# Authenticate an MCP client

Collection: mcp
Human docs: https://zei.sh/docs/mcp

Choose an API key for headless use or OAuth for interactive clients.

Headless clients can send a standalone API key directly. Interactive connectors use OAuth Authorization Code with PKCE and dynamic client registration.
OAuth metadata is at /api/v1/.well-known/oauth-authorization-server. Register at /api/v1/mcp-auth/register, authorize at /api/v1/mcp-auth/authorize, and exchange codes at /api/v1/mcp-auth/token.

Example:

```
Authorization: Bearer zeish_live_...
```