Services

Services let you deploy multiple backends and frontends within a single Vercel project. For example, a Next.js frontend and a FastAPI backend in the same repository deploy together with shared routing, environment variables, and a unique domain, replacing the need to split monorepos into separate Vercel projects.

A service is an independently built unit within your project that is deployed to the same domain under a unique subpath. At build time, Vercel builds each service separately. At request time, Vercel routes incoming requests to the correct service based on the URL path prefix.

A project can contain multiple services across different frameworks or runtimes, such as:

• A Next.js frontend at /
• A Python FastAPI backend, e.g. at /backend
• A Go server, e.g. at /svc/go

All services share the same deployment URL.

Services are valuable when you have:

• A polyglot monorepo: A JavaScript frontend and a Python backend in the same repository that you want to deploy as one project.
• Multiple backends: Several API services, each with its own dependencies and build step.

If your project uses a single framework (for example, a Next.js with API routes), you don't need services. If your monorepo contains separate applications that you would prefer to mount under separate domains, consider deploying them as separate projects in a monorepo instead.

Define services in vercel.json using the experimentalServices key:

{
  "experimentalServices": {
    "web": {
      "entrypoint": "apps/web",
      "routePrefix": "/"
    },
    "api": {
      "entrypoint": "backend/main.py",
      "routePrefix": "/server"
    }
  }
}

To deploy a project that uses multiple services, your project framework setting must be set to Services and experimentalServices must be present in vercel.json.

Run all services together locally, without authenticating with the Vercel Cloud, by adding the -L flag (short for --local):

vercel dev -L

• Routing and communication: How request routing, route prefixes, environment variables, and cross-service communication work.