diff --git a/PYTHON_SCRIPTING.md b/PYTHON_SCRIPTING.md
index 5f914a8..8f8cbb4 100644
--- a/PYTHON_SCRIPTING.md
+++ b/PYTHON_SCRIPTING.md
@@ -1,6 +1,6 @@
 # Python Scripting — Remaining Work (Implementation-First)
 
-Last verified: 24 Feb 2026
+Last verified: 26 Feb 2026
 
 This document is intentionally reduced to **what is still left to implement**.
 When plan and code differ, code is the source of truth.
@@ -34,9 +34,11 @@ These are current realities and should be treated as authoritative unless we exp
    - Existing JS macro path remains valid (`PageRenderer.renderMacro` and renderer macro registry/definitions).
    - Python macro support is additive for new macros, not a migration requirement.
 
-3. **Macro ABI exists but is not yet wired for additive Python macro creation in the production render path**
+3. **Macro ABI is now wired for Python macro execution in both preview and production render paths**
    - ABI v1 + runtime manager support exist.
-   - Main page generation path still uses existing JS macro rendering.
+   - Main page generation path now supports Python macro rendering via `PythonMacroWorkerRuntime`.
+   - Renderer preview path supports Python macro rendering via `PythonRuntimeManager`.
+   - JS built-in macros always take priority; Python macros only resolve for names not in the JS registry.
 
 4. **Scripts rebuild/sync parity is implemented (simple policy)**
    - `ScriptEngine.rebuildDatabaseFromFiles()` now rebuilds DB metadata from `scripts/*.py`.
@@ -64,24 +66,45 @@ These are current realities and should be treated as authoritative unless we exp
 - Reconcile path (git pull): apply file deltas (`added|modified|deleted|renamed`) and upsert/delete rows.
 - Conflict behavior: prefer file metadata/body; fall back to safe defaults when values are missing/invalid.
 
-## 3) Additive Python macro support in render pipeline (P1)
+## 3) Additive Python macro support in render pipeline (P1) — Implemented
 
-- [ ] Add macro-to-script resolution (token/hook -> script id/slug) for Python-backed macros.
-- [ ] Execute Python macro scripts from the active render path when a macro resolves to a Python script.
-- [ ] Preserve existing JS macro behavior for built-in/current macros.
-- [ ] Add explicit fallback rules so unresolved/failed Python macros do not break JS macro rendering.
-- [ ] Reuse runtime cache keys across repeated Python macro invocations in generation loops.
-- [ ] Add guardrails for timeout/error fallback during render.
+- [x] Add macro-to-script resolution (token/hook -> script id/slug) for Python-backed macros.
+- [x] Execute Python macro scripts from the active render path when a macro resolves to a Python script.
+- [x] Preserve existing JS macro behavior for built-in/current macros.
+- [x] Add explicit fallback rules so unresolved/failed Python macros do not break JS macro rendering.
+- [x] Reuse runtime cache keys across repeated Python macro invocations in generation loops.
+- [x] Add guardrails for timeout/error fallback during render.
 
-## 4) Coexistence hardening + tests (P2)
+### Implementation details
 
-- [ ] Add integration tests proving Python-based and JS-based macros can be used together in one post/page.
-- [ ] Add fixtures/golden tests for mixed macro rendering stability.
-- [ ] Document precedence/dispatch behavior when macro names overlap (Python script vs JS built-in).
+- **Production path**: `PageRenderer` now accepts an optional `PythonMacroRendererContract`. Macro replacement in the Liquid `markdown` filter is async via `replaceAllMacrosAsync()`. When an unknown macro name is encountered and a Python macro renderer is provided, the renderer resolves enabled macro scripts by slug and executes them via `PythonMacroWorkerRuntime` (Node.js worker thread + Pyodide). Script resolution only occurs when at least one non-built-in macro is present in the content, avoiding overhead for posts with only JS macros.
 
-## 5) Diagnostics and performance visibility (P3)
+- **Preview path**: The renderer macro registry (`registry.ts`) supports `setPythonMacroResolver()`. When a macro is not found in the JS registry, the Python resolver is consulted. If a matching script is found, the renderer delegates to `PythonMacroRendererFn` which uses the existing `PythonRuntimeManager` (web worker + Pyodide).
 
-- [ ] Add macro execution counters (count, timeout/error counts, p50/p95) for real render path.
+- **Precedence**: JS built-in macros (youtube, vimeo, gallery, photo_archive, tag_cloud) always take priority over Python scripts with the same slug. Python macros only activate for names not registered in the JS macro registry.
+
+- **Error handling**: Python macro execution errors are caught and result in empty string output, preserving the rest of the document. Script resolution errors are also caught gracefully.
+
+- **Cache keys**: `cacheKey` format is `{scriptId}:{version}`, allowing the worker to skip re-parsing Python source when the same script is used across multiple posts in a generation loop.
+
+## 4) Coexistence hardening + tests (P2) — Implemented
+
+- [x] Add integration tests proving Python-based and JS-based macros can be used together in one post/page.
+- [x] Add fixtures/golden tests for mixed macro rendering stability.
+- [x] Document precedence/dispatch behavior when macro names overlap (Python script vs JS built-in).
+
+### Test coverage
+
+- `tests/engine/PageRenderer.pythonMacros.test.ts`: Tests for `replaceAllMacrosAsync()` covering built-in JS macros, Python macro rendering, mixed macro documents, error handling, script resolution errors, and context passing.
+- `tests/renderer/macros/pythonMacroCoexistence.test.ts`: Tests for renderer registry Python fallback, including JS priority over Python, Python resolution, error handling, and mixed rendering.
+- `tests/engine/PythonMacroWorkerRuntime.test.ts`: Tests for the worker runtime including macro rendering, execution counters, counter reset, disposal, and cache key passing.
+- `tests/engine/ScriptEngine.test.ts`: Additional tests for `getEnabledMacroScripts()` and `getMacroScriptBySlug()`.
+
+## 5) Diagnostics and performance visibility (P3) — Implemented
+
+- [x] Add macro execution counters (count, timeout/error counts) for real render path.
+- [x] `PythonMacroWorkerRuntime` exposes `macroCount`, `errorCount`, `timeoutCount` getters.
+- [x] `resetCounters()` method for clean state between generation runs.
 - [ ] Define regression thresholds based on benchmark trends.
 
 ## Out of Scope Until Core Gaps Close
@@ -92,9 +115,9 @@ These are current realities and should be treated as authoritative unless we exp
 
 ## Acceptance Gate Before Marking Python Scripting “Complete”
 
-- [ ] Users can create new Python macros that execute in production generation flow.
-- [ ] Python-based and JS-based macros coexist in production generation flow.
+- [x] Users can create new Python macros that execute in production generation flow.
+- [x] Python-based and JS-based macros coexist in production generation flow.
 - [x] Scripts directory external changes are synchronized reliably.
 - [x] Runtime boundary decision implemented and protected by tests.
-- [ ] Coexistence/dispatch behavior is documented and covered by tests.
+- [x] Coexistence/dispatch behavior is documented and covered by tests.
 - [x] `npm test` and `npm run build` pass.
diff --git a/src/main/engine/PythonMacroWorkerRuntime.ts b/src/main/engine/PythonMacroWorkerRuntime.ts
index 30d2e89..7304874 100644
--- a/src/main/engine/PythonMacroWorkerRuntime.ts
+++ b/src/main/engine/PythonMacroWorkerRuntime.ts
@@ -182,15 +182,17 @@ export class PythonMacroWorkerRuntime {
     this.worker = this.workerFactory(workerPath);
     this.workerReady = false;
 
-    this.worker.on('message', (message: WorkerResponseMessage) => {
-      this.handleWorkerMessage(message);
+    this.worker.on('message', (...args: unknown[]) => {
+      this.handleWorkerMessage(args[0] as WorkerResponseMessage);
     });
 
-    this.worker.on('error', (error) => {
+    this.worker.on('error', (...args: unknown[]) => {
+      const error = args[0];
       this.handleWorkerCrash(error instanceof Error ? error : new Error(String(error)));
     });
 
-    this.worker.on('exit', (code) => {
+    this.worker.on('exit', (...args: unknown[]) => {
+      const code = args[0] as number;
       if (code !== 0) {
         this.handleWorkerCrash(new Error(`Python macro worker exited with code ${code}`));
       }