# auth.md — Authenticating with Close

The close.com marketing site is public and requires no authentication.
Programmatic access to Close happens through the Close API and the Close
MCP server.

## Close API

- Base URL: `https://api.close.com/api/v1`
- **API keys** — HTTP Basic auth with the key as the username and an
  empty password. Create keys in Close under Settings → API Keys.
  Guide: https://developer.close.com/topics/authentication/
- **OAuth 2.0** — authorization-code grant with refresh tokens.
  Authorize at `https://app.close.com/oauth2/authorize`, exchange at
  `https://api.close.com/oauth2/token`.
  Guide: https://developer.close.com/topics/oauth/
- Discovery documents: `/.well-known/openid-configuration` and
  `/.well-known/api-catalog` on this host.

## Close MCP server

- Endpoint: `https://mcp.close.com/mcp` (streamable HTTP)
- OAuth-protected. Resource metadata:
  `https://mcp.close.com/.well-known/oauth-protected-resource`
  (scopes: `mcp.read`, `mcp.write_safe`, `mcp.write_destructive`,
  `offline_access`)
- Server card: `/.well-known/mcp.json` on this host.
- Documentation and tool list: https://developer.close.com/mcp/