job_not_input_accepting:session_mismatch:${active.session_id

Error message

job_not_input_accepting:session_mismatch:${active.session_id}

What it means

Thrown by injectExecFollowup when the supplied session id does not match the currently usable session in that cwd. The active session's session_id and native_session_id both differ from the requested id, so the library refuses to inject into a session that is no longer the active one (unless allowInactiveSession is set). The message embeds the actual active session id for diagnosis.

Source

Thrown at src/exec/followup.ts:235

  options: InjectExecFollowupOptions,
): Promise<InjectExecFollowupResult> {
  const sessionId = normalizeSessionId(options.sessionId);
  const prompt = normalizePrompt(options.prompt);
  const actor = normalizeActor(options.actor);
  const nowIso = options.nowIso ?? new Date().toISOString();

  const active = await readUsableSessionState(options.cwd);
  const activeUsable = active && isSessionStateUsable(active, options.cwd);
  if (!activeUsable && !options.allowInactiveSession) {
    throw new Error("job_not_input_accepting:no_active_exec_session");
  }
  if (
    activeUsable
    && active.session_id !== sessionId
    && active.native_session_id !== sessionId
    && !options.allowInactiveSession
  ) {
    throw new Error(`job_not_input_accepting:session_mismatch:${active.session_id}`);
  }

  const canonicalSessionId = activeUsable && (active.session_id === sessionId || active.native_session_id === sessionId)
    ? active.session_id
    : sessionId;
  const queuePath = sessionQueuePath(options.cwd, canonicalSessionId);
  const queued: ExecFollowupRecord = {
    id: randomUUID(),
    session_id: canonicalSessionId,
    actor,
    prompt,
    created_at: nowIso,
  };
  await withQueueLock(queuePath, async () => {
    const queue = await readQueue(queuePath, canonicalSessionId, {
      cwd: options.cwd,
      nowIso,
      recoverCorrupt: true,

View on GitHub (pinned to 3ad79a8a6f)

Solutions

Re-read the current session id from the active session state (or the error message, which contains active.session_id) and retry with that id.
If injecting into a superseded session is intentional, pass allowInactiveSession: true.
Make your orchestrator re-resolve the session id immediately before each injection rather than caching it.
Guard against races by retrying once with the freshly resolved id on session_mismatch.

Example fix

// before
await injectExecFollowup(cwd, cachedSessionId, { prompt });

// after
const active = await readUsableSessionState(cwd);
if (!active) throw new Error('no active session');
await injectExecFollowup(cwd, active.session_id, { prompt });

Defensive patterns

Strategy: validation

Validate before calling

const active = await readUsableSessionState(cwd);
if (!active) throw new Error('no active session');
const id = (active.session_id === wanted || active.native_session_id === wanted) ? active.session_id : active.session_id;
await injectExecFollowup(cwd, id, { prompt });

Type guard

function sessionMatches(active: SessionState, id: string): boolean {
  return active.session_id === id || active.native_session_id === id;
}

Try / catch

try { await injectExecFollowup(cwd, sessionId, { prompt }); }
catch (e) {
  const m = e instanceof Error && e.message.match(/^job_not_input_accepting:session_mismatch:(.+)$/);
  if (m) return injectExecFollowup(cwd, m[1]!, { prompt }); // retry with active id
  throw e;
}

Prevention

Never cache session ids across session restarts.
Resolve the active session id at call time.
Handle races by retrying once with the id from the error message.

When it happens

Trigger: Passing a stale session id from a previous exec session while a new one is active in the same cwd; hardcoding or caching a session id that has since been rotated; copy-pasting an id from another checkout; racing with a session restart between reading the id and injecting.

Common situations: Scripts cache the session id from an earlier run and reuse it after the session was restarted; orchestrator reads the id at job start but the session rotates mid-job; multiple sessions historically ran in the directory and an old id is used.

Related errors

AI-assisted analysis of Yeachan-Heo/oh-my-codex@3ad79a8a6f (2026-08-27). Data as JSON: /api/errors/2e2cc964d25033b5. Report an issue: GitHub.