# Deploy at a subpath with Vercel

> Serve your Mintlify site at a subpath on your main domain using Vercel rewrites, with a step-by-step vercel.json configuration walkthrough.

Configure your `vercel.json` file to proxy requests from your main domain to your documentation at a subpath.

## The vercel.json file

The `vercel.json` file configures how your project builds and deploys. It sits in your project's root directory and controls various aspects of your deployment, including routing, redirects, headers, and build settings.

Mintlify uses the `rewrites` configuration in your `vercel.json` file to proxy requests from your main domain to your documentation.

Rewrites map incoming requests to different destinations without changing the URL in the browser. When someone visits `yoursite.com/docs`, Vercel internally fetches content from `your-subdomain.mintlify.site/docs`, but the user still sees `yoursite.com/docs` in their browser. This is different from redirects, which send users to another URL entirely.

## Configuration

### Host at `/docs` subpath

1. Navigate to [Custom domain setup](https://app.mintlify.com/settings/project/custom-domain) in your dashboard.
2. Enable the **Host at** toggle.
3. Enter your domain.
4. Enter `docs` as your base path.
5. Click **Add domain**.
6. Add the following rewrites to your `vercel.json` file. Replace `[subdomain]` with your subdomain, which appears at the end of your dashboard URL. For example, `app.mintlify.com/your-organization/your-subdomain` has a domain identifier of `your-subdomain`.

   ```json theme={null}
   {
     "rewrites": [
       {
         "source": "/_mintlify/:path*",
         "destination": "https://[subdomain].mintlify.site/_mintlify/:path*"
       },
       {
         "source": "/api/request",
         "destination": "https://[subdomain].mintlify.site/_mintlify/api/request"
       },
       {
         "source": "/docs",
         "destination": "https://[subdomain].mintlify.site/docs"
       },
       {
         "source": "/docs/:match*",
         "destination": "https://[subdomain].mintlify.site/docs/:match*"
       },
       {
         "source": "/mintlify-assets/:path+",
         "destination": "https://[subdomain].mintlify.site/mintlify-assets/:path+"
       }
     ]
   }
   ```

The `rewrites` configuration maps the `/docs` subpath on your domain to the `/docs` subpath on your documentation.

- **`source`**: The path pattern on your domain that triggers the rewrite.
- **`destination`**: Where the request should be proxied to.
- **`:match*`**: A wildcard that captures any path segments after your subpath.

The `/_mintlify` and `/mintlify-assets` rewrites are required for the API playground and static assets.

For more information, see [Configuring projects with vercel.json: Rewrites](https://vercel.com/docs/projects/project-configuration#rewrites) in the Vercel documentation.

### Host at custom subpath

To use a custom subpath (any path other than `/docs`):

1. Navigate to the [Custom domain setup](https://app.mintlify.com/settings/project/custom-domain) page in your dashboard.
2. Enable the **Host at** toggle.
3. Enter your domain.
4. Enter your base path. For example, `/docs` or `/help`.
5. Click **Add domain**.

Then use the generator below to create your rewrites configuration and add the rewrites to your `vercel.json` file.

Mintlify rebuilds your documentation to serve at your base path, so your documentation files do not need to be in a directory that matches your subpath.

## External proxies in front of Vercel

If you have an external proxy like Cloudflare or AWS CloudFront in front of your Vercel deployment, configure it properly. This avoids conflicts with Vercel's domain verification and SSL certificate provisioning.

Improper proxy configuration can prevent Vercel from provisioning Let's Encrypt SSL certificates and cause domain verification failures.

See the [supported providers](https://vercel.com/guides/how-to-setup-verified-proxy#supported-providers-verified-proxy-lite) in the Vercel documentation.

### Required path allowlist

Your external proxy must allow traffic to these specific paths without blocking, redirecting, or heavily caching:

- `/.well-known/acme-challenge/*`: Required for Let's Encrypt certificate verification.
- `/.well-known/vercel/*`: Required for Vercel domain verification.
- `/mintlify-assets/_next/static/*`: Required for static assets.

Your proxy should pass these paths directly to your Vercel deployment without modification.

### Header forwarding requirements

Ensure that your proxy correctly forwards the `Host` header. Without proper header forwarding, verification requests fail.

### Test your proxy setup

To verify your proxy is correctly configured:

1. Test that `https://[yourdomain].com/.well-known/vercel/` returns a response.
2. Ensure SSL certificates are provisioning correctly in your Vercel dashboard.
3. Check that domain verification completes successfully.

## Related topics

- [Deploy at a subpath with Cloudflare Workers](/docs/deploy/cloudflare.md)
- [Deploy at a subpath with AWS Route 53 and CloudFront](/docs/deploy/route53-cloudfront.md)
- [Host docs at a subpath](/docs/deploy/docs-subpath.md)

## Related pages

- [Ai](./ai-index.md)
- [Analytics overview](./analytics-index.md)
- [Api](./api-index.md)
- [Api playground](./api-playground-index.md)
- [Assistant](./assistant-index.md)
- [Automations overview](./automations-index.md)
- [Components overview](./components-index.md)
- [Create](./create-index.md)
- [Customize](./customize-index.md)
- [Dashboard](./dashboard-index.md)

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