fix(model): keep public signatures on the deprecated aliases

The public API check compares rendered signatures, and rustdoc records a
type alias by the name it was written with. Respelling
`ServerHandler::get_info`, `ClientHandler::get_info`,
`DiscoverResult::from_server_info` and `impl ClientHandler for ClientInfo`
onto `InitializeResult`/`InitializeRequestParams` therefore reads as
changed public items even though the aliases resolve to those exact types
and nothing downstream breaks.

Put those four signatures back on the aliases so the published API is
byte-identical, and note why at the alias definitions. The deprecation
still steers new code, and the macro output, tests, examples and docs
keep using the canonical names.

Author: teddytennant

crates/rmcp/src/handler/client.rs

@@ -274,7 +274,7 @@ macro_rules! client_handler_methods {
             std::future::ready(())
         }
 
-        fn get_info(&self) -> InitializeRequestParams {
+        fn get_info(&self) -> ClientInfo {
             InitializeRequestParams::default()
         }
     };
@@ -296,8 +296,8 @@ pub trait ClientHandler: Sized + 'static {
 impl ClientHandler for () {}
 
 /// Do nothing, with a specific client info.
-impl ClientHandler for InitializeRequestParams {
-    fn get_info(&self) -> InitializeRequestParams {
+impl ClientHandler for ClientInfo {
+    fn get_info(&self) -> ClientInfo {
         self.clone()
     }
 }
@@ -422,7 +422,7 @@ macro_rules! impl_client_handler_for_wrapper {
                 (**self).on_custom_notification(notification, context)
             }
 
-            fn get_info(&self) -> InitializeRequestParams {
+            fn get_info(&self) -> ClientInfo {
                 (**self).get_info()
             }
         }

crates/rmcp/src/handler/server.rs

@@ -550,7 +550,7 @@ macro_rules! server_handler_methods {
             std::future::ready(())
         }
 
-        fn get_info(&self) -> InitializeResult {
+        fn get_info(&self) -> ServerInfo {
             InitializeResult::default()
         }
 
@@ -782,7 +782,7 @@ macro_rules! impl_server_handler_for_wrapper {
                 (**self).on_custom_notification(notification, context)
             }
 
-            fn get_info(&self) -> InitializeResult {
+            fn get_info(&self) -> ServerInfo {
                 (**self).get_info()
             }
 

crates/rmcp/src/model.rs

@@ -1086,6 +1086,14 @@ impl InitializeResult {
 ///
 /// Prefer [`InitializeResult`]. The name collides with the protocol's
 /// `serverInfo` field, which is only the [`Implementation`] identity (#1082).
+//
+// The signatures this crate publishes (`ServerHandler::get_info`,
+// `DiscoverResult::from_server_info`, and the `ClientInfo` equivalents below)
+// keep spelling the alias. It resolves to the same type, so the spelling makes
+// no difference to callers, but rustdoc records the name as written and the
+// public API check treats a respelling as a changed item. Moving those
+// signatures onto the canonical names is a documented API change and belongs in
+// the next major release.
 #[deprecated(note = "use `InitializeResult` instead")]
 pub type ServerInfo = InitializeResult;
 
@@ -1256,7 +1264,7 @@ impl DiscoverResult {
     /// Create a discovery result from the server's initialization information.
     pub fn from_server_info(
         supported_versions: Vec<ProtocolVersion>,
-        server_info: InitializeResult,
+        server_info: ServerInfo,
     ) -> Self {
         let InitializeResult {
             capabilities,