Activity

Source: src/AWS/StepFunctions/Activity.ts

An AWS Step Functions activity — a named endpoint that external workers poll for tasks (GetActivityTask) and complete with the SendTask* callback operations.

Activities support worker-hosted task processing outside Lambda. For most callback flows the .waitForTaskToken service-integration pattern on a StateMachine Task state is preferred.

Creating Activities

Basic Activity

import * as StepFunctions from "alchemy/AWS/StepFunctions";

const activity = yield* StepFunctions.Activity("ApprovalActivity");

Reference an Activity from a State Machine

const machine = yield* StepFunctions.StateMachine("ApprovalFlow", {
  definition: {
    StartAt: "WaitForWorker",
    States: {
      WaitForWorker: {
        Type: "Task",
        Resource: activity.activityArn,
        End: true,
      },
    },
  },
});

Completing Tasks at Runtime

// init
const sendTaskSuccess = yield* StepFunctions.SendTaskSuccess(activity);

// runtime
yield* sendTaskSuccess({
  taskToken: token,
  output: JSON.stringify({ approved: true }),
});