durable-execution-sdk-js.durablecontext.createcallback.md

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DurableContext.createCallback() method

Creates a callback that external systems can complete

Signature:

createCallback<TOutput = string>(name: string | undefined, config?: CreateCallbackConfig<TOutput>): DurablePromise<CreateCallbackResult<TOutput>>;

Parameters

Parameter	Type	Description
name	string | undefined	Step name for tracking and debugging
config	CreateCallbackConfig<TOutput>	(Optional) Optional configuration for timeout and serialization

Returns:

DurablePromise<CreateCallbackResult<TOutput>>

Tuple of [promise that resolves when callback is submitted, callback ID]

Exceptions

{CallbackError} When callback fails, times out, or external system reports failure (thrown by the returned promise)

Example

const [callbackPromise, callbackId] = await context.createCallback(
  "external-approval",
  { timeout: { hours: 1 } }, // 1 hour timeout
);

// Send callback ID to external system
await sendApprovalRequest(callbackId, requestData);

// Wait for external system to submit callback
const approvalResult = await callbackPromise;