Behind an MCP gateway

Put HTTP behind an MCP/API gateway or reverse proxy. The server does not authenticate end users; the gateway must.

The contract

For every forwarded request:

1. Authenticate the caller: OIDC, API key, or mutual TLS.
2. Set the profile header from a stable verified identity, typically token sub. It selects the caller's catalog.
3. Overwrite, never forward, that header. Client-supplied values could expose another caller's catalog.
4. Send the shared secret as Authorization: Bearer <token> to authenticate the gateway to the server.

caller ──(OIDC token)──▶ gateway ──(Authorization: Bearer <shared secret>
                                    X-Kibana-Profile: <caller id>)──▶ kibana-mcp-server ──▶ Kibana

Server side

Set a profile header, or name one default profile. Non-loopback HTTP requires KIBANA_HTTP_AUTH_TOKEN; otherwise startup is refused.

KIBANA_HTTP_AUTH_TOKEN=change-me \
kibana-mcp-server serve --http \
  --config ./kibana.mcp.config.ts \
  --profile-header x-kibana-profile

Example: nginx with an auth subrequest

With nginx and an OAuth2 proxy, authenticate and overwrite headers:

location /mcp/kibana {
  auth_request /oauth2/auth;
  auth_request_set $caller $upstream_http_x_auth_request_user;

  proxy_set_header X-Kibana-Profile $caller;          # always overwritten
  proxy_set_header Authorization "Bearer change-me";  # shared secret
  proxy_pass http://127.0.0.1:3000/mcp;
  proxy_buffering off;                                # responses may be streamed
}

One server per Kibana

Run one process per Kibana instance. Give each its own port and store prefix or table, then route from the gateway.

Callers without an identity

Reject identities without a stable identifier, or map them to a named profile at the gateway. An empty profile header (for example, a token without sub) returns 401.