Function●Since v1.0

dispatchCustomEvent

Dispatch a custom event. Requires an explicit config object.

dispatchCustomEvent(
  name: string,
  payload: any,
  config: RunnableConfig<Record<string, any>>
): Promise<void>

Parameters

Name	Type	Description
`name`*	`string`	The name of the custom event.
`payload`*	`any`	The data for the custom event. Ideally should be JSON serializable to avoid serialization issues downstream, but not enforced.
`config`	`RunnableConfig<Record<string, any>>`	Config object.

Example

import { dispatchCustomEvent } from "@langchain/core/callbacks/dispatch";

const foo = RunnableLambda.from(async (input: string, config?: RunnableConfig) => {
  await dispatchCustomEvent(
    "my_custom_event",
    { arbitraryField: "someval" },
    config
  );
  return input;
});

const callbacks = [{
  handleCustomEvent: (eventName: string, payload: any) => {
    // Logs "my_custom_event" and { arbitraryField: "someval" }
    console.log(eventName, payload);
  }
}];

await foo.invoke("hi", { callbacks })

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dispatchCustomEvent

Parameters

Example

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dispatchCustomEvent

Parameters

Example