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

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DurableContext.runInChildContext() method

Runs a function in a child context with isolated state and execution tracking

Signature:

runInChildContext<TOutput>(name: string | undefined, fn: ChildFunc<TOutput, TLogger>, config?: ChildConfig<TOutput>): DurablePromise<TOutput>;

Parameters

Parameter	Type	Description
name	string | undefined	Step name for tracking and debugging
fn	ChildFunc<TOutput, TLogger>	Function to execute in the child context
config	ChildConfig<TOutput>	(Optional) Optional configuration for serialization and sub-typing

Returns:

DurablePromise<TOutput>

Exceptions

{ChildContextError} When the child context function fails

Example

const result = await context.runInChildContext(
  "process-batch",
  async (childCtx) => {
    // Child context has its own step counter and state
    const step1 = await childCtx.step("validate", async () => validate(data));
    const step2 = await childCtx.step("transform", async () =>
      transform(step1),
    );
    return step2;
  },
  { subType: "batch-processor" },
);