golem-add-http-endpoint-rust

Add a mount parameter to the #[agent_definition] attribute, annotate trait methods with #[endpoint(get = "/path")] or other HTTP methods, then add an httpApi deployment section to golem.yaml. Build and deploy to make the routes live.

Unit returns 204 No Content, plain values return 200 OK with JSON, Option<T> returns 404 when None, and Result<T, E> returns 500 on Err. UnstructuredBinary<M> returns raw binary with a Content-Type header. This mapping is not configurable.

Yes, path variables in {braces} map to method parameters by exact name match. Catch-all {*name} variables are allowed only as the last path segment in endpoint paths, but they are not permitted in mount paths.

Setting phantom_agent = true on #[agent_definition] creates a new agent instance for each HTTP request instead of routing to a persistent instance. This enables fully parallel request processing without shared state between requests.

All custom types used in endpoint parameters or return values must derive the Schema trait from golem_rust. Without #[derive(Schema)], the agent cannot serialize or deserialize the type for HTTP requests and responses.