ConduitMcp.Client.OAuth.Registration (ConduitMCP v0.11.0)

Chooses the client identity presented to an authorization server, in the MCP authorization spec's order (compiled only with :finch):

Pre-registered - pre_registered[issuer] from the OAuth options. When pre-registered clients are configured but none is for this issuer, the server has moved to another authorization server and the flow stops with :authorization_server_changed (OA-6): credentials are bound to their issuer, and falling back to another method would silently re-identify the client.
Client ID Metadata Document - when the authorization server advertises client_id_metadata_document_supported: true and :client_metadata_url is set, that URL is the client id (see ConduitMcp.Client.OAuth.CIMD).
Dynamic client registration (RFC 7591; deprecated in MCP 2026-07-28, kept for older authorization servers) - when the metadata has a registration_endpoint. The request declares application_type (native for a loopback or custom-scheme redirect URI, else web, unless client_metadata says otherwise), grant_types: ["authorization_code", "refresh_token"], response_types: ["code"] and token_endpoint_auth_method: "none". The registered client is kept in the token store under the issuer (ConduitMcp.Client.OAuth.TokenStore.put_client/3) and reused while its redirect_uris include the redirect URI, so a client registered with one authorization server is never shown to another.
Otherwise :no_registration_method.

Summary

t()

A resolved client identity and how it was obtained.

Resolves the client identity for authorization server issuer with validated metadata.

@type t() :: %{
  :client_id => String.t(),
  :auth_method => atom(),
  :method => :pre_registered | :cimd | :dcr,
  optional(atom()) => term()
}

A resolved client identity and how it was obtained.

@spec resolve(ConduitMcp.Client.OAuth.Config.t(), String.t(), map(), keyword()) ::
  {:ok, t()} | {:error, ConduitMcp.Client.OAuth.Error.t()}

Resolves the client identity for authorization server issuer with validated metadata.

:redirect_uri - the redirect URI of the flow (needed to register).
:register - whether dynamic registration may send a request (default true; false only reuses a stored registration, as a token refresh does).