AI agents with Plain webhooks

Receive Plain webhooks on Trigger.dev and use them to start, resume or message your AI agents.

Get started now

What you can do with Plain webhooks

Start an agent

Plain events can start a new agent run. For example, an agent that drafts a reply to every new Plain thread.

Resume an agent

An agent can pause until the Plain event it needs arrives, for up to 90 days, and costs nothing while it waits.

Message an agent

Plain events can land in a running agent's conversation, so it acts on them with full context.

Events you can receive from Plain

Some of the events Plain sends. Your agent can filter on any of them.

View all events
thread.thread_created

Thread created

thread.email_received

Email received

thread.chat_received

Chat message received

thread.thread_status_transitioned

Thread status changed

customer.customer_created

Customer created

Example

An agent that drafts a reply to every new Plain thread

import { webhook, webhooks } from "@trigger.dev/sdk";


export const plain = webhooks.endpoint.define({
  id: "plain",
  source: webhooks.plain(),
});


export const plainEvents = webhook({
  id: "plain-events",
  endpoint: plain,
  filter: "event.type == 'thread.thread_created'",
  onEvent: async ({ event }) => {
    // Start, resume or message your agent with the event
    console.log(event);
  },
});

Handled for you

Docs

Verified for you

webhooks.plain() checks the Plain-Request-Signature header on every request. Bad requests are rejected before anything runs.

Retries don't run twice

Retries are matched on event.id, so a retried webhook doesn't start a second run.

Filter before anything runs

Only the Plain events you care about start a run. Filtered webhooks use no compute.

See every delivery

Every webhook is recorded with its payload, headers and the agents it reached, so you can debug it and replay it.

Get started

  1. 1

    Set up the agent

    Copy the starter prompt into your coding agent, like Claude Code, Cursor or Codex. It creates a Trigger.dev project and adds the webhook endpoint. Prefer to write it yourself? Start from the example above.

  2. 2

    Add the webhook in Plain

    Deploy your project, or run trigger dev, and the endpoint appears on the Webhooks page of the Trigger.dev dashboard with its URL. Add that URL in Plain's webhook settings and pick the events you need. The endpoint's Copy setup prompt button gives your coding agent the exact steps.

  3. 3

    Add Plain's HMAC secret

    Copy the HMAC secret from Plain. Then on the endpoint's page in the Trigger.dev dashboard, choose Set signing secret and paste it in, so Trigger.dev can check every request really came from Plain.

  4. 4

    Try it

    Send a test event from Plain, or use the endpoint's Test tab. It appears on the endpoint's Deliveries tab, with the agents it reached.

Related integrations

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Linear

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Slack

Communication

Attio

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Autumn

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Brex

Payments & billing

Cal.com

Productivity

Ready to build with Plain webhooks?

Declare an endpoint, deploy, and paste the URL into your provider.

Get started for free