---
title: Developing with multiple Workers
description: Learn how to develop with multiple Workers using different approaches and configurations.
image: https://developers.cloudflare.com/dev-products-preview.png
---

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# Developing with multiple Workers

When building complex applications, you may want to run multiple Workers during development. This guide covers the different approaches for running multiple Workers locally and when to use each approach.

## Single dev command

Note

We recommend this approach as the default for most development workflows as it ensures the best compatibility with bindings.

You can run multiple Workers in a single dev command by passing multiple configuration files to your dev server:

**Using Wrangler**

 npm  yarn  pnpm 

```
npx wrangler dev -c ./app/wrangler.jsonc -c ./api/wrangler.jsonc
```

```
yarn wrangler dev -c ./app/wrangler.jsonc -c ./api/wrangler.jsonc
```

```
pnpm wrangler dev -c ./app/wrangler.jsonc -c ./api/wrangler.jsonc
```

The first config (`./app/wrangler.jsonc`) is treated as the primary Worker, exposed at `http://localhost:8787`. Additional configs (e.g. `./api/wrangler.jsonc`) run as auxiliary Workers, available via service bindings or tail consumers from the primary Worker.

**Using the Vite plugin**

Configure `auxiliaryWorkers` in your Vite configuration:

vite.config.js

```

import { defineConfig } from "vite";

import { cloudflare } from "@cloudflare/vite-plugin";


export default defineConfig({

  plugins: [

    cloudflare({

      configPath: "./app/wrangler.jsonc",

      auxiliaryWorkers: [

        {

          configPath: "./api/wrangler.jsonc",

        },

      ],

    }),

  ],

});


```

Then run:

 npm  yarn  pnpm 

```
npx vite dev
```

```
yarn vite dev
```

```
pnpm vite dev
```

**Use this approach when:**

* You want the simplest setup for development
* Workers are part of the same application or codebase
* You need to access a Durable Object namespace or Workflow from another Worker using `script_name`, or set up Queues where the producer and consumer Workers are separated.

## Multiple dev commands

You can also run each Worker in separate dev commands, each with its own terminal and configuration.

 npm  yarn  pnpm 

```
# Terminal 1
npx wrangler dev -c ./app/wrangler.jsonc
```

```
# Terminal 1
yarn wrangler dev -c ./app/wrangler.jsonc
```

```
# Terminal 1
pnpm wrangler dev -c ./app/wrangler.jsonc
```

 npm  yarn  pnpm 

```
# Terminal 2
npx wrangler dev -c ./api/wrangler.jsonc
```

```
# Terminal 2
yarn wrangler dev -c ./api/wrangler.jsonc
```

```
# Terminal 2
pnpm wrangler dev -c ./api/wrangler.jsonc
```

These Workers run in different dev commands but can still communicate with each other via service bindings or tail consumers **regardless of whether they are started with `wrangler dev` or `vite dev`**.

Note

You can also combine both approaches — for example, run a group of Workers together through `vite dev` using `auxiliaryWorkers`, while running another Worker separately with `wrangler dev`. This allows you to keep tightly coupled Workers running under a single dev command, while keeping independent or shared Workers in separate ones.

**Use this approach when:**

* You want each Worker to be accessible on its own local URL during development, since only the primary Worker is exposed when using a single dev command
* Each Worker has its own build setup or tooling — for example, one uses Vite with custom plugins while another is a vanilla Wrangler project
* You need the flexibility to run and develop Workers independently without restructuring your project or consolidating configs

This setup is especially useful in larger projects where each team maintains a subset of Workers. Running everything in a single dev command might require significant restructuring or build integration that isn't always practical.

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```