Attribute Macro tool_handler 

#[tool_handler]

Available on crate features macros and server only.

tool_handler

This macro generates the call_tool, list_tools, get_tool, and (optionally) get_info methods for a ServerHandler implementation, using a ToolRouter.

Usage

field	type	usage
router	Expr	The expression to access the ToolRouter instance. Defaults to Self::tool_router().
meta	Expr	Optional metadata for ListToolsResult.
name	String	Custom server name. Defaults to CARGO_CRATE_NAME.
version	String	Custom server version. Defaults to CARGO_PKG_VERSION.
instructions	String	Optional human-readable instructions about using this server.

Minimal example (no boilerplate)

The macro automatically generates get_info() with tools capability enabled and reads the server name/version from Cargo.toml:

struct TimeServer;

#[tool_router]
impl TimeServer {
    #[tool(description = "Get current time")]
    async fn get_time(&self) -> String { "12:00".into() }
}

#[tool_handler]
impl ServerHandler for TimeServer {}

Custom server info

#[tool_handler(name = "my-server", version = "1.0.0", instructions = "A helpful server")]
impl ServerHandler for MyToolHandler {}

Custom router expression

#[tool_handler(router = self.tool_router)]
impl ServerHandler for MyToolHandler {
   // ...implement other handler
}

Manual get_info()

If you provide your own get_info(), the macro will not generate one:

#[tool_handler]
impl ServerHandler for MyToolHandler {
    fn get_info(&self) -> ServerInfo {
        ServerInfo::new(ServerCapabilities::builder().enable_tools().build())
    }
}