The server module lists the components and their scopes.

defmodule MyApp.MCP do
  use Sake.Server, name: "myapp", version: "1.0.0", instructions: "..."
  scope "issues:read", "Read issues"
  tools [MyApp.MCP.SearchIssues]
  resources [MyApp.MCP.Issue]
  prompts [MyApp.MCP.Triage]
end

Options: name, version (required), instructions, ttl (default 300 000 ms), cache_scope (:public or :private; default: private when the endpoint has authorization, public otherwise), page_size (default 100), extensions (a map for extension negotiation).

On the modern protocol, list and read results carry ttlMs: the server's ttl, or less. A tool, resource or prompt with its own ttl: shortens the ttlMs of every list page that includes it, and a resource's ttl: also sets the ttlMs of its resources/read result (the shortest ttl always wins).