An open-source API for collecting and managing contacts and signups.
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:
Authorization: Bearer YOUR_KEY
| 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:
https://contactapi.dev/mcp
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.
npm install
vc dev
open http://localhost:3000
npm install
vc build
npm install
vc deploy
Source-derived launch command. Check the maintainer’s required arguments and credentials before running:
npx -y @kozmos-tech/contactapiMerge this template into ~/Library/Application Support/Claude/claude_desktop_config.json. Keep existing servers. Add any arguments, credentials, and permissions required by the maintainer; this template has not been install-tested.
{
"mcpServers": {
"io-github-kozmos-tech-contactapi": {
"command": "npx",
"args": [
"-y",
"@kozmos-tech/contactapi"
]
}
}
}Restart Claude Desktop completely for changes to take effect. Confirm the server appears connected in the client’s tool list, then try a read-only example from its documentation.
Claude Desktop setup reference@kozmos-tech/contactapinpmio.github.kozmos-tech/contactapi works with any MCP-compatible client. Copy the config snippet from the Configuration section above and add it to the file shown for your client, then restart the application.
~/Library/Application Support/Claude/claude_desktop_config.jsonRestart Claude Desktop completely for changes to take effect.~/.cursor/mcp.jsonRestart Cursor for changes to take effect..vscode/mcp.jsonReload VS Code window for changes to take effect.~/.codeium/windsurf/mcp_config.jsonRestart Windsurf for changes to take effect..mcp.jsonSave at the project root, then start Claude Code in that project and review the MCP server approval prompt. Keep real credentials out of shared files.