diff --git a/packages/agent/src/harness/agent-harness.ts b/packages/agent/src/harness/agent-harness.ts
index cbc2d0a4a..c8004aa0d 100644
--- a/packages/agent/src/harness/agent-harness.ts
+++ b/packages/agent/src/harness/agent-harness.ts
@@ -529,7 +529,7 @@ export class AgentHarness<
 			} else if (write.type === "session_info") {
 				await this.session.appendSessionName(write.name ?? "");
 			} else if (write.type === "leaf") {
-				await this.session.getStorage().setLeafId(write.targetId);
+				await this.session.moveTo(write.targetId);
 			}
 			this.pendingSessionWrites.shift();
 		}
diff --git a/packages/agent/src/harness/session/jsonl-repo.ts b/packages/agent/src/harness/session/jsonl-repo.ts
index f1f165223..62fcec5b3 100644
--- a/packages/agent/src/harness/session/jsonl-repo.ts
+++ b/packages/agent/src/harness/session/jsonl-repo.ts
@@ -5,12 +5,15 @@ import type {
 	JsonlSessionMetadata,
 	JsonlSessionRepoApi,
 	Session,
+	SessionSearchHit,
+	SessionSearchOptions,
 } from "../types.ts";
 import { SessionError, toError } from "../types.ts";
 import { JsonlSessionStorage, loadJsonlSessionMetadata } from "./jsonl-storage.ts";
 import {
 	createSessionId,
 	createTimestamp,
+	findSessionEntryMatches,
 	getEntriesToFork,
 	getFileSystemResultOrThrow,
 	toSession,
@@ -124,6 +127,15 @@ export class JsonlSessionRepo implements JsonlSessionRepoApi {
 		return sessions;
 	}
 
+	async search(options: SessionSearchOptions): Promise<SessionSearchHit<JsonlSessionMetadata>[]> {
+		const hits: SessionSearchHit<JsonlSessionMetadata>[] = [];
+		for (const metadata of await this.list({ cwd: options.cwd })) {
+			const session = await this.open(metadata);
+			hits.push(...findSessionEntryMatches(metadata, await session.getEntries(), options.text));
+		}
+		return hits;
+	}
+
 	async delete(metadata: JsonlSessionMetadata): Promise<void> {
 		getFileSystemResultOrThrow(
 			await this.fs.remove(metadata.path, { force: true }),
diff --git a/packages/agent/src/harness/session/jsonl-storage.ts b/packages/agent/src/harness/session/jsonl-storage.ts
index fea97fbdc..943ccfb0a 100644
--- a/packages/agent/src/harness/session/jsonl-storage.ts
+++ b/packages/agent/src/harness/session/jsonl-storage.ts
@@ -251,7 +251,7 @@ export class JsonlSessionStorage implements SessionStorage<JsonlSessionMetadata>
 		return this.currentLeafId;
 	}
 
-	async setLeafId(leafId: string | null): Promise<void> {
+	async setLeafId(leafId: string | null): Promise<LeafEntry> {
 		if (leafId !== null && !this.byId.has(leafId)) {
 			throw new SessionError("not_found", `Entry ${leafId} not found`);
 		}
@@ -269,6 +269,7 @@ export class JsonlSessionStorage implements SessionStorage<JsonlSessionMetadata>
 		this.entries.push(entry);
 		this.byId.set(entry.id, entry);
 		this.currentLeafId = leafId;
+		return entry;
 	}
 
 	async createEntryId(): Promise<string> {
diff --git a/packages/agent/src/harness/session/memory-repo.ts b/packages/agent/src/harness/session/memory-repo.ts
index 145bc2b7c..34ab0ffe5 100644
--- a/packages/agent/src/harness/session/memory-repo.ts
+++ b/packages/agent/src/harness/session/memory-repo.ts
@@ -1,6 +1,19 @@
-import { type Session, SessionError, type SessionMetadata, type SessionRepo } from "../types.ts";
+import {
+	type Session,
+	SessionError,
+	type SessionMetadata,
+	type SessionRepo,
+	type SessionSearchHit,
+	type SessionSearchOptions,
+} from "../types.ts";
 import { InMemorySessionStorage } from "./memory-storage.ts";
-import { createSessionId, createTimestamp, getEntriesToFork, toSession } from "./repo-utils.ts";
+import {
+	createSessionId,
+	createTimestamp,
+	findSessionEntryMatches,
+	getEntriesToFork,
+	toSession,
+} from "./repo-utils.ts";
 
 export class InMemorySessionRepo implements SessionRepo<SessionMetadata, { id?: string }, void> {
 	private sessions = new Map<string, Session<SessionMetadata>>();
@@ -28,6 +41,15 @@ export class InMemorySessionRepo implements SessionRepo<SessionMetadata, { id?:
 		return Promise.all([...this.sessions.values()].map((session) => session.getMetadata()));
 	}
 
+	async search(options: SessionSearchOptions): Promise<SessionSearchHit<SessionMetadata>[]> {
+		const hits: SessionSearchHit<SessionMetadata>[] = [];
+		for (const session of this.sessions.values()) {
+			const metadata = await session.getMetadata();
+			hits.push(...findSessionEntryMatches(metadata, await session.getEntries(), options.text));
+		}
+		return hits;
+	}
+
 	async delete(metadata: SessionMetadata): Promise<void> {
 		this.sessions.delete(metadata.id);
 	}
diff --git a/packages/agent/src/harness/session/memory-storage.ts b/packages/agent/src/harness/session/memory-storage.ts
index 1bc24f04f..d8e53be3b 100644
--- a/packages/agent/src/harness/session/memory-storage.ts
+++ b/packages/agent/src/harness/session/memory-storage.ts
@@ -72,7 +72,7 @@ export class InMemorySessionStorage<TMetadata extends SessionMetadata = SessionM
 		return this.leafId;
 	}
 
-	async setLeafId(leafId: string | null): Promise<void> {
+	async setLeafId(leafId: string | null): Promise<LeafEntry> {
 		if (leafId !== null && !this.byId.has(leafId)) {
 			throw new SessionError("not_found", `Entry ${leafId} not found`);
 		}
@@ -86,6 +86,7 @@ export class InMemorySessionStorage<TMetadata extends SessionMetadata = SessionM
 		this.entries.push(entry);
 		this.byId.set(entry.id, entry);
 		this.leafId = leafId;
+		return entry;
 	}
 
 	async createEntryId(): Promise<string> {
diff --git a/packages/agent/src/harness/session/repo-utils.ts b/packages/agent/src/harness/session/repo-utils.ts
index fd6ee4f2a..e830e7678 100644
--- a/packages/agent/src/harness/session/repo-utils.ts
+++ b/packages/agent/src/harness/session/repo-utils.ts
@@ -4,6 +4,8 @@ import {
 	type Result,
 	SessionError,
 	type SessionMetadata,
+	type SessionSearchHit,
+	type SessionSearchIndexSink,
 	type SessionStorage,
 	type SessionTreeEntry,
 } from "../types.ts";
@@ -17,8 +19,25 @@ export function createTimestamp(): string {
 	return new Date().toISOString();
 }
 
-export function toSession<TMetadata extends SessionMetadata>(storage: SessionStorage<TMetadata>): Session<TMetadata> {
-	return new Session(storage);
+export function toSession<TMetadata extends SessionMetadata>(
+	storage: SessionStorage<TMetadata>,
+	searchIndexSink?: SessionSearchIndexSink,
+): Session<TMetadata> {
+	return new Session(storage, {}, searchIndexSink);
+}
+
+export function findSessionEntryMatches<TMetadata extends SessionMetadata>(
+	metadata: TMetadata,
+	entries: SessionTreeEntry[],
+	text: string,
+): SessionSearchHit<TMetadata>[] {
+	const normalizedText = text.trim().toLowerCase();
+	if (!normalizedText) return [];
+	return entries.flatMap((entry) => {
+		const payload = JSON.stringify(entry);
+		if (!payload.toLowerCase().includes(normalizedText)) return [];
+		return [{ metadata, entryId: entry.id, timestamp: entry.timestamp, snippet: payload }];
+	});
 }
 
 export function getFileSystemResultOrThrow<TValue>(result: Result<TValue, FileError>, message: string): TValue {
diff --git a/packages/agent/src/harness/session/search-index-sink.ts b/packages/agent/src/harness/session/search-index-sink.ts
new file mode 100644
index 000000000..7745e99cd
--- /dev/null
+++ b/packages/agent/src/harness/session/search-index-sink.ts
@@ -0,0 +1,8 @@
+import type { SessionMetadata, SessionSearchIndexRecord, SessionTreeEntry } from "../types.ts";
+
+export function toSessionSearchIndexRecord<TMetadata extends SessionMetadata>(
+	metadata: TMetadata,
+	entry: SessionTreeEntry,
+): SessionSearchIndexRecord<TMetadata> {
+	return { metadata, entry };
+}
diff --git a/packages/agent/src/harness/session/session.ts b/packages/agent/src/harness/session/session.ts
index 13007bc65..6e380f519 100644
--- a/packages/agent/src/harness/session/session.ts
+++ b/packages/agent/src/harness/session/session.ts
@@ -14,12 +14,14 @@ import type {
 	SessionEntryCursorOptions,
 	SessionInfoEntry,
 	SessionMetadata,
+	SessionSearchIndexSink,
 	SessionStats,
 	SessionStorage,
 	SessionTreeEntry,
 	ThinkingLevelChangeEntry,
 } from "../types.ts";
 import { SessionError } from "../types.ts";
+import { toSessionSearchIndexRecord } from "./search-index-sink.ts";
 
 export type ContextEntryTransform = (entries: readonly SessionTreeEntry[]) => readonly SessionTreeEntry[];
 
@@ -150,10 +152,16 @@ export function buildSessionContext(
 export class Session<TMetadata extends SessionMetadata = SessionMetadata> {
 	private storage: SessionStorage<TMetadata>;
 	private contextBuildOptions: SessionContextBuildOptions;
+	private searchIndexSink: SessionSearchIndexSink | undefined;
 
-	constructor(storage: SessionStorage<TMetadata>, contextBuildOptions: SessionContextBuildOptions = {}) {
+	constructor(
+		storage: SessionStorage<TMetadata>,
+		contextBuildOptions: SessionContextBuildOptions = {},
+		searchIndexSink?: SessionSearchIndexSink,
+	) {
 		this.storage = storage;
 		this.contextBuildOptions = contextBuildOptions;
+		this.searchIndexSink = searchIndexSink;
 	}
 
 	getMetadata(): Promise<TMetadata> {
@@ -211,8 +219,15 @@ export class Session<TMetadata extends SessionMetadata = SessionMetadata> {
 		return this.storage.getSessionName();
 	}
 
+	private async writeSearchIndexRecord(entry: SessionTreeEntry): Promise<void> {
+		if (this.searchIndexSink) {
+			await this.searchIndexSink.write(toSessionSearchIndexRecord(await this.storage.getMetadata(), entry));
+		}
+	}
+
 	private async appendTypedEntry<TEntry extends SessionTreeEntry>(entry: TEntry): Promise<string> {
 		await this.storage.appendEntry(entry);
+		await this.writeSearchIndexRecord(entry);
 		return entry.id;
 	}
 
@@ -342,7 +357,8 @@ export class Session<TMetadata extends SessionMetadata = SessionMetadata> {
 		if (entryId !== null && !(await this.storage.getEntry(entryId))) {
 			throw new SessionError("not_found", `Entry ${entryId} not found`);
 		}
-		await this.storage.setLeafId(entryId);
+		const leafEntry = await this.storage.setLeafId(entryId);
+		await this.writeSearchIndexRecord(leafEntry);
 		if (!summary) return undefined;
 		return this.appendTypedEntry({
 			type: "branch_summary",
diff --git a/packages/agent/src/harness/types.ts b/packages/agent/src/harness/types.ts
index 7a217ae34..76743791e 100644
--- a/packages/agent/src/harness/types.ts
+++ b/packages/agent/src/harness/types.ts
@@ -499,7 +499,7 @@ export interface SessionStorage<TMetadata extends SessionMetadata = SessionMetad
 	getMetadata(): Promise<TMetadata>;
 	getLeafId(): Promise<string | null>;
 	/** Persist a leaf entry that records the active session-tree leaf. */
-	setLeafId(leafId: string | null): Promise<void>;
+	setLeafId(leafId: string | null): Promise<LeafEntry>;
 	createEntryId(): Promise<string>;
 	appendEntry(entry: SessionTreeEntry): Promise<void>;
 	getEntry(id: string): Promise<SessionTreeEntry | undefined>;
@@ -519,6 +519,30 @@ export interface SessionCreateOptions {
 	id?: string;
 }
 
+export interface SessionSearchOptions {
+	text: string;
+	cwd?: string;
+}
+
+export interface SessionSearchHit<TMetadata extends SessionMetadata = SessionMetadata> {
+	metadata: TMetadata;
+	entryId: string;
+	timestamp: string;
+	snippet?: string;
+	score?: number;
+}
+
+/** A persisted session entry delivered to a search index. */
+export interface SessionSearchIndexRecord<TMetadata extends SessionMetadata = SessionMetadata> {
+	metadata: TMetadata;
+	entry: SessionTreeEntry;
+}
+
+/** Receives entries after their session storage has persisted them for search indexing. */
+export interface SessionSearchIndexSink {
+	write(record: SessionSearchIndexRecord): Promise<void>;
+}
+
 export interface SessionForkOptions {
 	entryId?: string;
 	position?: "before" | "at";
@@ -533,6 +557,7 @@ export interface SessionRepo<
 	create(options: TCreateOptions): Promise<Session<TMetadata>>;
 	open(metadata: TMetadata): Promise<Session<TMetadata>>;
 	list(options?: TListOptions): Promise<TMetadata[]>;
+	search(options: SessionSearchOptions): Promise<SessionSearchHit<TMetadata>[]>;
 	delete(metadata: TMetadata): Promise<void>;
 	fork(source: TMetadata, options: SessionForkOptions & TCreateOptions): Promise<Session<TMetadata>>;
 }
diff --git a/packages/agent/src/index.ts b/packages/agent/src/index.ts
index e9bed1550..c0583af3d 100644
--- a/packages/agent/src/index.ts
+++ b/packages/agent/src/index.ts
@@ -34,6 +34,7 @@ export * from "./harness/session/jsonl-storage.ts";
 export * from "./harness/session/memory-repo.ts";
 export * from "./harness/session/memory-storage.ts";
 export * from "./harness/session/repo-utils.ts";
+export * from "./harness/session/search-index-sink.ts";
 export * from "./harness/session/session.ts";
 export * from "./harness/skills.ts";
 export * from "./harness/system-prompt.ts";
diff --git a/packages/agent/test/harness/repo.test.ts b/packages/agent/test/harness/repo.test.ts
index 009fb0ce7..aeaa5b0f0 100644
--- a/packages/agent/test/harness/repo.test.ts
+++ b/packages/agent/test/harness/repo.test.ts
@@ -22,6 +22,16 @@ describe("InMemorySessionRepo", () => {
 		await repo.delete(metadata);
 		await expect(repo.open(metadata)).rejects.toThrow("Session not found: session-1");
 	});
+
+	it("searches canonical entry JSON", async () => {
+		const repo = new InMemorySessionRepo();
+		const session = await repo.create({ id: "session-1" });
+		const entryId = await session.appendMessage(createUserMessage("Find the auth defect"));
+
+		await expect(repo.search({ text: "AUTH" })).resolves.toEqual([
+			expect.objectContaining({ entryId, metadata: expect.objectContaining({ id: "session-1" }) }),
+		]);
+	});
 });
 
 describe("JsonlSessionRepo", () => {
@@ -44,6 +54,20 @@ describe("JsonlSessionRepo", () => {
 		);
 	});
 
+	it("searches session entries and filters by cwd", async () => {
+		const root = createTempDir();
+		const env = new NodeExecutionEnv({ cwd: root });
+		const repo = new JsonlSessionRepo({ fs: env, sessionsRoot: root });
+		const included = await repo.create({ cwd: "/tmp/included", id: "included" });
+		const excluded = await repo.create({ cwd: "/tmp/excluded", id: "excluded" });
+		const entryId = await included.appendMessage(createUserMessage("Find the auth defect"));
+		await excluded.appendMessage(createUserMessage("Find the auth defect"));
+
+		await expect(repo.search({ text: "AUTH", cwd: "/tmp/included" })).resolves.toEqual([
+			expect.objectContaining({ entryId, metadata: expect.objectContaining({ id: "included" }) }),
+		]);
+	});
+
 	it("opens, deletes, and forks by metadata", async () => {
 		const root = createTempDir();
 		const env = new NodeExecutionEnv({ cwd: root });
diff --git a/packages/agent/test/harness/sqlite-migrations.test.ts b/packages/agent/test/harness/sqlite-migrations.test.ts
index 0cf74938d..6b91eb9d7 100644
--- a/packages/agent/test/harness/sqlite-migrations.test.ts
+++ b/packages/agent/test/harness/sqlite-migrations.test.ts
@@ -5,6 +5,7 @@ import { describe, expect, it } from "vitest";
 import {
 	applyMigrations,
 	createNodeSqliteFactory,
+	loadMigrations,
 	type SqliteDatabase,
 	type SqliteDatabaseFactory,
 	type SqliteRunResult,
@@ -75,7 +76,7 @@ describe("SQLite migrations", () => {
 		const db = await sqlite.open(databasePath);
 		try {
 			const rows = await db.prepare("SELECT id FROM migrations ORDER BY id").all<{ id: string }>();
-			expect(rows.map((row) => row.id)).toEqual(["001_initial.sql"]);
+			expect(rows.map((row) => row.id)).toEqual(["001_initial.sql", "002_session_search.sql"]);
 			const tables = await db
 				.prepare("SELECT name, sql FROM sqlite_master WHERE type = 'table' ORDER BY name")
 				.all<{ name: string; sql: string | null }>();
@@ -107,6 +108,53 @@ describe("SQLite migrations", () => {
 		}
 	});
 
+	it("does not materialize existing entry data when the search migration runs", async () => {
+		const root = createTempDir();
+		const db = await createNodeSqliteFactory().open(join(root, "sessions.sqlite"));
+		try {
+			const [initialMigration] = await loadMigrations();
+			await db.exec(initialMigration!.sql);
+			await db.exec("CREATE TABLE migrations (id TEXT PRIMARY KEY, applied_at TEXT NOT NULL)");
+			await db.prepare("INSERT INTO migrations (id, applied_at) VALUES (?, ?)").run("001_initial.sql", "now");
+			await db
+				.prepare(
+					"INSERT INTO session_entries (session_id, id, entry_seq, parent_id, type, timestamp, payload) VALUES (?, ?, ?, ?, ?, ?, ?)",
+				)
+				.run(
+					"session-1",
+					"entry-1",
+					1,
+					null,
+					"custom",
+					"2026-01-01T00:00:00.000Z",
+					'{"customType":"note","data":{"text":"backfilled"}}',
+				);
+
+			await applyMigrations(db);
+
+			await expect(
+				db
+					.prepare(
+						"SELECT session_entries.session_id, session_entries.id AS entry_id FROM session_entry_search_fts JOIN session_entries ON session_entries.rowid = session_entry_search_fts.rowid WHERE session_entry_search_fts MATCH ?",
+					)
+					.get<{ session_id: string; entry_id: string }>("backfilled"),
+			).resolves.toBeUndefined();
+
+			await expect(
+				db.prepare("SELECT name FROM sqlite_master WHERE type = 'table' AND name = 'session_search_records'").get(),
+			).resolves.toBeUndefined();
+			await expect(
+				db
+					.prepare(
+						"SELECT name FROM sqlite_master WHERE type = 'trigger' AND name LIKE 'session_entries_search_%'",
+					)
+					.get(),
+			).resolves.toBeUndefined();
+		} finally {
+			await db.close();
+		}
+	});
+
 	it("persists session metadata through create, list, open, and fork", async () => {
 		const root = createTempDir();
 		const databasePath = join(root, "sessions.sqlite");
diff --git a/packages/agent/test/harness/sqlite-node.test.ts b/packages/agent/test/harness/sqlite-node.test.ts
index a94d37858..a4248aa96 100644
--- a/packages/agent/test/harness/sqlite-node.test.ts
+++ b/packages/agent/test/harness/sqlite-node.test.ts
@@ -1,7 +1,8 @@
 import { join } from "node:path";
 import { describe, expect, it } from "vitest";
-import { createNodeSqliteFactory } from "../../../storage/sqlite-node/src/index.ts";
-import { createTempDir } from "./session-test-utils.ts";
+import { createNodeSqliteFactory, SqliteSessionRepo } from "../../../storage/sqlite-node/src/index.ts";
+import { NodeExecutionEnv } from "../../src/harness/env/nodejs.ts";
+import { createTempDir, createUserMessage } from "./session-test-utils.ts";
 
 describe("sqlite-node adapter", () => {
 	it("supports node:sqlite-style named parameters", async () => {
@@ -18,4 +19,29 @@ describe("sqlite-node adapter", () => {
 			await db.close();
 		}
 	});
+
+	it("searches and deletes transactionally indexed canonical entries", async () => {
+		const root = createTempDir();
+		const databasePath = join(root, "sessions.sqlite");
+		const repo = new SqliteSessionRepo({
+			env: new NodeExecutionEnv({ cwd: root }),
+			sqlite: createNodeSqliteFactory(),
+			databasePath,
+		});
+		const included = await repo.create({ cwd: root, id: "included" });
+		const excluded = await repo.create({ cwd: `${root}/other`, id: "excluded" });
+		const metadata = await included.getMetadata();
+		const entryId = await included.appendMessage(createUserMessage("Find the auth defect"));
+		await excluded.appendMessage(createUserMessage("Find the auth defect"));
+
+		await expect(repo.search({ text: "auth", cwd: root })).resolves.toEqual([
+			expect.objectContaining({ entryId, metadata: expect.objectContaining({ id: "included" }) }),
+		]);
+		await expect(repo.search({ text: "uth", cwd: root })).resolves.toEqual([
+			expect.objectContaining({ entryId, metadata: expect.objectContaining({ id: "included" }) }),
+		]);
+
+		await repo.delete(metadata);
+		await expect(repo.search({ text: "auth", cwd: root })).resolves.toEqual([]);
+	});
 });
diff --git a/packages/agent/vitest.config.ts b/packages/agent/vitest.config.ts
index 834c56a55..ed0ab064a 100644
--- a/packages/agent/vitest.config.ts
+++ b/packages/agent/vitest.config.ts
@@ -3,6 +3,7 @@ import { defineConfig } from "vitest/config";
 
 const aiSrcIndex = fileURLToPath(new URL("../ai/src/index.ts", import.meta.url));
 const aiSrcCompat = fileURLToPath(new URL("../ai/src/compat.ts", import.meta.url));
+const agentSrcIndex = fileURLToPath(new URL("./src/index.ts", import.meta.url));
 
 export default defineConfig({
 	test: {
@@ -14,6 +15,7 @@ export default defineConfig({
 	},
 	resolve: {
 		alias: [
+			{ find: /^@earendil-works\/pi-agent-core$/, replacement: agentSrcIndex },
 			{ find: /^@earendil-works\/pi-ai$/, replacement: aiSrcIndex },
 			{ find: /^@earendil-works\/pi-ai\/compat$/, replacement: aiSrcCompat },
 		],
diff --git a/packages/ai/test/openai-responses-reasoning-replay-e2e.test.ts b/packages/ai/test/openai-responses-reasoning-replay-e2e.test.ts
index 85753c039..26cd19d90 100644
--- a/packages/ai/test/openai-responses-reasoning-replay-e2e.test.ts
+++ b/packages/ai/test/openai-responses-reasoning-replay-e2e.test.ts
@@ -83,14 +83,14 @@ describe.skipIf(!process.env.OPENAI_API_KEY || !process.env.ANTHROPIC_API_KEY)(
 		it("handles same-provider different-model handoff with tool calls", { retry: 2 }, async () => {
 			// This tests the scenario where:
 			// 1. Model A (gpt-5-mini) generates reasoning + function_call
-			// 2. User switches to Model B (gpt-5.2-codex) - same provider, different model
+			// 2. User switches to Model B (gpt-5.3-codex) - same provider, different model
 			// 3. transform-messages: isSameModel=false, thinking converted to text
 			// 4. But tool call ID still has OpenAI pairing history (fc_xxx paired with rs_xxx)
 			// 5. Without fix: OpenAI returns 400 "function_call without required reasoning item"
 			// 6. With fix: tool calls/results converted to text, conversation continues
 
 			const modelA = getModel("openai", "gpt-5-mini");
-			const modelB = getModel("openai", "gpt-5.2-codex");
+			const modelB = getModel("openai", "gpt-5.3-codex");
 
 			const apiKey = getEnvApiKey("openai");
 			if (!apiKey) {
@@ -189,7 +189,7 @@ describe.skipIf(!process.env.OPENAI_API_KEY || !process.env.ANTHROPIC_API_KEY)(
 			// 5. Should work because foreign IDs have no pairing expectation
 
 			const anthropicModel = getModel("anthropic", "claude-sonnet-4-5");
-			const codexModel = getModel("openai", "gpt-5.2-codex");
+			const codexModel = getModel("openai", "gpt-5.3-codex");
 
 			const anthropicApiKey = getEnvApiKey("anthropic");
 			const openaiApiKey = getEnvApiKey("openai");
diff --git a/packages/ai/test/xhigh.test.ts b/packages/ai/test/xhigh.test.ts
index f1722b9a7..1e2d461ba 100644
--- a/packages/ai/test/xhigh.test.ts
+++ b/packages/ai/test/xhigh.test.ts
@@ -18,7 +18,7 @@ describe.skipIf(!process.env.OPENAI_API_KEY)("xhigh reasoning", () => {
 	describe("codex-max (supports xhigh)", () => {
 		// Note: codex models only support the responses API, not chat completions
 		it("should work with openai-responses", async () => {
-			const model = getModel("openai", "gpt-5.1-codex-max");
+			const model = getModel("openai", "gpt-5.3-codex");
 			const s = stream(model, makeContext(), { reasoningEffort: "xhigh" });
 			let hasThinking = false;
 
diff --git a/packages/storage/sqlite-node/src/sqlite/migrations.ts b/packages/storage/sqlite-node/src/sqlite/migrations.ts
index 2ccd70fc3..69b8a9709 100644
--- a/packages/storage/sqlite-node/src/sqlite/migrations.ts
+++ b/packages/storage/sqlite-node/src/sqlite/migrations.ts
@@ -19,6 +19,11 @@ export async function loadMigrations(): Promise<SqliteMigration[]> {
 			order: 1,
 			sql: await loadMigrationSql("./migrations/001_initial.sql"),
 		},
+		{
+			id: "002_session_search.sql",
+			order: 2,
+			sql: await loadMigrationSql("./migrations/002_session_search.sql"),
+		},
 	];
 }
 
diff --git a/packages/storage/sqlite-node/src/sqlite/migrations/002_session_search.sql b/packages/storage/sqlite-node/src/sqlite/migrations/002_session_search.sql
new file mode 100644
index 000000000..c6681c8ad
--- /dev/null
+++ b/packages/storage/sqlite-node/src/sqlite/migrations/002_session_search.sql
@@ -0,0 +1,5 @@
+CREATE VIRTUAL TABLE IF NOT EXISTS session_entry_search_fts USING fts5(
+	search_text,
+	content = '',
+	tokenize = 'trigram remove_diacritics 1'
+);
diff --git a/packages/storage/sqlite-node/src/sqlite/repo.ts b/packages/storage/sqlite-node/src/sqlite/repo.ts
index 12a4f9d02..4efc7e6ff 100644
--- a/packages/storage/sqlite-node/src/sqlite/repo.ts
+++ b/packages/storage/sqlite-node/src/sqlite/repo.ts
@@ -1,13 +1,22 @@
-import type { Session, SessionStorage, SessionTreeEntry } from "@earendil-works/pi-agent-core";
+import type {
+	Session,
+	SessionSearchHit,
+	SessionSearchOptions,
+	SessionStorage,
+	SessionTreeEntry,
+} from "@earendil-works/pi-agent-core";
 import {
 	createSessionId,
 	getEntriesToFork,
 	getFileSystemResultOrThrow,
 	SessionError,
 	toSession,
+	toSessionSearchIndexRecord,
 } from "@earendil-works/pi-agent-core";
 import { applyMigrations } from "./migrations.ts";
+import { SqliteSessionSearchIndex } from "./search-index-sink.ts";
 import { SqliteSessionStorage } from "./storage/index.ts";
+import { decodeEntry, type SessionEntryRow } from "./storage/session-entries.ts";
 import { rowToMetadata, type SessionRow } from "./storage/sessions.ts";
 import type {
 	SqliteDatabase,
@@ -94,7 +103,7 @@ export class SqliteSessionRepo implements SqliteSessionRepoApi {
 				parentSessionId: options.parentSessionId,
 				metadata: options.metadata,
 			});
-			return toSession(storage);
+			return toSession(storage, new SqliteSessionSearchIndex(db, await this.getDatabasePath()));
 		} catch (error) {
 			await db.close();
 			throw error;
@@ -110,7 +119,7 @@ export class SqliteSessionRepo implements SqliteSessionRepoApi {
 		const db = await this.openDatabase();
 		try {
 			const storage = await SqliteSessionStorage.open(db, metadata);
-			return toSession(storage);
+			return toSession(storage, new SqliteSessionSearchIndex(db, await this.getDatabasePath()));
 		} catch (error) {
 			await db.close();
 			throw error;
@@ -141,10 +150,30 @@ export class SqliteSessionRepo implements SqliteSessionRepoApi {
 		}
 	}
 
+	async search(options: SessionSearchOptions): Promise<SessionSearchHit<SqliteSessionMetadata>[]> {
+		const path = await this.getDatabasePath();
+		if (!getFileSystemResultOrThrow(await this.env.exists(path), `Failed to check database ${path}`)) return [];
+		const db = await this.openDatabase();
+		try {
+			return await new SqliteSessionSearchIndex(db, path).search(options);
+		} finally {
+			await db.close();
+		}
+	}
+
 	async delete(metadata: SqliteSessionMetadata): Promise<void> {
 		const db = await this.openDatabase();
 		try {
 			await db.transaction(async () => {
+				const searchIndexSink = new SqliteSessionSearchIndex(db, await this.getDatabasePath());
+				const entries = await db
+					.prepare(
+						"SELECT rowid, session_id, id, entry_seq, parent_id, type, timestamp, payload FROM session_entries WHERE session_id = ?",
+					)
+					.all<SessionEntryRow & { rowid: number }>(metadata.id);
+				for (const row of entries) {
+					await searchIndexSink.remove(toSessionSearchIndexRecord(metadata, decodeEntry(row)));
+				}
 				await db.prepare("DELETE FROM branch_entries WHERE session_id = ?").run(metadata.id);
 				await db.prepare("DELETE FROM session_entries WHERE session_id = ?").run(metadata.id);
 				await db.prepare("DELETE FROM entry_materialized WHERE session_id = ?").run(metadata.id);
@@ -180,10 +209,13 @@ export class SqliteSessionRepo implements SqliteSessionRepoApi {
 				parentSessionId: options.parentSessionId ?? sourceMetadata.id,
 				metadata: options.metadata ?? sourceMetadata.metadata,
 			});
+			const searchIndexSink = new SqliteSessionSearchIndex(db, await this.getDatabasePath());
+			const metadata = await storage.getMetadata();
 			for (const entry of forkedEntries) {
 				await storage.appendEntry(entry);
+				await searchIndexSink.write(toSessionSearchIndexRecord(metadata, entry));
 			}
-			return toSession(storage);
+			return toSession(storage, searchIndexSink);
 		} catch (error) {
 			await db.close();
 			throw error;
diff --git a/packages/storage/sqlite-node/src/sqlite/search-index-sink.ts b/packages/storage/sqlite-node/src/sqlite/search-index-sink.ts
new file mode 100644
index 000000000..0f271a51c
--- /dev/null
+++ b/packages/storage/sqlite-node/src/sqlite/search-index-sink.ts
@@ -0,0 +1,65 @@
+import type {
+	SessionSearchHit,
+	SessionSearchIndexRecord,
+	SessionSearchIndexSink,
+	SessionSearchOptions,
+} from "@earendil-works/pi-agent-core";
+import { SessionError } from "@earendil-works/pi-agent-core";
+import { rowToMetadata, type SessionRow } from "./storage/sessions.ts";
+import type { SqliteDatabase, SqliteSessionMetadata } from "./types.ts";
+
+/** SQLite-backed search index and sink for persisted session entries. */
+export class SqliteSessionSearchIndex implements SessionSearchIndexSink {
+	private readonly db: SqliteDatabase;
+	private readonly databasePath: string;
+
+	constructor(db: SqliteDatabase, databasePath: string) {
+		this.db = db;
+		this.databasePath = databasePath;
+	}
+
+	async write(record: SessionSearchIndexRecord): Promise<void> {
+		const row = await this.db
+			.prepare("SELECT rowid FROM session_entries WHERE session_id = ? AND id = ?")
+			.get<{ rowid: number }>(record.metadata.id, record.entry.id);
+		if (!row) {
+			throw new SessionError("not_found", `Entry ${record.entry.id} not found for search indexing`);
+		}
+		await this.db
+			.prepare("INSERT INTO session_entry_search_fts (rowid, search_text) VALUES (?, ?)")
+			.run(row.rowid, JSON.stringify(record.entry));
+	}
+
+	async remove(record: SessionSearchIndexRecord): Promise<void> {
+		const row = await this.db
+			.prepare("SELECT rowid FROM session_entries WHERE session_id = ? AND id = ?")
+			.get<{ rowid: number }>(record.metadata.id, record.entry.id);
+		if (!row) return;
+		await this.db
+			.prepare(
+				"INSERT INTO session_entry_search_fts(session_entry_search_fts, rowid, search_text) VALUES ('delete', ?, ?)",
+			)
+			.run(row.rowid, JSON.stringify(record.entry));
+	}
+
+	async search(options: SessionSearchOptions): Promise<SessionSearchHit<SqliteSessionMetadata>[]> {
+		const text = options.text.trim();
+		if (!text) return [];
+		const query = `"${text.replaceAll('"', '""')}"`;
+		const rows = await this.db
+			.prepare(
+				"SELECT sessions.id, sessions.created_at, sessions.metadata, sessions.cwd, sessions.parent_session_id, sessions.active_leaf_id, session_entries.id AS entry_id, session_entries.timestamp, bm25(session_entry_search_fts) AS score FROM session_entry_search_fts JOIN session_entries ON session_entries.rowid = session_entry_search_fts.rowid JOIN sessions ON sessions.id = session_entries.session_id WHERE session_entry_search_fts MATCH ? AND (? IS NULL OR sessions.cwd = ?) ORDER BY score",
+			)
+			.all<SessionRow & { entry_id: string; timestamp: string; score: number }>(
+				query,
+				options.cwd ?? null,
+				options.cwd ?? null,
+			);
+		return rows.map((row) => ({
+			metadata: rowToMetadata(row, this.databasePath),
+			entryId: row.entry_id,
+			timestamp: row.timestamp,
+			score: row.score,
+		}));
+	}
+}
diff --git a/packages/storage/sqlite-node/src/sqlite/storage/index.ts b/packages/storage/sqlite-node/src/sqlite/storage/index.ts
index 93376852e..833d5d7da 100644
--- a/packages/storage/sqlite-node/src/sqlite/storage/index.ts
+++ b/packages/storage/sqlite-node/src/sqlite/storage/index.ts
@@ -263,7 +263,7 @@ export class SqliteSessionStorage implements SessionStorage<SqliteSessionMetadat
 		return this.currentLeafId;
 	}
 
-	async setLeafId(leafId: string | null): Promise<void> {
+	async setLeafId(leafId: string | null): Promise<LeafEntry> {
 		if (leafId !== null && !(await this.getEntry(leafId))) {
 			throw new SessionError("not_found", `Entry ${leafId} not found`);
 		}
@@ -275,6 +275,7 @@ export class SqliteSessionStorage implements SessionStorage<SqliteSessionMetadat
 			targetId: leafId,
 		};
 		await this.appendEntry(entry);
+		return entry;
 	}
 
 	async createEntryId(): Promise<string> {