diff --git a/packages/coding-agent/CHANGELOG.md b/packages/coding-agent/CHANGELOG.md
index 1fbfd8663..6c1414359 100644
--- a/packages/coding-agent/CHANGELOG.md
+++ b/packages/coding-agent/CHANGELOG.md
@@ -11,6 +11,7 @@
 - Added `replace block N:` and `delete block N` operators to the `edit` tool: they resolve the syntactic block beginning on line N via tree-sitter (native `blockRangeAt`) and replace or delete its full line span, so a construct can be rewritten or removed without counting its closing line. Unresolvable blocks (unsupported language, blank/closing-delimiter line, or a parse error) are rejected with guidance to use an explicit `replace N..M:` / `delete N..M` range.
 - Added an animated pending border for `bash` and `eval` execution blocks: while a command/cell is running, a single dark segment glides clockwise around the block's outer edge (top → right → bottom → left), replacing the previous static accent border. Motion is eased per edge (decelerating into each corner) and timed against a fixed lap duration mapped onto the live perimeter, so streaming a new output line or resizing the terminal nudges the segment proportionally instead of resetting its position. Driven by the existing spinner cadence and gated on the `display.shimmer` setting (no motion when `disabled`).
 - Added a `PI_TINY_DTYPE` environment variable that overrides the ONNX quantization/precision used for local tiny models (session titles and Mnemosyne memory tasks), mirroring `PI_TINY_DEVICE`. Unset keeps each model's shipped dtype (currently `q4`); `PI_TINY_DTYPE=fp16` trades speed for fidelity and `PI_TINY_DTYPE=q8` is also accepted, alongside `auto`, `fp32`, `int8`, `uint8`, `bnb4`, `q4f16`, `q2`, `q2f16`, `q1`, and `q1f16`. An unrecognized value fails loudly at worker startup instead of silently loading a different precision.
+- Added a bundled set of default rules shipped with the agent (TypeScript/Rust convention rules registered as TTSR conditions). They load via the new lowest-priority `builtin-defaults` discovery provider, so any user/project/tool rule of the same name overrides the bundled copy. Disable the whole set with `ttsr.builtinRules: false`, or drop individual rules (bundled or your own) by name via `ttsr.disabledRules`.
 
 ### Changed
 
diff --git a/packages/coding-agent/src/capability/rule-buckets.ts b/packages/coding-agent/src/capability/rule-buckets.ts
new file mode 100644
index 000000000..16afdc307
--- /dev/null
+++ b/packages/coding-agent/src/capability/rule-buckets.ts
@@ -0,0 +1,64 @@
+/**
+ * Rule bucketing
+ *
+ * Single funnel that every discovered rule passes through on its way into a
+ * session. It applies the user's disable levers, registers TTSR rules with the
+ * manager, and splits the rest into the always-apply and rulebook buckets.
+ *
+ * Bucket precedence (matches docs/rulebook-matching-pipeline.md §5):
+ *   1. TTSR     — non-empty `condition` that `TtsrManager.addRule` accepts
+ *   2. always   — `alwaysApply === true`
+ *   3. rulebook — has a `description`
+ */
+import type { TtsrManager } from "../export/ttsr";
+import { BUILTIN_DEFAULTS_PROVIDER_ID, type Rule } from "./rule";
+
+export interface RuleBuckets {
+	rulebookRules: Rule[];
+	alwaysApplyRules: Rule[];
+}
+
+export interface BucketRulesOptions {
+	/** Rule names to drop entirely (bundled defaults and user rules alike). */
+	disabledRules?: readonly string[];
+	/** When false, drop every rule from the bundled `builtin-defaults` provider. */
+	builtinRules?: boolean;
+}
+
+/**
+ * Filter and bucket rules, registering TTSR rules on `ttsrManager` as a side
+ * effect. Disabled rules are dropped before any bucket assignment, so a
+ * disabled rule is neither matched as TTSR nor surfaced via `rule://`.
+ */
+export function bucketRules(
+	rules: readonly Rule[],
+	ttsrManager: TtsrManager,
+	options: BucketRulesOptions = {},
+): RuleBuckets {
+	const includeBuiltin = options.builtinRules !== false;
+	const disabled = new Set<string>();
+	for (const raw of options.disabledRules ?? []) {
+		const name = raw.trim();
+		if (name.length > 0) disabled.add(name);
+	}
+
+	const rulebookRules: Rule[] = [];
+	const alwaysApplyRules: Rule[] = [];
+
+	for (const rule of rules) {
+		if (disabled.has(rule.name)) continue;
+		if (!includeBuiltin && rule._source?.provider === BUILTIN_DEFAULTS_PROVIDER_ID) continue;
+
+		const isTtsrRule = rule.condition && rule.condition.length > 0 ? ttsrManager.addRule(rule) : false;
+		if (isTtsrRule) continue;
+		if (rule.alwaysApply === true) {
+			alwaysApplyRules.push(rule);
+			continue;
+		}
+		if (rule.description) {
+			rulebookRules.push(rule);
+		}
+	}
+
+	return { rulebookRules, alwaysApplyRules };
+}
diff --git a/packages/coding-agent/src/capability/rule.ts b/packages/coding-agent/src/capability/rule.ts
index 8b4623dd2..0b5d8d2b3 100644
--- a/packages/coding-agent/src/capability/rule.ts
+++ b/packages/coding-agent/src/capability/rule.ts
@@ -9,6 +9,14 @@ import type { SourceMeta } from "./types";
 
 const CONDITION_GLOB_SCOPE_TOOLS = ["edit", "write"] as const;
 
+/**
+ * Provider id for the bundled default rules shipped with the agent.
+ * Lowest priority, so any user/project/tool rule of the same name overrides
+ * a bundled default. Also used to gate the whole bundled set via
+ * `ttsr.builtinRules`.
+ */
+export const BUILTIN_DEFAULTS_PROVIDER_ID = "builtin-defaults";
+
 /**
  * Parsed frontmatter from rule files.
  */
diff --git a/packages/coding-agent/src/config/settings-schema.ts b/packages/coding-agent/src/config/settings-schema.ts
index 2622b0797..fa1095fee 100644
--- a/packages/coding-agent/src/config/settings-schema.ts
+++ b/packages/coding-agent/src/config/settings-schema.ts
@@ -1705,6 +1705,26 @@ export const SETTINGS_SCHEMA = {
 		},
 	},
 
+	"ttsr.builtinRules": {
+		type: "boolean",
+		default: true,
+		ui: {
+			tab: "context",
+			label: "Builtin Rules",
+			description: "Load the default rules shipped with the agent (override individually with ttsr.disabledRules)",
+		},
+	},
+
+	"ttsr.disabledRules": {
+		type: "array",
+		default: [] as string[],
+		ui: {
+			tab: "context",
+			label: "Disabled Rules",
+			description: "Rule names to ignore entirely (applies to bundled defaults and your own rules)",
+		},
+	},
+
 	// ────────────────────────────────────────────────────────────────────────
 	// Editing
 	// ────────────────────────────────────────────────────────────────────────
@@ -3299,6 +3319,10 @@ export interface TtsrSettings {
 	interruptMode: "never" | "prose-only" | "tool-only" | "always";
 	repeatMode: "once" | "after-gap";
 	repeatGap: number;
+	/** Bucketing-only (read by bucketRules, not the TtsrManager). */
+	builtinRules?: boolean;
+	/** Bucketing-only (read by bucketRules, not the TtsrManager). */
+	disabledRules?: string[];
 }
 
 export interface ExaSettings {
diff --git a/packages/coding-agent/src/discovery/builtin-defaults.ts b/packages/coding-agent/src/discovery/builtin-defaults.ts
new file mode 100644
index 000000000..e4d3d6887
--- /dev/null
+++ b/packages/coding-agent/src/discovery/builtin-defaults.ts
@@ -0,0 +1,39 @@
+/**
+ * Builtin Defaults Provider
+ *
+ * Ships a curated set of default rules (mostly TTSR conventions) embedded into
+ * the binary. Registered at the lowest priority so any user/project/tool rule
+ * with the same `name` overrides the bundled copy (first-wins dedup by name).
+ *
+ * Users disable bundled rules three ways:
+ *   - flip `ttsr.builtinRules` off (drops the whole set),
+ *   - list a name in `ttsr.disabledRules` (drops one rule),
+ *   - define a same-named rule in any higher-priority source (overrides it).
+ * The first two are enforced in `bucketRules` (see capability/rule-buckets.ts).
+ */
+import { registerProvider } from "../capability";
+import { BUILTIN_DEFAULTS_PROVIDER_ID, type Rule, ruleCapability } from "../capability/rule";
+import type { LoadContext, LoadResult } from "../capability/types";
+import { BUILTIN_RULE_SOURCES } from "./builtin-rules";
+import { buildRuleFromMarkdown, createSourceMeta } from "./helpers";
+
+const DISPLAY_NAME = "Builtin Defaults";
+// Lowest priority: every other rule provider wins a name conflict.
+const PRIORITY = 1;
+
+async function loadRules(_ctx: LoadContext): Promise<LoadResult<Rule>> {
+	const items = BUILTIN_RULE_SOURCES.map(({ name, content }) => {
+		const virtualPath = `${BUILTIN_DEFAULTS_PROVIDER_ID}:${name}.md`;
+		const source = createSourceMeta(BUILTIN_DEFAULTS_PROVIDER_ID, virtualPath, "user");
+		return buildRuleFromMarkdown(name, content, virtualPath, source, { ruleName: name });
+	});
+	return { items };
+}
+
+registerProvider<Rule>(ruleCapability.id, {
+	id: BUILTIN_DEFAULTS_PROVIDER_ID,
+	displayName: DISPLAY_NAME,
+	description: "Default rules shipped with the agent (disable via ttsr.builtinRules / ttsr.disabledRules)",
+	priority: PRIORITY,
+	load: loadRules,
+});
diff --git a/packages/coding-agent/src/discovery/builtin-rules/index.ts b/packages/coding-agent/src/discovery/builtin-rules/index.ts
new file mode 100644
index 000000000..392908144
--- /dev/null
+++ b/packages/coding-agent/src/discovery/builtin-rules/index.ts
@@ -0,0 +1,48 @@
+/**
+ * Bundled default rules shipped with the coding agent.
+ *
+ * Each markdown source is embedded via `with { type: "text" }` so it survives
+ * `bun build --compile` (the compiled binary ships no loose rule files; only
+ * the embedded text). The native source/tarball installs read the same modules.
+ *
+ * Registered by the lowest-priority `builtin-defaults` rule provider so any
+ * user/project/tool rule with the same name overrides the bundled copy.
+ */
+import rsBoxLeak from "./rs-box-leak.md" with { type: "text" };
+import rsFuturePrelude from "./rs-future-prelude.md" with { type: "text" };
+import rsLazylock from "./rs-lazylock.md" with { type: "text" };
+import rsMatchErgonomics from "./rs-match-ergonomics.md" with { type: "text" };
+import rsParkingLot from "./rs-parking-lot.md" with { type: "text" };
+import rsResultType from "./rs-result-type.md" with { type: "text" };
+import tsBareCatch from "./ts-bare-catch.md" with { type: "text" };
+import tsImportType from "./ts-import-type.md" with { type: "text" };
+import tsNoAny from "./ts-no-any.md" with { type: "text" };
+import tsNoDynamicImport from "./ts-no-dynamic-import.md" with { type: "text" };
+import tsNoReturnType from "./ts-no-return-type.md" with { type: "text" };
+import tsNoTinyFunctions from "./ts-no-tiny-functions.md" with { type: "text" };
+import tsPromiseWithResolvers from "./ts-promise-with-resolvers.md" with { type: "text" };
+import tsSetMap from "./ts-set-map.md" with { type: "text" };
+
+/** A bundled rule's stable name and raw markdown (frontmatter + body). */
+export interface BuiltinRuleSource {
+	name: string;
+	content: string;
+}
+
+/** All bundled default rules, ordered by name. */
+export const BUILTIN_RULE_SOURCES: readonly BuiltinRuleSource[] = [
+	{ name: "rs-box-leak", content: rsBoxLeak },
+	{ name: "rs-future-prelude", content: rsFuturePrelude },
+	{ name: "rs-lazylock", content: rsLazylock },
+	{ name: "rs-match-ergonomics", content: rsMatchErgonomics },
+	{ name: "rs-parking-lot", content: rsParkingLot },
+	{ name: "rs-result-type", content: rsResultType },
+	{ name: "ts-bare-catch", content: tsBareCatch },
+	{ name: "ts-import-type", content: tsImportType },
+	{ name: "ts-no-any", content: tsNoAny },
+	{ name: "ts-no-dynamic-import", content: tsNoDynamicImport },
+	{ name: "ts-no-return-type", content: tsNoReturnType },
+	{ name: "ts-no-tiny-functions", content: tsNoTinyFunctions },
+	{ name: "ts-promise-with-resolvers", content: tsPromiseWithResolvers },
+	{ name: "ts-set-map", content: tsSetMap },
+];
diff --git a/packages/coding-agent/src/discovery/builtin-rules/rs-box-leak.md b/packages/coding-agent/src/discovery/builtin-rules/rs-box-leak.md
new file mode 100644
index 000000000..e6abd0e55
--- /dev/null
+++ b/packages/coding-agent/src/discovery/builtin-rules/rs-box-leak.md
@@ -0,0 +1,48 @@
+---
+description: Never use Box::leak - it intentionally leaks memory
+condition: "Box::leak"
+scope: "tool:edit(*.rs), tool:write(*.rs)"
+---
+
+Never use `Box::leak` to satisfy a lifetime. It intentionally leaks the allocation for the rest of the process.
+
+## Why
+
+- The allocation is never freed.
+- It hides ownership bugs.
+- It turns lifetime errors into process lifetime growth.
+- It makes tests pass while production memory grows.
+
+## Use instead
+
+| Need | Use |
+| --- | --- |
+| Shared async/thread data | `Arc<T>` or owned values |
+| Global lazy state | `LazyLock<T>` or `OnceLock<T>` |
+| Text escaping a scope | `String` / `Arc<str>` |
+| `'static` callback | `move` closure with owned captures |
+| FFI pointer | Explicit owner that frees on drop |
+
+## Examples
+
+```rust
+// Bad — leaking to manufacture 'static.
+fn label(id: u64) -> &'static str {
+    Box::leak(Box::new(format!("item_{id}")))
+}
+
+// Good — return owned data.
+fn label(id: u64) -> String {
+    format!("item_{id}")
+}
+
+// Bad — leaking before spawn.
+let state = Box::leak(Box::new(state));
+tokio::spawn(async move { use_state(state) });
+
+// Good — share owned state.
+let state = Arc::new(state);
+tokio::spawn(async move { use_state(&state) });
+```
+
+If `Box::leak` looks necessary, fix ownership instead.
diff --git a/packages/coding-agent/src/discovery/builtin-rules/rs-future-prelude.md b/packages/coding-agent/src/discovery/builtin-rules/rs-future-prelude.md
new file mode 100644
index 000000000..4ffd17618
--- /dev/null
+++ b/packages/coding-agent/src/discovery/builtin-rules/rs-future-prelude.md
@@ -0,0 +1,23 @@
+---
+description: Use Future not std::future::Future - it's in the prelude
+condition: "std::future::Future"
+scope: "tool:edit(*.rs), tool:write(*.rs)"
+---
+
+Use `Future` directly instead of `std::future::Future` in type positions.
+
+Rust 2024 includes `Future` in the standard prelude. Older editions can import it once with `use std::future::Future;`. Repeating the fully qualified path makes signatures harder to read without adding safety.
+
+## Examples
+
+```rust
+// Bad — fully qualified in every signature.
+fn fetch() -> impl std::future::Future<Output = Result<Data>> { ... }
+fn poll(fut: Pin<&mut dyn std::future::Future<Output = i32>>) { ... }
+
+// Good — use the prelude or one import.
+fn fetch() -> impl Future<Output = Result<Data>> { ... }
+fn poll(fut: Pin<&mut dyn Future<Output = i32>>) { ... }
+```
+
+Pre-2024 edition? Add `use std::future::Future;` at the top.
diff --git a/packages/coding-agent/src/discovery/builtin-rules/rs-lazylock.md b/packages/coding-agent/src/discovery/builtin-rules/rs-lazylock.md
new file mode 100644
index 000000000..c82a9e0af
--- /dev/null
+++ b/packages/coding-agent/src/discovery/builtin-rules/rs-lazylock.md
@@ -0,0 +1,51 @@
+---
+description: Prefer std::sync::LazyLock over OnceLock and once_cell
+condition:
+  - "once_cell::"
+  - "OnceLock::new"
+scope: "tool:edit(*.rs), tool:write(*.rs)"
+---
+
+Prefer `std::sync::LazyLock` over `OnceLock` and the `once_cell` crate when the initializer is known at declaration time.
+
+`LazyLock` stores the cell and initializer together. There is no separate `init()` function, no repeated `get_or_init`, and no missing initialization path.
+
+## once_cell → std
+
+```rust
+// Before
+use once_cell::sync::Lazy;
+static CONFIG: Lazy<String> = Lazy::new(|| "value".to_string());
+
+// After
+use std::sync::LazyLock;
+static CONFIG: LazyLock<String> = LazyLock::new(|| "value".to_string());
+```
+
+## OnceLock → LazyLock
+
+```rust
+// Before — fixed initializer hidden in accessor.
+use std::sync::OnceLock;
+static SETTINGS: OnceLock<Settings> = OnceLock::new();
+fn settings() -> &'static Settings {
+    SETTINGS.get_or_init(Settings::load)
+}
+
+// After — initializer lives with the static.
+use std::sync::LazyLock;
+static SETTINGS: LazyLock<Settings> = LazyLock::new(Settings::load);
+```
+
+## Keep OnceLock when runtime input is required
+
+```rust
+use std::sync::OnceLock;
+static DATABASE: OnceLock<Database> = OnceLock::new();
+
+fn init_database(url: &str) {
+    let _ = DATABASE.set(Database::connect(url));
+}
+```
+
+Do not add `once_cell` for new code. Use the standard library equivalent.
diff --git a/packages/coding-agent/src/discovery/builtin-rules/rs-match-ergonomics.md b/packages/coding-agent/src/discovery/builtin-rules/rs-match-ergonomics.md
new file mode 100644
index 000000000..8f4d34280
--- /dev/null
+++ b/packages/coding-agent/src/discovery/builtin-rules/rs-match-ergonomics.md
@@ -0,0 +1,67 @@
+---
+description: Use match ergonomics instead of ref/ref mut patterns
+condition:
+  - "\\(ref mut "
+  - "\\(ref [a-z_]"
+scope: "tool:edit(*.rs), tool:write(*.rs)"
+---
+
+Use match ergonomics instead of explicit `ref` / `ref mut` patterns. Borrow the scrutinee and let bindings receive references.
+
+## Shared references
+
+```rust
+// Before
+match value {
+    Some(ref item) => println!("{item}"),
+    None => {}
+}
+
+// After
+match &value {
+    Some(item) => println!("{item}"),
+    None => {}
+}
+
+if let Some(item) = &value {
+    println!("{item}");
+}
+```
+
+## Mutable references
+
+```rust
+// Before
+match value {
+    Some(ref mut item) => *item += 1,
+    None => {}
+}
+
+// After
+match &mut value {
+    Some(item) => *item += 1,
+    None => {}
+}
+
+if let Some(item) = &mut value {
+    *item += 1;
+}
+```
+
+## Result
+
+```rust
+// Before
+match result {
+    Ok(ref data) => println!("{data}"),
+    Err(ref err) => eprintln!("{err}"),
+}
+
+// After
+match &result {
+    Ok(data) => println!("{data}"),
+    Err(err) => eprintln!("{err}"),
+}
+```
+
+Modern Rust rarely needs `ref` in patterns. Borrow the value being matched.
diff --git a/packages/coding-agent/src/discovery/builtin-rules/rs-parking-lot.md b/packages/coding-agent/src/discovery/builtin-rules/rs-parking-lot.md
new file mode 100644
index 000000000..3a6d18b22
--- /dev/null
+++ b/packages/coding-agent/src/discovery/builtin-rules/rs-parking-lot.md
@@ -0,0 +1,44 @@
+---
+description: Use parking_lot instead of std::sync for Mutex/RwLock
+condition:
+  - "\\.lock\\(\\)\\.unwrap\\(\\)"
+  - "\\.read\\(\\)\\.unwrap\\(\\)"
+  - "\\.write\\(\\)\\.unwrap\\(\\)"
+scope: "tool:edit(*.rs), tool:write(*.rs)"
+---
+
+Use `parking_lot::{Mutex, RwLock}` instead of `std::sync::{Mutex, RwLock}` when code immediately unwraps lock results.
+
+## Why
+
+- `lock()`, `read()`, and `write()` return guards directly.
+- No poisoning error path to unwrap.
+- Guards are smaller and faster in common contention cases.
+- The call site shows locking, not error handling boilerplate.
+
+## Migration
+
+```rust
+// Before
+use std::sync::Mutex;
+let data = Mutex::new(Vec::new());
+let guard = data.lock().unwrap();
+
+// After
+use parking_lot::Mutex;
+let data = Mutex::new(Vec::new());
+let guard = data.lock();
+```
+
+## Equivalents
+
+| std::sync | parking_lot |
+| --- | --- |
+| `Mutex<T>` | `Mutex<T>` |
+| `RwLock<T>` | `RwLock<T>` |
+| `Condvar` | `Condvar` |
+| `Once` | `Once` |
+
+## Keep async locks async
+
+Use `tokio::sync::Mutex` / `tokio::sync::RwLock` when a guard is held across `.await` or the lock belongs to async coordination.
diff --git a/packages/coding-agent/src/discovery/builtin-rules/rs-result-type.md b/packages/coding-agent/src/discovery/builtin-rules/rs-result-type.md
new file mode 100644
index 000000000..6515e0736
--- /dev/null
+++ b/packages/coding-agent/src/discovery/builtin-rules/rs-result-type.md
@@ -0,0 +1,19 @@
+---
+description: Result type aliases must include a defaulted error type parameter
+condition: "type\\s+Result<[A-Za-z_]\\w*>\\s*="
+scope: "tool:edit(*.rs), tool:write(*.rs)"
+---
+
+`Result` aliases must expose the error type as a defaulted parameter.
+
+```rust
+pub type Result<T, E = anyhow::Error> = std::result::Result<T, E>;
+```
+
+Never write:
+
+```rust
+type Result<T> = std::result::Result<T, anyhow::Error>;
+```
+
+The default keeps common call sites short while preserving escape hatches for precise errors.
diff --git a/packages/coding-agent/src/discovery/builtin-rules/ts-bare-catch.md b/packages/coding-agent/src/discovery/builtin-rules/ts-bare-catch.md
new file mode 100644
index 000000000..accc6a95d
--- /dev/null
+++ b/packages/coding-agent/src/discovery/builtin-rules/ts-bare-catch.md
@@ -0,0 +1,38 @@
+---
+description: Use bare `catch {` when the error binding is unused
+condition: "catch \\(_"
+scope: "tool:edit(*.ts), tool:edit(*.tsx), tool:write(*.ts), tool:write(*.tsx)"
+---
+
+Use bare `catch {}` when the caught value is unused. An underscore-prefixed binding adds noise and still allocates a local name.
+
+## Replace
+
+```typescript
+// Bad
+try {
+	await loadConfig();
+} catch (_err) {
+	return null;
+}
+
+// Good
+try {
+	await loadConfig();
+} catch {
+	return null;
+}
+```
+
+## Keep a real name when used
+
+```typescript
+try {
+	await saveConfig();
+} catch (err) {
+	logger.error("save failed", { err });
+	throw err;
+}
+```
+
+Unused error? Bare `catch`. Used error? Name it for what it carries.
diff --git a/packages/coding-agent/src/discovery/builtin-rules/ts-import-type.md b/packages/coding-agent/src/discovery/builtin-rules/ts-import-type.md
new file mode 100644
index 000000000..5bf88d830
--- /dev/null
+++ b/packages/coding-agent/src/discovery/builtin-rules/ts-import-type.md
@@ -0,0 +1,42 @@
+---
+description: "Use `import type`, not `import('pkg').Type` in type positions"
+condition: "import\\("
+scope: "tool:edit(*.ts), tool:edit(*.tsx), tool:write(*.ts), tool:write(*.tsx)"
+---
+
+Use top-level `import type` declarations for type-only dependencies. NEVER write `import("pkg").Type` inside source annotations.
+
+## Why
+
+- Top-level imports expose dependencies immediately.
+- Import sorting and deduplication can manage them.
+- Signatures stay readable and reviewable.
+- Re-exports do not inherit noisy inline paths.
+
+## Avoid
+
+```typescript
+// Bad — inline imports hide dependencies in signatures.
+function run(client: import("some-sdk").Client, input: import("zod/v4").infer<Schema>): Promise<Output>;
+
+// Bad — annotations become path dumps.
+const options: import("some-sdk/config").ClientOptions = { ... };
+```
+
+## Use
+
+```typescript
+import type { Client } from "some-sdk";
+import type { ClientOptions } from "some-sdk/config";
+import type { infer as Infer } from "zod/v4";
+
+function run(client: Client, input: Infer<Schema>): Promise<Output>;
+const options: ClientOptions = { ... };
+```
+
+## Exceptions
+
+- Ambient `.d.ts` globals that must not become modules.
+- Generated files whose generator owns import management.
+
+In normal `.ts` / `.tsx` source, use `import type`.
diff --git a/packages/coding-agent/src/discovery/builtin-rules/ts-no-any.md b/packages/coding-agent/src/discovery/builtin-rules/ts-no-any.md
new file mode 100644
index 000000000..d2df70b96
--- /dev/null
+++ b/packages/coding-agent/src/discovery/builtin-rules/ts-no-any.md
@@ -0,0 +1,56 @@
+---
+description: "Never use `any` in TypeScript annotations or assertions — use `unknown`, generics, or the actual type"
+condition: ": any|as any"
+scope: "tool:edit(*.ts), tool:edit(*.tsx), tool:write(*.ts), tool:write(*.tsx)"
+---
+
+Never use `: any` or `as any`. They disable type checking exactly where the boundary needs precision.
+
+## Use instead
+
+- `unknown` for unvalidated input.
+- A domain type when the shape is known.
+- A generic when the caller supplies the shape.
+- A type guard when runtime checks establish shape.
+- `satisfies` for object literals that must match a contract.
+
+## Parameters and returns
+
+```typescript
+// Bad
+function readId(value: any): any {
+	return value.id;
+}
+
+// Good — validate unknown input.
+function readId(value: unknown): string | undefined {
+	if (value && typeof value === "object" && "id" in value) {
+		const candidate = (value as { id: unknown }).id;
+		return typeof candidate === "string" ? candidate : undefined;
+	}
+}
+```
+
+## Assertions
+
+```typescript
+// Bad
+const root = document.getElementById("root") as any;
+root.innerText = "ready";
+
+// Good
+const root = document.getElementById("root") as HTMLElement | null;
+root?.innerText = "ready";
+```
+
+## Object literals
+
+```typescript
+// Bad
+const config = { port: 3000 } as any as ServerConfig;
+
+// Good
+const config = { port: 3000 } satisfies ServerConfig;
+```
+
+If a library boundary truly requires an unchecked cast, use `as unknown as T` with a short reason. Never leave a bare `any`.
diff --git a/packages/coding-agent/src/discovery/builtin-rules/ts-no-dynamic-import.md b/packages/coding-agent/src/discovery/builtin-rules/ts-no-dynamic-import.md
new file mode 100644
index 000000000..831aed215
--- /dev/null
+++ b/packages/coding-agent/src/discovery/builtin-rules/ts-no-dynamic-import.md
@@ -0,0 +1,39 @@
+---
+description: "Do not use `await import()` — use static imports unless dynamic loading is unavoidable"
+condition: "await import\\("
+scope: "tool:edit(*.ts), tool:edit(*.tsx), tool:write(*.ts), tool:write(*.tsx)"
+---
+
+Use static imports for modules known at author time. Reach for `await import()` only when the module specifier is genuinely runtime-selected.
+
+## Why
+
+- Static imports fail during build, not under load.
+- Bundlers, type checkers, and tree shakers see them.
+- The dependency graph remains reviewable.
+- Consumers keep precise module types without casts.
+
+## Avoid
+
+```typescript
+// Bad — the module path is a literal.
+const { createClient } = await import("some-sdk");
+
+// Bad — dynamic import followed by a shape assertion.
+const mod = (await import("./known-module")) as { run?: unknown };
+```
+
+## Use
+
+```typescript
+import { createClient } from "some-sdk";
+import { run } from "./known-module";
+```
+
+## Exceptions
+
+- Plugin loading from a runtime registry.
+- Platform-specific modules that do not exist everywhere.
+- Test cases that intentionally exercise module loading boundaries.
+
+Exception? Add a short comment naming why static import cannot work.
diff --git a/packages/coding-agent/src/discovery/builtin-rules/ts-no-return-type.md b/packages/coding-agent/src/discovery/builtin-rules/ts-no-return-type.md
new file mode 100644
index 000000000..cbba659af
--- /dev/null
+++ b/packages/coding-agent/src/discovery/builtin-rules/ts-no-return-type.md
@@ -0,0 +1,45 @@
+---
+description: "Do not use `ReturnType<typeof fn>` — name the type explicitly"
+condition: "ReturnType<"
+scope: "tool:edit(*.ts), tool:edit(*.tsx), tool:write(*.ts), tool:write(*.tsx)"
+---
+
+Do not publish contracts through `ReturnType<typeof fn>`. Name the type at the module that owns the value and import that name at consumers.
+
+## Why
+
+- Named types document the contract directly.
+- Consumers stop coupling to implementation helpers.
+- JSDoc and changelog notes attach to the exported type.
+- Type errors point at the intended API boundary.
+
+## Avoid
+
+```typescript
+// Bad — opaque and coupled to implementation names.
+type Config = Awaited<ReturnType<typeof loadConfig>>;
+type Message = ReturnType<typeof buildMessage>["message"];
+let service: ReturnType<typeof createService> | undefined;
+```
+
+## Use
+
+```typescript
+// In the module that owns the function:
+export interface LoadedConfig {
+	path: string;
+	values: Record<string, unknown>;
+}
+
+export function loadConfig(path: string): Promise<LoadedConfig> { ... }
+
+// At the consumer:
+import type { LoadedConfig } from "./config";
+```
+
+## Exceptions
+
+- Timer handles: `ReturnType<typeof setTimeout>` / `setInterval`.
+- Generic type utilities where the function is a type parameter.
+
+Concrete function? Export a concrete type.
diff --git a/packages/coding-agent/src/discovery/builtin-rules/ts-no-tiny-functions.md b/packages/coding-agent/src/discovery/builtin-rules/ts-no-tiny-functions.md
new file mode 100644
index 000000000..a359fc4dc
--- /dev/null
+++ b/packages/coding-agent/src/discovery/builtin-rules/ts-no-tiny-functions.md
@@ -0,0 +1,50 @@
+---
+description: "Do not extract 1-2 line functions that only wrap an expression — inline them"
+condition: "\\{\\s*return [^;{}\\n]+;?\\s*\\}|\\b(?:const|let|var)\\s+[\\w$]+\\s*=\\s*(\\([^)]*\\)|[a-zA-Z_$][\\w$]*)\\s*=>\\s*[^{\\n]+$"
+scope: "tool:edit(*.ts), tool:edit(*.tsx), tool:write(*.ts), tool:write(*.tsx)"
+interruptMode: never
+---
+
+Do not extract a function whose whole body is one expression or one `return`. Inline it unless the name creates a durable contract.
+
+## Why
+
+- One-line wrappers hide no real behavior.
+- Readers must jump to verify trivial code.
+- The signature freezes a shape too early.
+- Search and type flow work better with inline expressions.
+
+## Avoid
+
+```typescript
+// Bad — pure rename, no behavior added.
+function isEmpty(value: string): boolean {
+	return value.length === 0;
+}
+
+const getDisplayName = (user: User) => user.profile.displayName;
+
+function double(value: number) {
+	return value * 2;
+}
+
+if (isEmpty(name)) { ... }
+```
+
+## Use
+
+```typescript
+if (name.length === 0) { ... }
+const displayName = user.profile.displayName;
+const doubled = value * 2;
+```
+
+## Allowed tiny functions
+
+- Three or more call sites need lockstep behavior.
+- Exported name represents a stable domain concept.
+- Callback identity matters.
+- Type guard preserves narrowing.
+- Public API, test seam, or DI boundary needs indirection.
+
+If none apply, inline it.
diff --git a/packages/coding-agent/src/discovery/builtin-rules/ts-promise-with-resolvers.md b/packages/coding-agent/src/discovery/builtin-rules/ts-promise-with-resolvers.md
new file mode 100644
index 000000000..27d14a62f
--- /dev/null
+++ b/packages/coding-agent/src/discovery/builtin-rules/ts-promise-with-resolvers.md
@@ -0,0 +1,65 @@
+---
+description: Use Promise.withResolvers() instead of new Promise() constructor
+condition: "new Promise\\("
+scope: "tool:edit(*.ts), tool:edit(*.tsx), tool:write(*.ts), tool:write(*.tsx)"
+---
+
+Use `Promise.withResolvers()` instead of `new Promise((resolve, reject) => ...)`. It keeps control flow linear and exposes typed resolver functions without callback nesting.
+
+## Basic operation
+
+```typescript
+// Bad
+function delay(ms: number): Promise<void> {
+	return new Promise(resolve => {
+		setTimeout(resolve, ms);
+	});
+}
+
+// Good
+function delay(ms: number): Promise<void> {
+	const { promise, resolve } = Promise.withResolvers<void>();
+	setTimeout(resolve, ms);
+	return promise;
+}
+```
+
+## Event-based completion
+
+```typescript
+// Bad
+function waitForEvent(emitter: EventEmitter, event: string): Promise<unknown> {
+	return new Promise((resolve, reject) => {
+		emitter.once(event, resolve);
+		emitter.once("error", reject);
+	});
+}
+
+// Good
+function waitForEvent(emitter: EventEmitter, event: string): Promise<unknown> {
+	const { promise, resolve, reject } = Promise.withResolvers<unknown>();
+	emitter.once(event, resolve);
+	emitter.once("error", reject);
+	return promise;
+}
+```
+
+## Stored resolver
+
+```typescript
+class Gate {
+	#promise: Promise<void>;
+	#resolve: () => void;
+
+	constructor() {
+		const { promise, resolve } = Promise.withResolvers<void>();
+		this.#promise = promise;
+		this.#resolve = resolve;
+	}
+
+	open(): void { this.#resolve(); }
+	wait(): Promise<void> { return this.#promise; }
+}
+```
+
+Use the constructor only when an API specifically requires the executor form.
diff --git a/packages/coding-agent/src/discovery/builtin-rules/ts-set-map.md b/packages/coding-agent/src/discovery/builtin-rules/ts-set-map.md
new file mode 100644
index 000000000..7cca8e11f
--- /dev/null
+++ b/packages/coding-agent/src/discovery/builtin-rules/ts-set-map.md
@@ -0,0 +1,28 @@
+---
+description: Prefer Record<K, V> for small static literals; use Set/Map for anything dynamic
+condition: "\\bnew\\s+(Set|Map)\\b"
+scope: "tool:edit(**/*.{ts,tsx}), tool:write(**/*.{ts,tsx})"
+interruptMode: never
+---
+
+Use `Record<K, V>` / `Record<K, true>` for small, static string-keyed lookup tables.
+
+Use `Set` / `Map` when keys are dynamic, non-string, inserted or deleted at runtime, or when code needs `.size`, `.clear()`, stable insertion order, or iterator APIs.
+
+```typescript
+// Static literal → Record
+const LABEL_BY_KIND: Record<string, string> = {
+	text: "Text",
+	json: "JSON",
+	binary: "Binary",
+};
+
+// Dynamic membership → Set
+const seen = new Set<string>();
+for (const item of items) {
+	if (seen.has(item.id)) continue;
+	seen.add(item.id);
+}
+```
+
+Small fixed table? `Record`. Runtime collection? `Set` / `Map`.
diff --git a/packages/coding-agent/src/discovery/index.ts b/packages/coding-agent/src/discovery/index.ts
index 5b9c16847..c5ed5fd00 100644
--- a/packages/coding-agent/src/discovery/index.ts
+++ b/packages/coding-agent/src/discovery/index.ts
@@ -22,6 +22,7 @@ import "../capability/tool";
 // Import providers (each registers itself on import)
 import "./agents-md";
 import "./builtin";
+import "./builtin-defaults";
 import "./claude";
 import "./claude-plugins";
 import "./cline";
diff --git a/packages/coding-agent/src/export/ttsr.ts b/packages/coding-agent/src/export/ttsr.ts
index bdc0f47e9..ae0710bdf 100644
--- a/packages/coding-agent/src/export/ttsr.ts
+++ b/packages/coding-agent/src/export/ttsr.ts
@@ -54,6 +54,8 @@ const DEFAULT_SETTINGS: Required<TtsrSettings> = {
 	interruptMode: "always",
 	repeatMode: "once",
 	repeatGap: 10,
+	builtinRules: true,
+	disabledRules: [],
 };
 
 const DEFAULT_SCOPE: TtsrScope = {
diff --git a/packages/coding-agent/src/sdk.ts b/packages/coding-agent/src/sdk.ts
index 315e413bf..86ad1297e 100644
--- a/packages/coding-agent/src/sdk.ts
+++ b/packages/coding-agent/src/sdk.ts
@@ -38,6 +38,7 @@ import { type AsyncJob, AsyncJobManager, isBackgroundJobSupportEnabled } from ".
 import { createAutoresearchExtension } from "./autoresearch";
 import { loadCapability } from "./capability";
 import { type Rule, ruleCapability, setActiveRules } from "./capability/rule";
+import { bucketRules } from "./capability/rule-buckets";
 import { ModelRegistry } from "./config/model-registry";
 import {
 	formatModelString,
@@ -1045,21 +1046,10 @@ export async function createAgentSession(options: CreateAgentSessionOptions = {}
 			options.rules !== undefined
 				? { items: options.rules, warnings: undefined }
 				: await loadCapability<Rule>(ruleCapability.id, { cwd });
-		const rulebookRules: Rule[] = [];
-		const alwaysApplyRules: Rule[] = [];
-		for (const rule of rulesResult.items) {
-			const isTtsrRule = rule.condition && rule.condition.length > 0 ? ttsrManager.addRule(rule) : false;
-			if (isTtsrRule) {
-				continue;
-			}
-			if (rule.alwaysApply === true) {
-				alwaysApplyRules.push(rule);
-				continue;
-			}
-			if (rule.description) {
-				rulebookRules.push(rule);
-			}
-		}
+		const { rulebookRules, alwaysApplyRules } = bucketRules(rulesResult.items, ttsrManager, {
+			builtinRules: ttsrSettings.builtinRules,
+			disabledRules: ttsrSettings.disabledRules,
+		});
 		if (existingSession.injectedTtsrRules.length > 0) {
 			ttsrManager.restoreInjected(existingSession.injectedTtsrRules);
 		}
diff --git a/packages/coding-agent/test/capability/rule-buckets.test.ts b/packages/coding-agent/test/capability/rule-buckets.test.ts
new file mode 100644
index 000000000..96bbfa273
--- /dev/null
+++ b/packages/coding-agent/test/capability/rule-buckets.test.ts
@@ -0,0 +1,99 @@
+import { describe, expect, it } from "bun:test";
+import { BUILTIN_DEFAULTS_PROVIDER_ID, type Rule } from "@oh-my-pi/pi-coding-agent/capability/rule";
+import { bucketRules } from "@oh-my-pi/pi-coding-agent/capability/rule-buckets";
+import { TtsrManager } from "@oh-my-pi/pi-coding-agent/export/ttsr";
+
+function source(provider: string): Rule["_source"] {
+	return { provider, providerName: provider, path: "/tmp/rule.md", level: "user" };
+}
+
+function makeRule(partial: Partial<Rule>): Rule {
+	return {
+		name: partial.name ?? "rule",
+		path: partial.path ?? "/tmp/rule.md",
+		content: partial.content ?? "body",
+		globs: partial.globs,
+		alwaysApply: partial.alwaysApply,
+		description: partial.description,
+		condition: partial.condition,
+		scope: partial.scope,
+		interruptMode: partial.interruptMode,
+		_source: partial._source ?? source("native"),
+	};
+}
+
+describe("bucketRules", () => {
+	it("registers a condition rule as TTSR and excludes it from rulebook/always buckets", () => {
+		const mgr = new TtsrManager();
+		const ttsr = makeRule({ name: "no-foo", condition: ["FORBIDDEN"], description: "blocks foo" });
+
+		const { rulebookRules, alwaysApplyRules } = bucketRules([ttsr], mgr);
+
+		expect(rulebookRules).toHaveLength(0);
+		expect(alwaysApplyRules).toHaveLength(0);
+		expect(mgr.checkDelta("contains FORBIDDEN token", { source: "text" }).map(r => r.name)).toEqual(["no-foo"]);
+	});
+
+	it("splits non-TTSR rules into always-apply and rulebook by metadata", () => {
+		const mgr = new TtsrManager();
+		const sticky = makeRule({ name: "sticky", alwaysApply: true, description: "sticky desc" });
+		const book = makeRule({ name: "book", description: "rulebook desc" });
+		const orphan = makeRule({ name: "orphan" });
+
+		const { rulebookRules, alwaysApplyRules } = bucketRules([sticky, book, orphan], mgr);
+
+		expect(alwaysApplyRules.map(r => r.name)).toEqual(["sticky"]);
+		expect(rulebookRules.map(r => r.name)).toEqual(["book"]);
+		expect(mgr.hasRules()).toBe(false);
+	});
+
+	it("disabledRules drops a rule from every bucket and from TTSR registration", () => {
+		const mgr = new TtsrManager();
+		const ttsr = makeRule({ name: "no-foo", condition: ["FORBIDDEN"], description: "blocks foo" });
+		const book = makeRule({ name: "book", description: "rulebook desc" });
+
+		const { rulebookRules } = bucketRules([ttsr, book], mgr, { disabledRules: ["no-foo", "book"] });
+
+		expect(rulebookRules).toHaveLength(0);
+		expect(mgr.hasRules()).toBe(false);
+		expect(mgr.checkDelta("contains FORBIDDEN token", { source: "text" })).toHaveLength(0);
+	});
+
+	it("disabledRules trims entries and ignores blanks", () => {
+		const mgr = new TtsrManager();
+		const ttsr = makeRule({ name: "no-foo", condition: ["FORBIDDEN"] });
+
+		bucketRules([ttsr], mgr, { disabledRules: ["  no-foo  ", "", "   "] });
+
+		expect(mgr.hasRules()).toBe(false);
+	});
+
+	it("builtinRules:false drops builtin-defaults rules but keeps the rest", () => {
+		const mgr = new TtsrManager();
+		const builtin = makeRule({
+			name: "builtin-foo",
+			condition: ["FORBIDDEN"],
+			_source: source(BUILTIN_DEFAULTS_PROVIDER_ID),
+		});
+		const userRule = makeRule({ name: "user-foo", condition: ["BANNED"], _source: source("native") });
+
+		bucketRules([builtin, userRule], mgr, { builtinRules: false });
+
+		expect(mgr.checkDelta("contains FORBIDDEN token", { source: "text" })).toHaveLength(0);
+		mgr.resetBuffer();
+		expect(mgr.checkDelta("contains BANNED token", { source: "text" }).map(r => r.name)).toEqual(["user-foo"]);
+	});
+
+	it("includes builtin-defaults rules when builtinRules is unset (default on)", () => {
+		const mgr = new TtsrManager();
+		const builtin = makeRule({
+			name: "builtin-foo",
+			condition: ["FORBIDDEN"],
+			_source: source(BUILTIN_DEFAULTS_PROVIDER_ID),
+		});
+
+		bucketRules([builtin], mgr);
+
+		expect(mgr.checkDelta("contains FORBIDDEN token", { source: "text" }).map(r => r.name)).toEqual(["builtin-foo"]);
+	});
+});
diff --git a/packages/coding-agent/test/discovery/builtin-defaults.test.ts b/packages/coding-agent/test/discovery/builtin-defaults.test.ts
new file mode 100644
index 000000000..0664c5fe0
--- /dev/null
+++ b/packages/coding-agent/test/discovery/builtin-defaults.test.ts
@@ -0,0 +1,80 @@
+/**
+ * The bundled `builtin-defaults` rule provider ships a curated default rule set
+ * embedded into the binary. These tests defend that the whole set loads and
+ * parses, and that the provider sits at the lowest priority so any user/project
+ * rule of the same name overrides a bundled default (first-wins dedup).
+ */
+import { describe, expect, it } from "bun:test";
+import { getCapability } from "@oh-my-pi/pi-coding-agent/capability";
+import { BUILTIN_DEFAULTS_PROVIDER_ID, type Rule, ruleCapability } from "@oh-my-pi/pi-coding-agent/capability/rule";
+import type { LoadContext } from "@oh-my-pi/pi-coding-agent/capability/types";
+// Register all discovery providers as a side effect.
+import "@oh-my-pi/pi-coding-agent/discovery";
+
+const EXPECTED_RULE_NAMES = [
+	"rs-box-leak",
+	"rs-future-prelude",
+	"rs-lazylock",
+	"rs-match-ergonomics",
+	"rs-parking-lot",
+	"rs-result-type",
+	"ts-bare-catch",
+	"ts-import-type",
+	"ts-no-any",
+	"ts-no-dynamic-import",
+	"ts-no-return-type",
+	"ts-no-tiny-functions",
+	"ts-promise-with-resolvers",
+	"ts-set-map",
+].sort();
+
+function ruleProvider() {
+	const cap = getCapability(ruleCapability.id);
+	if (!cap) throw new Error("rules capability missing");
+	const provider = cap.providers.find(p => p.id === BUILTIN_DEFAULTS_PROVIDER_ID);
+	if (!provider) throw new Error("builtin-defaults provider missing");
+	return { cap, provider };
+}
+
+async function loadBuiltinRules(): Promise<Rule[]> {
+	const { provider } = ruleProvider();
+	const ctx: LoadContext = { cwd: "/tmp", home: "/tmp/home", repoRoot: null };
+	const result = await (provider.load as (ctx: LoadContext) => Promise<{ items: Rule[] }>)(ctx);
+	return result.items;
+}
+
+describe("builtin-defaults rule provider", () => {
+	it("loads exactly the bundled default rule set, all attributed to the provider", async () => {
+		const rules = await loadBuiltinRules();
+		const names = rules.map(r => r.name).sort();
+		expect(names).toEqual(EXPECTED_RULE_NAMES);
+		expect(rules.every(r => r._source.provider === BUILTIN_DEFAULTS_PROVIDER_ID)).toBe(true);
+	});
+
+	it("parses every bundled rule as a TTSR rule (non-empty condition and scope)", async () => {
+		const rules = await loadBuiltinRules();
+		for (const rule of rules) {
+			expect(rule.condition?.length, `${rule.name} condition`).toBeGreaterThan(0);
+			expect(rule.scope?.length, `${rule.name} scope`).toBeGreaterThan(0);
+		}
+	});
+
+	it("parses YAML list-form conditions from the embedded text", async () => {
+		const rules = await loadBuiltinRules();
+		const lazylock = rules.find(r => r.name === "rs-lazylock");
+		// Frontmatter declares two condition patterns as a YAML sequence.
+		expect(lazylock?.condition).toHaveLength(2);
+	});
+
+	it("preserves a per-rule interruptMode override from frontmatter", async () => {
+		const rules = await loadBuiltinRules();
+		expect(rules.find(r => r.name === "ts-set-map")?.interruptMode).toBe("never");
+	});
+
+	it("is the lowest-priority rule provider so user/project rules override defaults", () => {
+		const { cap, provider } = ruleProvider();
+		const others = cap.providers.filter(p => p.id !== BUILTIN_DEFAULTS_PROVIDER_ID);
+		expect(others.length).toBeGreaterThan(0);
+		expect(others.every(p => p.priority > provider.priority)).toBe(true);
+	});
+});
diff --git a/packages/coding-agent/test/tiny-device.test.ts b/packages/coding-agent/test/tiny-device.test.ts
index 33337c9b6..6757070c7 100644
--- a/packages/coding-agent/test/tiny-device.test.ts
+++ b/packages/coding-agent/test/tiny-device.test.ts
@@ -2,8 +2,8 @@ import { describe, expect, it } from "bun:test";
 import {
 	normalizeTinyModelDevice,
 	resolveTinyModelDevicePreference,
-	tinyModelDeviceLoadOrder,
 	type TinyModelDevice,
+	tinyModelDeviceLoadOrder,
 } from "../src/tiny/device";
 
 function expectedDefaultDevice(): TinyModelDevice {