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Run.start()

The .start() method starts a workflow run with input data, allowing you to execute the workflow from the beginning.

Usage exampleDirect link to Usage example

const run = await workflow.createRunAsync();

const result = await run.start({
  inputData: {
    value: "initial data",
  },
});

ParametersDirect link to Parameters

inputData?:

z.infer<TInput>
Input data that matches the workflow's input schema

runtimeContext?:

RuntimeContext
Runtime context data to use during workflow execution

writableStream?:

WritableStream<ChunkType>
Optional writable stream for streaming workflow output

tracingContext?:

TracingContext
AI tracing context for creating child spans and adding metadata. Automatically injected when using Mastra's tracing system.

currentSpan?:

AISpan
Current AI span for creating child spans and adding metadata. Use this to create custom child spans or update span attributes during execution.

tracingOptions?:

TracingOptions
Options for AI tracing configuration.

metadata?:

Record<string, any>
Metadata to add to the root trace span. Useful for adding custom attributes like user IDs, session IDs, or feature flags.

outputOptions?:

OutputOptions
Options for AI tracing configuration.

includeState?:

boolean
Whether to include the workflow run state in the result.

ReturnsDirect link to Returns

result:

Promise<WorkflowResult<TState, TOutput, TSteps>>
A promise that resolves to the workflow execution result containing step outputs and status

traceId?:

string
The trace ID associated with this execution when AI tracing is enabled. Use this to correlate logs and debug execution flow.

Extended usage exampleDirect link to Extended usage example

import { RuntimeContext } from "@mastra/core/runtime-context";

const run = await workflow.createRunAsync();

const runtimeContext = new RuntimeContext();
runtimeContext.set("variable", false);

const result = await run.start({
  inputData: {
    value: "initial data",
  },
  runtimeContext,
});

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