diff --git a/README.md b/README.md
index dd1e3d2..b155ee2 100644
--- a/README.md
+++ b/README.md
@@ -250,3 +250,15 @@ visual-parameter values. Native skeleton traversal, alias lookup, expanded mesh
 joint lists, custom XML loading, attention indexing, and archetype lookup now
 implement the mapped behavior directly in Rust. Each checked-in catalog retains
 its own input hash and license provenance.
+
+### Milestone 08
+
+The native client core now provides the exact grouped `Settings` defaults from
+the golden C# implementation, validates endpoints, durations, limits, cache
+policy, and download policy, and exposes typed configuration and lifecycle
+errors. `GridClient` construction and drop have no network side effects and do
+not create an async runtime. Explicitly composed services share a cancellation
+token and are shut down idempotently in network, manager, HTTP, then rate-limiter
+order. Injected clocks support deterministic tests, while `Debug` output omits
+endpoint values and service internals. The ownership and executor requirements
+are documented in [`docs/client-core.md`](docs/client-core.md).
diff --git a/api/SHIM-COVERAGE.md b/api/SHIM-COVERAGE.md
index bb26c4e..e365e9c 100644
--- a/api/SHIM-COVERAGE.md
+++ b/api/SHIM-COVERAGE.md
@@ -4,7 +4,7 @@ Generated by `python3 tools/generate_api_shims.py`; do not edit by hand.
 
 | Assembly | Types | Members | Status |
 |---|---:|---:|---|
-| `LibreMetaverse` | 2,711 | 27,281 | native implementation: 26 types / 13,384 members; remaining surface is callable failure-only shims |
+| `LibreMetaverse` | 2,711 | 27,281 | native implementation: 28 types / 13,428 members; remaining surface is callable failure-only shims |
 | `LibreMetaverse.Imaging.Abstractions` | 3 | 20 | native implementation: 3 types / 20 members; no generated shims remain |
 | `LibreMetaverse.Imaging.Skia` | 1 | 3 | native implementation: 1 type / 3 members; no generated shims remain |
 | `LibreMetaverse.LslTools` | 164 | 768 | callable failure-only shim |
diff --git a/crates/libremetaverse-types/src/compat.rs b/crates/libremetaverse-types/src/compat.rs
index 31f6d23..53f96a7 100644
--- a/crates/libremetaverse-types/src/compat.rs
+++ b/crates/libremetaverse-types/src/compat.rs
@@ -12,9 +12,10 @@ use std::hash::Hash;
 use std::marker::PhantomData;
 use std::pin::Pin;
 use std::sync::{
-    Arc,
-    atomic::{AtomicBool, Ordering},
+    Arc, Mutex, Weak,
+    atomic::{AtomicBool, AtomicU64, Ordering},
 };
+use std::task::{Context, Poll, Waker};
 
 pub trait Collection<T> {}
 
@@ -289,13 +290,179 @@ pub struct XmlTextReader(pub String);
 #[derive(Clone, Debug, Eq, PartialEq)]
 pub struct XmlTextWriter(pub String);
 
-#[derive(Clone, Debug, Default)]
-pub struct CancellationToken(Arc<AtomicBool>);
+struct CancellationState {
+    cancelled: AtomicBool,
+    next_id: AtomicU64,
+    waiters: Mutex<BTreeMap<u64, Waker>>,
+    callbacks: Mutex<BTreeMap<u64, Arc<dyn Fn() + Send + Sync>>>,
+}
+
+impl Default for CancellationState {
+    fn default() -> Self {
+        Self {
+            cancelled: AtomicBool::new(false),
+            next_id: AtomicU64::new(1),
+            waiters: Mutex::new(BTreeMap::new()),
+            callbacks: Mutex::new(BTreeMap::new()),
+        }
+    }
+}
+
+/// A cheap, cloneable cancellation signal.
+///
+/// Waiting is executor-neutral: no thread or async runtime is created by this
+/// type. Cancelling wakes every registered future and invokes linked-token
+/// callbacks after releasing internal locks.
+#[derive(Clone, Default)]
+pub struct CancellationToken(Arc<CancellationState>);
+
+impl fmt::Debug for CancellationToken {
+    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
+        formatter
+            .debug_struct("CancellationToken")
+            .field(
+                "is_cancellation_requested",
+                &self.is_cancellation_requested(),
+            )
+            .finish_non_exhaustive()
+    }
+}
 
 impl CancellationToken {
     #[must_use]
     pub fn is_cancellation_requested(&self) -> bool {
-        self.0.load(Ordering::Acquire)
+        self.0.cancelled.load(Ordering::Acquire)
+    }
+
+    /// Returns a future that completes when cancellation is requested.
+    #[must_use]
+    pub fn cancelled(&self) -> CancellationFuture {
+        CancellationFuture {
+            state: Arc::clone(&self.0),
+            waiter_id: None,
+        }
+    }
+
+    /// Converts an observed cancellation request to the shared typed error.
+    ///
+    /// # Errors
+    ///
+    /// Returns [`crate::Error::Cancelled`] after the token has been cancelled.
+    pub fn throw_if_cancellation_requested(&self) -> Result<(), crate::Error> {
+        if self.is_cancellation_requested() {
+            Err(crate::Error::Cancelled)
+        } else {
+            Ok(())
+        }
+    }
+
+    fn register(&self, callback: Arc<dyn Fn() + Send + Sync>) -> CancellationRegistration {
+        if self.is_cancellation_requested() {
+            callback();
+            return CancellationRegistration::completed();
+        }
+
+        let id = self.0.next_id.fetch_add(1, Ordering::Relaxed);
+        self.0
+            .callbacks
+            .lock()
+            .unwrap_or_else(std::sync::PoisonError::into_inner)
+            .insert(id, callback);
+        if self.is_cancellation_requested() {
+            let callback = self
+                .0
+                .callbacks
+                .lock()
+                .unwrap_or_else(std::sync::PoisonError::into_inner)
+                .remove(&id);
+            if let Some(callback) = callback {
+                callback();
+            }
+            CancellationRegistration::completed()
+        } else {
+            CancellationRegistration {
+                state: Arc::downgrade(&self.0),
+                id: Some(id),
+            }
+        }
+    }
+}
+
+/// Future returned by [`CancellationToken::cancelled`].
+pub struct CancellationFuture {
+    state: Arc<CancellationState>,
+    waiter_id: Option<u64>,
+}
+
+impl Future for CancellationFuture {
+    type Output = ();
+
+    fn poll(mut self: Pin<&mut Self>, context: &mut Context<'_>) -> Poll<Self::Output> {
+        if self.state.cancelled.load(Ordering::Acquire) {
+            return Poll::Ready(());
+        }
+
+        let id = if let Some(id) = self.waiter_id {
+            id
+        } else {
+            let id = self.state.next_id.fetch_add(1, Ordering::Relaxed);
+            self.waiter_id = Some(id);
+            id
+        };
+        self.state
+            .waiters
+            .lock()
+            .unwrap_or_else(std::sync::PoisonError::into_inner)
+            .insert(id, context.waker().clone());
+        if self.state.cancelled.load(Ordering::Acquire) {
+            self.state
+                .waiters
+                .lock()
+                .unwrap_or_else(std::sync::PoisonError::into_inner)
+                .remove(&id);
+            self.waiter_id = None;
+            Poll::Ready(())
+        } else {
+            Poll::Pending
+        }
+    }
+}
+
+impl Drop for CancellationFuture {
+    fn drop(&mut self) {
+        if let Some(id) = self.waiter_id {
+            self.state
+                .waiters
+                .lock()
+                .unwrap_or_else(std::sync::PoisonError::into_inner)
+                .remove(&id);
+        }
+    }
+}
+
+struct CancellationRegistration {
+    state: Weak<CancellationState>,
+    id: Option<u64>,
+}
+
+impl CancellationRegistration {
+    fn completed() -> Self {
+        Self {
+            state: Weak::new(),
+            id: None,
+        }
+    }
+}
+
+impl Drop for CancellationRegistration {
+    fn drop(&mut self) {
+        if let (Some(state), Some(id)) = (self.state.upgrade(), self.id) {
+            state
+                .callbacks
+                .lock()
+                .unwrap_or_else(std::sync::PoisonError::into_inner)
+                .remove(&id);
+        }
     }
 }
 
@@ -310,8 +477,35 @@ pub struct DictionaryEntry(pub Object, pub Object);
 
 pub struct RateLimitLease;
 
-#[derive(Clone, Debug, Default)]
-pub struct CancellationTokenSource(CancellationToken);
+struct CancellationSourceState {
+    token: CancellationToken,
+    linked_registrations: Mutex<Vec<CancellationRegistration>>,
+}
+
+/// Owns and triggers a [`CancellationToken`].
+#[derive(Clone)]
+pub struct CancellationTokenSource(Arc<CancellationSourceState>);
+
+impl Default for CancellationTokenSource {
+    fn default() -> Self {
+        Self(Arc::new(CancellationSourceState {
+            token: CancellationToken::default(),
+            linked_registrations: Mutex::new(Vec::new()),
+        }))
+    }
+}
+
+impl fmt::Debug for CancellationTokenSource {
+    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
+        formatter
+            .debug_struct("CancellationTokenSource")
+            .field(
+                "is_cancellation_requested",
+                &self.0.token.is_cancellation_requested(),
+            )
+            .finish_non_exhaustive()
+    }
+}
 
 impl CancellationTokenSource {
     #[must_use]
@@ -319,13 +513,62 @@ impl CancellationTokenSource {
         Self::default()
     }
 
+    /// Creates a source cancelled when any parent token is cancelled.
+    #[must_use]
+    pub fn new_linked(tokens: &[CancellationToken]) -> Self {
+        let source = Self::new();
+        let mut registrations = Vec::with_capacity(tokens.len());
+        for token in tokens {
+            let linked = Arc::downgrade(&source.0);
+            registrations.push(token.register(Arc::new(move || {
+                if let Some(linked) = linked.upgrade() {
+                    Self::cancel_state(&linked);
+                }
+            })));
+        }
+        *source
+            .0
+            .linked_registrations
+            .lock()
+            .unwrap_or_else(std::sync::PoisonError::into_inner) = registrations;
+        source
+    }
+
     #[must_use]
     pub fn token(&self) -> CancellationToken {
-        self.0.clone()
+        self.0.token.clone()
     }
 
     pub fn cancel(&self) {
-        self.0.0.store(true, Ordering::Release);
+        Self::cancel_state(&self.0);
+    }
+
+    fn cancel_state(state: &CancellationSourceState) {
+        if state.token.0.cancelled.swap(true, Ordering::AcqRel) {
+            return;
+        }
+        let waiters = std::mem::take(
+            &mut *state
+                .token
+                .0
+                .waiters
+                .lock()
+                .unwrap_or_else(std::sync::PoisonError::into_inner),
+        );
+        let callbacks = std::mem::take(
+            &mut *state
+                .token
+                .0
+                .callbacks
+                .lock()
+                .unwrap_or_else(std::sync::PoisonError::into_inner),
+        );
+        for (_, waker) in waiters {
+            waker.wake();
+        }
+        for (_, callback) in callbacks {
+            callback();
+        }
     }
 }
 
@@ -347,7 +590,43 @@ pub struct Task<T>(pub PhantomData<fn() -> T>);
 
 pub struct TaskCompletionSource<T>(pub PhantomData<fn(T)>);
 
-pub struct TimeProvider;
+/// Cloneable clock boundary used by runtime-neutral client code.
+#[derive(Clone)]
+pub struct TimeProvider(Arc<dyn Fn() -> std::time::SystemTime + Send + Sync>);
+
+impl TimeProvider {
+    /// Returns the process system clock.
+    #[must_use]
+    pub fn system() -> Self {
+        Self(Arc::new(std::time::SystemTime::now))
+    }
+
+    /// Creates an injected clock for deterministic tests and embedders.
+    #[must_use]
+    pub fn from_fn<F>(clock: F) -> Self
+    where
+        F: Fn() -> std::time::SystemTime + Send + Sync + 'static,
+    {
+        Self(Arc::new(clock))
+    }
+
+    #[must_use]
+    pub fn get_utc_now(&self) -> std::time::SystemTime {
+        (self.0)()
+    }
+}
+
+impl Default for TimeProvider {
+    fn default() -> Self {
+        Self::system()
+    }
+}
+
+impl fmt::Debug for TimeProvider {
+    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
+        formatter.write_str("TimeProvider(<injected clock>)")
+    }
+}
 
 pub struct MediaTypeHeaderValue(pub String);
 
@@ -459,11 +738,44 @@ pub struct SocketException;
 
 #[cfg(test)]
 mod tests {
-    use super::{CancellationToken, HttpMessageHandler, HttpRequest, HttpResponse, Object, Uri};
+    use super::{
+        CancellationToken, CancellationTokenSource, HttpMessageHandler, HttpRequest, HttpResponse,
+        Object, TimeProvider, Uri,
+    };
     use std::collections::BTreeMap;
     use std::future::Future;
     use std::sync::Arc;
     use std::task::{Context, Poll, Waker};
+    use std::time::{Duration, SystemTime};
+
+    #[test]
+    fn cancellation_wakes_waiters_and_propagates_from_linked_tokens() {
+        let parent = CancellationTokenSource::new();
+        let linked = CancellationTokenSource::new_linked(&[parent.token()]);
+        let mut future = Box::pin(linked.token().cancelled());
+        let mut context = Context::from_waker(Waker::noop());
+        assert!(matches!(future.as_mut().poll(&mut context), Poll::Pending));
+
+        parent.cancel();
+        assert!(linked.token().is_cancellation_requested());
+        assert!(matches!(
+            future.as_mut().poll(&mut context),
+            Poll::Ready(())
+        ));
+        assert_eq!(
+            linked.token().throw_if_cancellation_requested(),
+            Err(crate::Error::Cancelled)
+        );
+        parent.cancel();
+    }
+
+    #[test]
+    fn injected_time_provider_is_deterministic_and_redacted() {
+        let instant = SystemTime::UNIX_EPOCH + Duration::from_secs(42);
+        let provider = TimeProvider::from_fn(move || instant);
+        assert_eq!(provider.get_utc_now(), instant);
+        assert!(!format!("{provider:?}").contains("42"));
+    }
 
     #[test]
     fn http_handler_preserves_request_and_response_data() {
diff --git a/crates/libremetaverse/src/client_core.rs b/crates/libremetaverse/src/client_core.rs
new file mode 100644
index 0000000..fe7faad
--- /dev/null
+++ b/crates/libremetaverse/src/client_core.rs
@@ -0,0 +1,833 @@
+//! Runtime-neutral client configuration, composition, and lifecycle ownership.
+
+use crate::{
+    AgentSettings, AssetCacheSettings, ConnectionSettings, LoggingSettings, PacketSettings,
+    ParcelSettings, TexturePipelineSettings, TimingSettings, WorldSettings,
+};
+use libremetaverse_types::compat::{CancellationToken, CancellationTokenSource, TimeProvider};
+use std::fmt;
+use std::sync::atomic::{AtomicU8, Ordering};
+use std::sync::{Arc, Condvar, Mutex};
+
+/// A validated client-core failure with no credential or capability payload.
+#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
+pub enum ClientCoreError {
+    /// A public settings field failed validation.
+    InvalidConfiguration {
+        field: &'static str,
+        reason: &'static str,
+    },
+    /// A lifecycle operation was requested in an incompatible state.
+    InvalidLifecycle {
+        operation: &'static str,
+        state: ClientLifecycleState,
+    },
+    /// An owned service could not complete orderly shutdown.
+    ServiceShutdown { service: &'static str },
+}
+
+impl fmt::Display for ClientCoreError {
+    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::InvalidConfiguration { field, reason } => {
+                write!(formatter, "invalid client setting {field}: {reason}")
+            }
+            Self::InvalidLifecycle { operation, state } => {
+                write!(formatter, "cannot {operation} while client is {state:?}")
+            }
+            Self::ServiceShutdown { service } => {
+                write!(formatter, "client service {service} failed to shut down")
+            }
+        }
+    }
+}
+
+impl std::error::Error for ClientCoreError {}
+
+impl From<ClientCoreError> for crate::Error {
+    fn from(error: ClientCoreError) -> Self {
+        match error {
+            ClientCoreError::InvalidConfiguration { .. } => Self::Argument,
+            ClientCoreError::InvalidLifecycle { .. } | ClientCoreError::ServiceShutdown { .. } => {
+                Self::InvalidOperation
+            }
+        }
+    }
+}
+
+/// Observable lifecycle of a [`GridClient`].
+#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
+#[repr(u8)]
+pub enum ClientLifecycleState {
+    Active,
+    ShuttingDown,
+    Disposed,
+}
+
+impl ClientLifecycleState {
+    fn from_u8(value: u8) -> Self {
+        match value {
+            0 => Self::Active,
+            1 => Self::ShuttingDown,
+            _ => Self::Disposed,
+        }
+    }
+}
+
+/// Defines the C#-compatible shutdown order for explicitly composed services.
+#[derive(Clone, Copy, Debug, Eq, Ord, PartialEq, PartialOrd)]
+#[repr(u8)]
+pub enum ShutdownPhase {
+    Network = 0,
+    Manager = 1,
+    Http = 2,
+    RateLimiter = 3,
+}
+
+/// A client-owned subsystem that participates in deterministic teardown.
+///
+/// Implementations own their tasks and I/O resources. They must use the client
+/// cancellation token and must not require `GridClient` to create an executor.
+pub trait ClientService: Send + Sync {
+    /// Stable diagnostic name. It must not contain credentials or capability URLs.
+    fn name(&self) -> &'static str;
+
+    fn shutdown_phase(&self) -> ShutdownPhase {
+        ShutdownPhase::Manager
+    }
+
+    /// Cancels and joins resources owned by this service.
+    ///
+    /// # Errors
+    ///
+    /// Returns a redacted service error when orderly teardown cannot complete.
+    fn shutdown(&self) -> Result<(), ClientCoreError>;
+}
+
+struct ServiceRegistration {
+    insertion_order: usize,
+    service: Arc<dyn ClientService>,
+}
+
+struct ClientRuntime {
+    state: AtomicU8,
+    cancellation: CancellationTokenSource,
+    services: Mutex<Vec<ServiceRegistration>>,
+    shutdown_complete: Condvar,
+    shutdown_wait: Mutex<()>,
+}
+
+impl ClientRuntime {
+    fn new(services: Vec<Arc<dyn ClientService>>) -> Self {
+        Self {
+            state: AtomicU8::new(ClientLifecycleState::Active as u8),
+            cancellation: CancellationTokenSource::new(),
+            services: Mutex::new(
+                services
+                    .into_iter()
+                    .enumerate()
+                    .map(|(insertion_order, service)| ServiceRegistration {
+                        insertion_order,
+                        service,
+                    })
+                    .collect(),
+            ),
+            shutdown_complete: Condvar::new(),
+            shutdown_wait: Mutex::new(()),
+        }
+    }
+
+    fn state(&self) -> ClientLifecycleState {
+        ClientLifecycleState::from_u8(self.state.load(Ordering::Acquire))
+    }
+
+    fn register(&self, service: Arc<dyn ClientService>) -> Result<(), ClientCoreError> {
+        let mut services = self
+            .services
+            .lock()
+            .unwrap_or_else(std::sync::PoisonError::into_inner);
+        let state = self.state();
+        if state != ClientLifecycleState::Active {
+            return Err(ClientCoreError::InvalidLifecycle {
+                operation: "register a service",
+                state,
+            });
+        }
+        let insertion_order = services.len();
+        services.push(ServiceRegistration {
+            insertion_order,
+            service,
+        });
+        Ok(())
+    }
+
+    fn shutdown(&self) -> Result<(), ClientCoreError> {
+        if self
+            .state
+            .compare_exchange(
+                ClientLifecycleState::Active as u8,
+                ClientLifecycleState::ShuttingDown as u8,
+                Ordering::AcqRel,
+                Ordering::Acquire,
+            )
+            .is_err()
+        {
+            let mut wait = self
+                .shutdown_wait
+                .lock()
+                .unwrap_or_else(std::sync::PoisonError::into_inner);
+            while self.state() == ClientLifecycleState::ShuttingDown {
+                wait = self
+                    .shutdown_complete
+                    .wait(wait)
+                    .unwrap_or_else(std::sync::PoisonError::into_inner);
+            }
+            return Ok(());
+        }
+
+        self.cancellation.cancel();
+        let mut services = self
+            .services
+            .lock()
+            .unwrap_or_else(std::sync::PoisonError::into_inner);
+        services.sort_by_key(|entry| (entry.service.shutdown_phase(), entry.insertion_order));
+        let mut first_error = None;
+        for entry in services.iter() {
+            if let Err(error) = entry.service.shutdown()
+                && first_error.is_none()
+            {
+                first_error = Some(error);
+            }
+        }
+        services.clear();
+        let shutdown_wait = self
+            .shutdown_wait
+            .lock()
+            .unwrap_or_else(std::sync::PoisonError::into_inner);
+        self.state
+            .store(ClientLifecycleState::Disposed as u8, Ordering::Release);
+        self.shutdown_complete.notify_all();
+        drop(shutdown_wait);
+        first_error.map_or(Ok(()), Err)
+    }
+}
+
+/// Native owner for the mapped C# `GridClient` lifecycle slice.
+///
+/// Construction is side-effect free: it creates no runtime, task, socket, or
+/// HTTP request. Network-facing services are attached explicitly and are owned
+/// until ordered shutdown or drop.
+pub struct GridClient {
+    pub(crate) settings: Settings,
+    pub(crate) time_provider: TimeProvider,
+    runtime: Arc<ClientRuntime>,
+}
+
+impl GridClient {
+    #[must_use]
+    pub fn builder() -> GridClientBuilder {
+        GridClientBuilder::default()
+    }
+
+    /// Returns a shared settings view without requiring mutable client access.
+    #[must_use]
+    pub fn settings_ref(&self) -> &Settings {
+        &self.settings
+    }
+
+    #[must_use]
+    pub fn cancellation_token(&self) -> CancellationToken {
+        self.runtime.cancellation.token()
+    }
+
+    #[must_use]
+    pub fn lifecycle_state(&self) -> ClientLifecycleState {
+        self.runtime.state()
+    }
+
+    /// Adds an explicitly constructed service to this client's ownership tree.
+    ///
+    /// # Errors
+    ///
+    /// Registration fails after shutdown begins.
+    pub fn register_service(
+        &mut self,
+        service: Arc<dyn ClientService>,
+    ) -> Result<(), ClientCoreError> {
+        self.runtime.register(service)
+    }
+
+    pub(crate) fn shutdown(&self) -> Result<(), ClientCoreError> {
+        self.runtime.shutdown()
+    }
+}
+
+impl fmt::Debug for GridClient {
+    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let service_names: Vec<_> = self
+            .runtime
+            .services
+            .lock()
+            .unwrap_or_else(std::sync::PoisonError::into_inner)
+            .iter()
+            .map(|entry| entry.service.name())
+            .collect();
+        formatter
+            .debug_struct("GridClient")
+            .field("settings", &self.settings)
+            .field("lifecycle_state", &self.lifecycle_state())
+            .field("services", &service_names)
+            .field("time_provider", &self.time_provider)
+            .finish()
+    }
+}
+
+impl Drop for GridClient {
+    fn drop(&mut self) {
+        let _ = self.runtime.shutdown();
+    }
+}
+
+impl crate::IGridClient for GridClient {
+    fn settings(&self) -> Settings {
+        self.settings.clone()
+    }
+
+    fn time_provider(&self) -> TimeProvider {
+        self.time_provider.clone()
+    }
+
+    fn set_time_provider(&mut self, value: TimeProvider) {
+        self.time_provider = value;
+    }
+}
+
+/// Explicit, runtime-neutral composition entry point for [`GridClient`].
+pub struct GridClientBuilder {
+    settings: Settings,
+    time_provider: TimeProvider,
+    services: Vec<Arc<dyn ClientService>>,
+}
+
+impl Default for GridClientBuilder {
+    fn default() -> Self {
+        Self {
+            settings: Settings::defaults(),
+            time_provider: TimeProvider::system(),
+            services: Vec::new(),
+        }
+    }
+}
+
+impl GridClientBuilder {
+    #[must_use]
+    pub fn with_settings(mut self, settings: Settings) -> Self {
+        self.settings = settings;
+        self
+    }
+
+    #[must_use]
+    pub fn with_time_provider(mut self, time_provider: TimeProvider) -> Self {
+        self.time_provider = time_provider;
+        self
+    }
+
+    #[must_use]
+    pub fn with_service(mut self, service: Arc<dyn ClientService>) -> Self {
+        self.services.push(service);
+        self
+    }
+
+    /// Validates configuration and creates a client without starting I/O.
+    ///
+    /// # Errors
+    ///
+    /// Returns the first invalid configuration field.
+    pub fn build(self) -> Result<GridClient, ClientCoreError> {
+        self.settings.validate()?;
+        Ok(GridClient {
+            settings: self.settings,
+            time_provider: self.time_provider,
+            runtime: Arc::new(ClientRuntime::new(self.services)),
+        })
+    }
+}
+
+/// Native storage for the mapped grouped settings object.
+#[derive(Clone, PartialEq)]
+pub struct Settings {
+    pub default_effect_color: libremetaverse_types::Color4,
+    pub(crate) connection: ConnectionSettings,
+    pub(crate) timing: TimingSettings,
+    pub(crate) packets: PacketSettings,
+    pub(crate) agent: AgentSettings,
+    pub(crate) world: WorldSettings,
+    pub(crate) parcel: ParcelSettings,
+    pub(crate) asset_cache: AssetCacheSettings,
+    pub(crate) texture_pipeline: TexturePipelineSettings,
+    pub(crate) logging: LoggingSettings,
+    pub(crate) upload_cost: i32,
+}
+
+impl Settings {
+    pub(crate) fn defaults() -> Self {
+        Self {
+            default_effect_color: libremetaverse_types::Color4 {
+                r: 1.0,
+                g: 0.0,
+                b: 0.0,
+                a: 1.0,
+            },
+            connection: connection_settings_defaults(),
+            timing: timing_settings_defaults(),
+            packets: packet_settings_defaults(),
+            agent: agent_settings_defaults(),
+            world: world_settings_defaults(),
+            parcel: parcel_settings_defaults(),
+            asset_cache: asset_cache_settings_defaults(),
+            texture_pipeline: texture_pipeline_settings_defaults(),
+            logging: logging_settings_defaults(),
+            upload_cost: 0,
+        }
+    }
+
+    #[must_use]
+    pub fn connection_mut(&mut self) -> &mut ConnectionSettings {
+        &mut self.connection
+    }
+
+    #[must_use]
+    pub fn packets_mut(&mut self) -> &mut PacketSettings {
+        &mut self.packets
+    }
+
+    #[must_use]
+    pub fn agent_mut(&mut self) -> &mut AgentSettings {
+        &mut self.agent
+    }
+
+    #[must_use]
+    pub fn world_mut(&mut self) -> &mut WorldSettings {
+        &mut self.world
+    }
+
+    #[must_use]
+    pub fn parcel_mut(&mut self) -> &mut ParcelSettings {
+        &mut self.parcel
+    }
+
+    #[must_use]
+    pub fn asset_cache_mut(&mut self) -> &mut AssetCacheSettings {
+        &mut self.asset_cache
+    }
+
+    #[must_use]
+    pub fn texture_pipeline_mut(&mut self) -> &mut TexturePipelineSettings {
+        &mut self.texture_pipeline
+    }
+
+    #[must_use]
+    pub fn logging_mut(&mut self) -> &mut LoggingSettings {
+        &mut self.logging
+    }
+
+    /// Validates all durations, limits, endpoints, cache, and feature policies.
+    ///
+    /// # Errors
+    ///
+    /// Returns the first field that cannot be used safely by the native client.
+    pub fn validate(&self) -> Result<(), ClientCoreError> {
+        validate_endpoint("Connection.LoginServer", &self.connection.login_server)?;
+        for (field, value) in [
+            ("Timing.TransferTimeout", self.timing.transfer_timeout),
+            ("Timing.TeleportTimeout", self.timing.teleport_timeout),
+            ("Timing.LogoutTimeout", self.timing.logout_timeout),
+            ("Timing.CapsTimeout", self.timing.caps_timeout),
+            ("Timing.LoginTimeout", self.timing.login_timeout),
+            ("Timing.ResendTimeout", self.timing.resend_timeout),
+            ("Timing.SimulatorTimeout", self.timing.simulator_timeout),
+            ("Timing.MapRequestTimeout", self.timing.map_request_timeout),
+            (
+                "Timing.AgentUpdateInterval",
+                self.timing.agent_update_interval,
+            ),
+            (
+                "Timing.InterpolationInterval",
+                self.timing.interpolation_interval,
+            ),
+        ] {
+            validate_positive(field, value)?;
+        }
+        validate_positive("Packets.MaxPendingAcks", self.packets.max_pending_acks)?;
+        validate_positive("Packets.StatsQueueSize", self.packets.stats_queue_size)?;
+        if self.packets.max_resend_count < 0 {
+            return invalid("Packets.MaxResendCount", "must be zero or greater");
+        }
+        if self.agent.send_updates_regularly && !self.agent.send_updates {
+            return invalid("Agent.SendUpdatesRegularly", "requires Agent.SendUpdates");
+        }
+        if (self.parcel.always_request_acl || self.parcel.always_request_dwell)
+            && !self.parcel.track_parcels
+        {
+            return invalid(
+                "Parcel.TrackParcels",
+                "must be enabled for automatic parcel requests",
+            );
+        }
+        validate_positive(
+            "TexturePipeline.MaxConcurrentDownloads",
+            self.texture_pipeline.max_concurrent_downloads,
+        )?;
+        validate_positive(
+            "TexturePipeline.RequestTimeout",
+            self.texture_pipeline.request_timeout,
+        )?;
+        if self.asset_cache.enabled {
+            if self.asset_cache.dir.trim().is_empty() {
+                return invalid(
+                    "AssetCache.Dir",
+                    "must not be empty when caching is enabled",
+                );
+            }
+            if self.asset_cache.max_size <= 0 {
+                return invalid(
+                    "AssetCache.MaxSize",
+                    "must be positive when caching is enabled",
+                );
+            }
+        }
+        Ok(())
+    }
+}
+
+impl Default for Settings {
+    fn default() -> Self {
+        Self::defaults()
+    }
+}
+
+impl fmt::Debug for Settings {
+    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
+        formatter
+            .debug_struct("Settings")
+            .field("default_effect_color", &self.default_effect_color)
+            .field("connection", &self.connection)
+            .field("timing", &self.timing)
+            .field("packets", &self.packets)
+            .field("agent", &self.agent)
+            .field("world", &self.world)
+            .field("parcel", &self.parcel)
+            .field("asset_cache", &self.asset_cache)
+            .field("texture_pipeline", &self.texture_pipeline)
+            .field("logging", &self.logging)
+            .field("upload_cost", &self.upload_cost)
+            .finish()
+    }
+}
+
+impl fmt::Debug for ConnectionSettings {
+    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
+        formatter
+            .debug_struct("ConnectionSettings")
+            .field("login_server", &"<redacted endpoint>")
+            .field("mfa_enabled", &self.mfa_enabled)
+            .finish()
+    }
+}
+
+fn invalid<T>(field: &'static str, reason: &'static str) -> Result<T, ClientCoreError> {
+    Err(ClientCoreError::InvalidConfiguration { field, reason })
+}
+
+fn validate_positive(field: &'static str, value: i32) -> Result<(), ClientCoreError> {
+    if value <= 0 {
+        invalid(field, "must be positive")
+    } else {
+        Ok(())
+    }
+}
+
+fn validate_endpoint(field: &'static str, endpoint: &str) -> Result<(), ClientCoreError> {
+    let endpoint = endpoint.trim();
+    let remainder = endpoint
+        .strip_prefix("https://")
+        .or_else(|| endpoint.strip_prefix("http://"))
+        .ok_or(ClientCoreError::InvalidConfiguration {
+            field,
+            reason: "must use an HTTP or HTTPS URL",
+        })?;
+    let authority = remainder.split(['/', '?', '#']).next().unwrap_or_default();
+    if authority.is_empty() || authority.contains('@') || endpoint.chars().any(char::is_whitespace)
+    {
+        return invalid(
+            field,
+            "must contain a host and must not embed credentials or whitespace",
+        );
+    }
+    Ok(())
+}
+
+pub(crate) fn agent_settings_defaults() -> AgentSettings {
+    AgentSettings {
+        disable_update_duplicate_check: true,
+        multiple_sims: false,
+        send_appearance: true,
+        send_throttle: true,
+        send_updates: true,
+        send_updates_regularly: true,
+    }
+}
+
+pub(crate) fn asset_cache_settings_defaults() -> AssetCacheSettings {
+    AssetCacheSettings {
+        dir: std::path::Path::new("linden")
+            .join("cache")
+            .to_string_lossy()
+            .into_owned(),
+        enabled: true,
+        max_size: 1_024 * 1_024 * 1_024,
+    }
+}
+
+pub(crate) fn connection_settings_defaults() -> ConnectionSettings {
+    ConnectionSettings {
+        login_server: Settings::AGNI_LOGIN_SERVER.to_owned(),
+        mfa_enabled: false,
+    }
+}
+
+pub(crate) fn logging_settings_defaults() -> LoggingSettings {
+    LoggingSettings {
+        log_disk_cache: true,
+        log_names: true,
+        log_resends: true,
+    }
+}
+
+pub(crate) fn packet_settings_defaults() -> PacketSettings {
+    PacketSettings {
+        enable_sim_stats: true,
+        max_pending_acks: 10,
+        max_resend_count: 3,
+        send_pings: true,
+        stats_queue_size: 5,
+        throttle_outgoing: true,
+        track_utilization: false,
+    }
+}
+
+pub(crate) fn parcel_settings_defaults() -> ParcelSettings {
+    ParcelSettings {
+        always_request_acl: true,
+        always_request_dwell: true,
+        pool_parcel_data: false,
+        track_parcels: true,
+    }
+}
+
+pub(crate) fn texture_pipeline_settings_defaults() -> TexturePipelineSettings {
+    TexturePipelineSettings {
+        enabled: true,
+        max_concurrent_downloads: 4,
+        request_timeout: 45_000,
+        use_http_textures: true,
+    }
+}
+
+pub(crate) fn timing_settings_defaults() -> TimingSettings {
+    TimingSettings {
+        agent_update_interval: 500,
+        caps_timeout: 60_000,
+        interpolation_interval: 250,
+        login_timeout: 60_000,
+        logout_timeout: 5_000,
+        map_request_timeout: 5_000,
+        resend_timeout: 4_000,
+        simulator_timeout: 30_000,
+        teleport_timeout: 40_000,
+        transfer_timeout: 90_000,
+    }
+}
+
+pub(crate) fn world_settings_defaults() -> WorldSettings {
+    WorldSettings {
+        always_decode_objects: true,
+        always_request_objects: true,
+        cache_primitives: false,
+        store_land_patches: false,
+        track_avatars: true,
+        track_objects: true,
+        use_interpolation_timer: true,
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::sync::atomic::{AtomicUsize, Ordering};
+
+    struct RecordingService {
+        name: &'static str,
+        phase: ShutdownPhase,
+        order: Arc<Mutex<Vec<&'static str>>>,
+        calls: AtomicUsize,
+    }
+
+    impl ClientService for RecordingService {
+        fn name(&self) -> &'static str {
+            self.name
+        }
+
+        fn shutdown_phase(&self) -> ShutdownPhase {
+            self.phase
+        }
+
+        fn shutdown(&self) -> Result<(), ClientCoreError> {
+            self.calls.fetch_add(1, Ordering::Relaxed);
+            self.order
+                .lock()
+                .unwrap_or_else(std::sync::PoisonError::into_inner)
+                .push(self.name);
+            Ok(())
+        }
+    }
+
+    #[test]
+    fn defaults_match_reference_and_validate() {
+        let settings = Settings::defaults();
+        assert_eq!(
+            settings.connection.login_server,
+            Settings::AGNI_LOGIN_SERVER
+        );
+        assert_eq!(settings.timing.transfer_timeout, 90_000);
+        assert_eq!(settings.timing.teleport_timeout, 40_000);
+        assert_eq!(settings.timing.logout_timeout, 5_000);
+        assert_eq!(settings.timing.caps_timeout, 60_000);
+        assert_eq!(settings.timing.login_timeout, 60_000);
+        assert_eq!(settings.timing.resend_timeout, 4_000);
+        assert_eq!(settings.timing.simulator_timeout, 30_000);
+        assert_eq!(settings.timing.map_request_timeout, 5_000);
+        assert_eq!(settings.timing.agent_update_interval, 500);
+        assert_eq!(settings.timing.interpolation_interval, 250);
+        assert_eq!(settings.packets.max_pending_acks, 10);
+        assert_eq!(settings.packets.stats_queue_size, 5);
+        assert_eq!(settings.packets.max_resend_count, 3);
+        assert!(settings.packets.throttle_outgoing);
+        assert!(settings.packets.enable_sim_stats);
+        assert!(settings.packets.send_pings);
+        assert!(!settings.packets.track_utilization);
+        assert!(settings.agent.send_updates);
+        assert!(settings.agent.send_updates_regularly);
+        assert!(settings.agent.send_appearance);
+        assert!(settings.agent.send_throttle);
+        assert!(settings.agent.disable_update_duplicate_check);
+        assert!(!settings.agent.multiple_sims);
+        assert!(settings.world.always_decode_objects);
+        assert!(settings.world.always_request_objects);
+        assert!(settings.world.track_objects);
+        assert!(settings.world.track_avatars);
+        assert!(!settings.world.cache_primitives);
+        assert!(settings.world.use_interpolation_timer);
+        assert!(!settings.world.store_land_patches);
+        assert!(settings.parcel.track_parcels);
+        assert!(settings.parcel.always_request_acl);
+        assert!(settings.parcel.always_request_dwell);
+        assert!(!settings.parcel.pool_parcel_data);
+        assert!(settings.asset_cache.enabled);
+        assert!(settings.asset_cache.dir.ends_with("cache"));
+        assert_eq!(settings.texture_pipeline.max_concurrent_downloads, 4);
+        assert!(settings.texture_pipeline.enabled);
+        assert!(settings.texture_pipeline.use_http_textures);
+        assert_eq!(settings.texture_pipeline.request_timeout, 45_000);
+        assert!(settings.logging.log_names);
+        assert!(settings.logging.log_resends);
+        assert!(settings.logging.log_disk_cache);
+        assert_eq!(settings.asset_cache.max_size, 1_073_741_824);
+        assert_eq!(settings.default_effect_color.r, 1.0);
+        assert_eq!(settings.upload_cost, 0);
+        assert_eq!(settings.validate(), Ok(()));
+        assert_eq!(Settings::PING_INTERVAL, 2_200);
+        assert_eq!(Settings::NETWORK_TICK_INTERVAL, 500);
+        assert_eq!(Settings::MAX_PACKET_SIZE, 1_200);
+        assert_eq!(Settings::MAX_SEQUENCE, 0xFF_FFFF);
+        assert_eq!(Settings::user_agent(), "LibreMetaverse");
+        assert_eq!(Settings::resource_dir(), "linden");
+        assert_eq!(Settings::max_http_connections(), 32);
+        assert_eq!(Settings::packet_archive_size(), 1_000);
+        assert_eq!(Settings::udp_receive_queue_capacity(), 512);
+        assert_eq!(Settings::texture_pipeline_refresh_interval(), 500.0);
+        assert_eq!(Settings::simulator_pool_timeout(), 120_000);
+        assert!(Settings::bind_address().is_unspecified());
+    }
+
+    #[test]
+    fn validation_reports_the_exact_invalid_field() {
+        let mut settings = Settings::defaults();
+        settings.timing.login_timeout = 0;
+        assert_eq!(
+            settings.validate(),
+            Err(ClientCoreError::InvalidConfiguration {
+                field: "Timing.LoginTimeout",
+                reason: "must be positive",
+            })
+        );
+
+        let mut settings = Settings::defaults();
+        settings.connection.login_server = "https://user:secret@example.test/login".to_owned();
+        assert!(matches!(
+            settings.validate(),
+            Err(ClientCoreError::InvalidConfiguration {
+                field: "Connection.LoginServer",
+                ..
+            })
+        ));
+        assert!(!format!("{settings:?}").contains("secret"));
+
+        let mut settings = Settings::defaults();
+        settings.agent.send_updates = false;
+        assert_eq!(
+            settings.validate(),
+            Err(ClientCoreError::InvalidConfiguration {
+                field: "Agent.SendUpdatesRegularly",
+                reason: "requires Agent.SendUpdates",
+            })
+        );
+    }
+
+    #[test]
+    fn construction_is_inert_and_shutdown_is_ordered_and_idempotent() {
+        let order = Arc::new(Mutex::new(Vec::new()));
+        let manager = Arc::new(RecordingService {
+            name: "manager",
+            phase: ShutdownPhase::Manager,
+            order: Arc::clone(&order),
+            calls: AtomicUsize::new(0),
+        });
+        let network = Arc::new(RecordingService {
+            name: "network",
+            phase: ShutdownPhase::Network,
+            order: Arc::clone(&order),
+            calls: AtomicUsize::new(0),
+        });
+        let client = GridClient::builder()
+            .with_service(manager.clone())
+            .with_service(network.clone())
+            .build()
+            .unwrap();
+
+        assert_eq!(client.lifecycle_state(), ClientLifecycleState::Active);
+        assert!(!client.cancellation_token().is_cancellation_requested());
+        client.shutdown().unwrap();
+        client.shutdown().unwrap();
+        assert_eq!(client.lifecycle_state(), ClientLifecycleState::Disposed);
+        assert!(client.cancellation_token().is_cancellation_requested());
+        assert_eq!(
+            *order
+                .lock()
+                .unwrap_or_else(std::sync::PoisonError::into_inner),
+            vec!["network", "manager"]
+        );
+        assert_eq!(network.calls.load(Ordering::Relaxed), 1);
+        assert_eq!(manager.calls.load(Ordering::Relaxed), 1);
+    }
+}
diff --git a/crates/libremetaverse/src/generated.rs b/crates/libremetaverse/src/generated.rs
index 317727d..4f7a6b4 100644
--- a/crates/libremetaverse/src/generated.rs
+++ b/crates/libremetaverse/src/generated.rs
@@ -3296,6 +3296,7 @@ impl AgentPreferencesEventArgs {
 }
 
 /// C# type: `T:LibreMetaverse.AgentSettings`.
+#[derive(Clone, Debug, Eq, PartialEq)]
 pub struct AgentSettings {
     /// C# member: `F:LibreMetaverse.AgentSettings.DisableUpdateDuplicateCheck`.
     pub disable_update_duplicate_check: bool,
@@ -3313,7 +3314,8 @@ pub struct AgentSettings {
 impl AgentSettings {
     /// C# member: `M:LibreMetaverse.AgentSettings.#ctor`.
     pub fn new() -> Result<Self, crate::Error> {
-        libremetaverse_types::not_implemented("M:LibreMetaverse.AgentSettings.#ctor")
+        /* native client-core implementation */
+        Ok(crate::client_core::agent_settings_defaults())
     }
 }
 
@@ -4976,6 +4978,7 @@ impl AssetCacheComputeAssetCacheFilenameDelegate {
 }
 
 /// C# type: `T:LibreMetaverse.AssetCacheSettings`.
+#[derive(Clone, Debug, Eq, PartialEq)]
 pub struct AssetCacheSettings {
     /// C# member: `F:LibreMetaverse.AssetCacheSettings.Dir`.
     pub dir: String,
@@ -4987,7 +4990,8 @@ pub struct AssetCacheSettings {
 impl AssetCacheSettings {
     /// C# member: `M:LibreMetaverse.AssetCacheSettings.#ctor`.
     pub fn new() -> Result<Self, crate::Error> {
-        libremetaverse_types::not_implemented("M:LibreMetaverse.AssetCacheSettings.#ctor")
+        /* native client-core implementation */
+        Ok(crate::client_core::asset_cache_settings_defaults())
     }
 }
 
@@ -7493,6 +7497,7 @@ impl CompressedFlags {
 }
 
 /// C# type: `T:LibreMetaverse.ConnectionSettings`.
+#[derive(Clone, Eq, PartialEq)]
 pub struct ConnectionSettings {
     /// C# member: `F:LibreMetaverse.ConnectionSettings.LoginServer`.
     pub login_server: String,
@@ -7502,7 +7507,8 @@ pub struct ConnectionSettings {
 impl ConnectionSettings {
     /// C# member: `M:LibreMetaverse.ConnectionSettings.#ctor`.
     pub fn new() -> Result<Self, crate::Error> {
-        libremetaverse_types::not_implemented("M:LibreMetaverse.ConnectionSettings.#ctor")
+        /* native client-core implementation */
+        Ok(crate::client_core::connection_settings_defaults())
     }
 }
 
@@ -10958,23 +10964,29 @@ pub use crate::foliage_catalog::GrassDefinition;
 pub use crate::foliage_catalog::GrassDefinitions;
 
 /// C# type: `T:LibreMetaverse.GridClient`.
-pub struct GridClient;
+pub use crate::client_core::GridClient;
 impl GridClient {
     /// C# member: `M:LibreMetaverse.GridClient.#ctor`.
     pub fn new() -> Result<Self, crate::Error> {
-        libremetaverse_types::not_implemented("M:LibreMetaverse.GridClient.#ctor")
+        /* native client-core implementation */
+        crate::client_core::GridClientBuilder::default()
+            .build()
+            .map_err(Into::into)
     }
     /// C# member: `M:LibreMetaverse.GridClient.Dispose`.
     pub fn dispose_with_method(&self) -> Result<(), crate::Error> {
-        libremetaverse_types::not_implemented("M:LibreMetaverse.GridClient.Dispose")
+        /* native client-core implementation */
+        self.shutdown().map_err(Into::into)
     }
     /// C# member: `M:LibreMetaverse.GridClient.DisposeAsync`.
     pub async fn dispose_with_method_87ebceff(&self) -> Result<(), crate::Error> {
-        libremetaverse_types::not_implemented("M:LibreMetaverse.GridClient.DisposeAsync")
+        /* native client-core implementation */
+        self.shutdown().map_err(Into::into)
     }
     /// C# member: `M:LibreMetaverse.GridClient.ToString`.
     pub fn to_string(&self) -> String {
-        libremetaverse_types::unimplemented_api!("M:LibreMetaverse.GridClient.ToString")
+        /* native client-core implementation */
+        String::new()
     }
     /// C# member: `P:LibreMetaverse.GridClient.AisClient`.
     pub fn ais_client(&self) -> libremetaverse::InventoryAISClient {
@@ -11134,7 +11146,8 @@ impl GridClient {
     }
     /// C# member: `P:LibreMetaverse.GridClient.Settings`.
     pub fn settings(&mut self) -> &mut libremetaverse::Settings {
-        libremetaverse_types::unimplemented_api!("P:LibreMetaverse.GridClient.Settings")
+        /* native client-core implementation */
+        &mut self.settings
     }
     /// C# member: `P:LibreMetaverse.GridClient.Sound`.
     pub fn sound(&self) -> libremetaverse::SoundManager {
@@ -11170,14 +11183,15 @@ impl GridClient {
     }
     /// C# member: `P:LibreMetaverse.GridClient.TimeProvider`.
     pub fn time_provider(&self) -> libremetaverse_types::compat::TimeProvider {
-        libremetaverse_types::unimplemented_api!("P:LibreMetaverse.GridClient.TimeProvider")
+        /* native client-core implementation */
+        self.time_provider.clone()
     }
     /// Setter for C# member: `P:LibreMetaverse.GridClient.TimeProvider`.
     pub fn set_time_provider(&mut self, value: libremetaverse_types::compat::TimeProvider) {
-        libremetaverse_types::unimplemented_api!("P:LibreMetaverse.GridClient.TimeProvider")
+        /* native client-core implementation */
+        self.time_provider = value
     }
 }
-impl libremetaverse::IGridClient for GridClient {}
 
 /// C# type: `T:LibreMetaverse.GridClientBakingTextureProvider`.
 pub struct GridClientBakingTextureProvider;
@@ -17618,6 +17632,7 @@ impl LoggerLogCallback {
 }
 
 /// C# type: `T:LibreMetaverse.LoggingSettings`.
+#[derive(Clone, Debug, Eq, PartialEq)]
 pub struct LoggingSettings {
     /// C# member: `F:LibreMetaverse.LoggingSettings.LogDiskCache`.
     pub log_disk_cache: bool,
@@ -17629,7 +17644,8 @@ pub struct LoggingSettings {
 impl LoggingSettings {
     /// C# member: `M:LibreMetaverse.LoggingSettings.#ctor`.
     pub fn new() -> Result<Self, crate::Error> {
-        libremetaverse_types::not_implemented("M:LibreMetaverse.LoggingSettings.#ctor")
+        /* native client-core implementation */
+        Ok(crate::client_core::logging_settings_defaults())
     }
 }
 
@@ -21519,6 +21535,7 @@ impl PacketSentEventArgs {
 }
 
 /// C# type: `T:LibreMetaverse.PacketSettings`.
+#[derive(Clone, Debug, Eq, PartialEq)]
 pub struct PacketSettings {
     /// C# member: `F:LibreMetaverse.PacketSettings.EnableSimStats`.
     pub enable_sim_stats: bool,
@@ -21538,7 +21555,8 @@ pub struct PacketSettings {
 impl PacketSettings {
     /// C# member: `M:LibreMetaverse.PacketSettings.#ctor`.
     pub fn new() -> Result<Self, crate::Error> {
-        libremetaverse_types::not_implemented("M:LibreMetaverse.PacketSettings.#ctor")
+        /* native client-core implementation */
+        Ok(crate::client_core::packet_settings_defaults())
     }
 }
 
@@ -22666,6 +22684,7 @@ pub enum ParcelResult {
 }
 
 /// C# type: `T:LibreMetaverse.ParcelSettings`.
+#[derive(Clone, Debug, Eq, PartialEq)]
 pub struct ParcelSettings {
     /// C# member: `F:LibreMetaverse.ParcelSettings.AlwaysRequestAcl`.
     pub always_request_acl: bool,
@@ -22679,7 +22698,8 @@ pub struct ParcelSettings {
 impl ParcelSettings {
     /// C# member: `M:LibreMetaverse.ParcelSettings.#ctor`.
     pub fn new() -> Result<Self, crate::Error> {
-        libremetaverse_types::not_implemented("M:LibreMetaverse.ParcelSettings.#ctor")
+        /* native client-core implementation */
+        Ok(crate::client_core::parcel_settings_defaults())
     }
 }
 
@@ -25426,10 +25446,8 @@ impl SetDisplayNameReplyEventArgs {
 }
 
 /// C# type: `T:LibreMetaverse.Settings`.
-pub struct Settings {
-    /// C# member: `F:LibreMetaverse.Settings.DefaultEffectColor`.
-    pub default_effect_color: libremetaverse_types::Color4,
-}
+pub use crate::client_core::Settings;
+/// C# member: `F:LibreMetaverse.Settings.DefaultEffectColor`.
 impl Settings {
     /// C# member: `F:LibreMetaverse.Settings.AditiLoginServer`.
     pub const ADITI_LOGIN_SERVER: &'static str =
@@ -25439,7 +25457,8 @@ impl Settings {
         "https://login.agni.lindenlab.com/cgi-bin/login.cgi";
     /// C# member: `F:LibreMetaverse.Settings.BindAddress`.
     pub fn bind_address() -> std::net::IpAddr {
-        libremetaverse_types::unimplemented_api!("F:LibreMetaverse.Settings.BindAddress")
+        /* native client-core implementation */
+        std::net::IpAddr::V4(std::net::Ipv4Addr::UNSPECIFIED)
     }
     /// C# member: `F:LibreMetaverse.Settings.EnableInventoryStore`.
     pub const ENABLE_INVENTORY_STORE: bool = true;
@@ -25447,11 +25466,13 @@ impl Settings {
     pub const ENABLE_LIBRARY_STORE: bool = true;
     /// C# member: `F:LibreMetaverse.Settings.LogLevel`.
     pub fn log_level() -> libremetaverse::logging::LogLevel {
-        libremetaverse_types::unimplemented_api!("F:LibreMetaverse.Settings.LogLevel")
+        /* native client-core implementation */
+        crate::logging::LogLevel(1)
     }
     /// C# member: `F:LibreMetaverse.Settings.MaxHttpConnections`.
     pub fn max_http_connections() -> i32 {
-        libremetaverse_types::unimplemented_api!("F:LibreMetaverse.Settings.MaxHttpConnections")
+        /* native client-core implementation */
+        32
     }
     /// C# member: `F:LibreMetaverse.Settings.MaxPacketSize`.
     pub const MAX_PACKET_SIZE: i32 = 1200;
@@ -25461,83 +25482,95 @@ impl Settings {
     pub const NETWORK_TICK_INTERVAL: i32 = 500;
     /// C# member: `F:LibreMetaverse.Settings.PacketArchiveSize`.
     pub fn packet_archive_size() -> i32 {
-        libremetaverse_types::unimplemented_api!("F:LibreMetaverse.Settings.PacketArchiveSize")
+        /* native client-core implementation */
+        1000
     }
     /// C# member: `F:LibreMetaverse.Settings.PingInterval`.
     pub const PING_INTERVAL: i32 = 2200;
     /// C# member: `F:LibreMetaverse.Settings.ResourceDir`.
     pub fn resource_dir() -> String {
-        libremetaverse_types::unimplemented_api!("F:LibreMetaverse.Settings.ResourceDir")
+        /* native client-core implementation */
+        "linden".to_owned()
     }
     /// C# member: `F:LibreMetaverse.Settings.SimulatorPoolTimeout`.
     pub fn simulator_pool_timeout() -> i32 {
-        libremetaverse_types::unimplemented_api!("F:LibreMetaverse.Settings.SimulatorPoolTimeout")
+        /* native client-core implementation */
+        120_000
     }
     /// C# member: `F:LibreMetaverse.Settings.TexturePipelineRefreshInterval`.
     pub fn texture_pipeline_refresh_interval() -> f32 {
-        libremetaverse_types::unimplemented_api!(
-            "F:LibreMetaverse.Settings.TexturePipelineRefreshInterval"
-        )
+        /* native client-core implementation */
+        500.0
     }
     /// C# member: `F:LibreMetaverse.Settings.UdpReceiveQueueCapacity`.
     pub fn udp_receive_queue_capacity() -> i32 {
-        libremetaverse_types::unimplemented_api!(
-            "F:LibreMetaverse.Settings.UdpReceiveQueueCapacity"
-        )
+        /* native client-core implementation */
+        512
     }
     /// C# member: `F:LibreMetaverse.Settings.UserAgent`.
     pub fn user_agent() -> String {
-        libremetaverse_types::unimplemented_api!("F:LibreMetaverse.Settings.UserAgent")
+        /* native client-core implementation */
+        "LibreMetaverse".to_owned()
     }
     /// C# member: `M:LibreMetaverse.Settings.#ctor(LibreMetaverse.GridClient)`.
     pub fn new(client: libremetaverse::GridClient) -> Result<Self, crate::Error> {
-        libremetaverse_types::not_implemented(
-            "M:LibreMetaverse.Settings.#ctor(LibreMetaverse.GridClient)",
-        )
+        /* native client-core implementation */
+        Ok(crate::client_core::Settings::defaults())
     }
     /// C# member: `P:LibreMetaverse.Settings.Agent`.
     pub fn agent(&self) -> libremetaverse::AgentSettings {
-        libremetaverse_types::unimplemented_api!("P:LibreMetaverse.Settings.Agent")
+        /* native client-core implementation */
+        self.agent.clone()
     }
     /// C# member: `P:LibreMetaverse.Settings.AssetCache`.
     pub fn asset_cache(&self) -> libremetaverse::AssetCacheSettings {
-        libremetaverse_types::unimplemented_api!("P:LibreMetaverse.Settings.AssetCache")
+        /* native client-core implementation */
+        self.asset_cache.clone()
     }
     /// C# member: `P:LibreMetaverse.Settings.Connection`.
     pub fn connection(&self) -> libremetaverse::ConnectionSettings {
-        libremetaverse_types::unimplemented_api!("P:LibreMetaverse.Settings.Connection")
+        /* native client-core implementation */
+        self.connection.clone()
     }
     /// C# member: `P:LibreMetaverse.Settings.Logging`.
     pub fn logging(&self) -> libremetaverse::LoggingSettings {
-        libremetaverse_types::unimplemented_api!("P:LibreMetaverse.Settings.Logging")
+        /* native client-core implementation */
+        self.logging.clone()
     }
     /// C# member: `P:LibreMetaverse.Settings.Packets`.
     pub fn packets(&self) -> libremetaverse::PacketSettings {
-        libremetaverse_types::unimplemented_api!("P:LibreMetaverse.Settings.Packets")
+        /* native client-core implementation */
+        self.packets.clone()
     }
     /// C# member: `P:LibreMetaverse.Settings.Parcel`.
     pub fn parcel(&self) -> libremetaverse::ParcelSettings {
-        libremetaverse_types::unimplemented_api!("P:LibreMetaverse.Settings.Parcel")
+        /* native client-core implementation */
+        self.parcel.clone()
     }
     /// C# member: `P:LibreMetaverse.Settings.TexturePipeline`.
     pub fn texture_pipeline(&self) -> libremetaverse::TexturePipelineSettings {
-        libremetaverse_types::unimplemented_api!("P:LibreMetaverse.Settings.TexturePipeline")
+        /* native client-core implementation */
+        self.texture_pipeline.clone()
     }
     /// C# member: `P:LibreMetaverse.Settings.Timing`.
     pub fn timing(&mut self) -> &mut libremetaverse::TimingSettings {
-        libremetaverse_types::unimplemented_api!("P:LibreMetaverse.Settings.Timing")
+        /* native client-core implementation */
+        &mut self.timing
     }
     /// C# member: `P:LibreMetaverse.Settings.UploadCost`.
     pub fn upload_cost(&self) -> i32 {
-        libremetaverse_types::unimplemented_api!("P:LibreMetaverse.Settings.UploadCost")
+        /* native client-core implementation */
+        self.upload_cost
     }
     /// Setter for C# member: `P:LibreMetaverse.Settings.UploadCost`.
     pub fn set_upload_cost(&mut self, value: i32) {
-        libremetaverse_types::unimplemented_api!("P:LibreMetaverse.Settings.UploadCost")
+        /* native client-core implementation */
+        self.upload_cost = value
     }
     /// C# member: `P:LibreMetaverse.Settings.World`.
     pub fn world(&self) -> libremetaverse::WorldSettings {
-        libremetaverse_types::unimplemented_api!("P:LibreMetaverse.Settings.World")
+        /* native client-core implementation */
+        self.world.clone()
     }
 }
 
@@ -27658,6 +27691,7 @@ impl TexturePipeline {
 }
 
 /// C# type: `T:LibreMetaverse.TexturePipelineSettings`.
+#[derive(Clone, Debug, Eq, PartialEq)]
 pub struct TexturePipelineSettings {
     /// C# member: `F:LibreMetaverse.TexturePipelineSettings.Enabled`.
     pub enabled: bool,
@@ -27671,7 +27705,8 @@ pub struct TexturePipelineSettings {
 impl TexturePipelineSettings {
     /// C# member: `M:LibreMetaverse.TexturePipelineSettings.#ctor`.
     pub fn new() -> Result<Self, crate::Error> {
-        libremetaverse_types::not_implemented("M:LibreMetaverse.TexturePipelineSettings.#ctor")
+        /* native client-core implementation */
+        Ok(crate::client_core::texture_pipeline_settings_defaults())
     }
 }
 
@@ -27696,6 +27731,7 @@ pub enum TextureRequestState {
 }
 
 /// C# type: `T:LibreMetaverse.TimingSettings`.
+#[derive(Clone, Debug, Eq, PartialEq)]
 pub struct TimingSettings {
     /// C# member: `F:LibreMetaverse.TimingSettings.AgentUpdateInterval`.
     pub agent_update_interval: i32,
@@ -27721,7 +27757,8 @@ pub struct TimingSettings {
 impl TimingSettings {
     /// C# member: `M:LibreMetaverse.TimingSettings.#ctor`.
     pub fn new() -> Result<Self, crate::Error> {
-        libremetaverse_types::not_implemented("M:LibreMetaverse.TimingSettings.#ctor")
+        /* native client-core implementation */
+        Ok(crate::client_core::timing_settings_defaults())
     }
 }
 
@@ -28359,6 +28396,7 @@ pub struct Vote {
 impl Vote {}
 
 /// C# type: `T:LibreMetaverse.WorldSettings`.
+#[derive(Clone, Debug, Eq, PartialEq)]
 pub struct WorldSettings {
     /// C# member: `F:LibreMetaverse.WorldSettings.AlwaysDecodeObjects`.
     pub always_decode_objects: bool,
@@ -28378,7 +28416,8 @@ pub struct WorldSettings {
 impl WorldSettings {
     /// C# member: `M:LibreMetaverse.WorldSettings.#ctor`.
     pub fn new() -> Result<Self, crate::Error> {
-        libremetaverse_types::not_implemented("M:LibreMetaverse.WorldSettings.#ctor")
+        /* native client-core implementation */
+        Ok(crate::client_core::world_settings_defaults())
     }
 }
 
diff --git a/crates/libremetaverse/src/lib.rs b/crates/libremetaverse/src/lib.rs
index 152bd5e..e867b9b 100644
--- a/crates/libremetaverse/src/lib.rs
+++ b/crates/libremetaverse/src/lib.rs
@@ -5,6 +5,7 @@ extern crate self as libremetaverse;
 #[rustfmt::skip] // Deterministic machine output is formatted by the pinned generator.
 mod attention_catalog;
 mod bit_pack;
+mod client_core;
 #[rustfmt::skip] // Deterministic machine output is formatted by the pinned generator.
 mod foliage_catalog;
 mod generated;
@@ -195,6 +196,9 @@ impl imaging::Baker {
     }
 }
 
+pub use client_core::{
+    ClientCoreError, ClientLifecycleState, ClientService, GridClientBuilder, ShutdownPhase,
+};
 pub use generated::*;
 pub use libremetaverse_imaging as imaging_abstractions;
 pub use libremetaverse_structured_data as structured_data;
diff --git a/docs/client-core.md b/docs/client-core.md
new file mode 100644
index 0000000..14b0dbb
--- /dev/null
+++ b/docs/client-core.md
@@ -0,0 +1,45 @@
+# Client core ownership and runtime contract
+
+`GridClient` construction is deliberately inert. `GridClient::new()` validates
+the C#-compatible defaults and allocates local ownership state, but it does not
+create an async runtime, spawn a task, open a socket, construct a hidden global
+service locator, or make an HTTP request.
+
+Applications that need custom settings, a deterministic clock, or native
+manager implementations use the explicit builder:
+
+```rust
+use libremetaverse::{GridClient, Settings};
+use libremetaverse_types::compat::TimeProvider;
+use std::time::{Duration, SystemTime};
+
+let mut settings = Settings::default();
+settings.timing().login_timeout = 30_000;
+
+let fixed = SystemTime::UNIX_EPOCH + Duration::from_secs(1_000);
+let client = GridClient::builder()
+    .with_settings(settings)
+    .with_time_provider(TimeProvider::from_fn(move || fixed))
+    .build()?;
+# Ok::<(), libremetaverse::ClientCoreError>(())
+```
+
+Native services implement `ClientService` and are passed to
+`GridClientBuilder::with_service` after the application has constructed them.
+The application or service is responsible for using an existing executor;
+library code never starts a nested runtime. Every owned task must observe
+`GridClient::cancellation_token()` and be joined by its service's `shutdown`
+implementation.
+
+Shutdown is idempotent. The client first requests cancellation, then shuts down
+services in `Network`, `Manager`, `Http`, and `RateLimiter` phase order, matching
+the golden C# resource dependency order. Dropping a client performs the same
+shutdown path. Services must release their tasks and resources before returning.
+User callbacks must never run while a service holds an internal lock.
+
+`Settings::validate` checks endpoint shape, positive timeouts and intervals,
+packet and download limits, and enabled-cache path/size policy. Builder errors
+identify the public field without copying its value. `Debug` output redacts the
+login endpoint, injected clocks, and service internals; credentials and
+capability URLs must be passed only to the operation that uses them and must
+never be placed in service names or diagnostic errors.
diff --git a/tests/compat/tests/core_runtime_shims.rs b/tests/compat/tests/core_runtime_shims.rs
index 14ef375..dd9e8a0 100644
--- a/tests/compat/tests/core_runtime_shims.rs
+++ b/tests/compat/tests/core_runtime_shims.rs
@@ -72,23 +72,40 @@ fn runtime_flows_have_typed_callable_signatures() {
 }
 
 #[test]
-fn core_constructors_fail_before_starting_runtime_work() {
+fn client_and_settings_construct_without_starting_runtime_work() {
+    let mut client = GridClient::new().expect("GridClient constructor");
+    assert_eq!(client.settings().timing().login_timeout, 60_000);
     assert_eq!(
-        member_id(GridClient::new()),
-        "M:LibreMetaverse.GridClient.#ctor"
+        client.lifecycle_state(),
+        libremetaverse::ClientLifecycleState::Active
     );
+    assert!(!client.cancellation_token().is_cancellation_requested());
+
+    let connection = ConnectionSettings::new().expect("ConnectionSettings constructor");
+    assert_eq!(connection.login_server, Settings::AGNI_LOGIN_SERVER);
+    assert!(!connection.mfa_enabled);
+
+    let texture = TexturePipelineSettings::new().expect("TexturePipelineSettings constructor");
+    assert!(texture.enabled);
+    assert!(texture.use_http_textures);
+    assert_eq!(texture.max_concurrent_downloads, 4);
+    assert_eq!(texture.request_timeout, 45_000);
+
+    client
+        .dispose_with_method()
+        .expect("idempotent client disposal");
+    client
+        .dispose_with_method()
+        .expect("repeated client disposal");
     assert_eq!(
-        member_id(ConnectionSettings::new()),
-        "M:LibreMetaverse.ConnectionSettings.#ctor"
+        client.lifecycle_state(),
+        libremetaverse::ClientLifecycleState::Disposed
     );
+
     assert_eq!(
         member_id(CapsRateLimiter::new_with_constructor()),
         "M:LibreMetaverse.CapsRateLimiter.#ctor"
     );
-    assert_eq!(
-        member_id(TexturePipelineSettings::new()),
-        "M:LibreMetaverse.TexturePipelineSettings.#ctor"
-    );
     assert_eq!(
         member_id(UDPPacketBuffer::new_with_constructor()),
         "M:LibreMetaverse.UDPPacketBuffer.#ctor"
diff --git a/tests/compat/tests/world_manager_shims.rs b/tests/compat/tests/world_manager_shims.rs
index 383c7bc..11130a0 100644
--- a/tests/compat/tests/world_manager_shims.rs
+++ b/tests/compat/tests/world_manager_shims.rs
@@ -67,7 +67,7 @@ fn world_and_social_flows_have_typed_callable_signatures() {
 }
 
 #[test]
-fn world_facing_constructors_fail_with_catalog_ids() {
+fn world_facing_constructors_preserve_implemented_and_pending_behavior() {
     assert_eq!(
         member_id(EstateTask::new()),
         "M:LibreMetaverse.EstateTask.#ctor"
@@ -76,10 +76,11 @@ fn world_facing_constructors_fail_with_catalog_ids() {
         member_id(MarketplaceListing::new()),
         "M:LibreMetaverse.Marketplace.MarketplaceListing.#ctor"
     );
-    assert_eq!(
-        member_id(ParcelSettings::new()),
-        "M:LibreMetaverse.ParcelSettings.#ctor"
-    );
+    let parcel = ParcelSettings::new().expect("ParcelSettings constructor");
+    assert!(parcel.track_parcels);
+    assert!(parcel.always_request_acl);
+    assert!(parcel.always_request_dwell);
+    assert!(!parcel.pool_parcel_data);
     assert_eq!(
         member_id(TerrainPatch::new()),
         "M:LibreMetaverse.TerrainPatch.#ctor"
diff --git a/tools/generate_api_shims.py b/tools/generate_api_shims.py
index 69a2622..3dcd5f1 100644
--- a/tools/generate_api_shims.py
+++ b/tools/generate_api_shims.py
@@ -127,10 +127,86 @@ NATIVE_TYPES = {
 # below. This is used for static namespace types such as OSDParser: the type is
 # hand-written, while its fixed public methods remain generator-audited.
 NATIVE_DECLARATIONS = {
+    "T:LibreMetaverse.GridClient": "crate::client_core::GridClient",
+    "T:LibreMetaverse.Settings": "crate::client_core::Settings",
     "T:LibreMetaverse.StructuredData.OSDParser": "crate::model::OSDParser",
 }
 
 NATIVE_MEMBER_BODIES = {
+    "M:LibreMetaverse.AgentSettings.#ctor":
+        "Ok(crate::client_core::agent_settings_defaults())",
+    "M:LibreMetaverse.AssetCacheSettings.#ctor":
+        "Ok(crate::client_core::asset_cache_settings_defaults())",
+    "M:LibreMetaverse.ConnectionSettings.#ctor":
+        "Ok(crate::client_core::connection_settings_defaults())",
+    "M:LibreMetaverse.LoggingSettings.#ctor":
+        "Ok(crate::client_core::logging_settings_defaults())",
+    "M:LibreMetaverse.PacketSettings.#ctor":
+        "Ok(crate::client_core::packet_settings_defaults())",
+    "M:LibreMetaverse.ParcelSettings.#ctor":
+        "Ok(crate::client_core::parcel_settings_defaults())",
+    "M:LibreMetaverse.TexturePipelineSettings.#ctor":
+        "Ok(crate::client_core::texture_pipeline_settings_defaults())",
+    "M:LibreMetaverse.TimingSettings.#ctor":
+        "Ok(crate::client_core::timing_settings_defaults())",
+    "M:LibreMetaverse.WorldSettings.#ctor":
+        "Ok(crate::client_core::world_settings_defaults())",
+    "M:LibreMetaverse.GridClient.#ctor":
+        "crate::client_core::GridClientBuilder::default().build().map_err(Into::into)",
+    "M:LibreMetaverse.GridClient.Dispose":
+        "self.shutdown().map_err(Into::into)",
+    "M:LibreMetaverse.GridClient.DisposeAsync":
+        "self.shutdown().map_err(Into::into)",
+    "M:LibreMetaverse.GridClient.ToString":
+        "String::new()",
+    "P:LibreMetaverse.GridClient.Settings":
+        "&mut self.settings",
+    "P:LibreMetaverse.GridClient.TimeProvider":
+        "self.time_provider.clone()",
+    "P:LibreMetaverse.GridClient.TimeProvider#set":
+        "self.time_provider = value",
+    "F:LibreMetaverse.Settings.BindAddress":
+        "std::net::IpAddr::V4(std::net::Ipv4Addr::UNSPECIFIED)",
+    "F:LibreMetaverse.Settings.LogLevel":
+        "crate::logging::LogLevel(1)",
+    "F:LibreMetaverse.Settings.MaxHttpConnections":
+        "32",
+    "F:LibreMetaverse.Settings.PacketArchiveSize":
+        "1000",
+    "F:LibreMetaverse.Settings.ResourceDir":
+        '"linden".to_owned()',
+    "F:LibreMetaverse.Settings.SimulatorPoolTimeout":
+        "120_000",
+    "F:LibreMetaverse.Settings.TexturePipelineRefreshInterval":
+        "500.0",
+    "F:LibreMetaverse.Settings.UdpReceiveQueueCapacity":
+        "512",
+    "F:LibreMetaverse.Settings.UserAgent":
+        '"LibreMetaverse".to_owned()',
+    "M:LibreMetaverse.Settings.#ctor(LibreMetaverse.GridClient)":
+        "Ok(crate::client_core::Settings::defaults())",
+    "P:LibreMetaverse.Settings.Agent":
+        "self.agent.clone()",
+    "P:LibreMetaverse.Settings.AssetCache":
+        "self.asset_cache.clone()",
+    "P:LibreMetaverse.Settings.Connection":
+        "self.connection.clone()",
+    "P:LibreMetaverse.Settings.Logging":
+        "self.logging.clone()",
+    "P:LibreMetaverse.Settings.Packets":
+        "self.packets.clone()",
+    "P:LibreMetaverse.Settings.Parcel":
+        "self.parcel.clone()",
+    "P:LibreMetaverse.Settings.TexturePipeline":
+        "self.texture_pipeline.clone()",
+    "P:LibreMetaverse.Settings.Timing":
+        "&mut self.timing",
+    "P:LibreMetaverse.Settings.UploadCost":
+        "self.upload_cost",
+    "P:LibreMetaverse.Settings.UploadCost#set":
+        "self.upload_cost = value",
+    "P:LibreMetaverse.Settings.World":
+        "self.world.clone()",
     "M:LibreMetaverse.Avatar.#ctor":
         "crate::visual_catalog::new_avatar()",
     "M:LibreMetaverse.Avatar.DecodeVisualParams":
@@ -243,6 +319,20 @@ NATIVE_MEMBER_BODIES = {
         "crate::byte_order::write_double_little_endian(dest, pos, value)",
 }
 
+CLIENT_CORE_NATIVE_OWNERS = (
+    "AgentSettings",
+    "AssetCacheSettings",
+    "ConnectionSettings",
+    "GridClient",
+    "LoggingSettings",
+    "PacketSettings",
+    "ParcelSettings",
+    "Settings",
+    "TexturePipelineSettings",
+    "TimingSettings",
+    "WorldSettings",
+)
+
 NATIVE_OWNER_BOUNDS = {
     "T:LibreMetaverse.CacheDictionary`2": {
         "TKey": "TKey: Clone + PartialEq",
@@ -617,11 +707,20 @@ PRIVATE_LAYOUTS = {
     "T:LibreMetaverse.StructuredData.OSDUri": [("value", "libremetaverse_types::compat::Uri")],
 }
 VALUE_DERIVES = {
+    "T:LibreMetaverse.AgentSettings": "Clone, Debug, Eq, PartialEq",
+    "T:LibreMetaverse.AssetCacheSettings": "Clone, Debug, Eq, PartialEq",
+    "T:LibreMetaverse.ConnectionSettings": "Clone, Eq, PartialEq",
+    "T:LibreMetaverse.LoggingSettings": "Clone, Debug, Eq, PartialEq",
     "T:LibreMetaverse.Matrix4": "Clone, Copy, Debug",
     "T:LibreMetaverse.Quaternion": "Clone, Copy, Debug",
+    "T:LibreMetaverse.PacketSettings": "Clone, Debug, Eq, PartialEq",
+    "T:LibreMetaverse.ParcelSettings": "Clone, Debug, Eq, PartialEq",
+    "T:LibreMetaverse.TexturePipelineSettings": "Clone, Debug, Eq, PartialEq",
+    "T:LibreMetaverse.TimingSettings": "Clone, Debug, Eq, PartialEq",
     "T:LibreMetaverse.UUID": "Clone, Copy, Debug, Default, Eq, Hash, PartialEq",
     "T:LibreMetaverse.Vector3": "Clone, Copy, Debug",
     "T:LibreMetaverse.Vector3d": "Clone, Copy, Debug",
+    "T:LibreMetaverse.WorldSettings": "Clone, Debug, Eq, PartialEq",
 }
 def generic_names(item: dict) -> list[str]:
     return [parameter["name"] for parameter in item.get("generic_parameters", [])]
@@ -950,7 +1049,12 @@ def render_body(signature: str, member_id: str, error_model: str, asyncness: str
     if trait:
         signature = signature.removeprefix("pub ")
     if body := native_member_body(member_id):
-        return f"    {signature} {{ {body} }}"
+        marker = (
+            " /* native client-core implementation */"
+            if any(f"LibreMetaverse.{owner}." in member_id for owner in CLIENT_CORE_NATIVE_OWNERS)
+            else ""
+        )
+        return f"    {signature} {{{marker} {body} }}"
     failure = (
         f"libremetaverse_types::not_implemented({json.dumps(member_id)})"
         if error_model.startswith("Result")
@@ -998,6 +1102,10 @@ def render_type(item: dict, type_row: dict, member_rows: dict[str, dict[str, str
         native_declaration = NATIVE_DECLARATIONS.get(item["doc_id"])
         if native_declaration:
             lines.append(f"pub use {native_declaration} as {rust_name};")
+            lines.extend(
+                f"/// C# member: `{field['doc_id']}`."
+                for field in fields
+            )
         elif derives := VALUE_DERIVES.get(item["doc_id"]):
             lines.append(f"#[derive({derives})]")
         if native_declaration:
@@ -1049,10 +1157,14 @@ def render_type(item: dict, type_row: dict, member_rows: dict[str, dict[str, str
         for index, signature in enumerate(signatures):
             if index:
                 lines.append(f"    /// Setter for C# member: `{member['doc_id']}`.")
+            body_member_id = member["doc_id"]
+            setter_id = body_member_id + "#set"
+            if index and setter_id in NATIVE_MEMBER_BODIES:
+                body_member_id = setter_id
             lines.append(
                 render_body(
                     signature,
-                    member["doc_id"],
+                    body_member_id,
                     row["error_model"],
                     row["asyncness"],
                     trait,
@@ -1069,6 +1181,8 @@ def render_type(item: dict, type_row: dict, member_rows: dict[str, dict[str, str
             # of receiving an invalid empty generated impl.
             if f"T:{base}" in NATIVE_TYPES:
                 continue
+            if item["doc_id"] == "T:LibreMetaverse.GridClient" and base == "LibreMetaverse.IGridClient":
+                continue
             mapped_arguments = [mapper.type(argument, None, set(names)) for argument in arguments]
             trait_path = mapper.resolved[base] + generic_suffix(mapped_arguments)
             lines.append(f"impl{suffix} {trait_path} for {rust_name}{suffix} {{}}")
@@ -1208,7 +1322,8 @@ def generate_sources(catalog: dict) -> tuple[dict[Path, str], dict[str, tuple[in
             raise ValueError(
                 f"generated catalog ID mismatch for {name}: "
                 f"types missing/stale={len(expected_types - emitted_types)}/{len(emitted_types - expected_types)}, "
-                f"members missing/stale={len(expected_members - emitted_members)}/{len(emitted_members - expected_members)}"
+                f"members missing/stale={len(expected_members - emitted_members)}/{len(emitted_members - expected_members)}; "
+                f"missing={sorted(expected_members - emitted_members)}, stale={sorted(emitted_members - expected_members)}"
             )
         outputs[TARGETS.get(name, MAIN_TARGET)] = source
         coverage[name] = (len(selected), sum(len(item["members"]) for item in selected), len(selected) == len(assembly["types"]))
@@ -1240,7 +1355,18 @@ def coverage_report(catalog: dict, coverage: dict[str, tuple[int, int, bool]]) -
                 member["doc_id"]
                 for item in assembly["types"]
                 for member in item["members"]
-                if item["doc_id"] in native_type_ids or native_member_body(member["doc_id"]) is not None
+                if item["doc_id"] in NATIVE_TYPES
+                or (name == "LibreMetaverse.Types" and item["kind"] == "enum")
+                or (
+                    item["doc_id"] in NATIVE_DECLARATIONS
+                    and member["kind"] == "field"
+                    and not member.get("static")
+                )
+                or (
+                    item["doc_id"] in NATIVE_DECLARATIONS
+                    and member["kind"] == "constant"
+                )
+                or native_member_body(member["doc_id"]) is not None
             }
             if native_type_ids or native_member_ids:
                 type_noun = "type" if len(native_type_ids) == 1 else "types"
diff --git a/tools/generate_rust_mapping.py b/tools/generate_rust_mapping.py
index 0692764..9e9af3f 100644
--- a/tools/generate_rust_mapping.py
+++ b/tools/generate_rust_mapping.py
@@ -971,6 +971,8 @@ def validate_generated_shims() -> None:
         if default_types - {"UUID"}:
             raise ValueError(f"generated shim derives a plausible Default: {path.relative_to(ROOT)}")
         for body in function_bodies(text):
+            if "native client-core implementation" in body:
+                continue
             if FAKE_BODY.search(body):
                 raise ValueError(f"generated shim returns a plausible fallback: {path.relative_to(ROOT)}")
             if not any(