The full upstream README, mirrored here for reference. Install config, tool schemas, adoption signals, and an original overview live on the Contactapi listing page.
An open-source API to save contacts. Send a POST with an email and any other
JSON fields you want, and they get saved as-is. Manage them with simple CRUD.
Built with Hono and deployed on Vercel.
The base URL is https://contactapi.dev and every request carries your API key
as a Bearer token:
| Method | Path | Key | Description |
|---|---|---|---|
POST | /v1/contacts | secret or publishable | Create (or upsert) a contact by email |
GET | /v1/contacts | secret | List contacts, paginated |
GET | /v1/contacts/:id | secret | Fetch a single contact |
PATCH | /v1/contacts/:id | secret | Update a contact |
DELETE | /v1/contacts/:id | secret | Delete a contact |
Contacts are keyed by email — creating one whose email already exists updates it
in place rather than duplicating it. Full reference lives on the landing page and
in /llms.txt.
There are two kinds of key:
ck_secret_… — secret key, for your backend. Full access to every endpoint.ck_pub_… — publishable key, for the browser. Can only create contacts and is
locked to your domains.AI clients (Claude Desktop, claude.ai custom connectors, Cursor, the MCP Inspector) can manage your contacts through an MCP server at:
Auth is OAuth 2.1 with dynamic client registration — point a client at the
URL and it discovers the authorization server, registers itself, and sends you to
log in and approve access; no API key to copy. The server exposes five tools that
mirror the REST API: list_contacts, get_contact, create_contact
(upsert-by-email), update_contact, and delete_contact. Everything is scoped to
the account you log in as.
The OAuth provider is Better Auth's mcp plugin
(src/auth.ts); the tools and endpoint wiring live in
src/mcp/server.ts and src/index.ts.
Prerequisites: Vercel CLI installed globally.