fix(v2): persist SDK session ID across container restarts

The v2 poll loop held the session ID in a local variable, so every
container restart started a fresh SDK session even though the .jsonl
transcript was still sitting in the shared .claude mount. Store it in
outbound.db (container-owned, already per channel/thread), seed the
loop on startup, clear on /clear, and recover from stale-session
errors the same way v1 did.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

container/agent-runner/src/db/connection.ts

@@ -38,6 +38,16 @@ export function getOutboundDb(): Database.Database {
     _outbound.pragma('journal_mode = DELETE');
     _outbound.pragma('busy_timeout = 5000');
     _outbound.pragma('foreign_keys = ON');
+    // Lightweight forward-compat: session_state was added after the initial
+    // v2 schema, so older session DBs don't have it. Create it on demand
+    // instead of requiring a formal migration pass.
+    _outbound.exec(`
+      CREATE TABLE IF NOT EXISTS session_state (
+        key        TEXT PRIMARY KEY,
+        value      TEXT NOT NULL,
+        updated_at TEXT NOT NULL
+      );
+    `);
   }
   return _outbound;
 }
@@ -126,6 +136,11 @@ export function initTestSessionDb(): { inbound: Database.Database; outbound: Dat
       status         TEXT NOT NULL,
       status_changed TEXT NOT NULL
     );
+    CREATE TABLE session_state (
+      key        TEXT PRIMARY KEY,
+      value      TEXT NOT NULL,
+      updated_at TEXT NOT NULL
+    );
   `);
 
   return { inbound: _inbound, outbound: _outbound };

container/agent-runner/src/db/session-state.ts

@@ -0,0 +1,41 @@
+/**
+ * Persistent key/value state for the container. Lives in outbound.db
+ * (container-owned, already scoped per channel/thread).
+ *
+ * Primary use: remember the SDK session ID so the agent's conversation
+ * resumes across container restarts. Cleared by /clear.
+ */
+import { getOutboundDb } from './connection.js';
+
+const SDK_SESSION_KEY = 'sdk_session_id';
+
+function getValue(key: string): string | undefined {
+  const row = getOutboundDb()
+    .prepare('SELECT value FROM session_state WHERE key = ?')
+    .get(key) as { value: string } | undefined;
+  return row?.value;
+}
+
+function setValue(key: string, value: string): void {
+  getOutboundDb()
+    .prepare(
+      'INSERT OR REPLACE INTO session_state (key, value, updated_at) VALUES (?, ?, ?)',
+    )
+    .run(key, value, new Date().toISOString());
+}
+
+function deleteValue(key: string): void {
+  getOutboundDb().prepare('DELETE FROM session_state WHERE key = ?').run(key);
+}
+
+export function getStoredSessionId(): string | undefined {
+  return getValue(SDK_SESSION_KEY);
+}
+
+export function setStoredSessionId(sessionId: string): void {
+  setValue(SDK_SESSION_KEY, sessionId);
+}
+
+export function clearStoredSessionId(): void {
+  deleteValue(SDK_SESSION_KEY);
+}

container/agent-runner/src/poll-loop.ts

@@ -2,6 +2,7 @@ import { findByName, getAllDestinations, type DestinationEntry } from './destina
 import { getPendingMessages, markProcessing, markCompleted, type MessageInRow } from './db/messages-in.js';
 import { writeMessageOut } from './db/messages-out.js';
 import { touchHeartbeat, clearStaleProcessingAcks } from './db/connection.js';
+import { getStoredSessionId, setStoredSessionId, clearStoredSessionId } from './db/session-state.js';
 import { formatMessages, extractRouting, categorizeMessage, type RoutingContext } from './formatter.js';
 import type { AgentProvider, AgentQuery, McpServerConfig, ProviderEvent } from './providers/types.js';
 
@@ -37,9 +38,17 @@ export interface PollLoopConfig {
  * 6. Loop
  */
 export async function runPollLoop(config: PollLoopConfig): Promise<void> {
-  let sessionId: string | undefined;
+  // Resume the SDK session from a prior container run if one was persisted.
+  // The SDK's .jsonl transcripts live in the shared ~/.claude mount, so the
+  // conversation history is already on disk — we just need the session ID
+  // to tell the SDK which one to continue.
+  let sessionId: string | undefined = getStoredSessionId();
   let resumeAt: string | undefined;
 
+  if (sessionId) {
+    log(`Resuming SDK session ${sessionId}`);
+  }
+
   // Clear leftover 'processing' acks from a previous crashed container.
   // This lets the new container re-process those messages.
   clearStaleProcessingAcks();
@@ -104,6 +113,7 @@ export async function runPollLoop(config: PollLoopConfig): Promise<void> {
           log('Clearing session (resetting sessionId)');
           sessionId = undefined;
           resumeAt = undefined;
+          clearStoredSessionId();
           writeMessageOut({
             id: generateId(),
             kind: 'chat',
@@ -159,10 +169,26 @@ export async function runPollLoop(config: PollLoopConfig): Promise<void> {
     const processingIds = ids.filter((id) => !commandIds.includes(id));
     try {
       const result = await processQuery(query, routing, config, processingIds);
-      if (result.sessionId) sessionId = result.sessionId;
+      if (result.sessionId && result.sessionId !== sessionId) {
+        sessionId = result.sessionId;
+        setStoredSessionId(sessionId);
+      }
       if (result.resumeAt) resumeAt = result.resumeAt;
     } catch (err) {
-      log(`Query error: ${err instanceof Error ? err.message : String(err)}`);
+      const errMsg = err instanceof Error ? err.message : String(err);
+      log(`Query error: ${errMsg}`);
+
+      // Stale/corrupt session recovery: if the SDK can't find the session
+      // we asked it to resume, clear the stored ID so the next attempt
+      // starts fresh. The transcript .jsonl can go missing after a crash
+      // mid-write, manual deletion, or disk-full.
+      if (sessionId && /no conversation found|ENOENT.*\.jsonl|session.*not found/i.test(errMsg)) {
+        log(`Stale session detected (${sessionId}) — clearing for next retry`);
+        sessionId = undefined;
+        resumeAt = undefined;
+        clearStoredSessionId();
+      }
+
       // Write error response so the user knows something went wrong
       writeMessageOut({
         id: generateId(),
@@ -170,7 +196,7 @@ export async function runPollLoop(config: PollLoopConfig): Promise<void> {
         platform_id: routing.platformId,
         channel_type: routing.channelType,
         thread_id: routing.threadId,
-        content: JSON.stringify({ text: `Error: ${err instanceof Error ? err.message : String(err)}` }),
+        content: JSON.stringify({ text: `Error: ${errMsg}` }),
       });
     }
 

src/db/schema.ts

@@ -140,4 +140,13 @@ CREATE TABLE processing_ack (
   status         TEXT NOT NULL,
   status_changed TEXT NOT NULL
 );
+
+-- Persistent key/value state owned by the container. Used (among other things)
+-- to store the SDK session ID so the agent's conversation resumes across
+-- container restarts. Cleared by /clear.
+CREATE TABLE session_state (
+  key        TEXT PRIMARY KEY,
+  value      TEXT NOT NULL,
+  updated_at TEXT NOT NULL
+);
 `;