---
title: "Bun guide"
sidebarTitle: "Bun"
description: "This guide will show you how to setup Trigger.dev with Bun"
icon: "js"
---

import Prerequisites from "/snippets/framework-prerequisites.mdx";
import CliRunTestStep from "/snippets/step-run-test.mdx";
import CliViewRunStep from "/snippets/step-view-run.mdx";

We now have experimental support for Bun. This guide will show you have to setup Trigger.dev in your existing Bun project, test an example task, and view the run.

<Warn>
  The trigger.dev CLI does not yet support Bun. So you will need to run the CLI using Node.js. But
  Bun will still be used to execute your tasks, even in the `dev` environment.
</Warn>

<Prerequisites framework="Bun" />

## Initial setup

<Steps>
  <Step title="Run the CLI `init` command">

The easiest way to get started is to use the CLI. It will add Trigger.dev to your existing project, create a `/trigger` folder and give you an example task.

Run this command in the root of your project to get started:

<CodeGroup>

```bash npm
npx trigger.dev@latest init --runtime bun
```

```bash pnpm
pnpm dlx trigger.dev@latest init --runtime bun
```

```bash yarn
yarn dlx trigger.dev@latest init --runtime bun
```

</CodeGroup>

It will do a few things:

1. Log you into the CLI if you're not already logged in.
2. Create a `trigger.config.ts` file in the root of your project.
3. Ask where you'd like to create the `/trigger` directory.
4. Create the `/src/trigger` directory with an example task, `/src/trigger/example.[ts/js]`.

Install the "Hello World" example task when prompted. We'll use this task to test the setup.

</Step>

  <Step title="Update example.ts to use Bun">

    Open the `/src/trigger/example.ts` file and replace the contents with the following:

    ```ts example.ts
    import { Database } from "bun:sqlite";
    import { task } from "@trigger.dev/sdk/v3";

    export const bunTask = task({
      id: "bun-task",
      run: async (payload: { query: string }) => {
        const db = new Database(":memory:");
        const query = db.query("select 'Hello world' as message;");
        console.log(query.get()); // => { message: "Hello world" }

        return {
          message: "Query executed",
        };
      },
    });

    ```

  </Step>

  <Step title="Run the CLI `dev` command">

The CLI `dev` command runs a server for your tasks. It watches for changes in your `/trigger` directory and communicates with the Trigger.dev platform to register your tasks, perform runs, and send data back and forth.

It can also update your `@trigger.dev/*` packages to prevent version mismatches and failed deploys. You will always be prompted first.

<CodeGroup>

```bash npm
npx trigger.dev@latest dev
```

```bash pnpm
pnpm dlx trigger.dev@latest dev
```

```bash yarn
yarn dlx trigger.dev@latest dev
```

</CodeGroup>

</Step>

<CliRunTestStep />
<CliViewRunStep />

</Steps>

## Known issues

- Certain OpenTelemetry instrumentation will not work with Bun, because Bun does not support Node's `register` hook. This means that some libraries that rely on this hook will not work with Bun.
