoryMetadata);
+
+    try {
+      await window.electronAPI?.meta.updateProjectMetadata({ categoryMetadata: nextCategoryMetadata });
+    } catch (error) {
+      console.error('Failed to update category settings:', error);
+      showToast.error(t('settings.toast.categorySettingsUpdateFailed'));
+    }
+  };
+
   const renderContentSettings = () => (
     <SettingSection
       id="settings-section-content"
@@ -786,6 +829,8 @@ export const SettingsView: React.FC = () => {
                 <th>{t('settings.content.titleColumn')}</th>
                 <th>{t('settings.content.renderInLists')}</th>
                 <th>{t('settings.content.showTitles')}</th>
+                <th>{t('settings.content.postTemplateColumn')}</th>
+                <th>{t('settings.content.listTemplateColumn')}</th>
                 <th>{t('settings.content.actionsColumn')}</th>
               </tr>
             </thead>
@@ -823,6 +868,30 @@ export const SettingsView: React.FC = () => {
                         onChange={(event) => handleCategorySettingToggle(cat, 'showTitle', event.target.checked)}
                       />
                     </td>
+                    <td>
+                      <select
+                        value={metadata.postTemplateSlug || ''}
+                        onChange={(event) => handleCategoryTemplateChange(cat, 'postTemplateSlug', event.target.value)}
+                        aria-label={t('settings.content.postTemplateAria', { category: cat })}
+                      >
+                        <option value="">{t('editor.field.templateDefault')}</option>
+                        {postTemplates.map((tpl) => (
+                          <option key={tpl.slug} value={tpl.slug}>{tpl.title}</option>
+                        ))}
+                      </select>
+                    </td>
+                    <td>
+                      <select
+                        value={metadata.listTemplateSlug || ''}
+                        onChange={(event) => handleCategoryTemplateChange(cat, 'listTemplateSlug', event.target.value)}
+                        aria-label={t('settings.content.listTemplateAria', { category: cat })}
+                      >
+                        <option value="">{t('editor.field.templateDefault')}</option>
+                        {listTemplates.map((tpl) => (
+                          <option key={tpl.slug} value={tpl.slug}>{tpl.title}</option>
+                        ))}
+                      </select>
+                    </td>
                     <td className="category-actions-cell">
                       {!isProtected && (
                         <button
@@ -1213,6 +1282,29 @@ export const SettingsView: React.FC = () => {
           </button>
         </SettingRow>
 
+        <SettingRow
+          id="rebuild-templates"
+          label={t('settings.data.rebuildTemplatesLabel')}
+          description={t('settings.data.rebuildTemplatesDescription')}
+        >
+          <button
+            className="secondary"
+            onClick={async () => {
+              showToast.loading(t('settings.toast.rebuildTemplatesLoading'));
+              try {
+                await window.electronAPI?.templates.rebuildFromFiles();
+                showToast.dismiss();
+                showToast.success(t('settings.toast.rebuildTemplatesSuccess'));
+              } catch {
+                showToast.dismiss();
+                showToast.error(t('settings.toast.rebuildTemplatesFailed'));
+              }
+            }}
+          >
+            {t('settings.data.rebuildTemplatesAction')}
+          </button>
+        </SettingRow>
+
         <SettingRow
           id="rebuild-links"
           label={t('settings.data.rebuildLinksLabel')}

src/renderer/components/Sidebar/Sidebar.tsx

@@ -1,14 +1,14 @@
 import React, { useState, useEffect, useCallback, useMemo, useRef } from 'react';
 import { useAppStore, PostData, MediaData } from '../../store';
 import { showToast } from '../Toast';
-import { BDS_EVENT_SCRIPTS_CHANGED, dispatchWindowEvent, getContrastColor, groupPostsByStatus, loadTagColorMap } from '../../utils';
+import { BDS_EVENT_SCRIPTS_CHANGED, BDS_EVENT_TEMPLATES_CHANGED, dispatchWindowEvent, getContrastColor, groupPostsByStatus, loadTagColorMap } from '../../utils';
 import type { ChatConversation, ImportDefinitionData } from '../../types/electron';
 import { GitSidebar } from '../GitSidebar/GitSidebar';
 import { scrollToSettingsSection, SettingsCategory } from '../SettingsView/SettingsView';
 import { scrollToTagsSection, TagsCategory } from '../TagsView';
 import { activateSidebarSection } from '../../navigation/sectionActivation';
 import { getPersistedSidebarSection, setPersistedSidebarSection } from '../../navigation/sidebarUiPersistence';
-import { openChatTab, openEntityTab, openImportTab, openScriptTab, openSingletonToolTab } from '../../navigation/tabPolicy';
+import { openChatTab, openEntityTab, openImportTab, openScriptTab, openTemplateTab, openSingletonToolTab } from '../../navigation/tabPolicy';
 import { createAndFocusPost } from '../../navigation/postCreation';
 import type { SidebarView } from '../../navigation/sidebarViewRegistry';
 import { useI18n } from '../../i18n';
@@ -1702,6 +1702,139 @@ const ScriptsList: React.FC = () => {
   );
 };
 
+const TemplatesList: React.FC = () => {
+  const { t, language } = useI18n();
+  const { openTab, activeTabId, closeTab } = useAppStore();
+  const activeProjectId = useAppStore((state) => state.activeProject?.id);
+
+  const loadTemplates = useCallback(async (): Promise<Array<{ id: string; title: string; updatedAt: string }>> => {
+    const items = await window.electronAPI?.templates.getAll();
+    return (items ?? []).map((item) => ({ id: item.id, title: item.title, updatedAt: item.updatedAt }));
+  }, []);
+
+  const {
+    items: templates,
+    setItems: setTemplates,
+    isLoading,
+    reload: reloadTemplates,
+  } = useProjectScopedSidebarData<Array<{ id: string; title: string; updatedAt: string }>[number]>({
+    load: loadTemplates,
+    activeProjectId,
+    refreshEventName: BDS_EVENT_TEMPLATES_CHANGED,
+  });
+
+  const handleCreateTemplate = async () => {
+    try {
+      const created = await window.electronAPI?.templates.create({
+        title: t('sidebar.templates.newTemplate'),
+        kind: 'post',
+        content: '',
+        enabled: true,
+      });
+
+      if (!created) {
+        return;
+      }
+
+      setTemplates((prev) => [
+        { id: created.id, title: created.title, updatedAt: created.updatedAt },
+        ...prev.filter((tmpl) => tmpl.id !== created.id),
+      ]);
+      dispatchWindowEvent(BDS_EVENT_TEMPLATES_CHANGED);
+      openTemplateTab(openTab, created.id, 'pin');
+      void reloadTemplates();
+    } catch (error) {
+      console.error('Failed to create template:', error);
+      showToast.error(t('sidebar.templates.createFailed'));
+    }
+  };
+
+  const handleDeleteTemplate = async (event: React.MouseEvent, templateId: string) => {
+    event.stopPropagation();
+    try {
+      const result = await window.electronAPI?.templates.delete(templateId);
+      if (!result) {
+        showToast.error(t('sidebar.templates.deleteFailed'));
+        return;
+      }
+
+      if (!result.deleted && result.references) {
+        const { postIds, tagIds } = result.references;
+        const confirmed = window.confirm(
+          t('sidebar.templates.deleteConfirmWithRefs', {
+            postCount: String(postIds.length),
+            tagCount: String(tagIds.length),
+          }),
+        );
+        if (!confirmed) {
+          return;
+        }
+        const forceResult = await window.electronAPI?.templates.delete(templateId, { force: true });
+        if (!forceResult?.deleted) {
+          showToast.error(t('sidebar.templates.deleteFailed'));
+          return;
+        }
+      }
+
+      setTemplates((prev) => prev.filter((tmpl) => tmpl.id !== templateId));
+      closeTab(templateId);
+      dispatchWindowEvent(BDS_EVENT_TEMPLATES_CHANGED);
+    } catch (error) {
+      console.error('Failed to delete template:', error);
+      showToast.error(t('sidebar.templates.deleteFailed'));
+    }
+  };
+
+  return (
+    <SidebarEntityList
+      header={t('sidebar.templates.header')}
+      createTitle={t('sidebar.templates.newTemplate')}
+      onCreate={handleCreateTemplate}
+      isLoading={isLoading}
+      loadingLabel={t('sidebar.loading')}
+      emptyMessage={t('sidebar.templates.none')}
+      emptyActionLabel={t('sidebar.templates.createTemplate')}
+      onEmptyAction={handleCreateTemplate}
+      items={templates}
+      getItemKey={(tmpl) => tmpl.id}
+      renderItem={(tmpl) => (
+        <div
+          role="button"
+          tabIndex={0}
+          aria-label={tmpl.title}
+          className={`chat-list-item ${activeTabId === tmpl.id ? 'active' : ''}`}
+          onClick={() => openTemplateTab(openTab, tmpl.id, 'preview')}
+          onDoubleClick={() => openTemplateTab(openTab, tmpl.id, 'pin')}
+          onKeyDown={(event) => {
+            if (event.key === 'Enter') {
+              openTemplateTab(openTab, tmpl.id, 'pin');
+              return;
+            }
+            if (event.key === ' ') {
+              event.preventDefault();
+              openTemplateTab(openTab, tmpl.id, 'preview');
+            }
+          }}
+        >
+          <div className="chat-item-content">
+            <div className="chat-item-title">{tmpl.title}</div>
+            <div className="chat-item-date">
+              {formatSidebarRelativeDate({ dateString: tmpl.updatedAt, language, t })}
+            </div>
+          </div>
+          <button
+            className="chat-item-delete"
+            onClick={(event) => handleDeleteTemplate(event, tmpl.id)}
+            title={t('sidebar.templates.deleteTemplate')}
+          >
+            ×
+          </button>
+        </div>
+      )}
+    />
+  );
+};
+
 export const Sidebar: React.FC = () => {
   const { activeView, sidebarVisible } = useAppStore();
 
@@ -1714,6 +1847,7 @@ export const Sidebar: React.FC = () => {
     pages: <PostsList mode="pages" isActive={true} />,
     media: <MediaList />,
     scripts: <ScriptsList />,
+    templates: <TemplatesList />,
     settings: <SettingsNav />,
     tags: <TagsNav />,
     chat: <ChatList />,

src/renderer/components/TabBar/TabBar.tsx

@@ -1,6 +1,7 @@
 import React, { useRef, useState, useEffect, useCallback } from 'react';
 import { useAppStore, Tab } from '../../store';
 import { parseGitDiffTabId } from '../../navigation/tabPolicy';
+import { BDS_EVENT_TEMPLATES_CHANGED, addWindowEventListener } from '../../utils';
 import { useI18n } from '../../i18n';
 import './TabBar.css';
 
@@ -14,6 +15,7 @@ const getTabTitle = (
   chatTitles: Map<string, string>,
   importDefTitles: Map<string, string>,
   commitTitles: Map<string, string>,
+  templateTitles: Map<string, string>,
   tr: (key: string, vars?: Record<string, string | number>) => string,
 ): string => {
   if (tab.type === 'git-diff') {
@@ -89,6 +91,10 @@ const getTabTitle = (
     return scriptTitles.get(tab.id) || tr('tabBar.scripts');
   }
 
+  if (tab.type === 'templates') {
+    return templateTitles.get(tab.id) || tr('editor.untitled');
+  }
+
   return tr('tabBar.unknown');
 };
 
@@ -180,6 +186,12 @@ const getTabIcon = (tab: Tab): React.ReactNode => {
           <path d="M20 3H4a1 1 0 0 0-1 1v11a1 1 0 0 0 1 1h7v2H8v2h8v-2h-3v-2h7a1 1 0 0 0 1-1V4a1 1 0 0 0-1-1zM5 14V5h14v9H5zm2-7.5L9.5 9 7 11.5l1.4 1.4L12.3 9 8.4 5.1 7 6.5zm6.5 5.5h4v-2h-4v2z"/>
         </svg>
       );
+    case 'templates':
+      return (
+        <svg width="16" height="16" viewBox="0 0 16 16" fill="currentColor">
+          <path d="M14 2H2v4h12V2zM3 3h10v2H3V3zm-1 5h5v7H2V8zm1 1v5h3V9H3zm5-1h6v3H8V8zm1 1v1h4V9H9zm0 3h6v3H9v-3zm1 1v1h4v-1h-4z"/>
+        </svg>
+      );
     default:
       return (
         <svg width="16" height="16" viewBox="0 0 16 16" fill="currentColor">
@@ -230,6 +242,7 @@ export const TabBar: React.FC = () => {
   const [chatTitles, setChatTitles] = useState<Map<string, string>>(new Map());
   const [importDefTitles, setImportDefTitles] = useState<Map<string, string>>(new Map());
   const [commitTitles, setCommitTitles] = useState<Map<string, string>>(new Map());
+  const [templateTitles, setTemplateTitles] = useState<Map<string, string>>(new Map());
 
   // Fetch post titles from database for post tabs
   useEffect(() => {
@@ -552,6 +565,94 @@ export const TabBar: React.FC = () => {
     };
   }, [tabs, activeProject, tr]);
 
+  // Fetch template titles for template tabs
+  useEffect(() => {
+    const templateTabs = tabs.filter((t) => t.type === 'templates');
+    const templateTabIds = new Set(templateTabs.map((t) => t.id));
+
+    setTemplateTitles((previous) => {
+      const next = new Map(previous);
+      let changed = false;
+
+      for (const id of Array.from(next.keys())) {
+        if (!templateTabIds.has(id)) {
+          next.delete(id);
+          changed = true;
+        }
+      }
+
+      return changed ? next : previous;
+    });
+
+    if (templateTabs.length === 0) {
+      return;
+    }
+
+    const fetchTemplateTitles = async () => {
+      const newTitles = new Map(templateTitles);
+      let changed = false;
+
+      for (const tab of templateTabs) {
+        if (templateTitles.has(tab.id)) {
+          continue;
+        }
+
+        try {
+          const tmpl = await window.electronAPI?.templates.get(tab.id);
+          if (tmpl) {
+            const title = tmpl.title || tr('editor.untitled');
+            if (newTitles.get(tab.id) !== title) {
+              newTitles.set(tab.id, title);
+              changed = true;
+            }
+          }
+        } catch (error) {
+          console.error(tr('tabBar.error.fetchTemplateTitle'), error);
+        }
+      }
+
+      if (changed) {
+        setTemplateTitles(newTitles);
+      }
+    };
+
+    void fetchTemplateTitles();
+  }, [tabs, tr]); // Note: intentionally not including templateTitles to avoid infinite loops
+
+  // Listen for template updates to refresh titles
+  useEffect(() => {
+    const handleTemplatesChanged = async () => {
+      const templateTabs = tabs.filter((t) => t.type === 'templates');
+      if (templateTabs.length === 0) {
+        return;
+      }
+
+      const updated = new Map(templateTitles);
+      let changed = false;
+
+      for (const tab of templateTabs) {
+        try {
+          const tmpl = await window.electronAPI?.templates.get(tab.id);
+          if (tmpl) {
+            const title = tmpl.title || tr('editor.untitled');
+            if (updated.get(tab.id) !== title) {
+              updated.set(tab.id, title);
+              changed = true;
+            }
+          }
+        } catch (error) {
+          console.error(tr('tabBar.error.fetchTemplateTitle'), error);
+        }
+      }
+
+      if (changed) {
+        setTemplateTitles(updated);
+      }
+    };
+
+    return addWindowEventListener(BDS_EVENT_TEMPLATES_CHANGED, handleTemplatesChanged);
+  }, [tabs, templateTitles, tr]);
+
   // Check if arrows are needed based on scroll position
   const updateArrowVisibility = useCallback(() => {
     const container = tabsContainerRef.current;
@@ -674,7 +775,7 @@ export const TabBar: React.FC = () => {
         {tabs.map((tab) => {
           const isActive = tab.id === activeTabId;
           const isDirty = tab.type === 'post' && dirtyPosts.has(tab.id);
-          const title = getTabTitle(tab, postTitles, media, scriptTitles, chatTitles, importDefTitles, commitTitles, tr);
+          const title = getTabTitle(tab, postTitles, media, scriptTitles, chatTitles, importDefTitles, commitTitles, templateTitles, tr);
           const icon = getTabIcon(tab);
           
           return (

src/renderer/components/TagsView/TagsView.tsx

@@ -18,6 +18,7 @@ interface TagData {
   projectId: string;
   name: string;
   color?: string;
+  postTemplateSlug?: string;
   createdAt: string;
   updatedAt: string;
 }
@@ -147,6 +148,8 @@ export const TagsView: React.FC = () => {
   const [editingTagId, setEditingTagId] = useState<string | null>(null);
   const [editTagColor, setEditTagColor] = useState<string>('');
   const [editTagName, setEditTagName] = useState('');
+  const [editTagTemplate, setEditTagTemplate] = useState<string>('');
+  const [postTemplates, setPostTemplates] = useState<Array<{ slug: string; title: string }>>([]);
   
   // Merge tags state
   const [mergeTargetName, setMergeTargetName] = useState('');
@@ -188,6 +191,13 @@ export const TagsView: React.FC = () => {
     });
   }, [loadTags]);
 
+  // Load post templates on mount
+  useEffect(() => {
+    window.electronAPI?.templates.getEnabledByKind('post').then((templates) => {
+      setPostTemplates(templates.map((t) => ({ slug: t.slug, title: t.title })));
+    });
+  }, []);
+
   // Handle tag selection
   const handleTagSelect = (name: string) => {
     setSelectedTags(prev => {
@@ -247,6 +257,7 @@ export const TagsView: React.FC = () => {
     setEditingTagId(tag.id);
     setEditTagColor(tag.color || '');
     setEditTagName(tag.name);
+    setEditTagTemplate(tag.postTemplateSlug || '');
   };
 
   // Save tag edit
@@ -254,9 +265,10 @@ export const TagsView: React.FC = () => {
     if (!editingTagId) return;
 
     try {
-      // Update color
+      // Update color and template
       await window.electronAPI?.tags.update(editingTagId, {
         color: editTagColor || null,
+        postTemplateSlug: editTagTemplate || null,
       });
 
       // If name changed, rename the tag
@@ -455,6 +467,7 @@ export const TagsView: React.FC = () => {
             <div className="tag-edit-form">
               <h4>{t('tagsView.edit.title', { name: selectedTagObjects[0].name })}</h4>
               {editingTagId === selectedTagObjects[0].id ? (
+                <>
                 <div className="tag-form-row">
                   <input
                     type="text"
@@ -469,8 +482,8 @@ export const TagsView: React.FC = () => {
                       onChange={(e) => setEditTagColor(e.target.value)}
                     />
                     {editTagColor && (
-                      <button 
-                        className="clear-color" 
+                      <button
+                        className="clear-color"
                         onClick={() => setEditTagColor('')}
                         title={t('tagsView.removeColor')}
                       >
@@ -481,6 +494,14 @@ export const TagsView: React.FC = () => {
                   <button onClick={handleSaveEdit} className="primary">{t('common.save')}</button>
                   <button onClick={() => setEditingTagId(null)}>{t('common.cancel')}</button>
                 </div>
+                <div className="tagsview-field">
+                  <label>{t('tagsView.edit.postTemplate')}</label>
+                  <select value={editTagTemplate} onChange={(e) => setEditTagTemplate(e.target.value)}>
+                    <option value="">{t('editor.field.templateDefault')}</option>
+                    {postTemplates.map(tmpl => <option key={tmpl.slug} value={tmpl.slug}>{tmpl.title}</option>)}
+                  </select>
+                </div>
+                </>
               ) : (
                 <div className="tag-form-row">
                   <span className="tag-preview" style={

src/renderer/components/TemplatesView/TemplatesView.css

@@ -0,0 +1,54 @@
+.templates-view-shell {
+  display: flex;
+  flex: 1;
+  flex-direction: column;
+  min-height: 0;
+}
+
+.templates-view {
+  flex: 1;
+  min-height: 0;
+}
+
+.templates-meta-row {
+  margin-bottom: 8px;
+}
+
+.templates-enabled-field {
+  align-self: flex-end;
+}
+
+.templates-enabled-field label {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+}
+
+.templates-editor {
+  flex: 1;
+  min-height: 0;
+}
+
+.templates-toolbar {
+  margin-bottom: 8px;
+}
+
+.templates-monaco {
+  flex: 1;
+  min-height: 0;
+  border-radius: 4px;
+  overflow: hidden;
+  background-color: var(--vscode-input-background);
+}
+
+.templates-save-button {
+  padding: 4px 12px;
+  font-size: 12px;
+  border-radius: 4px;
+}
+
+.templates-validate-button {
+  padding: 4px 12px;
+  font-size: 12px;
+  border-radius: 4px;
+}

src/renderer/components/TemplatesView/TemplatesView.tsx

@@ -0,0 +1,379 @@
+import React, { useEffect, useState } from 'react';
+import MonacoEditor from '@monaco-editor/react';
+import type { TemplateData, TemplateKind } from '../../../main/shared/electronApi';
+import { useAppStore } from '../../store';
+import { BDS_EVENT_TEMPLATES_CHANGED, dispatchWindowEvent } from '../../utils';
+import { useI18n } from '../../i18n';
+import { showToast } from '../Toast';
+import './TemplatesView.css';
+
+const UI_DATE_LOCALE: Record<string, string> = {
+  en: 'en-US',
+  de: 'de-DE',
+  fr: 'fr-FR',
+  it: 'it-IT',
+  es: 'es-ES',
+};
+
+const toTemplateSlug = (value: string) => {
+  const normalized = value
+    .toLowerCase()
+    .replace(/[^a-z0-9]+/g, '_')
+    .replace(/^_+|_+$/g, '');
+  return normalized || 'template';
+};
+
+interface TemplatesViewProps {
+  templateId: string | null;
+}
+
+export const TemplatesView: React.FC<TemplatesViewProps> = ({ templateId }) => {
+  const { t, language } = useI18n();
+  const closeTab = useAppStore((state) => state.closeTab);
+  const [template, setTemplate] = useState<TemplateData | null>(null);
+  const [title, setTitle] = useState('');
+  const [slug, setSlug] = useState('');
+  const [kind, setKind] = useState<TemplateKind>('post');
+  const [enabled, setEnabled] = useState(true);
+  const [templateContent, setTemplateContent] = useState('');
+  const [isSlugManuallyEdited, setIsSlugManuallyEdited] = useState(false);
+  const [isSaving, setIsSaving] = useState(false);
+  const [isValidating, setIsValidating] = useState(false);
+  const [monacoResetToken, setMonacoResetToken] = useState(0);
+
+  useEffect(() => {
+    let cancelled = false;
+
+    const loadTemplate = async () => {
+      if (!templateId) {
+        setTemplate(null);
+        setTitle('');
+        setSlug('');
+        setKind('post');
+        setEnabled(true);
+        setTemplateContent('');
+        setMonacoResetToken((prev) => prev + 1);
+        setIsSlugManuallyEdited(false);
+        return;
+      }
+
+      const item = await window.electronAPI?.templates.get(templateId);
+      if (cancelled || !item) {
+        setTemplate(null);
+        setTitle('');
+        setSlug('');
+        setKind('post');
+        setEnabled(true);
+        setTemplateContent('');
+        setMonacoResetToken((prev) => prev + 1);
+        setIsSlugManuallyEdited(false);
+        return;
+      }
+
+      setTemplate(item);
+      setTitle(item.title || '');
+      setSlug(item.slug || toTemplateSlug(item.title || ''));
+      setKind(item.kind || 'post');
+      setEnabled(item.enabled ?? true);
+      setTemplateContent(item.content || '');
+      setMonacoResetToken((prev) => prev + 1);
+      const normalizedExisting = toTemplateSlug(item.slug || item.title || '');
+      setIsSlugManuallyEdited(normalizedExisting !== toTemplateSlug(item.title || ''));
+    };
+
+    void loadTemplate();
+
+    return () => {
+      cancelled = true;
+    };
+  }, [templateId]);
+
+  const hasChanges =
+    !!template &&
+    (title !== template.title ||
+      slug !== template.slug ||
+      kind !== template.kind ||
+      enabled !== template.enabled ||
+      templateContent !== template.content);
+
+  const handleTitleChange = (nextTitle: string) => {
+    setTitle(nextTitle);
+    if (!isSlugManuallyEdited) {
+      setSlug(toTemplateSlug(nextTitle));
+    }
+  };
+
+  const handleSlugChange = (nextSlug: string) => {
+    setIsSlugManuallyEdited(true);
+    setSlug(toTemplateSlug(nextSlug));
+  };
+
+  const handleValidate = async (options: { notify: boolean } = { notify: true }): Promise<boolean> => {
+    if (!template || isValidating) {
+      return false;
+    }
+
+    setIsValidating(true);
+    try {
+      const result = await window.electronAPI?.templates.validate(templateContent);
+      if (!result) {
+        return false;
+      }
+
+      if (!result.valid) {
+        if (options.notify) {
+          showToast.error(t('templates.validate.invalid', { count: result.errors.length }));
+        }
+        return false;
+      }
+
+      if (options.notify) {
+        showToast.success(t('templates.validate.valid'));
+      }
+      return true;
+    } catch {
+      return false;
+    } finally {
+      setIsValidating(false);
+    }
+  };
+
+  const handleSaveTemplate = async () => {
+    if (!template || isSaving || !hasChanges) {
+      return;
+    }
+
+    setIsSaving(true);
+    try {
+      const isValid = await handleValidate({ notify: true });
+      if (!isValid) {
+        return;
+      }
+
+      const updated = await window.electronAPI?.templates.update(template.id, {
+        title,
+        slug,
+        kind,
+        enabled,
+        content: templateContent,
+      });
+
+      if (!updated) {
+        return;
+      }
+
+      setTemplate(updated);
+      setTitle(updated.title || '');
+      setSlug(updated.slug || toTemplateSlug(updated.title || ''));
+      setKind(updated.kind || 'post');
+      setEnabled(updated.enabled ?? true);
+      setTemplateContent(updated.content || '');
+      const normalizedExisting = toTemplateSlug(updated.slug || updated.title || '');
+      setIsSlugManuallyEdited(normalizedExisting !== toTemplateSlug(updated.title || ''));
+      dispatchWindowEvent(BDS_EVENT_TEMPLATES_CHANGED);
+    } finally {
+      setIsSaving(false);
+    }
+  };
+
+  const handleDeleteTemplate = async () => {
+    if (!template) {
+      return;
+    }
+
+    try {
+      const result = await window.electronAPI?.templates.delete(template.id);
+      if (!result) {
+        showToast.error(t('sidebar.templates.deleteFailed'));
+        return;
+      }
+
+      if (!result.deleted && result.references) {
+        const { postIds, tagIds } = result.references;
+        const confirmed = window.confirm(
+          t('sidebar.templates.deleteConfirmWithRefs', {
+            postCount: String(postIds.length),
+            tagCount: String(tagIds.length),
+          }),
+        );
+        if (!confirmed) {
+          return;
+        }
+        const forceResult = await window.electronAPI?.templates.delete(template.id, { force: true });
+        if (!forceResult?.deleted) {
+          showToast.error(t('sidebar.templates.deleteFailed'));
+          return;
+        }
+      }
+
+      closeTab(template.id);
+      dispatchWindowEvent(BDS_EVENT_TEMPLATES_CHANGED);
+    } catch (error) {
+      console.error('Failed to delete template:', error);
+      showToast.error(t('sidebar.templates.deleteFailed'));
+    }
+  };
+
+  useEffect(() => {
+    const handleKeyDown = (event: KeyboardEvent) => {
+      if ((event.ctrlKey || event.metaKey) && event.key === 's') {
+        event.preventDefault();
+        void handleSaveTemplate();
+      }
+    };
+
+    if (typeof window.addEventListener !== 'function' || typeof window.removeEventListener !== 'function') {
+      return;
+    }
+
+    window.addEventListener('keydown', handleKeyDown);
+    return () => window.removeEventListener('keydown', handleKeyDown);
+  }, [handleSaveTemplate]);
+
+  return (
+    <div className="templates-view-shell">
+      <div className="editor-header templates-header">
+        <div className="editor-tabs">
+          <div className="editor-tab active">
+            <span className="editor-tab-title">{title || t('editor.untitled')}</span>
+          </div>
+        </div>
+        <div className="editor-actions">
+          <button
+            type="button"
+            className="templates-save-button"
+            onClick={handleSaveTemplate}
+            disabled={!template || !hasChanges || isSaving}
+          >
+            {isSaving ? t('editor.saving') : t('templates.save')}
+          </button>
+          <button
+            type="button"
+            className="templates-validate-button"
+            onClick={() => {
+              void handleValidate({ notify: true });
+            }}
+            disabled={!template || isValidating || isSaving}
+          >
+            {isValidating ? t('templates.validate.checking') : t('templates.validate')}
+          </button>
+          <button
+            type="button"
+            className="secondary danger"
+            onClick={handleDeleteTemplate}
+            disabled={!template}
+            title={t('templates.delete')}
+          >
+            {t('templates.delete')}
+          </button>
+        </div>
+      </div>
+
+      <div className="editor-content templates-view">
+        <div className="editor-header-row templates-meta-row">
+          <div className="editor-meta">
+            <div className="editor-field-row">
+              <div className="editor-field">
+                <label htmlFor="template-title">{t('editor.field.title')}</label>
+                <input
+                  id="template-title"
+                  type="text"
+                  value={title}
+                  onChange={(event) => handleTitleChange(event.target.value)}
+                  disabled={!template}
+                />
+              </div>
+              <div className="editor-field">
+                <label htmlFor="template-slug">{t('editor.field.slug')}</label>
+                <input
+                  id="template-slug"
+                  type="text"
+                  value={slug}
+                  onChange={(event) => handleSlugChange(event.target.value)}
+                  disabled={!template}
+                />
+              </div>
+            </div>
+            <div className="editor-field-row">
+              <div className="editor-field">
+                <label htmlFor="template-kind">{t('templates.field.kind')}</label>
+                <select
+                  id="template-kind"
+                  value={kind}
+                  onChange={(event) => setKind(event.target.value as TemplateKind)}
+                  disabled={!template}
+                >
+                  <option value="post">{t('templates.kind.post')}</option>
+                  <option value="list">{t('templates.kind.list')}</option>
+                  <option value="not-found">{t('templates.kind.not_found')}</option>
+                  <option value="partial">{t('templates.kind.partial')}</option>
+                </select>
+              </div>
+              <div className="editor-field templates-enabled-field">
+                <label htmlFor="template-enabled">
+                  <input
+                    id="template-enabled"
+                    type="checkbox"
+                    checked={enabled}
+                    onChange={(event) => setEnabled(event.target.checked)}
+                    disabled={!template}
+                  />
+                  {t('templates.field.enabled')}
+                </label>
+              </div>
+            </div>
+          </div>
+        </div>
+
+        <div className="editor-body templates-editor">
+          <div className="editor-toolbar templates-toolbar">
+            <div className="editor-toolbar-left">
+              <label>{t('templates.content')}</label>
+            </div>
+            <div className="editor-toolbar-center" />
+            <div className="editor-toolbar-right" />
+          </div>
+
+          <div className="templates-monaco">
+            <MonacoEditor
+              key={monacoResetToken}
+              height="100%"
+              language="html"
+              theme="vs-dark"
+              defaultValue={templateContent}
+              onChange={(value) => setTemplateContent(value || '')}
+              options={{
+                minimap: { enabled: false },
+                wordWrap: 'on',
+                lineNumbers: 'on',
+                fontSize: 14,
+                fontFamily: "'Cascadia Code', 'Consolas', 'Courier New', monospace",
+                padding: { top: 12, bottom: 12 },
+                automaticLayout: true,
+                scrollBeyondLastLine: false,
+                renderLineHighlight: 'line',
+                formatOnPaste: true,
+                cursorStyle: 'line',
+                cursorBlinking: 'smooth',
+                readOnly: !template,
+              }}
+            />
+          </div>
+        </div>
+
+        {template && (
+          <div className="editor-footer">
+            <span className="text-muted text-small">
+              {t('editor.footer.created')}:{' '}
+              {new Date(template.createdAt).toLocaleString(UI_DATE_LOCALE[language] || UI_DATE_LOCALE.en)}
+            </span>
+            <span className="text-muted text-small">
+              {t('editor.footer.updated')}:{' '}
+              {new Date(template.updatedAt).toLocaleString(UI_DATE_LOCALE[language] || UI_DATE_LOCALE.en)}
+            </span>
+          </div>
+        )}
+      </div>
+    </div>
+  );
+};

src/renderer/i18n/locales/de.json

@@ -11,6 +11,7 @@
   "activity.media": "Medien",
   "activity.scripts": "Skripte",
   "activity.tags": "Schlagwörter",
+  "activity.templates": "Vorlagen",
   "activity.aiAssistant": "KI-Assistent",
   "activity.import": "Importieren",
   "activity.sourceControl": "Versionskontrolle",
@@ -179,6 +180,9 @@
   "settings.toast.rebuildScriptsLoading": "Skriptdatenbank wird neu aufgebaut...",
   "settings.toast.rebuildScriptsSuccess": "Skriptdatenbank neu aufgebaut",
   "settings.toast.rebuildScriptsFailed": "Skriptdatenbank konnte nicht neu aufgebaut werden",
+  "settings.toast.rebuildTemplatesLoading": "Vorlagen-Datenbank wird neu aufgebaut...",
+  "settings.toast.rebuildTemplatesSuccess": "Vorlagen-Datenbank wurde neu aufgebaut",
+  "settings.toast.rebuildTemplatesFailed": "Fehler beim Neuaufbau der Vorlagen-Datenbank",
   "settings.toast.rebuildLinksLoading": "Beitragslinks werden neu aufgebaut...",
   "settings.toast.rebuildLinksSuccess": "Beitragslinks neu aufgebaut",
   "settings.toast.rebuildLinksFailed": "Beitragslinks konnten nicht neu aufgebaut werden",
@@ -367,6 +371,7 @@
   "tabBar.error.fetchChatTitle": "Chat-Titel konnte nicht geladen werden:",
   "tabBar.error.fetchImportTitle": "Titel der Importdefinition konnte nicht geladen werden:",
   "tabBar.error.fetchScriptTitle": "Skript-Titel konnte nicht geladen werden:",
+  "tabBar.error.fetchTemplateTitle": "Vorlagen-Titel konnte nicht geladen werden:",
   "tabBar.error.fetchCommitTitle": "Commit-Titel konnten nicht geladen werden:",
   "metadataDiff.title": "Metadaten-Diff-Werkzeug",
   "metadataDiff.description": "Vergleicht Beitragsmetadaten zwischen Datenbank und Markdown-Dateien. Behebt Abweichungen durch Bugs oder manuelle Änderungen.",
@@ -451,6 +456,19 @@
   "scripts.kind.utility": "utility",
   "scripts.kind.macro": "macro",
   "scripts.kind.transform": "transform",
+  "templates.save": "Vorlage speichern",
+  "templates.delete": "Vorlage löschen",
+  "templates.content": "Vorlageninhalt",
+  "templates.field.kind": "Art",
+  "templates.field.enabled": "Aktiviert",
+  "templates.validate": "Validieren",
+  "templates.validate.valid": "Vorlagensyntax ist gültig",
+  "templates.validate.invalid": "Vorlagensyntaxfehler: {count}",
+  "templates.validate.checking": "Wird validiert...",
+  "templates.kind.post": "Beitrag",
+  "templates.kind.list": "Liste",
+  "templates.kind.not_found": "Nicht gefunden",
+  "templates.kind.partial": "Partial",
   "sidebar.tagCloud": "Tag-Wolke",
   "sidebar.createEdit": "Erstellen & Bearbeiten",
   "sidebar.mergeTags": "Tags zusammenführen",
@@ -497,6 +515,8 @@
   "editor.field.slug": "Slug",
   "editor.field.categories": "Kategorien",
   "editor.field.content": "Inhalt",
+  "editor.field.template": "Vorlage",
+  "editor.field.templateDefault": "Standard",
   "editor.placeholder.tags": "Tags hinzufügen...",
   "editor.placeholder.author": "Autorenname",
   "editor.placeholder.categories": "Kategorien hinzufügen...",
@@ -587,6 +607,7 @@
   "tagsView.removeColor": "Farbe entfernen",
   "tagsView.edit.title": "Tag bearbeiten: {name}",
   "tagsView.edit.action": "Bearbeiten",
+  "tagsView.edit.postTemplate": "Beitragsvorlage",
   "tagsView.deleteAction": "Löschen",
   "tagsView.merge.title": "Tags zusammenführen",
   "tagsView.merge.description": "Wähle oben mehrere Tags aus und führe sie zu einem einzigen zusammen. Alle Beiträge werden aktualisiert.",
@@ -683,6 +704,10 @@
   "settings.content.categoryColumn": "Kategorie",
   "settings.content.titleColumn": "Titel",
   "settings.content.actionsColumn": "Aktionen",
+  "settings.content.postTemplateColumn": "Beitragsvorlage",
+  "settings.content.listTemplateColumn": "Listenvorlage",
+  "settings.content.postTemplateAria": "{category} Beitragsvorlage",
+  "settings.content.listTemplateAria": "{category} Listenvorlage",
   "settings.content.renderInListsAria": "{category} in Listen anzeigen",
   "settings.content.showTitlesAria": "{category} Titel anzeigen",
   "settings.content.categoryTitleAria": "{category} Anzeigename",
@@ -718,6 +743,9 @@
   "settings.data.rebuildScriptsLabel": "Skriptdatenbank neu aufbauen",
   "settings.data.rebuildScriptsDescription": "Alle Python-Skripte neu scannen und den Skript-Metadatenindex neu aufbauen.",
   "settings.data.rebuildScriptsAction": "Skripte neu aufbauen",
+  "settings.data.rebuildTemplatesLabel": "Vorlagen-Datenbank neu aufbauen",
+  "settings.data.rebuildTemplatesDescription": "Alle Liquid-Vorlagen neu scannen und den Vorlagen-Metadaten-Index neu aufbauen.",
+  "settings.data.rebuildTemplatesAction": "Vorlagen neu aufbauen",
   "settings.data.rebuildLinksLabel": "Beitragslinks neu aufbauen",
   "settings.data.rebuildLinksDescription": "Alle Beiträge neu scannen und den internen Linkgraphen zwischen Beiträgen neu aufbauen.",
   "settings.data.rebuildLinksAction": "Links neu aufbauen",
@@ -746,6 +774,14 @@
   "sidebar.scripts.createFailed": "Skript konnte nicht erstellt werden",
   "sidebar.scripts.deleteScript": "Skript löschen",
   "sidebar.scripts.deleteFailed": "Skript konnte nicht gelöscht werden",
+  "sidebar.templates.header": "VORLAGEN",
+  "sidebar.templates.newTemplate": "Neue Vorlage",
+  "sidebar.templates.none": "Noch keine Vorlagen",
+  "sidebar.templates.createTemplate": "Vorlage erstellen",
+  "sidebar.templates.createFailed": "Vorlage konnte nicht erstellt werden",
+  "sidebar.templates.deleteTemplate": "Vorlage löschen",
+  "sidebar.templates.deleteFailed": "Vorlage konnte nicht gelöscht werden",
+  "sidebar.templates.deleteConfirmWithRefs": "Diese Vorlage wird von {postCount} Beitrag/Beiträgen und {tagCount} Tag(s) referenziert. Trotzdem löschen? Die Referenzen werden entfernt.",
   "sidebar.import.none": "Noch keine Importdefinitionen",
   "sidebar.import.createDefinition": "Eine Importdefinition erstellen",
   "sidebar.import.deleteDefinition": "Importdefinition löschen",

src/renderer/i18n/locales/en.json

@@ -11,6 +11,7 @@
   "activity.media": "Media",
   "activity.scripts": "Scripts",
   "activity.tags": "Tags",
+  "activity.templates": "Templates",
   "activity.aiAssistant": "AI Assistant",
   "activity.import": "Import",
   "activity.sourceControl": "Source Control",
@@ -179,6 +180,9 @@
   "settings.toast.rebuildScriptsLoading": "Rebuilding scripts database...",
   "settings.toast.rebuildScriptsSuccess": "Scripts database rebuilt",
   "settings.toast.rebuildScriptsFailed": "Failed to rebuild scripts database",
+  "settings.toast.rebuildTemplatesLoading": "Rebuilding templates database...",
+  "settings.toast.rebuildTemplatesSuccess": "Templates database rebuilt",
+  "settings.toast.rebuildTemplatesFailed": "Failed to rebuild templates database",
   "settings.toast.rebuildLinksLoading": "Rebuilding post links...",
   "settings.toast.rebuildLinksSuccess": "Post links rebuilt",
   "settings.toast.rebuildLinksFailed": "Failed to rebuild post links",
@@ -367,6 +371,7 @@
   "tabBar.error.fetchChatTitle": "Failed to fetch chat title:",
   "tabBar.error.fetchImportTitle": "Failed to fetch import definition title:",
   "tabBar.error.fetchScriptTitle": "Failed to fetch script title:",
+  "tabBar.error.fetchTemplateTitle": "Failed to fetch template title:",
   "tabBar.error.fetchCommitTitle": "Failed to fetch commit titles:",
   "metadataDiff.title": "Metadata Diff Tool",
   "metadataDiff.description": "Compare post metadata between database and markdown files. Fix inconsistencies caused by bugs or manual edits.",
@@ -451,6 +456,19 @@
   "scripts.kind.utility": "utility",
   "scripts.kind.macro": "macro",
   "scripts.kind.transform": "transform",
+  "templates.save": "Save Template",
+  "templates.delete": "Delete Template",
+  "templates.content": "Template Content",
+  "templates.field.kind": "Kind",
+  "templates.field.enabled": "Enabled",
+  "templates.validate": "Validate",
+  "templates.validate.valid": "Template syntax is valid",
+  "templates.validate.invalid": "Template syntax errors: {count}",
+  "templates.validate.checking": "Validating...",
+  "templates.kind.post": "post",
+  "templates.kind.list": "list",
+  "templates.kind.not_found": "not found",
+  "templates.kind.partial": "partial",
   "sidebar.tagCloud": "Tag Cloud",
   "sidebar.createEdit": "Create & Edit",
   "sidebar.mergeTags": "Merge Tags",
@@ -497,6 +515,8 @@
   "editor.field.slug": "Slug",
   "editor.field.categories": "Categories",
   "editor.field.content": "Content",
+  "editor.field.template": "Template",
+  "editor.field.templateDefault": "Default",
   "editor.placeholder.tags": "Add tags...",
   "editor.placeholder.author": "Author name",
   "editor.placeholder.categories": "Add categories...",
@@ -587,6 +607,7 @@
   "tagsView.removeColor": "Remove color",
   "tagsView.edit.title": "Edit Tag: {name}",
   "tagsView.edit.action": "Edit",
+  "tagsView.edit.postTemplate": "Post Template",
   "tagsView.deleteAction": "Delete",
   "tagsView.merge.title": "Merge Tags",
   "tagsView.merge.description": "Select multiple tags above, then merge them into a single tag. All posts will be updated.",
@@ -683,6 +704,10 @@
   "settings.content.categoryColumn": "Category",
   "settings.content.titleColumn": "Title",
   "settings.content.actionsColumn": "Actions",
+  "settings.content.postTemplateColumn": "Post Template",
+  "settings.content.listTemplateColumn": "List Template",
+  "settings.content.postTemplateAria": "{category} post template",
+  "settings.content.listTemplateAria": "{category} list template",
   "settings.content.renderInListsAria": "{category} render in lists",
   "settings.content.showTitlesAria": "{category} show titles",
   "settings.content.categoryTitleAria": "{category} display title",
@@ -718,6 +743,9 @@
   "settings.data.rebuildScriptsLabel": "Rebuild Scripts Database",
   "settings.data.rebuildScriptsDescription": "Re-scan all Python scripts and rebuild the scripts metadata index.",
   "settings.data.rebuildScriptsAction": "Rebuild Scripts",
+  "settings.data.rebuildTemplatesLabel": "Rebuild Templates Database",
+  "settings.data.rebuildTemplatesDescription": "Re-scan all Liquid templates and rebuild the templates metadata index.",
+  "settings.data.rebuildTemplatesAction": "Rebuild Templates",
   "settings.data.rebuildLinksLabel": "Rebuild Post Links",
   "settings.data.rebuildLinksDescription": "Re-scan all posts and rebuild the internal link graph between posts.",
   "settings.data.rebuildLinksAction": "Rebuild Links",
@@ -746,6 +774,14 @@
   "sidebar.scripts.createFailed": "Failed to create script",
   "sidebar.scripts.deleteScript": "Delete script",
   "sidebar.scripts.deleteFailed": "Failed to delete script",
+  "sidebar.templates.header": "TEMPLATES",
+  "sidebar.templates.newTemplate": "New Template",
+  "sidebar.templates.none": "No templates yet",
+  "sidebar.templates.createTemplate": "Create a template",
+  "sidebar.templates.createFailed": "Failed to create template",
+  "sidebar.templates.deleteTemplate": "Delete template",
+  "sidebar.templates.deleteFailed": "Failed to delete template",
+  "sidebar.templates.deleteConfirmWithRefs": "This template is referenced by {postCount} post(s) and {tagCount} tag(s). Delete anyway? References will be cleared.",
   "sidebar.import.none": "No import definitions yet",
   "sidebar.import.createDefinition": "Create an import definition",
   "sidebar.import.deleteDefinition": "Delete import definition",

src/renderer/i18n/locales/es.json

@@ -11,6 +11,7 @@
   "activity.media": "Medios",
   "activity.scripts": "Scripts",
   "activity.tags": "Etiquetas",
+  "activity.templates": "Plantillas",
   "activity.aiAssistant": "Asistente IA",
   "activity.import": "Importar",
   "activity.sourceControl": "Control de código fuente",
@@ -179,6 +180,9 @@
   "settings.toast.rebuildScriptsLoading": "Reconstruyendo base de datos de scripts...",
   "settings.toast.rebuildScriptsSuccess": "Base de datos de scripts reconstruida",
   "settings.toast.rebuildScriptsFailed": "No se pudo reconstruir la base de datos de scripts",
+  "settings.toast.rebuildTemplatesLoading": "Reconstruyendo la base de datos de plantillas...",
+  "settings.toast.rebuildTemplatesSuccess": "Base de datos de plantillas reconstruida",
+  "settings.toast.rebuildTemplatesFailed": "Error al reconstruir la base de datos de plantillas",
   "settings.toast.rebuildLinksLoading": "Reconstruyendo enlaces de entradas...",
   "settings.toast.rebuildLinksSuccess": "Enlaces de publicaciones reconstruidos",
   "settings.toast.rebuildLinksFailed": "No se pudieron reconstruir los enlaces de entradas",
@@ -367,6 +371,7 @@
   "tabBar.error.fetchChatTitle": "No se pudo cargar el título del chat:",
   "tabBar.error.fetchImportTitle": "No se pudo cargar el título de la definición de importación:",
   "tabBar.error.fetchScriptTitle": "No se pudo cargar el título del script:",
+  "tabBar.error.fetchTemplateTitle": "No se pudo cargar el título de la plantilla:",
   "tabBar.error.fetchCommitTitle": "No se pudieron cargar los títulos de los commits:",
   "metadataDiff.title": "Herramienta diff de metadatos",
   "metadataDiff.description": "Compara los metadatos de las entradas entre la base de datos y los archivos Markdown. Corrige inconsistencias causadas por errores o ediciones manuales.",
@@ -451,6 +456,19 @@
   "scripts.kind.utility": "utility",
   "scripts.kind.macro": "macro",
   "scripts.kind.transform": "transform",
+  "templates.save": "Guardar plantilla",
+  "templates.delete": "Eliminar plantilla",
+  "templates.content": "Contenido de la plantilla",
+  "templates.field.kind": "Tipo",
+  "templates.field.enabled": "Habilitado",
+  "templates.validate": "Validar",
+  "templates.validate.valid": "La sintaxis de la plantilla es válida",
+  "templates.validate.invalid": "Errores de sintaxis de la plantilla: {count}",
+  "templates.validate.checking": "Validando...",
+  "templates.kind.post": "entrada",
+  "templates.kind.list": "lista",
+  "templates.kind.not_found": "no encontrado",
+  "templates.kind.partial": "parcial",
   "sidebar.tagCloud": "Nube de etiquetas",
   "sidebar.createEdit": "Crear y editar",
   "sidebar.mergeTags": "Combinar etiquetas",
@@ -497,6 +515,8 @@
   "editor.field.slug": "Slug",
   "editor.field.categories": "Categorías",
   "editor.field.content": "Contenido",
+  "editor.field.template": "Plantilla",
+  "editor.field.templateDefault": "Predeterminada",
   "editor.placeholder.tags": "Agregar etiquetas...",
   "editor.placeholder.author": "Nombre del autor",
   "editor.placeholder.categories": "Agregar categorías...",
@@ -587,6 +607,7 @@
   "tagsView.removeColor": "Quitar color",
   "tagsView.edit.title": "Editar etiqueta: {name}",
   "tagsView.edit.action": "Editar",
+  "tagsView.edit.postTemplate": "Plantilla de entrada",
   "tagsView.deleteAction": "Eliminar",
   "tagsView.merge.title": "Combinar etiquetas",
   "tagsView.merge.description": "Selecciona varias etiquetas arriba y combínalas en una sola. Se actualizarán todas las entradas.",
@@ -683,6 +704,10 @@
   "settings.content.categoryColumn": "Categoría",
   "settings.content.titleColumn": "Título",
   "settings.content.actionsColumn": "Acciones",
+  "settings.content.postTemplateColumn": "Plantilla de entrada",
+  "settings.content.listTemplateColumn": "Plantilla de lista",
+  "settings.content.postTemplateAria": "{category} plantilla de entrada",
+  "settings.content.listTemplateAria": "{category} plantilla de lista",
   "settings.content.renderInListsAria": "{category} mostrar en listas",
   "settings.content.showTitlesAria": "{category} mostrar títulos",
   "settings.content.categoryTitleAria": "Título visible para {category}",
@@ -718,6 +743,9 @@
   "settings.data.rebuildScriptsLabel": "Reconstruir base de datos de scripts",
   "settings.data.rebuildScriptsDescription": "Reescanea todos los scripts de Python y reconstruye el índice de metadatos de scripts.",
   "settings.data.rebuildScriptsAction": "Reconstruir scripts",
+  "settings.data.rebuildTemplatesLabel": "Reconstruir base de datos de plantillas",
+  "settings.data.rebuildTemplatesDescription": "Re-escanear todas las plantillas Liquid y reconstruir el índice de metadatos.",
+  "settings.data.rebuildTemplatesAction": "Reconstruir plantillas",
   "settings.data.rebuildLinksLabel": "Reconstruir enlaces de publicaciones",
   "settings.data.rebuildLinksDescription": "Reescanea todas las publicaciones y reconstruye el grafo interno de enlaces entre publicaciones.",
   "settings.data.rebuildLinksAction": "Reconstruir enlaces",
@@ -746,6 +774,14 @@
   "sidebar.scripts.createFailed": "No se pudo crear el script",
   "sidebar.scripts.deleteScript": "Eliminar script",
   "sidebar.scripts.deleteFailed": "No se pudo eliminar el script",
+  "sidebar.templates.header": "PLANTILLAS",
+  "sidebar.templates.newTemplate": "Nueva plantilla",
+  "sidebar.templates.none": "Aún no hay plantillas",
+  "sidebar.templates.createTemplate": "Crear una plantilla",
+  "sidebar.templates.createFailed": "No se pudo crear la plantilla",
+  "sidebar.templates.deleteTemplate": "Eliminar plantilla",
+  "sidebar.templates.deleteFailed": "No se pudo eliminar la plantilla",
+  "sidebar.templates.deleteConfirmWithRefs": "Esta plantilla está referenciada por {postCount} entrada(s) y {tagCount} etiqueta(s). ¿Eliminar de todos modos? Las referencias serán eliminadas.",
   "sidebar.import.none": "Sin definiciones de importación",
   "sidebar.import.createDefinition": "Crear definición",
   "sidebar.import.deleteDefinition": "Eliminar definición",

src/renderer/i18n/locales/fr.json

@@ -11,6 +11,7 @@
   "activity.media": "Médias",
   "activity.scripts": "Scripts",
   "activity.tags": "Étiquettes",
+  "activity.templates": "Modèles",
   "activity.aiAssistant": "Assistant IA",
   "activity.import": "Importation",
   "activity.sourceControl": "Contrôle de source",
@@ -177,6 +178,9 @@
   "settings.toast.rebuildScriptsLoading": "Reconstruction de la base des scripts...",
   "settings.toast.rebuildScriptsSuccess": "Base des scripts reconstruite",
   "settings.toast.rebuildScriptsFailed": "Impossible de reconstruire la base des scripts",
+  "settings.toast.rebuildTemplatesLoading": "Reconstruction de la base de données des modèles...",
+  "settings.toast.rebuildTemplatesSuccess": "Base de données des modèles reconstruite",
+  "settings.toast.rebuildTemplatesFailed": "Échec de la reconstruction de la base de données des modèles",
   "settings.toast.rebuildLinksLoading": "Reconstruction des liens d’articles...",
   "settings.toast.rebuildLinksSuccess": "Liens d’articles reconstruits",
   "settings.toast.rebuildLinksFailed": "Impossible de reconstruire les liens d’articles",
@@ -365,6 +369,7 @@
   "tabBar.error.fetchChatTitle": "Impossible de charger le titre du chat :",
   "tabBar.error.fetchImportTitle": "Impossible de charger le titre de la définition d’import :",
   "tabBar.error.fetchScriptTitle": "Impossible de charger le titre du script :",
+  "tabBar.error.fetchTemplateTitle": "Impossible de charger le titre du modèle :",
   "tabBar.error.fetchCommitTitle": "Impossible de charger les titres des commits :",
   "metadataDiff.title": "Outil de diff des métadonnées",
   "metadataDiff.description": "Compare les métadonnées des articles entre la base de données et les fichiers Markdown. Corrige les incohérences causées par des bugs ou des modifications manuelles.",
@@ -449,6 +454,19 @@
   "scripts.kind.utility": "utility",
   "scripts.kind.macro": "macro",
   "scripts.kind.transform": "transform",
+  "templates.save": "Enregistrer le modèle",
+  "templates.delete": "Supprimer le modèle",
+  "templates.content": "Contenu du modèle",
+  "templates.field.kind": "Type",
+  "templates.field.enabled": "Activé",
+  "templates.validate": "Valider",
+  "templates.validate.valid": "La syntaxe du modèle est valide",
+  "templates.validate.invalid": "Erreurs de syntaxe du modèle : {count}",
+  "templates.validate.checking": "Validation en cours...",
+  "templates.kind.post": "article",
+  "templates.kind.list": "liste",
+  "templates.kind.not_found": "non trouvé",
+  "templates.kind.partial": "partiel",
   "sidebar.tagCloud": "Nuage d’étiquettes",
   "sidebar.createEdit": "Créer & modifier",
   "sidebar.mergeTags": "Fusionner les étiquettes",
@@ -495,6 +513,8 @@
   "editor.field.slug": "Slug",
   "editor.field.categories": "Catégories",
   "editor.field.content": "Contenu",
+  "editor.field.template": "Modèle",
+  "editor.field.templateDefault": "Par défaut",
   "editor.placeholder.tags": "Ajouter des étiquettes...",
   "editor.placeholder.author": "Nom de l’auteur",
   "editor.placeholder.categories": "Ajouter des catégories...",
@@ -585,6 +605,7 @@
   "tagsView.removeColor": "Supprimer la couleur",
   "tagsView.edit.title": "Modifier le tag : {name}",
   "tagsView.edit.action": "Modifier",
+  "tagsView.edit.postTemplate": "Modèle d'article",
   "tagsView.deleteAction": "Supprimer",
   "tagsView.merge.title": "Fusionner des tags",
   "tagsView.merge.description": "Sélectionnez plusieurs tags ci-dessus puis fusionnez-les en un seul. Tous les articles seront mis à jour.",
@@ -681,6 +702,10 @@
   "settings.content.categoryColumn": "Catégorie",
   "settings.content.titleColumn": "Titre",
   "settings.content.actionsColumn": "Actions",
+  "settings.content.postTemplateColumn": "Modèle d'article",
+  "settings.content.listTemplateColumn": "Modèle de liste",
+  "settings.content.postTemplateAria": "{category} modèle d'article",
+  "settings.content.listTemplateAria": "{category} modèle de liste",
   "settings.content.renderInListsAria": "{category} afficher dans les listes",
   "settings.content.showTitlesAria": "{category} afficher les titres",
   "settings.content.categoryTitleAria": "Titre affiché pour {category}",
@@ -716,6 +741,9 @@
   "settings.data.rebuildScriptsLabel": "Reconstruire la base des scripts",
   "settings.data.rebuildScriptsDescription": "Réanalyse tous les scripts Python et reconstruit l’index des métadonnées de scripts.",
   "settings.data.rebuildScriptsAction": "Reconstruire les scripts",
+  "settings.data.rebuildTemplatesLabel": "Reconstruire la base de données des modèles",
+  "settings.data.rebuildTemplatesDescription": "Re-scanner tous les modèles Liquid et reconstruire l'index des métadonnées.",
+  "settings.data.rebuildTemplatesAction": "Reconstruire les modèles",
   "settings.data.rebuildLinksLabel": "Reconstruire les liens d’articles",
   "settings.data.rebuildLinksDescription": "Réanalyse tous les articles et reconstruit le graphe interne des liens entre articles.",
   "settings.data.rebuildLinksAction": "Reconstruire les liens",
@@ -744,6 +772,14 @@
   "sidebar.scripts.createFailed": "Impossible de créer le script",
   "sidebar.scripts.deleteScript": "Supprimer le script",
   "sidebar.scripts.deleteFailed": "Impossible de supprimer le script",
+  "sidebar.templates.header": "MODÈLES",
+  "sidebar.templates.newTemplate": "Nouveau modèle",
+  "sidebar.templates.none": "Aucun modèle",
+  "sidebar.templates.createTemplate": "Créer un modèle",
+  "sidebar.templates.createFailed": "Impossible de créer le modèle",
+  "sidebar.templates.deleteTemplate": "Supprimer le modèle",
+  "sidebar.templates.deleteFailed": "Impossible de supprimer le modèle",
+  "sidebar.templates.deleteConfirmWithRefs": "Ce modèle est référencé par {postCount} article(s) et {tagCount} tag(s). Supprimer quand même ? Les références seront supprimées.",
   "sidebar.import.none": "Aucune définition d’import",
   "sidebar.import.createDefinition": "Créer une définition",
   "sidebar.import.deleteDefinition": "Supprimer la définition",

src/renderer/i18n/locales/it.json

@@ -11,6 +11,7 @@
   "activity.media": "Contenuti media",
   "activity.scripts": "Script",
   "activity.tags": "Tag",
+  "activity.templates": "Modelli",
   "activity.aiAssistant": "Assistente IA",
   "activity.import": "Importa",
   "activity.sourceControl": "Controllo sorgente",
@@ -177,6 +178,9 @@
   "settings.toast.rebuildScriptsLoading": "Ricostruzione database script...",
   "settings.toast.rebuildScriptsSuccess": "Database script ricostruito",
   "settings.toast.rebuildScriptsFailed": "Impossibile ricostruire il database degli script",
+  "settings.toast.rebuildTemplatesLoading": "Ricostruzione del database dei modelli...",
+  "settings.toast.rebuildTemplatesSuccess": "Database dei modelli ricostruito",
+  "settings.toast.rebuildTemplatesFailed": "Impossibile ricostruire il database dei modelli",
   "settings.toast.rebuildLinksLoading": "Ricostruzione dei link dei post...",
   "settings.toast.rebuildLinksSuccess": "Link dei post ricostruiti",
   "settings.toast.rebuildLinksFailed": "Impossibile ricostruire i link dei post",
@@ -365,6 +369,7 @@
   "tabBar.error.fetchChatTitle": "Impossibile caricare il titolo della chat:",
   "tabBar.error.fetchImportTitle": "Impossibile caricare il titolo della definizione di importazione:",
   "tabBar.error.fetchScriptTitle": "Impossibile caricare il titolo dello script:",
+  "tabBar.error.fetchTemplateTitle": "Impossibile caricare il titolo del modello:",
   "tabBar.error.fetchCommitTitle": "Impossibile caricare i titoli dei commit:",
   "metadataDiff.title": "Strumento diff metadati",
   "metadataDiff.description": "Confronta i metadati dei post tra database e file markdown. Correggi incongruenze causate da bug o modifiche manuali.",
@@ -449,6 +454,19 @@
   "scripts.kind.utility": "utility",
   "scripts.kind.macro": "macro",
   "scripts.kind.transform": "transform",
+  "templates.save": "Salva modello",
+  "templates.delete": "Elimina modello",
+  "templates.content": "Contenuto del modello",
+  "templates.field.kind": "Tipo",
+  "templates.field.enabled": "Abilitato",
+  "templates.validate": "Valida",
+  "templates.validate.valid": "La sintassi del modello è valida",
+  "templates.validate.invalid": "Errori di sintassi del modello: {count}",
+  "templates.validate.checking": "Validazione in corso...",
+  "templates.kind.post": "articolo",
+  "templates.kind.list": "elenco",
+  "templates.kind.not_found": "non trovato",
+  "templates.kind.partial": "parziale",
   "sidebar.tagCloud": "Nuvola tag",
   "sidebar.createEdit": "Crea e modifica",
   "sidebar.mergeTags": "Unisci tag",
@@ -495,6 +513,8 @@
   "editor.field.slug": "Slug",
   "editor.field.categories": "Categorie",
   "editor.field.content": "Contenuto",
+  "editor.field.template": "Modello",
+  "editor.field.templateDefault": "Predefinito",
   "editor.placeholder.tags": "Aggiungi tag...",
   "editor.placeholder.author": "Nome autore",
   "editor.placeholder.categories": "Aggiungi categorie...",
@@ -585,6 +605,7 @@
   "tagsView.removeColor": "Rimuovi colore",
   "tagsView.edit.title": "Modifica tag: {name}",
   "tagsView.edit.action": "Modifica",
+  "tagsView.edit.postTemplate": "Modello articolo",
   "tagsView.deleteAction": "Elimina",
   "tagsView.merge.title": "Unisci tag",
   "tagsView.merge.description": "Seleziona più tag sopra, quindi uniscili in un unico tag. Tutti i post verranno aggiornati.",
@@ -681,6 +702,10 @@
   "settings.content.categoryColumn": "Categoria",
   "settings.content.titleColumn": "Titolo",
   "settings.content.actionsColumn": "Azioni",
+  "settings.content.postTemplateColumn": "Modello articolo",
+  "settings.content.listTemplateColumn": "Modello elenco",
+  "settings.content.postTemplateAria": "{category} modello articolo",
+  "settings.content.listTemplateAria": "{category} modello elenco",
   "settings.content.renderInListsAria": "{category} mostra negli elenchi",
   "settings.content.showTitlesAria": "{category} mostra i titoli",
   "settings.content.categoryTitleAria": "Titolo visualizzato per {category}",
@@ -716,6 +741,9 @@
   "settings.data.rebuildScriptsLabel": "Ricostruisci database script",
   "settings.data.rebuildScriptsDescription": "Rianalizza tutti gli script Python e ricostruisce l’indice dei metadati degli script.",
   "settings.data.rebuildScriptsAction": "Ricostruisci script",
+  "settings.data.rebuildTemplatesLabel": "Ricostruisci database modelli",
+  "settings.data.rebuildTemplatesDescription": "Scansiona tutti i modelli Liquid e ricostruisci l'indice dei metadati.",
+  "settings.data.rebuildTemplatesAction": "Ricostruisci modelli",
   "settings.data.rebuildLinksLabel": "Ricostruisci collegamenti post",
   "settings.data.rebuildLinksDescription": "Rianalizza tutti i post e ricostruisce il grafo interno dei collegamenti tra post.",
   "settings.data.rebuildLinksAction": "Ricostruisci collegamenti",
@@ -744,6 +772,14 @@
   "sidebar.scripts.createFailed": "Impossibile creare lo script",
   "sidebar.scripts.deleteScript": "Elimina script",
   "sidebar.scripts.deleteFailed": "Impossibile eliminare lo script",
+  "sidebar.templates.header": "MODELLI",
+  "sidebar.templates.newTemplate": "Nuovo modello",
+  "sidebar.templates.none": "Nessun modello",
+  "sidebar.templates.createTemplate": "Crea un modello",
+  "sidebar.templates.createFailed": "Impossibile creare il modello",
+  "sidebar.templates.deleteTemplate": "Elimina modello",
+  "sidebar.templates.deleteFailed": "Impossibile eliminare il modello",
+  "sidebar.templates.deleteConfirmWithRefs": "Questo modello è referenziato da {postCount} articolo/i e {tagCount} tag. Eliminare comunque? I riferimenti verranno rimossi.",
   "sidebar.import.none": "Nessuna definizione di importazione",
   "sidebar.import.createDefinition": "Crea definizione",
   "sidebar.import.deleteDefinition": "Elimina definizione",

src/renderer/navigation/activityBehavior.ts

@@ -1,7 +1,7 @@
 import type { Tab } from '../store/appStore';
 import type { SidebarView } from './sidebarViewRegistry';
 
-export type ActivityId = 'posts' | 'pages' | 'media' | 'scripts' | 'tags' | 'chat' | 'import' | 'git' | 'settings';
+export type ActivityId = 'posts' | 'pages' | 'media' | 'scripts' | 'templates' | 'tags' | 'chat' | 'import' | 'git' | 'settings';
 
 export interface ActivitySnapshot {
   activeView: SidebarView;
@@ -50,6 +50,13 @@ const ACTIVITY_CONFIG: Record<ActivityId, ActivityConfig> = {
     activeStrategy: 'sidebar-owner',
     clickStrategy: 'sidebar-toggle',
   },
+  templates: {
+    id: 'templates',
+    view: 'templates',
+    labelKey: 'activity.templates',
+    activeStrategy: 'sidebar-owner',
+    clickStrategy: 'sidebar-toggle',
+  },
   tags: {
     id: 'tags',
     view: 'tags',

src/renderer/navigation/editorRouting.ts

@@ -16,7 +16,8 @@ export type EditorRoute =
   | 'documentation'
   | 'api-documentation'
   | 'site-validation'
-  | 'scripts';
+  | 'scripts'
+  | 'templates';
 
 export const EDITOR_TAB_ROUTE_REGISTRY: Record<TabType, Exclude<EditorRoute, 'dashboard'>> = {
   post: 'post',
@@ -33,6 +34,7 @@ export const EDITOR_TAB_ROUTE_REGISTRY: Record<TabType, Exclude<EditorRoute, 'da
   'api-documentation': 'api-documentation',
   'site-validation': 'site-validation',
   scripts: 'scripts',
+  templates: 'templates',
 };
 
 export interface EditorRouteResolution {

src/renderer/navigation/sidebarViewRegistry.ts

@@ -3,6 +3,7 @@ export const SIDEBAR_VIEW_REGISTRY = [
   'pages',
   'media',
   'scripts',
+  'templates',
   'settings',
   'tags',
   'chat',

src/renderer/navigation/tabPolicy.ts

@@ -20,6 +20,7 @@ export interface CanonicalTabSpec {
 export type EntityTabType = 'post' | 'media';
 export type EntityTabOpenIntent = 'preview' | 'pin';
 export type ScriptTabOpenIntent = 'preview' | 'pin';
+export type TemplateTabOpenIntent = 'preview' | 'pin';
 export type GitDiffResourceOpenIntent = 'preview' | 'pin';
 
 const SINGLETON_TOOL_TAB_REGISTRY: Record<SingletonToolTabKey, CanonicalTabSpec> = {
@@ -112,6 +113,22 @@ export function openScriptTab(
   openTab(getScriptTabSpec(scriptId, intent));
 }
 
+export function getTemplateTabSpec(templateId: string, intent: TemplateTabOpenIntent): CanonicalTabSpec {
+  return {
+    type: 'templates',
+    id: templateId,
+    isTransient: intent === 'preview',
+  };
+}
+
+export function openTemplateTab(
+  openTab: (tab: CanonicalTabSpec) => void,
+  templateId: string,
+  intent: TemplateTabOpenIntent,
+): void {
+  openTab(getTemplateTabSpec(templateId, intent));
+}
+
 export function getGitDiffFileTabId(filePath: string): string {
   return `git-diff:${filePath}`;
 }

src/renderer/store/appStore.ts

@@ -13,7 +13,7 @@ import type {
 const STORAGE_KEY = 'bds-app-state';
 
 // Tab types
-export type TabType = 'post' | 'media' | 'settings' | 'style' | 'tags' | 'chat' | 'import' | 'menu-editor' | 'metadata-diff' | 'git-diff' | 'documentation' | 'api-documentation' | 'site-validation' | 'scripts';
+export type TabType = 'post' | 'media' | 'settings' | 'style' | 'tags' | 'chat' | 'import' | 'menu-editor' | 'metadata-diff' | 'git-diff' | 'documentation' | 'api-documentation' | 'site-validation' | 'scripts' | 'templates';
 
 export interface Tab {
   type: TabType;

src/renderer/utils/index.ts

@@ -4,4 +4,4 @@ export { unescapeMacroSyntax } from './markdownEscape';
 export { groupPostsByStatus, type GroupedPosts, type PostStatus } from './postGrouping';
 export { loadTabsForProject, saveTabsForProject } from './tabPersistence';
 export { buildTagColorMap, loadTagColorMap } from './tagColors';
-export { BDS_EVENT_SCRIPTS_CHANGED, addWindowEventListener, dispatchWindowEvent, type BdsWindowEventName } from './windowEvents';
+export { BDS_EVENT_SCRIPTS_CHANGED, BDS_EVENT_TEMPLATES_CHANGED, addWindowEventListener, dispatchWindowEvent, type BdsWindowEventName } from './windowEvents';

src/renderer/utils/windowEvents.ts

@@ -1,7 +1,9 @@
 export const BDS_EVENT_SCRIPTS_CHANGED = 'bds:scripts-changed' as const;
+export const BDS_EVENT_TEMPLATES_CHANGED = 'bds:templates-changed' as const;
 
 export type BdsWindowEventName =
   | typeof BDS_EVENT_SCRIPTS_CHANGED
+  | typeof BDS_EVENT_TEMPLATES_CHANGED
   | 'bds:site-validation-updated';
 
 export function addWindowEventListener<TDetail = unknown>(

tests/engine/PageRenderer.templateResolution.test.ts

@@ -0,0 +1,134 @@
+import { describe, expect, it } from 'vitest';
+import { resolvePostTemplateName, resolveListTemplateName, resolvePageRendererTemplateRoots } from '../../src/main/engine/PageRenderer';
+
+describe('resolvePostTemplateName', () => {
+  it('returns default single-post when no overrides exist', () => {
+    const result = resolvePostTemplateName({});
+    expect(result).toBe('single-post');
+  });
+
+  it('returns post-level templateSlug when set', () => {
+    const result = resolvePostTemplateName({ templateSlug: 'photo-post' });
+    expect(result).toBe('photo-post');
+  });
+
+  it('returns tag-level override when post has no template and tag does', () => {
+    const result = resolvePostTemplateName(
+      { tags: ['photography', 'travel'] },
+      { photography: { postTemplateSlug: 'photo-layout' } },
+    );
+    expect(result).toBe('photo-layout');
+  });
+
+  it('prioritizes post-level over tag-level', () => {
+    const result = resolvePostTemplateName(
+      { templateSlug: 'custom-post', tags: ['photography'] },
+      { photography: { postTemplateSlug: 'photo-layout' } },
+    );
+    expect(result).toBe('custom-post');
+  });
+
+  it('returns category-level override when no post or tag override', () => {
+    const result = resolvePostTemplateName(
+      { categories: ['article'] },
+      undefined,
+      { article: { postTemplateSlug: 'article-layout' } },
+    );
+    expect(result).toBe('article-layout');
+  });
+
+  it('prioritizes tag-level over category-level', () => {
+    const result = resolvePostTemplateName(
+      { tags: ['featured'], categories: ['article'] },
+      { featured: { postTemplateSlug: 'featured-layout' } },
+      { article: { postTemplateSlug: 'article-layout' } },
+    );
+    expect(result).toBe('featured-layout');
+  });
+
+  it('skips tags/categories with null postTemplateSlug', () => {
+    const result = resolvePostTemplateName(
+      { tags: ['empty'], categories: ['article'] },
+      { empty: { postTemplateSlug: null } },
+      { article: { postTemplateSlug: 'article-layout' } },
+    );
+    expect(result).toBe('article-layout');
+  });
+
+  it('returns default when all overrides are null/undefined', () => {
+    const result = resolvePostTemplateName(
+      { templateSlug: null, tags: ['empty'], categories: ['plain'] },
+      { empty: { postTemplateSlug: null } },
+      { plain: { postTemplateSlug: undefined } },
+    );
+    expect(result).toBe('single-post');
+  });
+
+  it('uses first matching tag with a template slug', () => {
+    const result = resolvePostTemplateName(
+      { tags: ['no-template', 'has-template', 'also-has'] },
+      {
+        'has-template': { postTemplateSlug: 'first-match' },
+        'also-has': { postTemplateSlug: 'second-match' },
+      },
+    );
+    expect(result).toBe('first-match');
+  });
+});
+
+describe('resolveListTemplateName', () => {
+  it('returns default post-list when no overrides exist', () => {
+    const result = resolveListTemplateName();
+    expect(result).toBe('post-list');
+  });
+
+  it('returns default when no route category', () => {
+    const result = resolveListTemplateName(undefined, {
+      article: { listTemplateSlug: 'article-list' },
+    });
+    expect(result).toBe('post-list');
+  });
+
+  it('returns category-level listTemplateSlug', () => {
+    const result = resolveListTemplateName('article', {
+      article: { listTemplateSlug: 'article-list' },
+    });
+    expect(result).toBe('article-list');
+  });
+
+  it('returns default when category has no listTemplateSlug', () => {
+    const result = resolveListTemplateName('article', {
+      article: { listTemplateSlug: undefined },
+    });
+    expect(result).toBe('post-list');
+  });
+
+  it('returns default when category not in settings', () => {
+    const result = resolveListTemplateName('unknown', {
+      article: { listTemplateSlug: 'article-list' },
+    });
+    expect(result).toBe('post-list');
+  });
+});
+
+describe('resolvePageRendererTemplateRoots with userTemplatesDir', () => {
+  it('adds user templates directory first when provided', () => {
+    const roots = resolvePageRendererTemplateRoots({
+      moduleDir: '/app/dist/main/engine',
+      cwd: '/app',
+      userTemplatesDir: '/data/project/templates',
+    });
+
+    expect(roots[0]).toBe('/data/project/templates');
+  });
+
+  it('does not add user templates when not provided', () => {
+    const roots = resolvePageRendererTemplateRoots({
+      moduleDir: '/app/dist/main/engine',
+      cwd: '/app',
+    });
+
+    expect(roots).not.toContain(undefined);
+    expect(roots.every(r => r.length > 0)).toBe(true);
+  });
+});

tests/engine/TemplateEngine.test.ts

@@ -0,0 +1,520 @@
+import { describe, it, expect, beforeEach, vi } from 'vitest';
+import { TemplateEngine } from '../../src/main/engine/TemplateEngine';
+import { posts, tags, templates } from '../../src/main/database/schema';
+
+const mockTemplates = new Map<string, any>();
+const mockPosts = new Map<string, any>();
+const mockTags = new Map<string, any>();
+const mockFiles = new Map<string, string>();
+
+function createSelectChain(dataSource: () => any[]) {
+  return {
+    from: vi.fn(function (this: any, table: any) {
+      if (table === posts) {
+        this.all = vi.fn(() => Promise.resolve(Array.from(mockPosts.values())));
+      } else if (table === tags) {
+        this.all = vi.fn(() => Promise.resolve(Array.from(mockTags.values())));
+      }
+      return this;
+    }),
+    where: vi.fn().mockReturnThis(),
+    orderBy: vi.fn().mockReturnThis(),
+    all: vi.fn().mockImplementation(() => Promise.resolve(dataSource())),
+    get: vi.fn().mockImplementation(() => Promise.resolve(undefined)),
+  };
+}
+
+function createDrizzleMock() {
+  return {
+    select: vi.fn(() => createSelectChain(() => Array.from(mockTemplates.values()))),
+    insert: vi.fn(() => ({
+      values: vi.fn((data: any) => {
+        mockTemplates.set(data.id, data);
+        return Promise.resolve();
+      }),
+    })),
+    update: vi.fn((table?: any) => ({
+      set: vi.fn((updates: any) => ({
+        where: vi.fn(async () => {
+          if (table === posts) {
+            for (const [postId, existing] of mockPosts.entries()) {
+              mockPosts.set(postId, { ...existing, ...updates });
+            }
+          } else if (table === tags) {
+            for (const [tagId, existing] of mockTags.entries()) {
+              mockTags.set(tagId, { ...existing, ...updates });
+            }
+          } else {
+            for (const [templateId, existing] of mockTemplates.entries()) {
+              mockTemplates.set(templateId, { ...existing, ...updates });
+            }
+          }
+        }),
+      })),
+    })),
+    delete: vi.fn(() => ({
+      where: vi.fn(async () => {
+        mockTemplates.clear();
+        return Promise.resolve();
+      }),
+    })),
+  };
+}
+
+const mockLocalDb = createDrizzleMock();
+
+vi.mock('../../src/main/database', () => ({
+  getDatabase: vi.fn(() => ({
+    getLocal: vi.fn(() => mockLocalDb),
+  })),
+}));
+
+vi.mock('uuid', () => ({
+  v4: vi.fn(() => 'mock-template-id'),
+}));
+
+vi.mock('fs/promises', () => ({
+  readdir: vi.fn(async (dirPath: string, options?: { withFileTypes?: boolean }) => {
+    if (options?.withFileTypes) {
+      const files = Array.from((globalThis as any).__mockTemplateFiles.keys()) as string[];
+      const names = files
+        .filter((filePath) => filePath.startsWith(`${dirPath}/`))
+        .map((filePath) => filePath.slice(dirPath.length + 1))
+        .filter((name) => !name.includes('/'));
+
+      return names.map((name) => ({
+        name,
+        isDirectory: () => false,
+        isFile: () => true,
+      }));
+    }
+
+    return [];
+  }),
+  readFile: vi.fn(async (filePath: string) => {
+    const value = (globalThis as any).__mockTemplateFiles.get(filePath);
+    if (typeof value !== 'string') {
+      const error = new Error('ENOENT');
+      (error as any).code = 'ENOENT';
+      throw error;
+    }
+    return value;
+  }),
+  writeFile: vi.fn(async (filePath: string, content: string) => {
+    (globalThis as any).__mockTemplateFiles.set(filePath, content);
+  }),
+  unlink: vi.fn(async (filePath: string) => {
+    (globalThis as any).__mockTemplateFiles.delete(filePath);
+  }),
+  rename: vi.fn(async (fromPath: string, toPath: string) => {
+    const files = (globalThis as any).__mockTemplateFiles;
+    const content = files.get(fromPath);
+    files.delete(fromPath);
+    files.set(toPath, content);
+  }),
+  mkdir: vi.fn(async () => {}),
+}));
+
+describe('TemplateEngine', () => {
+  let templateEngine: TemplateEngine;
+
+  beforeEach(() => {
+    vi.clearAllMocks();
+    mockTemplates.clear();
+    mockPosts.clear();
+    mockTags.clear();
+    mockFiles.clear();
+    (globalThis as any).__mockTemplateFiles = mockFiles;
+    vi.mocked(mockLocalDb.select).mockImplementation(() => createSelectChain(() => Array.from(mockTemplates.values())));
+
+    templateEngine = new TemplateEngine();
+    templateEngine.setProjectContext('default', '/mock/userData/projects/default');
+  });
+
+  it('creates template metadata and liquid file', async () => {
+    const created = await templateEngine.createTemplate({
+      title: 'Custom Post Layout',
+      kind: 'post',
+      content: '<main>\n  <article>{{ post.content | markdown }}</article>\n</main>',
+    });
+
+    expect(created.slug).toBe('custom_post_layout');
+    expect(mockTemplates.has(created.id)).toBe(true);
+    const persistedFile = mockFiles.get('/mock/userData/projects/default/templates/custom_post_layout.liquid') || '';
+    expect(persistedFile).toContain('---');
+    expect(persistedFile).toContain('title: "Custom Post Layout"');
+    expect(persistedFile).toContain('kind: "post"');
+    expect(persistedFile).toContain('<article>');
+    expect(created.content).toBe('<main>\n  <article>{{ post.content | markdown }}</article>\n</main>');
+  });
+
+  it('updates template metadata and file content', async () => {
+    const created = await templateEngine.createTemplate({
+      title: 'Custom Post Layout',
+      kind: 'post',
+      content: '<main><article>Original</article></main>',
+    });
+
+    const updated = await templateEngine.updateTemplate(created.id, {
+      title: 'Updated Post Layout',
+      content: '<main><article>Updated</article></main>',
+    });
+
+    expect(updated?.slug).toBe('updated_post_layout');
+    expect(mockFiles.get('/mock/userData/projects/default/templates/updated_post_layout.liquid')).toContain('Updated');
+  });
+
+  it('appends underscore numeric suffix for duplicate slugs', async () => {
+    const first = await templateEngine.createTemplate({
+      title: 'Custom Post',
+      kind: 'post',
+      content: '<main>First</main>',
+    });
+
+    vi.mocked((await import('uuid')).v4)
+      .mockReturnValueOnce('mock-template-id-2');
+
+    const second = await templateEngine.createTemplate({
+      title: 'Custom Post',
+      kind: 'post',
+      content: '<main>Second</main>',
+    });
+
+    expect(first.slug).toBe('custom_post');
+    expect(second.slug).toBe('custom_post_2');
+    expect(mockFiles.get('/mock/userData/projects/default/templates/custom_post_2.liquid')).toContain('Second');
+  });
+
+  it('deletes template metadata and liquid file', async () => {
+    const created = await templateEngine.createTemplate({
+      title: 'Delete Me',
+      kind: 'partial',
+      content: '<footer>Footer</footer>',
+    });
+
+    const result = await templateEngine.deleteTemplate(created.id);
+
+    expect(result).toEqual({ deleted: true });
+    expect(mockTemplates.has(created.id)).toBe(false);
+    expect(mockFiles.has('/mock/userData/projects/default/templates/delete_me.liquid')).toBe(false);
+  });
+
+  it('keeps template content clean when file contains YAML frontmatter', async () => {
+    const created = await templateEngine.createTemplate({
+      title: 'Metadata Test',
+      kind: 'list',
+      content: '<main>{{ day_blocks }}</main>',
+    });
+
+    const loaded = await templateEngine.getTemplate(created.id);
+
+    expect(loaded?.content).toBe('<main>{{ day_blocks }}</main>');
+    expect(loaded?.title).toBe('Metadata Test');
+    expect(loaded?.kind).toBe('list');
+  });
+
+  it('rebuilds templates from filesystem and applies external file metadata', async () => {
+    const templatePath = '/mock/userData/projects/default/templates/external_post.liquid';
+    mockFiles.set(templatePath, [
+      '---',
+      'id: "external-template-id"',
+      'projectId: "default"',
+      'slug: "external_post"',
+      'title: "External Post Layout"',
+      'kind: "post"',
+      'enabled: false',
+      'version: 3',
+      'createdAt: "2026-02-20T10:00:00.000Z"',
+      'updatedAt: "2026-02-21T11:00:00.000Z"',
+      '---',
+      '<main><article>{{ post.content | markdown }}</article></main>',
+    ].join('\n'));
+
+    await templateEngine.rebuildDatabaseFromFiles();
+
+    const all = await templateEngine.getAllTemplates();
+    expect(all).toHaveLength(1);
+    expect(all[0].id).toBe('external-template-id');
+    expect(all[0].slug).toBe('external_post');
+    expect(all[0].kind).toBe('post');
+    expect(all[0].enabled).toBe(false);
+    expect(all[0].version).toBe(3);
+    expect(all[0].title).toBe('External Post Layout');
+    expect(all[0].content).toContain('<article>');
+  });
+
+  it('reconciles git changes for templates (modify/add/delete)', async () => {
+    const created = await templateEngine.createTemplate({
+      title: 'Custom Post',
+      kind: 'post',
+      content: '<main>Original</main>',
+    });
+
+    const existingPath = '/repo/templates/custom_post.liquid';
+    mockFiles.set(existingPath, [
+      '---',
+      `id: "${created.id}"`,
+      'projectId: "default"',
+      'slug: "custom_post"',
+      'title: "Custom Post Updated Outside"',
+      'kind: "post"',
+      'enabled: true',
+      'version: 8',
+      'createdAt: "2026-02-20T10:00:00.000Z"',
+      'updatedAt: "2026-02-21T11:00:00.000Z"',
+      '---',
+      '<main>Updated Outside</main>',
+    ].join('\n'));
+
+    const addedPath = '/repo/templates/new_list.liquid';
+    mockFiles.set(addedPath, [
+      '---',
+      'id: "added-template-id"',
+      'projectId: "default"',
+      'slug: "new_list"',
+      'title: "New List Layout"',
+      'kind: "list"',
+      'enabled: true',
+      'version: 1',
+      'createdAt: "2026-02-22T10:00:00.000Z"',
+      'updatedAt: "2026-02-22T11:00:00.000Z"',
+      '---',
+      '<main>{{ day_blocks }}</main>',
+    ].join('\n'));
+
+    const result = await templateEngine.reconcileTemplatesFromGitChanges('/repo', [
+      { status: 'modified', path: 'templates/custom_post.liquid' },
+      { status: 'added', path: 'templates/new_list.liquid' },
+      { status: 'deleted', path: 'templates/custom_post.liquid' },
+    ]);
+
+    expect(result.updated).toBe(1);
+    expect(result.created).toBe(1);
+    expect(result.deleted).toBe(1);
+    expect(result.processedFiles).toBe(3);
+  });
+
+  describe('template kind queries', () => {
+    it('getEnabledTemplatesByKind returns only enabled templates of specified kind', async () => {
+      await templateEngine.createTemplate({
+        title: 'Post Template',
+        kind: 'post',
+        content: '<main>Post</main>',
+        enabled: true,
+      });
+
+      vi.mocked((await import('uuid')).v4).mockReturnValueOnce('mock-template-id-2');
+
+      await templateEngine.createTemplate({
+        title: 'List Template',
+        kind: 'list',
+        content: '<main>List</main>',
+        enabled: true,
+      });
+
+      vi.mocked((await import('uuid')).v4).mockReturnValueOnce('mock-template-id-3');
+
+      await templateEngine.createTemplate({
+        title: 'Disabled Post',
+        kind: 'post',
+        content: '<main>Disabled</main>',
+        enabled: false,
+      });
+
+      const postTemplates = await templateEngine.getEnabledTemplatesByKind('post');
+      expect(postTemplates).toHaveLength(1);
+      expect(postTemplates[0].kind).toBe('post');
+      expect(postTemplates[0].enabled).toBe(true);
+      expect(postTemplates[0].title).toBe('Post Template');
+    });
+  });
+
+  describe('template validation', () => {
+    it('validates correct liquid syntax', async () => {
+      const result = await templateEngine.validateTemplate('<main>{{ post.title }}</main>');
+      expect(result.valid).toBe(true);
+      expect(result.errors).toHaveLength(0);
+    });
+
+    it('reports invalid liquid syntax', async () => {
+      const result = await templateEngine.validateTemplate('<main>{% if unclosed %}</main>');
+      expect(result.valid).toBe(false);
+      expect(result.errors.length).toBeGreaterThan(0);
+    });
+  });
+
+  describe('template slug normalization', () => {
+    it('normalizes slugs to lowercase with underscores', async () => {
+      const created = await templateEngine.createTemplate({
+        title: 'My Custom Layout!',
+        kind: 'post',
+        content: '<main>test</main>',
+      });
+
+      expect(created.slug).toBe('my_custom_layout');
+    });
+
+    it('uses slug from input when provided', async () => {
+      const created = await templateEngine.createTemplate({
+        title: 'Custom Post Layout',
+        kind: 'post',
+        content: '<main>test</main>',
+        slug: 'my-custom-slug',
+      });
+
+      expect(created.slug).toBe('my_custom_slug');
+    });
+  });
+
+  describe('getTemplateBySlug', () => {
+    it('retrieves an enabled template by exact slug', async () => {
+      await templateEngine.createTemplate({
+        title: 'Custom Post',
+        kind: 'post',
+        content: '<main>Post</main>',
+        enabled: true,
+      });
+
+      const found = await templateEngine.getTemplateBySlug('custom_post');
+      expect(found).not.toBeNull();
+      expect(found?.slug).toBe('custom_post');
+      expect(found?.title).toBe('Custom Post');
+    });
+
+    it('matches slugs case-insensitively', async () => {
+      await templateEngine.createTemplate({
+        title: 'Custom Post',
+        kind: 'post',
+        content: '<main>Post</main>',
+        enabled: true,
+      });
+
+      const found = await templateEngine.getTemplateBySlug('CUSTOM_POST');
+      expect(found).not.toBeNull();
+      expect(found?.slug).toBe('custom_post');
+    });
+
+    it('returns null for non-existent slug', async () => {
+      const found = await templateEngine.getTemplateBySlug('does_not_exist');
+      expect(found).toBeNull();
+    });
+
+    it('does not return disabled templates', async () => {
+      await templateEngine.createTemplate({
+        title: 'Disabled Template',
+        kind: 'post',
+        content: '<main>Disabled</main>',
+        enabled: false,
+      });
+
+      const found = await templateEngine.getTemplateBySlug('disabled_template');
+      expect(found).toBeNull();
+    });
+  });
+
+  describe('referential integrity', () => {
+    it('getTemplateReferences returns empty arrays when no references exist', async () => {
+      const refs = await templateEngine.getTemplateReferences('custom_post');
+      expect(refs).toEqual({ postIds: [], tagIds: [] });
+    });
+
+    it('getTemplateReferences returns referencing post and tag IDs', async () => {
+      mockPosts.set('post-1', { id: 'post-1', projectId: 'default', templateSlug: 'custom_post' });
+      mockTags.set('tag-1', { id: 'tag-1', projectId: 'default', postTemplateSlug: 'custom_post' });
+
+      const refs = await templateEngine.getTemplateReferences('custom_post');
+      expect(refs.postIds).toContain('post-1');
+      expect(refs.tagIds).toContain('tag-1');
+    });
+
+    it('deleteTemplate blocks deletion when references exist and force is not set', async () => {
+      const created = await templateEngine.createTemplate({
+        title: 'Referenced Template',
+        kind: 'post',
+        content: '<main>Referenced</main>',
+      });
+
+      mockPosts.set('post-1', { id: 'post-1', projectId: 'default', templateSlug: created.slug });
+
+      const result = await templateEngine.deleteTemplate(created.id);
+
+      expect(result.deleted).toBe(false);
+      expect(result.references?.postIds).toContain('post-1');
+      expect(mockTemplates.has(created.id)).toBe(true);
+    });
+
+    it('deleteTemplate with force clears references and deletes', async () => {
+      const created = await templateEngine.createTemplate({
+        title: 'Force Delete',
+        kind: 'post',
+        content: '<main>Force</main>',
+      });
+
+      mockPosts.set('post-1', { id: 'post-1', projectId: 'default', templateSlug: created.slug });
+      mockTags.set('tag-1', { id: 'tag-1', projectId: 'default', postTemplateSlug: created.slug });
+
+      const result = await templateEngine.deleteTemplate(created.id, { force: true });
+
+      expect(result.deleted).toBe(true);
+      expect(mockTemplates.has(created.id)).toBe(false);
+      expect(mockPosts.get('post-1').templateSlug).toBeNull();
+      expect(mockTags.get('tag-1').postTemplateSlug).toBeNull();
+    });
+  });
+
+  describe('slug cascade on rename', () => {
+    it('cascades slug changes to posts.templateSlug on template rename', async () => {
+      const created = await templateEngine.createTemplate({
+        title: 'Original Name',
+        kind: 'post',
+        content: '<main>Content</main>',
+      });
+
+      mockPosts.set('post-1', { id: 'post-1', projectId: 'default', templateSlug: created.slug });
+
+      await templateEngine.updateTemplate(created.id, { title: 'Renamed Template' });
+
+      expect(mockPosts.get('post-1').templateSlug).toBe('renamed_template');
+    });
+
+    it('cascades slug changes to tags.postTemplateSlug on template rename', async () => {
+      const created = await templateEngine.createTemplate({
+        title: 'Original Name',
+        kind: 'post',
+        content: '<main>Content</main>',
+      });
+
+      mockTags.set('tag-1', { id: 'tag-1', projectId: 'default', postTemplateSlug: created.slug });
+
+      await templateEngine.updateTemplate(created.id, { title: 'Renamed Template' });
+
+      expect(mockTags.get('tag-1').postTemplateSlug).toBe('renamed_template');
+    });
+  });
+
+  describe('race condition protection', () => {
+    it('rolls back DB on file operation failure during update', async () => {
+      const created = await templateEngine.createTemplate({
+        title: 'Rollback Test',
+        kind: 'post',
+        content: '<main>Original</main>',
+      });
+
+      const originalSlug = created.slug;
+      const originalTitle = created.title;
+
+      // Make fs.rename throw to simulate file operation failure
+      const fsModule = await import('fs/promises');
+      vi.mocked(fsModule.rename).mockRejectedValueOnce(new Error('EPERM'));
+
+      await expect(
+        templateEngine.updateTemplate(created.id, { title: 'Should Fail' }),
+      ).rejects.toThrow('EPERM');
+
+      // DB should have been rolled back to original values
+      const row = mockTemplates.get(created.id);
+      expect(row.slug).toBe(originalSlug);
+      expect(row.title).toBe(originalTitle);
+    });
+  });
+});

tests/engine/mainProcessPythonApiInvoker.test.ts

@@ -39,6 +39,17 @@ const mockScriptEngine: Record<string, ReturnType<typeof vi.fn>> = {
   rebuildDatabaseFromFiles: vi.fn().mockResolvedValue(undefined),
 };
 
+const mockTemplateEngine: Record<string, ReturnType<typeof vi.fn>> = {
+  createTemplate: vi.fn().mockResolvedValue({ id: 't1' }),
+  updateTemplate: vi.fn().mockResolvedValue(null),
+  deleteTemplate: vi.fn().mockResolvedValue({ deleted: true }),
+  getTemplate: vi.fn().mockResolvedValue(null),
+  getAllTemplates: vi.fn().mockResolvedValue([]),
+  getEnabledTemplatesByKind: vi.fn().mockResolvedValue([]),
+  validateTemplate: vi.fn().mockResolvedValue({ valid: true, errors: [] }),
+  rebuildDatabaseFromFiles: vi.fn().mockResolvedValue(undefined),
+};
+
 const mockTagEngine: Record<string, ReturnType<typeof vi.fn>> = {
   getAllTags: vi.fn().mockResolvedValue([]),
   getTagsWithCounts: vi.fn().mockResolvedValue([]),
@@ -145,6 +156,7 @@ describe('invokeMainProcessPythonApi', () => {
     ENGINE_MAP.meta = () => mockMetaEngine as Record<string, (...args: unknown[]) => unknown>;
     ENGINE_MAP.tags = () => mockTagEngine as Record<string, (...args: unknown[]) => unknown>;
     ENGINE_MAP.scripts = () => mockScriptEngine as Record<string, (...args: unknown[]) => unknown>;
+    ENGINE_MAP.templates = () => mockTemplateEngine as Record<string, (...args: unknown[]) => unknown>;
     ENGINE_MAP.tasks = () => mockTaskManager as Record<string, (...args: unknown[]) => unknown>;
     ENGINE_MAP.sync = () => mockGitApiAdapter as Record<string, (...args: unknown[]) => unknown>;
     ENGINE_MAP.publish = () => mockPublishApiAdapter as Record<string, (...args: unknown[]) => unknown>;
@@ -188,6 +200,42 @@ describe('invokeMainProcessPythonApi', () => {
       expect(mockScriptEngine.deleteScript).toHaveBeenCalledWith('s1');
     });
 
+    it('routes templates.create to TemplateEngine.createTemplate', async () => {
+      const data = { title: 'My Template', kind: 'post', content: '<p>hello</p>' };
+      await invokeMainProcessPythonApi('templates.create', { data });
+      expect(mockTemplateEngine.createTemplate).toHaveBeenCalledWith(data);
+    });
+
+    it('routes templates.get to TemplateEngine.getTemplate', async () => {
+      await invokeMainProcessPythonApi('templates.get', { id: 't1' });
+      expect(mockTemplateEngine.getTemplate).toHaveBeenCalledWith('t1');
+    });
+
+    it('routes templates.delete to TemplateEngine.deleteTemplate', async () => {
+      await invokeMainProcessPythonApi('templates.delete', { id: 't1' });
+      expect(mockTemplateEngine.deleteTemplate).toHaveBeenCalledWith('t1', undefined);
+    });
+
+    it('routes templates.getAll to TemplateEngine.getAllTemplates', async () => {
+      await invokeMainProcessPythonApi('templates.getAll', {});
+      expect(mockTemplateEngine.getAllTemplates).toHaveBeenCalledWith();
+    });
+
+    it('routes templates.getEnabledByKind to TemplateEngine.getEnabledTemplatesByKind', async () => {
+      await invokeMainProcessPythonApi('templates.getEnabledByKind', { kind: 'post' });
+      expect(mockTemplateEngine.getEnabledTemplatesByKind).toHaveBeenCalledWith('post');
+    });
+
+    it('routes templates.validate to TemplateEngine.validateTemplate', async () => {
+      await invokeMainProcessPythonApi('templates.validate', { content: '<p>{{ title }}</p>' });
+      expect(mockTemplateEngine.validateTemplate).toHaveBeenCalledWith('<p>{{ title }}</p>');
+    });
+
+    it('routes templates.rebuildFromFiles to TemplateEngine.rebuildDatabaseFromFiles', async () => {
+      await invokeMainProcessPythonApi('templates.rebuildFromFiles', {});
+      expect(mockTemplateEngine.rebuildDatabaseFromFiles).toHaveBeenCalledWith();
+    });
+
     it('routes tags.getAll to TagEngine.getAllTags', async () => {
       await invokeMainProcessPythonApi('tags.getAll', {});
       expect(mockTagEngine.getAllTags).toHaveBeenCalledWith();

tests/ipc/handlers.test.ts

@@ -170,11 +170,28 @@ const mockScriptEngine = {
   reconcileScriptsFromGitChanges: vi.fn(),
 };
 
+const mockTemplateEngine = {
+  on: vi.fn(),
+  createTemplate: vi.fn(),
+  updateTemplate: vi.fn(),
+  deleteTemplate: vi.fn(),
+  getTemplate: vi.fn(),
+  getAllTemplates: vi.fn(),
+  getEnabledTemplatesByKind: vi.fn(),
+  getTemplateBySlug: vi.fn(),
+  validateTemplate: vi.fn(),
+  rebuildDatabaseFromFiles: vi.fn(),
+  reconcileTemplatesFromGitChanges: vi.fn(),
+  setProjectContext: vi.fn(),
+  getTemplatesDirectory: vi.fn().mockReturnValue('/tmp/templates'),
+};
+
 const mockGitEngine = {
   checkAvailability: vi.fn(),
   getHeadCommit: vi.fn(),
   getChangedPostFilesBetween: vi.fn(),
   getChangedScriptFilesBetween: vi.fn(),
+  getChangedTemplateFilesBetween: vi.fn(),
   getRepoState: vi.fn(),
   getStatus: vi.fn(),
   getDiff: vi.fn(),
@@ -280,6 +297,10 @@ vi.mock('../../src/main/engine/ScriptEngine', () => ({
   getScriptEngine: vi.fn(() => mockScriptEngine),
 }));
 
+vi.mock('../../src/main/engine/TemplateEngine', () => ({
+  getTemplateEngine: vi.fn(() => mockTemplateEngine),
+}));
+
 vi.mock('../../src/main/engine/GitEngine', () => ({
   getGitEngine: vi.fn(() => mockGitEngine),
 }));
@@ -581,6 +602,9 @@ describe('IPC Handlers', () => {
         mockGitEngine.getChangedScriptFilesBetween.mockResolvedValue([
           { status: 'modified', path: 'scripts/transform.py' },
         ]);
+        mockGitEngine.getChangedTemplateFilesBetween.mockResolvedValue([
+          { status: 'added', path: 'templates/custom_post.liquid' },
+        ]);
         mockPostEngine.reconcilePublishedPostsFromGitChanges.mockResolvedValue({
           created: 1,
           updated: 1,
@@ -593,6 +617,12 @@ describe('IPC Handlers', () => {
           deleted: 0,
           processedFiles: 1,
         });
+        mockTemplateEngine.reconcileTemplatesFromGitChanges.mockResolvedValue({
+          created: 1,
+          updated: 0,
+          deleted: 0,
+          processedFiles: 1,
+        });
 
         const result = await invokeHandler('git:pull', '/repo');
 
@@ -601,6 +631,7 @@ describe('IPC Handlers', () => {
         expect(mockGitEngine.getHeadCommit).toHaveBeenNthCalledWith(2, '/repo');
         expect(mockGitEngine.getChangedPostFilesBetween).toHaveBeenCalledWith('/repo', 'before-head', 'after-head');
         expect(mockGitEngine.getChangedScriptFilesBetween).toHaveBeenCalledWith('/repo', 'before-head', 'after-head');
+        expect(mockGitEngine.getChangedTemplateFilesBetween).toHaveBeenCalledWith('/repo', 'before-head', 'after-head');
         expect(mockPostEngine.reconcilePublishedPostsFromGitChanges).toHaveBeenCalledWith('/repo', [
           { status: 'modified', path: 'posts/2026/02/existing.md' },
           { status: 'added', path: 'posts/2026/02/new-post.md' },
@@ -608,6 +639,9 @@ describe('IPC Handlers', () => {
         expect(mockScriptEngine.reconcileScriptsFromGitChanges).toHaveBeenCalledWith('/repo', [
           { status: 'modified', path: 'scripts/transform.py' },
         ]);
+        expect(mockTemplateEngine.reconcileTemplatesFromGitChanges).toHaveBeenCalledWith('/repo', [
+          { status: 'added', path: 'templates/custom_post.liquid' },
+        ]);
         expect(result).toEqual({ success: true });
       });
 
@@ -620,8 +654,10 @@ describe('IPC Handlers', () => {
         expect(mockGitEngine.pull).toHaveBeenCalledWith('/repo');
         expect(mockGitEngine.getChangedPostFilesBetween).not.toHaveBeenCalled();
         expect(mockGitEngine.getChangedScriptFilesBetween).not.toHaveBeenCalled();
+        expect(mockGitEngine.getChangedTemplateFilesBetween).not.toHaveBeenCalled();
         expect(mockPostEngine.reconcilePublishedPostsFromGitChanges).not.toHaveBeenCalled();
         expect(mockScriptEngine.reconcileScriptsFromGitChanges).not.toHaveBeenCalled();
+        expect(mockTemplateEngine.reconcileTemplatesFromGitChanges).not.toHaveBeenCalled();
         expect(result).toEqual({ success: false, code: 'conflict' });
       });
 
@@ -636,8 +672,10 @@ describe('IPC Handlers', () => {
         expect(mockGitEngine.pull).toHaveBeenCalledWith('/repo');
         expect(mockGitEngine.getChangedPostFilesBetween).not.toHaveBeenCalled();
         expect(mockGitEngine.getChangedScriptFilesBetween).not.toHaveBeenCalled();
+        expect(mockGitEngine.getChangedTemplateFilesBetween).not.toHaveBeenCalled();
         expect(mockPostEngine.reconcilePublishedPostsFromGitChanges).not.toHaveBeenCalled();
         expect(mockScriptEngine.reconcileScriptsFromGitChanges).not.toHaveBeenCalled();
+        expect(mockTemplateEngine.reconcileTemplatesFromGitChanges).not.toHaveBeenCalled();
         expect(result).toEqual({ success: true });
       });
     });
@@ -2764,6 +2802,160 @@ describe('IPC Handlers', () => {
     });
   });
 
+  // ============ Template Handlers ============
+  describe('Template Handlers', () => {
+    describe('templates:create', () => {
+      it('should call TemplateEngine.createTemplate with payload', async () => {
+        const payload = {
+          title: 'Custom Post',
+          kind: 'post',
+          content: '<html>{{ post.title }}</html>',
+        };
+        const expected = {
+          id: 'template-1',
+          projectId: 'default',
+          ...payload,
+          slug: 'custom_post',
+          enabled: true,
+          version: 1,
+          filePath: '/mock/userData/projects/default/templates/custom_post.liquid',
+          createdAt: new Date().toISOString(),
+          updatedAt: new Date().toISOString(),
+        };
+
+        mockTemplateEngine.createTemplate.mockResolvedValue(expected);
+
+        const result = await invokeHandler('templates:create', payload);
+
+        expect(mockTemplateEngine.createTemplate).toHaveBeenCalledWith(payload);
+        expect(result).toEqual(expected);
+      });
+    });
+
+    describe('templates:update', () => {
+      it('should call TemplateEngine.updateTemplate with id and updates', async () => {
+        const updates = { title: 'Updated Template', content: '<html>{{ post.content }}</html>' };
+        const expected = {
+          id: 'template-1',
+          projectId: 'default',
+          slug: 'updated_template',
+          title: 'Updated Template',
+          kind: 'post',
+          enabled: true,
+          version: 2,
+          filePath: '/mock/userData/projects/default/templates/updated_template.liquid',
+          content: '<html>{{ post.content }}</html>',
+          createdAt: new Date().toISOString(),
+          updatedAt: new Date().toISOString(),
+        };
+
+        mockTemplateEngine.updateTemplate.mockResolvedValue(expected);
+
+        const result = await invokeHandler('templates:update', 'template-1', updates);
+
+        expect(mockTemplateEngine.updateTemplate).toHaveBeenCalledWith('template-1', updates);
+        expect(result).toEqual(expected);
+      });
+    });
+
+    describe('templates:delete', () => {
+      it('should call TemplateEngine.deleteTemplate with id', async () => {
+        mockTemplateEngine.deleteTemplate.mockResolvedValue({ deleted: true });
+
+        const result = await invokeHandler('templates:delete', 'template-1');
+
+        expect(mockTemplateEngine.deleteTemplate).toHaveBeenCalledWith('template-1', undefined);
+        expect(result).toEqual({ deleted: true });
+      });
+
+      it('should forward force option to TemplateEngine.deleteTemplate', async () => {
+        mockTemplateEngine.deleteTemplate.mockResolvedValue({ deleted: true });
+
+        const result = await invokeHandler('templates:delete', 'template-1', { force: true });
+
+        expect(mockTemplateEngine.deleteTemplate).toHaveBeenCalledWith('template-1', { force: true });
+        expect(result).toEqual({ deleted: true });
+      });
+    });
+
+    describe('templates:get', () => {
+      it('should call TemplateEngine.getTemplate with id', async () => {
+        const expected = {
+          id: 'template-1',
+          projectId: 'default',
+          slug: 'custom_post',
+          title: 'Custom Post',
+          kind: 'post',
+          enabled: true,
+          version: 1,
+          filePath: '/mock/userData/projects/default/templates/custom_post.liquid',
+          content: '<html>{{ post.title }}</html>',
+          createdAt: new Date().toISOString(),
+          updatedAt: new Date().toISOString(),
+        };
+        mockTemplateEngine.getTemplate.mockResolvedValue(expected);
+
+        const result = await invokeHandler('templates:get', 'template-1');
+
+        expect(mockTemplateEngine.getTemplate).toHaveBeenCalledWith('template-1');
+        expect(result).toEqual(expected);
+      });
+    });
+
+    describe('templates:getAll', () => {
+      it('should call TemplateEngine.getAllTemplates', async () => {
+        const expected = [{ id: 'template-1' }, { id: 'template-2' }];
+        mockTemplateEngine.getAllTemplates.mockResolvedValue(expected);
+
+        const result = await invokeHandler('templates:getAll');
+
+        expect(mockTemplateEngine.getAllTemplates).toHaveBeenCalled();
+        expect(result).toEqual(expected);
+      });
+    });
+
+    describe('templates:getEnabledByKind', () => {
+      it('should call TemplateEngine.getEnabledTemplatesByKind with kind', async () => {
+        const expected = [{ id: 'template-1', kind: 'post' }];
+        mockTemplateEngine.getEnabledTemplatesByKind.mockResolvedValue(expected);
+
+        const result = await invokeHandler('templates:getEnabledByKind', 'post');
+
+        expect(mockTemplateEngine.getEnabledTemplatesByKind).toHaveBeenCalledWith('post');
+        expect(result).toEqual(expected);
+      });
+    });
+
+    describe('templates:validate', () => {
+      it('should call TemplateEngine.validateTemplate with content', async () => {
+        const expected = { valid: true, errors: [] };
+        mockTemplateEngine.validateTemplate.mockResolvedValue(expected);
+
+        const result = await invokeHandler('templates:validate', '<html>{{ post.title }}</html>');
+
+        expect(mockTemplateEngine.validateTemplate).toHaveBeenCalledWith('<html>{{ post.title }}</html>');
+        expect(result).toEqual(expected);
+      });
+    });
+
+    describe('templates:rebuildFromFiles', () => {
+      it('should set project context and trigger TemplateEngine rebuild', async () => {
+        mockProjectEngine.getActiveProject.mockResolvedValue({
+          id: 'project-1',
+          dataPath: '/external/data',
+        });
+        mockProjectEngine.getDataDir.mockReturnValue('/resolved/project-data');
+        mockTemplateEngine.rebuildDatabaseFromFiles.mockResolvedValue(undefined);
+
+        const result = await invokeHandler('templates:rebuildFromFiles');
+
+        expect(mockTemplateEngine.setProjectContext).toHaveBeenCalledWith('project-1', '/resolved/project-data');
+        expect(mockTemplateEngine.rebuildDatabaseFromFiles).toHaveBeenCalled();
+        expect(result).toBe(true);
+      });
+    });
+  });
+
   // ============ Error Handling ============
   describe('Error Handling', () => {
     it('should silently handle "Database is closing" errors', async () => {

tests/renderer/components/SettingsView.i18n.test.tsx

@@ -46,6 +46,10 @@ describe('SettingsView i18n', () => {
         getApiKey: vi.fn().mockResolvedValue({ hasKey: false, maskedKey: '' }),
         getAvailableModels: vi.fn().mockResolvedValue({ success: true, models: [], selectedModel: '' }),
       },
+      templates: {
+        ...(window as Window & { electronAPI: any }).electronAPI?.templates,
+        getEnabledByKind: vi.fn().mockResolvedValue([]),
+      },
     };
   });
 

tests/renderer/components/SettingsView.test.tsx

@@ -61,6 +61,10 @@ describe('SettingsView Diff Preferences', () => {
         getApiKey: vi.fn().mockResolvedValue({ hasKey: false, maskedKey: '' }),
         getAvailableModels: vi.fn().mockResolvedValue({ success: true, models: [], selectedModel: '' }),
       },
+      templates: {
+        ...(window as any).electronAPI?.templates,
+        getEnabledByKind: vi.fn().mockResolvedValue([]),
+      },
       projects: {
         ...(window as any).electronAPI?.projects,
         update: updateProjectMock,
@@ -178,6 +182,107 @@ describe('SettingsView Diff Preferences', () => {
     expect(rebuildScriptsMock).toHaveBeenCalledTimes(1);
   });
 
+  it('triggers templates rebuild from data maintenance section', async () => {
+    const rebuildTemplatesMock = vi.fn().mockResolvedValue(undefined);
+    (window as any).electronAPI = {
+      ...(window as any).electronAPI,
+      templates: {
+        ...(window as any).electronAPI?.templates,
+        getEnabledByKind: vi.fn().mockResolvedValue([]),
+        rebuildFromFiles: rebuildTemplatesMock,
+      },
+    };
+
+    render(<SettingsView />);
+
+    const rebuildTemplatesButton = await screen.findByRole('button', { name: /rebuild templates/i });
+    fireEvent.click(rebuildTemplatesButton);
+
+    await new Promise((resolve) => setTimeout(resolve, 0));
+
+    expect(rebuildTemplatesMock).toHaveBeenCalledTimes(1);
+  });
+
+  it('renders category template dropdowns populated with enabled templates', async () => {
+    (window as any).electronAPI = {
+      ...(window as any).electronAPI,
+      templates: {
+        ...(window as any).electronAPI?.templates,
+        getEnabledByKind: vi.fn().mockImplementation((kind: string) => {
+          if (kind === 'post') {
+            return Promise.resolve([
+              { slug: 'custom_post', title: 'Custom Post' },
+            ]);
+          }
+          if (kind === 'list') {
+            return Promise.resolve([
+              { slug: 'custom_list', title: 'Custom List' },
+            ]);
+          }
+          return Promise.resolve([]);
+        }),
+      },
+    };
+
+    render(<SettingsView />);
+
+    const postTemplateSelect = await screen.findByLabelText(/article post template/i);
+    expect(postTemplateSelect).toBeInTheDocument();
+
+    await vi.waitFor(() => {
+      const options = postTemplateSelect.querySelectorAll('option');
+      const optionTexts = Array.from(options).map((o) => o.textContent);
+      expect(optionTexts).toContain('Custom Post');
+    });
+
+    const listTemplateSelect = screen.getByLabelText(/article list template/i);
+    expect(listTemplateSelect).toBeInTheDocument();
+
+    await vi.waitFor(() => {
+      const options = listTemplateSelect.querySelectorAll('option');
+      const optionTexts = Array.from(options).map((o) => o.textContent);
+      expect(optionTexts).toContain('Custom List');
+    });
+  });
+
+  it('persists category template selection via project metadata update', async () => {
+    (window as any).electronAPI = {
+      ...(window as any).electronAPI,
+      templates: {
+        ...(window as any).electronAPI?.templates,
+        getEnabledByKind: vi.fn().mockImplementation((kind: string) => {
+          if (kind === 'post') {
+            return Promise.resolve([
+              { slug: 'custom_post', title: 'Custom Post' },
+            ]);
+          }
+          return Promise.resolve([]);
+        }),
+      },
+    };
+
+    render(<SettingsView />);
+
+    const postTemplateSelect = await screen.findByLabelText(/article post template/i);
+
+    await vi.waitFor(() => {
+      const options = postTemplateSelect.querySelectorAll('option');
+      expect(Array.from(options).map((o) => o.textContent)).toContain('Custom Post');
+    });
+
+    fireEvent.change(postTemplateSelect, { target: { value: 'custom_post' } });
+
+    await new Promise((resolve) => setTimeout(resolve, 0));
+
+    expect((window as any).electronAPI.meta.updateProjectMetadata).toHaveBeenCalledWith(
+      expect.objectContaining({
+        categoryMetadata: expect.objectContaining({
+          article: expect.objectContaining({ postTemplateSlug: 'custom_post' }),
+        }),
+      })
+    );
+  });
+
   it('persists category settings changes via project metadata update', async () => {
     render(<SettingsView />);
 

tests/renderer/components/SidebarTemplates.test.tsx

@@ -0,0 +1,281 @@
+import React from 'react';
+import { describe, it, expect, beforeEach, vi } from 'vitest';
+import { act, render, screen, fireEvent } from '@testing-library/react';
+import { Sidebar } from '../../../src/renderer/components/Sidebar/Sidebar';
+import { useAppStore } from '../../../src/renderer/store';
+
+describe('Sidebar templates list behavior', () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+
+    const listeners = new Map<string, Set<(event: Event) => void>>();
+    (window as any).addEventListener = vi.fn((type: string, listener: (event: Event) => void) => {
+      if (!listeners.has(type)) {
+        listeners.set(type, new Set());
+      }
+      listeners.get(type)?.add(listener);
+    });
+    (window as any).removeEventListener = vi.fn((type: string, listener: (event: Event) => void) => {
+      listeners.get(type)?.delete(listener);
+    });
+    (window as any).dispatchEvent = vi.fn((event: Event) => {
+      listeners.get(event.type)?.forEach((listener) => listener(event));
+      return true;
+    });
+
+    (window as any).electronAPI = {
+      ...(window as any).electronAPI,
+      templates: {
+        create: vi.fn(),
+        update: vi.fn(),
+        delete: vi.fn().mockResolvedValue({ deleted: true }),
+        get: vi.fn(),
+        getAll: vi.fn().mockResolvedValue([
+          {
+            id: 'template-1',
+            projectId: 'default',
+            slug: 'custom_post',
+            title: 'Custom Post',
+            kind: 'post',
+            enabled: true,
+            version: 1,
+            filePath: '/tmp/custom_post.liquid',
+            content: '<main>{{ post.title }}</main>',
+            createdAt: '2026-02-22T00:00:00.000Z',
+            updatedAt: '2026-02-22T00:00:00.000Z',
+          },
+        ]),
+        getEnabledByKind: vi.fn().mockResolvedValue([]),
+        validate: vi.fn(),
+        rebuildFromFiles: vi.fn(),
+      },
+    };
+
+    useAppStore.setState({
+      activeView: 'templates',
+      sidebarVisible: true,
+      tabs: [],
+      activeTabId: null,
+    });
+  });
+
+  it('opens a transient template tab on single click', async () => {
+    const { container } = render(<Sidebar />);
+
+    const templateRow = await screen.findByRole('button', { name: 'Custom Post' });
+    expect(templateRow).toHaveClass('chat-list-item');
+    expect(container.querySelector('.chat-item-date')).not.toBeNull();
+    fireEvent.click(templateRow);
+
+    expect(useAppStore.getState().tabs).toEqual([
+      {
+        type: 'templates',
+        id: 'template-1',
+        isTransient: true,
+      },
+    ]);
+    expect(useAppStore.getState().activeTabId).toBe('template-1');
+  });
+
+  it('renders templates section title and create button', async () => {
+    render(<Sidebar />);
+
+    expect(screen.getByText('TEMPLATES')).toBeInTheDocument();
+    expect(await screen.findByRole('button', { name: 'New Template' })).toBeInTheDocument();
+  });
+
+  it('shows loading state while templates are being fetched', () => {
+    (window as any).electronAPI.templates.getAll = vi.fn().mockImplementation(
+      () => new Promise(() => {}),
+    );
+
+    render(<Sidebar />);
+
+    expect(screen.getByText('Loading...')).toBeInTheDocument();
+  });
+
+  it('shows empty state with create action when no templates exist', async () => {
+    (window as any).electronAPI.templates.getAll = vi.fn().mockResolvedValue([]);
+
+    render(<Sidebar />);
+
+    expect(await screen.findByText('No templates yet')).toBeInTheDocument();
+    expect(screen.getByRole('button', { name: 'Create a template' })).toBeInTheDocument();
+  });
+
+  it('creates a new template from the create button and opens it pinned', async () => {
+    const createMock = vi.fn().mockResolvedValue({
+      id: 'template-new',
+      projectId: 'default',
+      slug: 'new_template',
+      title: 'New Template',
+      kind: 'post',
+      enabled: true,
+      version: 1,
+      filePath: '/tmp/new_template.liquid',
+      content: '',
+      createdAt: '2026-02-22T00:00:00.000Z',
+      updatedAt: '2026-02-22T00:00:00.000Z',
+    });
+
+    (window as any).electronAPI.templates.create = createMock;
+
+    render(<Sidebar />);
+
+    fireEvent.click(await screen.findByRole('button', { name: 'New Template' }));
+
+    await vi.waitFor(() => {
+      expect(createMock).toHaveBeenCalledWith(
+        expect.objectContaining({
+          title: 'New Template',
+          kind: 'post',
+          content: '',
+          enabled: true,
+        }),
+      );
+    });
+
+    await vi.waitFor(() => {
+      expect(useAppStore.getState().tabs).toEqual([
+        {
+          type: 'templates',
+          id: 'template-new',
+          isTransient: false,
+        },
+      ]);
+      expect(useAppStore.getState().activeTabId).toBe('template-new');
+    });
+  });
+
+  it('opens a pinned template tab on double click', async () => {
+    render(<Sidebar />);
+
+    const templateRow = await screen.findByRole('button', { name: 'Custom Post' });
+    fireEvent.doubleClick(templateRow);
+
+    expect(useAppStore.getState().tabs).toEqual([
+      {
+        type: 'templates',
+        id: 'template-1',
+        isTransient: false,
+      },
+    ]);
+    expect(useAppStore.getState().activeTabId).toBe('template-1');
+  });
+
+  it('deletes a template from sidebar action', async () => {
+    const deleteMock = vi.fn().mockResolvedValue({ deleted: true });
+    (window as any).electronAPI.templates.delete = deleteMock;
+
+    useAppStore.setState({
+      tabs: [{ type: 'templates', id: 'template-1', isTransient: false }],
+      activeTabId: 'template-1',
+    });
+
+    render(<Sidebar />);
+
+    const deleteButton = await screen.findByTitle('Delete template');
+    fireEvent.click(deleteButton);
+
+    await vi.waitFor(() => {
+      expect(deleteMock).toHaveBeenCalledWith('template-1');
+      expect(useAppStore.getState().tabs).toEqual([]);
+    });
+  });
+
+  it('refreshes templates list when templates-changed event is emitted', async () => {
+    const getAllMock = vi
+      .fn()
+      .mockResolvedValueOnce([
+        {
+          id: 'template-1',
+          projectId: 'default',
+          slug: 'custom_post',
+          title: 'Custom Post',
+          kind: 'post',
+          enabled: true,
+          version: 1,
+          filePath: '/tmp/custom_post.liquid',
+          content: '<main>{{ post.title }}</main>',
+          createdAt: '2026-02-22T00:00:00.000Z',
+          updatedAt: '2026-02-22T00:00:00.000Z',
+        },
+      ])
+      .mockResolvedValueOnce([
+        {
+          id: 'template-1',
+          projectId: 'default',
+          slug: 'renamed_template',
+          title: 'Renamed Template',
+          kind: 'post',
+          enabled: true,
+          version: 2,
+          filePath: '/tmp/custom_post.liquid',
+          content: '<main>{{ post.title }}</main>',
+          createdAt: '2026-02-22T00:00:00.000Z',
+          updatedAt: '2026-02-22T00:01:00.000Z',
+        },
+      ]);
+
+    (window as any).electronAPI.templates.getAll = getAllMock;
+
+    render(<Sidebar />);
+
+    await screen.findByRole('button', { name: 'Custom Post' });
+    window.dispatchEvent(new CustomEvent('bds:templates-changed'));
+
+    expect(await screen.findByRole('button', { name: 'Renamed Template' })).toBeInTheDocument();
+  });
+
+  it('reloads templates when active project context becomes available after mount', async () => {
+    const getAllMock = vi
+      .fn()
+      .mockResolvedValueOnce([])
+      .mockResolvedValueOnce([
+        {
+          id: 'template-1',
+          projectId: 'project-1',
+          slug: 'custom_post',
+          title: 'Custom Post',
+          kind: 'post',
+          enabled: true,
+          version: 1,
+          filePath: '/tmp/custom_post.liquid',
+          content: '<main>{{ post.title }}</main>',
+          createdAt: '2026-02-22T00:00:00.000Z',
+          updatedAt: '2026-02-22T00:00:00.000Z',
+        },
+      ]);
+
+    (window as any).electronAPI.templates.getAll = getAllMock;
+
+    useAppStore.setState({
+      activeProject: null,
+      activeView: 'templates',
+      sidebarVisible: true,
+      tabs: [],
+      activeTabId: null,
+    });
+
+    render(<Sidebar />);
+
+    expect(await screen.findByText('No templates yet')).toBeInTheDocument();
+
+    act(() => {
+      useAppStore.setState({
+        activeProject: {
+          id: 'project-1',
+          name: 'Project 1',
+          slug: 'project-1',
+          dataPath: '/tmp/project-1',
+          isActive: true,
+          createdAt: '2026-02-22T00:00:00.000Z',
+          updatedAt: '2026-02-22T00:00:00.000Z',
+        },
+      });
+    });
+
+    expect(await screen.findByRole('button', { name: 'Custom Post' })).toBeInTheDocument();
+    expect(getAllMock).toHaveBeenCalledTimes(2);
+  });
+});

tests/renderer/components/TabBar.test.tsx

@@ -73,6 +73,10 @@ describe('TabBar', () => {
         ...(window as any).electronAPI?.scripts,
         get: vi.fn(),
       },
+      templates: {
+        ...(window as any).electronAPI?.templates,
+        get: vi.fn(),
+      },
     };
   });
 
@@ -160,4 +164,65 @@ describe('TabBar', () => {
     expect(await screen.findByText('Publish Macro')).toBeInTheDocument();
     expect((window as any).electronAPI.scripts.get).toHaveBeenCalledWith('script-1');
   });
+
+  it('renders template title for template tab', async () => {
+    useAppStore.setState({
+      tabs: [{ type: 'templates', id: 'template-1', isTransient: false }],
+      activeTabId: 'template-1',
+      posts: [],
+      media: [],
+      dirtyPosts: new Set<string>(),
+    });
+
+    (window as any).electronAPI.templates.get = vi.fn().mockResolvedValue({
+      id: 'template-1',
+      title: 'Blog Post Layout',
+    });
+
+    render(<TabBar />);
+
+    expect(await screen.findByText('Blog Post Layout')).toBeInTheDocument();
+    expect((window as any).electronAPI.templates.get).toHaveBeenCalledWith('template-1');
+  });
+
+  it('updates template tab title when template changes', async () => {
+    useAppStore.setState({
+      tabs: [{ type: 'templates', id: 'template-1', isTransient: false }],
+      activeTabId: 'template-1',
+      posts: [],
+      media: [],
+      dirtyPosts: new Set<string>(),
+    });
+
+    (window as any).electronAPI.templates.get = vi.fn().mockResolvedValue({
+      id: 'template-1',
+      title: 'Old Title',
+    });
+
+    // Capture the bds:templates-changed listener
+    let templatesChangedHandler: (() => void) | null = null;
+    (window as any).addEventListener = vi.fn((event: string, handler: () => void) => {
+      if (event === 'bds:templates-changed') {
+        templatesChangedHandler = handler;
+      }
+    });
+    (window as any).removeEventListener = vi.fn();
+
+    render(<TabBar />);
+
+    expect(await screen.findByText('Old Title')).toBeInTheDocument();
+
+    // Now simulate the template being updated
+    (window as any).electronAPI.templates.get = vi.fn().mockResolvedValue({
+      id: 'template-1',
+      title: 'New Title',
+    });
+
+    // Trigger the templates-changed event
+    await act(async () => {
+      templatesChangedHandler?.();
+    });
+
+    expect(await screen.findByText('New Title')).toBeInTheDocument();
+  });
 });

tests/renderer/components/TagsView.test.tsx

@@ -1,6 +1,6 @@
 import React from 'react';
 import { describe, it, expect, beforeEach, vi } from 'vitest';
-import { render, act } from '@testing-library/react';
+import { render, act, screen, fireEvent } from '@testing-library/react';
 import { TagsView } from '../../../src/renderer/components/TagsView/TagsView';
 
 describe('TagsView subscriptions', () => {
@@ -19,6 +19,9 @@ describe('TagsView subscriptions', () => {
         merge: vi.fn(),
         syncFromPosts: vi.fn(),
       },
+      templates: {
+        getEnabledByKind: vi.fn().mockResolvedValue([]),
+      },
       on: onMock,
     };
   });
@@ -58,3 +61,98 @@ describe('TagsView subscriptions', () => {
     });
   });
 });
+
+describe('TagsView template dropdown', () => {
+  beforeEach(() => {
+    const onMock = vi.fn((_channel: string, _callback: (...args: unknown[]) => void) => vi.fn());
+
+    (window as any).electronAPI = {
+      ...(window as any).electronAPI,
+      tags: {
+        getWithCounts: vi.fn().mockResolvedValue([
+          { name: 'javascript', count: 5 },
+        ]),
+        getAll: vi.fn().mockResolvedValue([
+          { id: 'tag-1', name: 'javascript', color: null, postTemplateSlug: null },
+        ]),
+        create: vi.fn(),
+        update: vi.fn().mockResolvedValue(undefined),
+        delete: vi.fn(),
+        rename: vi.fn(),
+        merge: vi.fn(),
+        syncFromPosts: vi.fn(),
+      },
+      templates: {
+        getEnabledByKind: vi.fn().mockResolvedValue([
+          { slug: 'custom_post', title: 'Custom Post' },
+        ]),
+      },
+      on: onMock,
+    };
+  });
+
+  it('loads post templates and shows them in tag edit dropdown', async () => {
+    render(<TagsView />);
+
+    // Wait for tags to load and click the tag to select it
+    const tagButton = await screen.findByText('javascript');
+    fireEvent.click(tagButton);
+
+    // Click the edit button to enter edit mode
+    const editButton = await screen.findByRole('button', { name: /edit/i });
+    fireEvent.click(editButton);
+
+    // Verify template dropdown appears with the loaded template
+    await vi.waitFor(() => {
+      const label = screen.getByText('Post Template');
+      const fieldDiv = label.closest('.tagsview-field')!;
+      const select = fieldDiv.querySelector('select')!;
+      const options = Array.from(select.querySelectorAll('option'));
+      const optionTexts = options.map((o) => o.textContent);
+      expect(optionTexts).toContain('Custom Post');
+    });
+  });
+
+  it('saves tag template selection via update IPC call', async () => {
+    const updateMock = vi.fn().mockResolvedValue(undefined);
+    (window as any).electronAPI.tags.update = updateMock;
+
+    render(<TagsView />);
+
+    // Select the tag
+    const tagButton = await screen.findByText('javascript');
+    fireEvent.click(tagButton);
+
+    // Enter edit mode
+    const editButton = await screen.findByRole('button', { name: /edit/i });
+    fireEvent.click(editButton);
+
+    // Wait for template dropdown to populate
+    await vi.waitFor(() => {
+      const label = screen.getByText('Post Template');
+      const fieldDiv = label.closest('.tagsview-field')!;
+      const select = fieldDiv.querySelector('select')!;
+      const options = Array.from(select.querySelectorAll('option'));
+      expect(options.map((o) => o.textContent)).toContain('Custom Post');
+    });
+
+    // Select a template
+    const label = screen.getByText('Post Template');
+    const fieldDiv = label.closest('.tagsview-field')!;
+    const templateSelect = fieldDiv.querySelector('select')!;
+    fireEvent.change(templateSelect, { target: { value: 'custom_post' } });
+
+    // Save
+    const saveButton = screen.getByRole('button', { name: /save/i });
+    fireEvent.click(saveButton);
+
+    await vi.waitFor(() => {
+      expect(updateMock).toHaveBeenCalledWith(
+        'tag-1',
+        expect.objectContaining({
+          postTemplateSlug: 'custom_post',
+        }),
+      );
+    });
+  });
+});

tests/renderer/components/TemplatesView.styles.test.ts

@@ -0,0 +1,23 @@
+import { describe, expect, it } from 'vitest';
+import * as fs from 'node:fs';
+import * as path from 'node:path';
+
+describe('TemplatesView styles', () => {
+  const cssPath = path.resolve(
+    __dirname,
+    '../../../src/renderer/components/TemplatesView/TemplatesView.css'
+  );
+
+  it('uses full editor area layout for the templates container', () => {
+    const css = fs.readFileSync(cssPath, 'utf8');
+
+    expect(css).toMatch(/\.templates-view\s*\{[^}]*flex:\s*1;[^}]*min-height:\s*0;[^}]*\}/s);
+  });
+
+  it('keeps editor and monaco stretched to fill available space', () => {
+    const css = fs.readFileSync(cssPath, 'utf8');
+
+    expect(css).toMatch(/\.templates-editor\s*\{[^}]*flex:\s*1;[^}]*min-height:\s*0;[^}]*\}/s);
+    expect(css).toMatch(/\.templates-monaco\s*\{[^}]*flex:\s*1;[^}]*min-height:\s*0;[^}]*\}/s);
+  });
+});

tests/renderer/components/TemplatesView.test.tsx

@@ -0,0 +1,211 @@
+import React from 'react';
+import { describe, it, expect, beforeEach, vi } from 'vitest';
+import { render, screen, fireEvent } from '@testing-library/react';
+import { TemplatesView } from '../../../src/renderer/components/TemplatesView/TemplatesView';
+import { useAppStore } from '../../../src/renderer/store';
+
+const monacoPropsSpy = vi.fn();
+
+vi.mock('@monaco-editor/react', () => ({
+  default: (props: {
+    value?: string;
+    defaultValue?: string;
+    onChange?: (value?: string) => void;
+    language?: string;
+  }) => {
+    monacoPropsSpy(props);
+    return (
+      <textarea
+        aria-label="Template Content"
+        defaultValue={props.defaultValue ?? props.value ?? ''}
+        onChange={(event) => props.onChange?.(event.target.value)}
+      />
+    );
+  },
+}));
+
+const mockTemplate = {
+  id: 'template-1',
+  projectId: 'default',
+  slug: 'custom_post',
+  title: 'Custom Post',
+  kind: 'post' as const,
+  enabled: true,
+  version: 1,
+  filePath: '/tmp/custom_post.liquid',
+  content: '<main>{{ post.title }}</main>',
+  createdAt: '2026-02-22T00:00:00.000Z',
+  updatedAt: '2026-02-22T00:00:00.000Z',
+};
+
+describe('TemplatesView', () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+
+    (window as any).electronAPI = {
+      ...(window as any).electronAPI,
+      templates: {
+        create: vi.fn(),
+        update: vi.fn(),
+        delete: vi.fn().mockResolvedValue({ deleted: true }),
+        get: vi.fn().mockResolvedValue({ ...mockTemplate }),
+        getAll: vi.fn().mockResolvedValue([]),
+        getEnabledByKind: vi.fn().mockResolvedValue([]),
+        validate: vi.fn().mockResolvedValue({ valid: true, errors: [] }),
+        rebuildFromFiles: vi.fn(),
+      },
+    };
+  });
+
+  it('loads template and displays metadata fields', async () => {
+    render(<TemplatesView templateId="template-1" />);
+
+    const titleInput = await screen.findByLabelText('Title') as HTMLInputElement;
+    const slugInput = screen.getByLabelText('Slug') as HTMLInputElement;
+    const kindSelect = screen.getByLabelText('Kind') as HTMLSelectElement;
+    const enabledInput = screen.getByLabelText('Enabled') as HTMLInputElement;
+
+    await vi.waitFor(() => {
+      expect(titleInput.value).toBe('Custom Post');
+      expect(slugInput.value).toBe('custom_post');
+    });
+    expect(kindSelect.value).toBe('post');
+    expect(enabledInput.checked).toBe(true);
+
+    expect(screen.getByText(/Created:/)).toBeInTheDocument();
+    expect(screen.getByText(/Updated:/)).toBeInTheDocument();
+  });
+
+  it('loads template content into Monaco editor with html language', async () => {
+    render(<TemplatesView templateId="template-1" />);
+
+    await vi.waitFor(() => {
+      const textarea = screen.getByLabelText('Template Content') as HTMLTextAreaElement;
+      expect(textarea.value).toContain('{{ post.title }}');
+    });
+
+    expect(monacoPropsSpy).toHaveBeenCalledWith(
+      expect.objectContaining({
+        language: 'html',
+      }),
+    );
+  });
+
+  it('saves template metadata via update IPC call', async () => {
+    const updateMock = vi.fn().mockResolvedValue({
+      ...mockTemplate,
+      kind: 'list',
+      enabled: false,
+      version: 2,
+      updatedAt: '2026-02-22T00:01:00.000Z',
+    });
+    (window as any).electronAPI.templates.update = updateMock;
+
+    render(<TemplatesView templateId="template-1" />);
+
+    const kindSelect = screen.getByLabelText('Kind');
+    const enabledInput = screen.getByLabelText('Enabled');
+
+    await vi.waitFor(() => {
+      expect((screen.getByLabelText('Title') as HTMLInputElement).value).toBe('Custom Post');
+    });
+
+    fireEvent.change(kindSelect, { target: { value: 'list' } });
+    fireEvent.click(enabledInput);
+
+    await vi.waitFor(() => {
+      expect((kindSelect as HTMLSelectElement).value).toBe('list');
+      expect((enabledInput as HTMLInputElement).checked).toBe(false);
+    });
+
+    fireEvent.click(screen.getByRole('button', { name: 'Save Template' }));
+
+    await vi.waitFor(() => {
+      expect(updateMock).toHaveBeenCalledWith(
+        'template-1',
+        expect.objectContaining({
+          title: 'Custom Post',
+          slug: 'custom_post',
+          kind: 'list',
+          enabled: false,
+          content: '<main>{{ post.title }}</main>',
+        }),
+      );
+    });
+  });
+
+  it('validates before saving and blocks save on invalid syntax', async () => {
+    const validateMock = vi.fn().mockResolvedValue({
+      valid: false,
+      errors: ['unexpected end of tag'],
+    });
+    const updateMock = vi.fn();
+    (window as any).electronAPI.templates.validate = validateMock;
+    (window as any).electronAPI.templates.update = updateMock;
+
+    render(<TemplatesView templateId="template-1" />);
+
+    await vi.waitFor(() => {
+      expect((screen.getByLabelText('Title') as HTMLInputElement).value).toBe('Custom Post');
+    });
+
+    // Trigger hasChanges via kind change (select events work reliably)
+    fireEvent.change(screen.getByLabelText('Kind'), { target: { value: 'list' } });
+
+    await vi.waitFor(() => {
+      expect((screen.getByLabelText('Kind') as HTMLSelectElement).value).toBe('list');
+    });
+
+    fireEvent.click(screen.getByRole('button', { name: 'Save Template' }));
+
+    await vi.waitFor(() => {
+      expect(validateMock).toHaveBeenCalled();
+    });
+
+    expect(updateMock).not.toHaveBeenCalled();
+  });
+
+  it('validates template content via validate button', async () => {
+    const validateMock = vi.fn().mockResolvedValue({ valid: true, errors: [] });
+    (window as any).electronAPI.templates.validate = validateMock;
+
+    render(<TemplatesView templateId="template-1" />);
+
+    await screen.findByLabelText('Title');
+    fireEvent.click(screen.getByRole('button', { name: 'Validate' }));
+
+    await vi.waitFor(() => {
+      expect(validateMock).toHaveBeenCalledWith('<main>{{ post.title }}</main>');
+    });
+  });
+
+  it('deletes template and closes tab', async () => {
+    const deleteMock = vi.fn().mockResolvedValue({ deleted: true });
+    (window as any).electronAPI.templates.delete = deleteMock;
+
+    useAppStore.setState({
+      tabs: [{ type: 'templates', id: 'template-1', isTransient: false }],
+      activeTabId: 'template-1',
+    });
+
+    render(<TemplatesView templateId="template-1" />);
+
+    fireEvent.click(await screen.findByRole('button', { name: 'Delete Template' }));
+
+    await vi.waitFor(() => {
+      expect(deleteMock).toHaveBeenCalledWith('template-1');
+      expect(useAppStore.getState().tabs).toEqual([]);
+    });
+  });
+
+  it('disables save button when no changes exist', async () => {
+    render(<TemplatesView templateId="template-1" />);
+
+    await screen.findByLabelText('Title');
+
+    await vi.waitFor(() => {
+      const saveButton = screen.getByRole('button', { name: 'Save Template' });
+      expect(saveButton).toBeDisabled();
+    });
+  });
+});

tests/renderer/navigation/editorRouting.test.ts

@@ -22,6 +22,7 @@ describe('editorRouting', () => {
       'api-documentation': 'api-documentation',
       'site-validation': 'site-validation',
       scripts: 'scripts',
+      templates: 'templates',
     });
   });
 

tests/renderer/navigation/sidebarViewRegistry.test.ts

@@ -12,6 +12,7 @@ describe('sidebarViewRegistry', () => {
       'pages',
       'media',
       'scripts',
+      'templates',
       'settings',
       'tags',
       'chat',

tests/renderer/navigation/tabPolicy.test.ts

@@ -6,6 +6,7 @@ import {
   getGitDiffFileTabSpec,
   getImportTabSpec,
   getScriptTabSpec,
+  getTemplateTabSpec,
   parseGitDiffTabId,
   openChatTab,
   getSingletonToolTabSpec,
@@ -14,6 +15,7 @@ import {
   openGitDiffFileTab,
   openImportTab,
   openScriptTab,
+  openTemplateTab,
   openSingletonToolTab,
 } from '../../../src/renderer/navigation/tabPolicy';
 
@@ -163,4 +165,33 @@ describe('tabPolicy', () => {
       { type: 'git-diff', id: 'git-diff:commit:def456', isTransient: false },
     ]);
   });
+
+  it('provides canonical template tab spec for preview and pin intents', () => {
+    expect(getTemplateTabSpec('template-1', 'preview')).toEqual({
+      type: 'templates',
+      id: 'template-1',
+      isTransient: true,
+    });
+
+    expect(getTemplateTabSpec('template-1', 'pin')).toEqual({
+      type: 'templates',
+      id: 'template-1',
+      isTransient: false,
+    });
+  });
+
+  it('opens template tabs from shared policy', () => {
+    const opened: Array<{ type: string; id: string; isTransient: boolean }> = [];
+    const openTab = (tab: { type: string; id: string; isTransient: boolean }) => {
+      opened.push(tab);
+    };
+
+    openTemplateTab(openTab, 'template-preview', 'preview');
+    openTemplateTab(openTab, 'template-pin', 'pin');
+
+    expect(opened).toEqual([
+      { type: 'templates', id: 'template-preview', isTransient: true },
+      { type: 'templates', id: 'template-pin', isTransient: false },
+    ]);
+  });
 });

tests/renderer/python/pythonApiContractV1.test.ts

@@ -67,7 +67,7 @@ describe('pythonApiContractV1', () => {
 
   it('contains semantic version metadata for compatibility checks', () => {
     expect(BDS_PYTHON_API_CONTRACT_V1).toMatchObject({
-      version: '1.7.0',
+      version: '1.9.0',
       generatedAt: expect.any(String),
     });
   });

tests/setup.ts

@@ -146,6 +146,16 @@ Object.defineProperty(globalThis, 'window', {
         update: vi.fn(),
         delete: vi.fn(),
       },
+      templates: {
+        getEnabledByKind: vi.fn().mockResolvedValue([]),
+        getAll: vi.fn().mockResolvedValue([]),
+        get: vi.fn().mockResolvedValue(null),
+        create: vi.fn().mockResolvedValue(null),
+        update: vi.fn().mockResolvedValue(null),
+        delete: vi.fn().mockResolvedValue({ deleted: true }),
+        validate: vi.fn().mockResolvedValue({ valid: true, errors: [] }),
+        rebuildFromFiles: vi.fn().mockResolvedValue(undefined),
+      },
       on: vi.fn(() => () => {}),
     },
   },