Vercel

Lightweight, dependency-free, in-memory Vercel REST API fake for testing code that uses the Vercel REST API or @vercel/client.

Default port: 4770

Quick start

import { VercelServer } from "./services/vercel/src/server.js";

const server = new VercelServer(4770);
await server.start();
// ... run your app/tests ...
await server.stop();

Point a client at it:

const res = await fetch("http://127.0.0.1:4770/v2/user", {
  headers: { Authorization: "Bearer vercel_parlel" },
});
const { user } = await res.json();
// user.username => "parlel-user"

Access via MCP / preview URL

REST base URL: http://127.0.0.1:4770
Set VERCEL_TOKEN=vercel_parlel and VERCEL_API_URL=http://127.0.0.1:4770.

All API routes require Authorization: Bearer <token> (any non-empty token accepted).

Implemented operations

State is in-memory and ephemeral. Versioned paths mirror the real Vercel API.

GET /v2/user — current user, wrapped as { user }.
GET /v9/projects — list projects ({ projects, pagination }).
POST /v9/projects — create project (requires name).
GET /v9/projects/:idOrName — retrieve a project by id or name.
PATCH /v9/projects/:idOrName — update name/framework.
DELETE /v9/projects/:idOrName — delete (204).
POST /v13/deployments — create a deployment (requires name); returns READY deployment with .vercel.app URL.
GET /v6/deployments — list deployments ({ deployments, pagination }).
GET /v6/deployments/:id — retrieve a deployment by id or url.

Service & inspection (parlel extensions)

GET / — service metadata.
GET /health — { status: "ok" }.
POST /__parlel/reset — reset state.

Surface coverage

This emulator faithfully replicates the API surface most application code and agents exercise. Anything below the supported lines is either an intentional design choice for a fast, zero-cost local emulator (✓ By design) or a candidate for a future release (⟳ Roadmap) — never a silent inaccuracy.

Legend: ✅ fully supported · ◐ accepted (stored, not strictly enforced) · ✓ by design · ⟳ on the roadmap.

Feature	Status
`GET /v2/user`	✅ Supported
Projects list / create / get / patch / delete	✅ Supported
Deployments create / list / get	✅ Supported
Bearer auth	✅ Required (any non-empty token)
Real build pipeline / file uploads	⟳ Roadmap — Deployment is instantly `READY`
Domains / env vars / aliases / teams	⟳ Roadmap
Cursor pagination	⟳ Roadmap — Single page
Scope / team enforcement	✓ By design — Any non-empty credential is accepted — no real secrets needed

Error codes & shapes

Vercel error envelope: { "error": { "code": "...", "message": "..." } }.

Status	When
`403`	missing/invalid authorization
`400`	missing required field (`name`)
`404`	unknown resource
`405`	method not allowed

Manifest

See services/vercel/manifest.json:

name: vercel, image: parlel/vercel:1
port: 4770, protocol: http, healthcheck: /health, startup ≈ 100ms
env: VERCEL_TOKEN, VERCEL_API_URL

Configuration — `test.env`

Copy these into your test.env (used by the bridge sidecar flow). Tokens are Parlel's seeded test credentials — any non-empty value is accepted by the emulator, so you rarely need to change them. Swap in real credentials only when pointing at the live service in prod.env.

VERCEL_TOKEN=vercel_parlel
VERCEL_API_URL=http://parlel-bridge:4770