Summary: The Neon CLI neon dev command runs Neon Functions locally with a dev server and hot reload. Pass --source to serve a single function entry module (optionally with --port for an explicit port), or omit --source to serve every function declared in neon.ts, each on its own dev server.

Run Neon Functions locally with a dev server

The dev command runs Neon Functions locally with a dev server and hot reload. Serve one function from its entry module, or every function declared in your neon.ts policy.

neon dev [--source <path>] [options]

Serve one function on a free port with hot reload:

neon dev --source ./functions/hello.ts

Serve every function declared in neon.ts (one dev server each):

neon dev

Serve one function on an explicit port (fails if the port is taken):

neon dev --source ./functions/hello.ts --port 3000

neon dev serves WebSocket upgrades locally, so you can test real-time functions before you deploy. Connect a client to the dev server's ws://localhost:<port> URL. See WebSockets and SSE for the function-side code.

• config
• deploy
• status

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