Vercel

Vercel Functions can run a server.ts with the Bun runtime. With it, a function accepts WebSocket upgrades and runs one voice session per socket. The code is the Vercel framework page, tested in examples/framework-snippets/vercel.

Set the runtime in vercel.json:

{ "bunVersion": "1.x" }

What worksCopy Anchor Link

• WebSocket sessions. The /ws endpoint upgrades in fetch and runs the agent on the socket, with protobuf audio frames.
• WebRTC signalling. The /api/offer route answers the SDP offer, but the media can't follow: see below.

LimitsCopy Anchor Link

• No WebRTC media. SmallWebRTC needs UDP, which Vercel Functions don't carry. Use the WebSocket transport, or run SmallWebRTC on a server.
• One instance per socket. Each WebSocket is pinned to one function instance for its lifetime, and messages don't cross instances. Keep shared state in a database.
• Duration. A function's maximum duration also ends a long session. Check your plan's limit against your longest calls.
• Vercel Daemons are always-on workers with no inbound HTTP or TCP traffic, so they can't serve these endpoints. They suit background workers that pull their own work.
• Next.js on Vercel. A Next.js route handler can answer the offer, but it can't upgrade a WebSocket. See Next.js.