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Reference: Run.resumeStream() | Streaming

docs/src/content/en/reference/streaming/workflows/resumeStream.mdx

2025-12-184.2 KB
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Run.resumeStream()

The .resumeStream() method resumes a suspended workflow run with new data, allowing you to continue execution from a specific step and to observe the stream of events.

Usage example

typescript
const run = await workflow.createRun()

const stream = run.stream({
  inputData: {
    value: 'initial data',
  },
})

const result = await stream.result

if (result!.status === 'suspended') {
  const resumedStream = await run.resumeStream({
    resumeData: {
      value: 'resume data',
    },
  })
}

Parameters

<PropertiesTable content={[ { name: 'resumeData', type: 'z.infer<TInput>', description: "Input data that matches the workflow's input schema", isOptional: true, }, { name: 'requestContext', type: 'RequestContext', description: 'Request Context data to use during workflow execution', isOptional: true, }, { name: 'step', type: 'Step<string, any, any, any, any, TEngineType>', description: 'The step to resume execution from', isOptional: true, }, { name: 'tracingOptions', type: 'TracingOptions', isOptional: true, description: 'Options for Tracing configuration.', properties: [ { parameters: [ { name: 'metadata', type: 'Record<string, any>', isOptional: true, description: 'Metadata to add to the root trace span. Useful for adding custom attributes like user IDs, session IDs, or feature flags.', }, ], }, { parameters: [ { name: 'requestContextKeys', type: 'string[]', isOptional: true, description: "Additional RequestContext keys to extract as metadata for this trace. Supports dot notation for nested values (e.g., 'user.id').", }, ], }, { parameters: [ { name: 'traceId', type: 'string', isOptional: true, description: 'Trace ID to use for this execution (1-32 hexadecimal characters). If provided, this trace will be part of the specified trace.', }, ], }, { parameters: [ { name: 'parentSpanId', type: 'string', isOptional: true, description: 'Parent span ID to use for this execution (1-16 hexadecimal characters). If provided, the root span will be created as a child of this span.', }, ], }, { parameters: [ { name: 'tags', type: 'string[]', isOptional: true, description: 'Tags to apply to this trace. String labels for categorizing and filtering traces.', }, ], }, ], }, ]} />

Returns

<PropertiesTable content={[ { name: 'stream', type: 'MastraWorkflowStream<ChunkType>', description: 'A custom stream that extends ReadableStream<ChunkType> with additional workflow-specific properties', }, { name: 'stream.status', type: 'Promise<RunStatus>', description: 'A promise that resolves to the current workflow run status', }, { name: 'stream.result', type: 'Promise<WorkflowResult<TState, TOutput, TSteps>>', description: 'A promise that resolves to the final workflow result', }, { name: 'stream.usage', type: 'Promise<{ inputTokens: number; outputTokens: number; totalTokens: number, reasoningTokens?: number, cacheInputTokens?: number }>', description: 'A promise that resolves to token usage statistics', }, ]} />

Stream events

The stream emits various event types during workflow execution. Each event has a type field and a payload containing relevant data:

  • workflow-start: Workflow execution begins
  • workflow-step-start: A step begins execution
  • workflow-step-output: Custom output from a step
  • workflow-step-result: A step completes with results
  • workflow-finish: Workflow execution completes with usage statistics