Type Alias: ToolExecutionContext\

type ToolExecutionContext<TContext> = RuntimeContextField<TContext> & object;

Defined in: packages/ai/src/types.ts:490

Context passed to tool execute functions, providing capabilities like emitting custom events during execution.

Type Declaration

abortSignal?

optional abortSignal: AbortSignal;

Abort signal for the current chat run. Aborts when the run's abortController fires (or middleware aborts). Long-running tools — e.g. MCP callTool — should forward this to cancel in-flight work.

emitCustomEvent()

emitCustomEvent: (eventName, value) => void;

Emit a custom event during tool execution. Events are streamed to the client in real-time as AG-UI CUSTOM events.

Parameters

eventName

string

Name of the custom event

value

Record\<`string`, `any`\>

Event payload value

Returns

void

Example

const tool = toolDefinition({ ... }).server(async (args, context) => {
  context?.emitCustomEvent('progress', { step: 1, total: 3 })
  // ... do work ...
  context?.emitCustomEvent('progress', { step: 2, total: 3 })
  // ... do more work ...
  return result
})