# Run.cancel() The `.cancel()` method cancels a workflow run, stopping execution and cleaning up resources. This method aborts any running steps and updates the workflow status to 'canceled'. It works for both actively running workflows and suspended/waiting workflows. ## Usage example ```typescript const run = await workflow.createRun(); await run.cancel(); // Returns: { message: 'Workflow run canceled' } ``` ## Parameters **No parameters:** (`void`): This method takes no parameters ## Returns **result:** (`Promise<{ message: string }>`): A promise that resolves with { message: 'Workflow run canceled' } when cancellation succeeds ## How cancellation works When called, the workflow will: 1. **Trigger the abort signal** - Uses the standard Web API AbortSignal to notify running steps 2. **Prevent subsequent steps** - No further steps will be executed ## Abort signal behavior Steps that check the `abortSignal` parameter can respond to cancellation: - Steps can listen to the 'abort' event: `abortSignal.addEventListener('abort', callback)` - Steps can check if already aborted: `if (abortSignal.aborted) { ... }` - Useful for cancelling timeouts, network requests, or long-running operations **Note:** Steps must actively check the abort signal to be canceled mid-execution. Steps that don't check the signal will run to completion, but subsequent steps won't execute. ## Extended usage examples ### Cancelling a workflow on error ```typescript const run = await workflow.createRun(); try { const result = await run.start({ inputData: { value: "initial data" } }); } catch (error) { await run.cancel(); } ``` ### Creating a step that responds to cancellation ```typescript const step = createStep({ id: 'long-running-step', execute: async ({ inputData, abortSignal, abort }) => { const timeout = new Promise((resolve) => { const timer = setTimeout(() => resolve('done'), 10000); // Clean up if canceled abortSignal.addEventListener('abort', () => { clearTimeout(timer); resolve('canceled'); }); }); const result = await timeout; // Check if aborted after async operation if (abortSignal.aborted) { return abort(); // Stop execution } return { result }; } }); ``` ## Related - [Workflows overview](https://mastra.ai/docs/workflows/overview) - [Workflow.createRun()](https://mastra.ai/reference/workflows/workflow-methods/create-run)