HTTP

stdio is the default and the arrangement to prefer: one client, one process, no socket and no credential. Turn on HTTP only when a second process genuinely has to reach a server that is already running. The listener always binds a loopback address, and every request is authenticated: reaching the socket proves nothing about who is calling.

Two modes

Mode	For	A request is accepted when
trusted_local	Another local process run by the same user	It carries the per-launch secret, and its Host and Origin match the configured ones exactly
proxied_oidc	A client on another host, through a reverse proxy on this one	It arrives through the proxy hop with the hop's own credential, carrying a valid token of the one configured end user

trusted_local

The secret is created fresh for every launch and handed over through an environment variable or a protected file; it is never written into the configuration:

transport = "http"

[http]
bind = "127.0.0.1:8765"
mode = "trusted_local"
host = "127.0.0.1:8765"
origin = "http://127.0.0.1:8765"

[http.local_secret.env]
var = "GODOT_MCP_LAUNCH_SECRET"

Start the server with godot-mcp serve --project /path/to/my-game --config /path/to/godot-mcp.toml; the MCP endpoint is /mcp on the bind address. A non-loopback bind is refused by the loader, so no configuration of this mode is reachable from another host. The trusted_local reference covers how the secret is produced and scoped.

proxied_oidc

The reverse proxy terminates TLS and authenticates the user; the server, still on loopback, accepts only requests that carry the proxy hop's credential and validates the user's token itself against the issuer, audience, scopes and signing keys you configure. Token validation refuses unsigned tokens, unexpected algorithms, keys a token tries to bring with it and every private or redirected key address. The proxied_oidc reference has the whole configuration and the residual risk you own.

Parity

HTTP calls the same kernel as stdio: the same tools, the same profiles, the same journal and the same answers. Anything an HTTP client can do, a stdio client of the same server can do, and the other way round.