Run.resumeStreamVNext() (Experimental)
Experimental API:
This is a new streaming implementation that supports multiple output formats (including AI SDK v5). It will replace .stream() and may change as we refine the feature based on feedback.
The .resumeStreamVNext() 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
const run = await workflow.createRunAsync();
const stream = run.streamVNext({
inputData: {
value: "initial data",
},
});
const result = await stream.result;
if (result.status === "suspended") {
const resumedStream = await run.resumeStreamVNext({
resumeData: { value: "resume data" }
});
}Parameters
resumeData?:
z.infer<TInput>
Input data that matches the workflow's input schema
runtimeContext?:
RuntimeContext
Runtime context data to use during workflow execution
step?:
Step<string, any, any, any, any, TEngineType>
The step to resume execution from
Returns
stream:
MastraWorkflowStream<ChunkType>
A custom stream that extends ReadableStream<ChunkType> with additional workflow-specific properties
stream.status:
Promise<RunStatus>
A promise that resolves to the current workflow run status
stream.result:
Promise<WorkflowResult<TOutput, TSteps>>
A promise that resolves to the final workflow result
stream.usage:
Promise<{ inputTokens: number; outputTokens: number; totalTokens: number, reasoningTokens?: number, cacheInputTokens?: number }>
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 beginsworkflow-step-start: A step begins executionworkflow-step-output: Custom output from a stepworkflow-step-result: A step completes with resultsworkflow-finish: Workflow execution completes with usage statistics