Attribute Macro session_open 

#[session_open]

Mark a function as act:sessions/session-provider.open-session.

Inside #[act_component], the component macro picks up this annotation, generates the session-provider Guest impl, and derives the get-open-session-args-schema JSON Schema from the function’s argument type via schemars::JsonSchema.

Signature: fn open(args: T) -> ActResult<String> (sync or async). T must implement serde::Deserialize and schemars::JsonSchema. The returned String is the session-id the host will use in subsequent capability calls.

Outside #[act_component], this attribute is a no-op pass-through.