What causes "OrchestrationWorker not initialized" in mastra-ai/mastra?

Always await init(deps) before start() and let its error stop startup instead of catching and continuing

OrchestrationWorker not initialized

Error message

OrchestrationWorker not initialized

What it means

start() wires #processor from init()-provided deps before the PullTransport routes events into #processEvent. If an event arrives while #processor is unset, the worker has no step-execution strategy to handle it and throws this internal-state error, protecting against processing events with an uninitialized pipeline.

Source

Thrown at packages/core/src/worker/workers/orchestration-worker.ts:109

    if (!this.#running) return;

    try {
      if (this.#transport) {
        await this.#transport.stop();
        this.#transport = undefined;
      }
    } finally {
      this.#running = false;
    }
  }

  get isRunning(): boolean {
    return this.#running;
  }

  async #processEvent(event: Event, ack?: () => Promise<void>, nack?: () => Promise<void>): Promise<void> {
    if (!this.#processor) {
      throw new Error('OrchestrationWorker not initialized');
    }

    // The local processor is used (rather than mastra.handleWorkflowEvent)
    // because it carries the standalone-worker step-execution strategy
    // (HttpRemoteStrategy when MASTRA_STEP_EXECUTION_URL is set), which the
    // shared in-process handler doesn't have.
    const result = await this.#processor.handle(event);
    if (result.ok) {
      try {
        await ack?.();
      } catch (e) {
        this.deps?.logger?.error('OrchestrationWorker: error acking event', { error: e });
      }
      return;
    }

    this.deps?.logger?.error('OrchestrationWorker: error processing event', {
      type: event.type,

View on GitHub (pinned to 75dd419e61)

Solutions

Always await init(deps) before start() and let its error stop startup instead of catching and continuing
Recreate (not reuse) the worker/transport after a failed init
Check that init() isn't rejecting after the transport already started; fix the underlying init error (e.g. missing mastra or push-only pubsub)

Example fix

// before
try { await w.init(deps); } catch (e) { /* swallowed */ }
await w.start(); // events arrive with no processor
// after
await w.init(deps); // let failures surface
await w.start();

Defensive patterns

Strategy: try-catch

Validate before calling

await worker.init(deps); // must fully succeed
if (!worker.deps) throw new Error('init incomplete');

Try / catch

try {
  await w.start();
} catch (e) {
  if (e.message === 'OrchestrationWorker not initialized') {
    logger.error('Event arrived before init completed — restart worker after full init');
    await w.stop?.();
  } else throw e;
}

Prevention

Let init() failures abort startup rather than continuing to start()
Recreate workers after failed init instead of reusing partially-built state
Sequence init→start strictly; avoid racing transports that deliver immediately

When it happens

Trigger: The transport's route callback fires before init() assigned the processor — e.g. start() called before/without init on a transport that's already running, or init() failing partway after the transport started delivering events.

Common situations: Reusing a running transport across a stop/start cycle without re-init; calling start() without init() in a code path that swallows the earlier 'call init() before start()' error; async races where an event is delivered during startup.

Related errors

AI-assisted analysis of mastra-ai/mastra@75dd419e61 (2026-08-30). Data as JSON: /api/errors/a95e2822bb900981. Report an issue: GitHub.