scheduling-future-tasks
Index

Scheduling future tasks

Pipedream includes an event source which exposes an HTTP API for scheduling one-time tasks. You can schedule tasks at any timestamp, with second-level precision, up to one year in the future.

Click here to create this source, or visit https://pipedream.com/sources/new, select the Pipedream app, and the New Scheduled Tasks source.

To schedule a new task, just send an HTTP POST request to your source's endpoint, at the /schedule path, with the following format:

{
  "timestamp": "2020-08-21T04:29:00.951Z", // timestamp: an ISO 8601 timestamp
  "message": { "name": "Luke" } // message: any object or string
}

When the timestamp arrives and the task is invoked, the source will emit the payload passed in your original, scheduled request. This allows you to trigger a Pipedream workflow at the scheduled time, passing the message and timestamp to the workflow as an incoming event.

You can also listen for these events in your own app / infra, by subscribing to your source's SSE stream. Each time a scheduled task is emitted from your Pipedream source, it also emits a message to that SSE stream. Any application (a Docker container, a Rails app, etc.) listening to that SSE stream can react to that message to run whatever code you'd like.

HTTP API

This source exposes an HTTP endpoint where you can send POST requests to schedule new tasks. Your endpoint URL should appear as the Endpoint in your source's details, in the Events tab.

Scheduling a task

POST /schedule

Pipedream built-in action

Use the Pipedream Task Scheduler - Schedule Task Helper Functions action to schedule a new task.

Node.js

Use the following code in a Node.js code step:

import { axios } from "@pipedream/platform"
 
export default defineComponent({
  props: {
    numSeconds: {
      type: "integer",
      label: "Num Seconds",
      description: "How many seconds in the future would you like to schedule the task?",
    },
    secret: {
      type: "string",
      optional: true,
    },
    taskSchedulerURL: {
      type: "string",
      label: "Task Scheduler URL",
      description: "Enter the URL as it appears in the **Endpoint** field of your Task Scheduler source",
    },
    message: {
      type: "string",
      description: "The message / payload to send to your task scheduler. Can be any string or JavaScript object. This message will be emitted by the task scheduler at the specified number of seconds in the future.",
    },
  },
  async run({ $ }) {
    const timestamp = (new Date(+new Date() + (this.numSeconds * 1000))).toISOString()
 
    const headers = {
      "Content-Type": "application/json",
    };
    if (this.secret) {
      headers["x-pd-secret"] = this.secret;
    }
 
    return await axios($, {
      url: `${this.taskSchedulerURL}/schedule`,
      method: "POST",
      headers,
      data: {
        timestamp,
        message: this.message,
      },
    });
  },
})

cURL

To schedule a new task, POST a JSON object with an ISO 8601 timestamp and a message to the /schedule path of your source's HTTP endpoint:

{
  "timestamp": "2020-08-21T04:29:00.951Z", // timestamp: an ISO 8601 timestamp
  "message": { "name": "Luke" } // message can be any object or string
}

Optionally, if you configured a secret in your source, you'll need to pass that in the x-pd-secret header. For example:

curl -X POST \
  -H 'Content-Type: application/json' \
  -H 'x-pd-secret: 123' \
  -d '{ "timestamp": "2020-09-18T04:40:59Z", "message": "foo" }' \
  https://endpoint.m.pipedream.net/schedule

Successful task schedule requests yield a 200 OK response, noting the task was successfully scheduled.

Cancelling a scheduled task

POST /cancel

When you schedule a task, you'll receive a unique ID assigned to that task in the id field of the HTTP response body. That id can be passed to the /cancel endpoint to cancel that task before its scheduled time arrives.

Node.js

Cancel tasks using the following code in a Node.js code step:

import { axios } from "@pipedream/platform"
 
export default defineComponent({
  props: {
    secret: {
      type: "string",
      optional: true,
    },
    taskSchedulerURL: {
      type: "string",
      label: "Task Scheduler URL",
      description: "Enter the URL as it appears in the **Endpoint** field of your Task Scheduler source",
    },
    taskId: {
      type: "string",
      description: "The ID of the task you'd like to cancel",
    },
  },
  async run({ $ }) {
    const headers = {
      "Content-Type": "application/json",
    };
    if (this.secret) {
      headers["x-pd-secret"] = this.secret;
    }
 
    return await axios($, {
      url: `${this.taskSchedulerURL}/cancel`,
      method: "DELETE",
      headers,
      data: {
        id: this.taskId,
      },
    });
  },
})

cURL

curl -X POST \
  -H 'Content-Type: application/json' \
  -H 'x-pd-secret: 123' \
  -d '{ "id": "8fceb45b-0241-4d04-9f3f-334679586370" }' \
  https://endpoint.m.pipedream.net/cancel

Processing scheduled tasks

Scheduled tasks are emitted by the event source as events, which you can consume with

See the docs on consuming events from sources for more information.