@webmcp-agents/vercel-api

The examples' /api/chat as Vercel web handlers.

The examples’ /api/chat as Vercel web handlers. It puts @webmcp-agents/chat’s server handler behind an origin check, per-IP rate limits and a global daily budget on model calls.

The package is private ("private": true). It is not published to npm. The example apps (examples/playground, examples/ecommerce, examples/flights) use it as a workspace dependency.

import { createVercelChatRoute } from "@webmcp-agents/vercel-api";

export const { GET, POST, OPTIONS } = createVercelChatRoute({ app: "playground" });

Env is read when the route is created (at the function’s cold start), never at import time.

Deployment

Project settings, environment variables, Upstash Redis and the smoke test are in Deploy.

How a request flows

1. OPTIONS answers 204. Other methods than GET and POST answer 405.
2. Cross-site browser requests are refused by the chat handler (403).
3. guard: originGuard() (403 forbidden_origin), then rateLimitGuard with a per-minute and a per-day limiter per IP (429 rate_limited). Only POST is checked.
4. GET answers { enabled, model }.
5. The chat handler validates the body.
6. beforeModel: budgetGuard counts the call against the global daily budget (503 unavailable).
7. The model runs.

API reference