A Task is a resumable unit of a Run that can be retried, resumed and is logged.

Tasks vs regular code

In the run() function you can use regular code and you can use Tasks.

  id: "new-user",
  name: "Run when a new user signs up",
  version: "0.0.1",
  trigger: eventTrigger({
    name: "new.user",
    schema: z.object({
      userId: z.string(),
  integrations: {
  run: async (payload, io, ctx) => {
    // regular code, not a Task
    // the inputs/outputs of this function are not sent to the Trigger.dev platform
    const user = await prisma.user.findUnique({
      where: { id: payload.userId },
      select: { email: true, name: true },
    if (!user) throw new Error(`User not found: ${payload.userId}`);

    // Integration functions are Tasks
    await io.resend.sendEmail("Welcome email", {
      to: user.email,
      from: "[email protected]",
      subject: "Welcome!",
      html: welcomeEmail(user.name),

    // built-in io functions are Tasks
    await io.wait("wait", 60 * 60 * 3); // wait for 3 hours

    // You can wrap your own code in a Task, for retrying, resumability and logging
    const response = await io.runTask(
      async () => {
        return await longRunningCode(payload.userId);
      { name: "My Task" }

    return response;

The benefits of Tasks

Tasks are a powerful concept that gives you a lot of benefits:

  • Resumability – Runs can exceed the maximum timeout on serverless platforms. If a Run exceeds this limit, it will be re-run. When it is re-run, any completed Tasks return their original output and they aren’t re-run. Read more about Resumability.
  • Retryable – If a Task fails, it will be retried. You can configure how (or if) a Task is retried. Full details in the io SDK reference.
  • Logging – Tasks are logged, so you can see what happened in a Run. Find out more about viewing runs.


A Task can have multiple subtasks, and so on. This is useful for breaking down a large Task into smaller Tasks. We currently support nesting 5 levels deep.

Task Keys

The first param of all Tasks is a key. This is a unique identifier for the Task inside that Run. It is used for resumability and logging. It is also used to identify the Task in the Viewing Runs Dashboard.