fix(runtime): clear stale SDK session IDs on startup to prevent CLI deadlock

src/agent/__tests__/session-store.test.ts

@@ -73,6 +73,29 @@ describe("SessionStore", () => {
 		expect(session?.status).toBe("active");
 	});
 
+	test("clearAllSdkSessionIds clears every stale SDK ID", () => {
+		store.create("cli", "conv-1");
+		store.create("slack", "conv-2");
+		store.create("web", "conv-3");
+
+		store.updateSdkSessionId("cli:conv-1", "sdk-aaa");
+		store.updateSdkSessionId("slack:conv-2", "sdk-bbb");
+		// web:conv-3 has no SDK session ID
+
+		const cleared = store.clearAllSdkSessionIds();
+		expect(cleared).toBe(2);
+
+		expect(store.getByKey("cli:conv-1")?.sdk_session_id).toBeNull();
+		expect(store.getByKey("slack:conv-2")?.sdk_session_id).toBeNull();
+		expect(store.getByKey("web:conv-3")?.sdk_session_id).toBeNull();
+	});
+
+	test("clearAllSdkSessionIds returns 0 when no sessions have SDK IDs", () => {
+		store.create("cli", "conv-1");
+		const cleared = store.clearAllSdkSessionIds();
+		expect(cleared).toBe(0);
+	});
+
 	test("create reactivates an expired session with the same key", () => {
 		store.create("cli", "conv-1");
 		store.updateSdkSessionId("cli:conv-1", "old-sdk-id");

src/agent/runtime.ts

@@ -280,6 +280,22 @@ export class AgentRuntime {
 						resultText = `Error: ${retryMsg}`;
 						onEvent?.({ type: "error", message: retryMsg });
 					}
+				} else if (isResume) {
+					// Any other error during a resume attempt — the SDK session is
+					// likely unusable.  Discard it and retry fresh.  See #25.
+					console.log(`[runtime] Resume failed (${errorMsg}), retrying without resume: ${sessionKey}`);
+					this.sessionStore.clearSdkSessionId(sessionKey);
+					sdkSessionId = "";
+					resultText = "";
+					cost = emptyCost();
+					emittedThinking = false;
+					try {
+						await runSdkQuery(false);
+					} catch (retryErr: unknown) {
+						const retryMsg = retryErr instanceof Error ? retryErr.message : String(retryErr);
+						resultText = `Error: ${retryMsg}`;
+						onEvent?.({ type: "error", message: retryMsg });
+					}
 				} else {
 					resultText = `Error: ${errorMsg}`;
 					onEvent?.({ type: "error", message: errorMsg });

src/agent/session-store.ts

@@ -77,6 +77,21 @@ export class SessionStore {
 		);
 	}
 
+	/**
+	 * Clear all SDK session IDs on startup.
+	 *
+	 * SDK session IDs are process-local and do not survive restarts.
+	 * Without this, container recreates leave stale IDs in SQLite
+	 * (persisted volume), causing the runtime to attempt impossible
+	 * resumes that deadlock the CLI channel.  See #25.
+	 */
+	clearAllSdkSessionIds(): number {
+		const result = this.db.run(
+			"UPDATE sessions SET sdk_session_id = NULL WHERE sdk_session_id IS NOT NULL",
+		);
+		return result.changes;
+	}
+
 	touch(sessionKey: string): void {
 		this.db.run("UPDATE sessions SET last_active_at = datetime('now') WHERE session_key = ?", [sessionKey]);
 	}

src/index.ts

@@ -122,6 +122,14 @@ async function main(): Promise<void> {
 	// agent, which means a single auth path and a single provider switch.
 	const runtime = new AgentRuntime(config, db);
 
+	// SDK session IDs are process-local and never survive restarts.
+	// Clear them so the runtime does not attempt impossible resumes
+	// that deadlock CLI or other persistent channels.  See #25.
+	{
+		const result = db.run("UPDATE sessions SET sdk_session_id = NULL WHERE sdk_session_id IS NOT NULL");
+		if (result.changes > 0) console.log(`[phantom] Cleared ${result.changes} stale SDK session ID(s)`);
+	}
+
 	let evolution: EvolutionEngine | null = null;
 	let evolutionCadence: EvolutionCadence | null = null;
 	try {