class RubyLLM::MCP::Auth::Flows::ClientCredentialsFlow

Used for application authentication without user interaction
Orchestrates OAuth 2.1 Client Credentials flow

def execute(server_url, redirect_uri, scope)

Returns:
  • (Token) - access token

Parameters:
  • scope (String, nil) -- requested scope
  • redirect_uri (String) -- redirect URI (used for registration only)
  • server_url (String) -- MCP server URL 
def execute(server_url, redirect_uri, scope)
  logger.debug("Starting OAuth client credentials flow")
  # 1. Discover authorization server
  server_metadata = discoverer.discover(server_url)
  raise Errors::TransportError.new(message: "OAuth server discovery failed") unless server_metadata
  # 2. Register client (or get cached client) with client credentials grant
  client_info = client_registrar.get_or_register(
    server_url,
    server_metadata,
    :client_credentials,
    redirect_uri,
    scope
  )
  # 3. Validate that we have a client secret
  unless client_info.client_secret
    raise Errors::TransportError.new(
      message: "Client credentials flow requires client_secret"
    )
  end
  # 4. Exchange client credentials for token
  token = token_manager.exchange_client_credentials(
    server_metadata,
    client_info,
    scope,
    server_url
  )
  # 5. Store token
  storage.set_token(server_url, token)
  logger.info("Client credentials authentication completed successfully")
  token
end

def initialize(discoverer:, client_registrar:, token_manager:, storage:, logger:) 

def initialize(discoverer:, client_registrar:, token_manager:, storage:, logger:)
  @discoverer = discoverer
  @client_registrar = client_registrar
  @token_manager = token_manager
  @storage = storage
  @logger = logger
end