mastra-ai/mastra · warning · TripWire

${tripwireChunk.payload?.reason || 'Agent tripwire triggered

Error message

${tripwireChunk.payload?.reason || 'Agent tripwire triggered'}

What it means

While streaming an agent step, the workflow consumes the stream watching for tripwire chunks emitted by input/output processors. If a tripwire is detected, runAgentEntry throws a TripWire (not a plain Error) carrying the processor-provided reason, retry, metadata, and processorId, to abort the workflow step.

Source

Thrown at packages/core/src/workflows/entry-executors/run-agent-entry.ts:130

    // throws inside the base output's try/catch (see output.ts:970-973,978-981)
    // and it fires BEFORE handleFinish, so racing here would poison
    // streamPromise. Only the rejection channel below is wired up so genuine
    // stream errors still propagate.
    void modelOutput.text.then(
      () => {},
      (err: unknown) => streamPromise.reject(err),
    );
    stream = modelOutput.fullStream as ReadableStream<ChunkType>;
  }

  const tripwireChunk =
    streamFormat === 'legacy'
      ? await bridgeLegacyWatchEvents({ stream, pubsub, runId, toolData })
      : await consumeStreamForTripwire(stream, writer);

  // If a tripwire was detected, throw TripWire to abort the workflow step
  if (tripwireChunk) {
    throw new TripWire(
      tripwireChunk.payload?.reason || 'Agent tripwire triggered',
      {
        retry: tripwireChunk.payload?.retry,
        metadata: tripwireChunk.payload?.metadata,
      },
      tripwireChunk.payload?.processorId,
    );
  }

  if (abortSignal.aborted) {
    return abort();
  }

  // Return structured output if available, otherwise default text
  if (structuredResult !== null) {
    return structuredResult;
  }
  return {

View on GitHub (pinned to 75dd419e61)

Solutions

1. Inspect TripWire.reason and processorId to identify which processor tripped and why.
2. Adjust or remove the offending processor configuration on the agent if the trip is a false positive.
3. Handle TripWire in your workflow error handling (it is distinct from Error) — catch it and branch or retry as appropriate.
4. Use the TripWire retry/metadata payload to decide whether to retry the step.

Example fix

// before
await wf.run({ input }); // unhandled TripWire aborts run
// after
try { await wf.run({ input }); }
catch (e) { if (e instanceof TripWire) { console.warn('Tripped by', e.processorId, e.reason); } else throw e; }

const processors = agent?.inputProcessors ?? [];
if (processors.some(p => p?.id === 'strict-moderation')) {
  // pre-screen input before running the workflow step
  if (await violatesPolicy(input)) throw new PolicyError('Input would trip moderation processor');
}

import { TripWire } from '@mastra/core/workflows';
function isTripWire(e: unknown): e is TripWire {
  return e instanceof TripWire;
}

try { await runWorkflow(input); }
catch (e) {
  if (e instanceof TripWire) {
    logger.warn({ reason: e.reason, processorId: e.processorId, metadata: e.metadata }, 'workflow tripped');
    return { status: 'blocked', reason: e.reason };
  }
  throw e;
}

When it happens

Trigger: An agent stream inside a workflow step emits a tripwire chunk — typically an input or output processor (e.g. moderation, guardrails) flagged the prompt or response — with streamFormat legacy or vnext handled via consumeStreamForTripwire.

Common situations: Content moderation / guardrail processors rejecting user input; custom output processors aborting on policy violations; users testing with prompts that trip configured safety processors.

Related errors

• Tripwire triggered in workflow ${workflow.id}
• Stream part blocked by ${processor.id}
• Aborted by processor
• TokenLimiterProcessor: System messages alone exceed token li
• TokenLimiterProcessor: No messages fit within the remaining

AI-assisted analysis of mastra-ai/mastra@75dd419e61 (2026-08-30). Data as JSON: /api/errors/396f2dcf5b0fcfab. Report an issue: GitHub.