docs: single-source SEP-2260 caller requirements on OriginatingRequestId

Author: gocamille

crates/rmcp/src/service.rs

@@ -183,6 +183,14 @@ pub(crate) fn in_request_handler_scope() -> bool {
 /// originating request's SSE stream. Never on the wire (SEP-2260 defines no
 /// wire field), so session managers that serialize messages between processes
 /// lose it and such requests fall back to the standalone stream with a warning.
+///
+/// # Caller requirements
+///
+/// From protocol version `2026-07-28`, server-to-client sampling, roots, and
+/// elicitation requests must be issued while handling a client request;
+/// outside a handler they return an `invalid_request` error. The association
+/// is task-local and does not cross `tokio::spawn`, so use the task manager
+/// for long-running work.
 #[derive(Debug, Clone, PartialEq, Eq)]
 #[expect(clippy::exhaustive_structs, reason = "intentionally exhaustive")]
 pub struct OriginatingRequestId(pub RequestId);

crates/rmcp/src/service/server.rs

@@ -772,9 +772,7 @@ impl Peer<RoleServer> {
     /// # SEP-2260: request association
     ///
     /// From protocol version `2026-07-28` this must be issued while handling a
-    /// client request; outside a handler it returns an `invalid_request` error.
-    /// The association does not cross `tokio::spawn`, so use the task manager
-    /// for long-running work.
+    /// client request; see [`OriginatingRequestId`].
     #[deprecated(
         since = "1.8.0",
         note = "Sampling is deprecated by SEP-2577 and will be removed in a future release. See https://github.com/modelcontextprotocol/modelcontextprotocol/pull/2577"
@@ -812,9 +810,7 @@ impl Peer<RoleServer> {
         /// # SEP-2260: request association
         ///
         /// From protocol version `2026-07-28` this must be issued while handling a
-        /// client request; outside a handler it returns an `invalid_request` error.
-        /// The association does not cross `tokio::spawn`, so use the task manager
-        /// for long-running work.
+        /// client request; see [`OriginatingRequestId`].
         #[deprecated(
             since = "1.8.0",
             note = "Roots is deprecated by SEP-2577 and will be removed in a future release. See https://github.com/modelcontextprotocol/modelcontextprotocol/pull/2577"
@@ -826,19 +822,15 @@ impl Peer<RoleServer> {
         /// # SEP-2260: request association
         ///
         /// From protocol version `2026-07-28` this must be issued while handling a
-        /// client request; outside a handler it returns an `invalid_request` error.
-        /// The association does not cross `tokio::spawn`, so use the task manager
-        /// for long-running work.
+        /// client request; see [`OriginatingRequestId`].
         peer_req create_elicitation ElicitRequest(ElicitRequestParams) => ElicitResult
     );
     #[cfg(feature = "elicitation")]
     method!(
         /// # SEP-2260: request association
         ///
         /// From protocol version `2026-07-28` this must be issued while handling a
-        /// client request; outside a handler it returns an `invalid_request` error.
-        /// The association does not cross `tokio::spawn`, so use the task manager
-        /// for long-running work.
+        /// client request; see [`OriginatingRequestId`].
         peer_req_with_timeout create_elicitation_with_timeout ElicitRequest(ElicitRequestParams) => ElicitResult
     );
 
@@ -1071,9 +1063,7 @@ impl Peer<RoleServer> {
     /// # SEP-2260: request association
     ///
     /// From protocol version `2026-07-28` this must be issued while handling a
-    /// client request; outside a handler it returns an `invalid_request` error.
-    /// The association does not cross `tokio::spawn`, so use the task manager
-    /// for long-running work.
+    /// client request; see [`OriginatingRequestId`].
     #[cfg(all(feature = "schemars", feature = "elicitation"))]
     pub async fn elicit<T>(&self, message: impl Into<String>) -> Result<Option<T>, ElicitationError>
     where
@@ -1139,9 +1129,7 @@ impl Peer<RoleServer> {
     /// # SEP-2260: request association
     ///
     /// From protocol version `2026-07-28` this must be issued while handling a
-    /// client request; outside a handler it returns an `invalid_request` error.
-    /// The association does not cross `tokio::spawn`, so use the task manager
-    /// for long-running work.
+    /// client request; see [`OriginatingRequestId`].
     #[cfg(all(feature = "schemars", feature = "elicitation"))]
     pub async fn elicit_with_timeout<T>(
         &self,
@@ -1241,9 +1229,7 @@ impl Peer<RoleServer> {
     /// # SEP-2260: request association
     ///
     /// From protocol version `2026-07-28` this must be issued while handling a
-    /// client request; outside a handler it returns an `invalid_request` error.
-    /// The association does not cross `tokio::spawn`, so use the task manager
-    /// for long-running work.
+    /// client request; see [`OriginatingRequestId`].
     #[cfg(feature = "elicitation")]
     pub async fn elicit_url(
         &self,
@@ -1299,9 +1285,7 @@ impl Peer<RoleServer> {
     /// # SEP-2260: request association
     ///
     /// From protocol version `2026-07-28` this must be issued while handling a
-    /// client request; outside a handler it returns an `invalid_request` error.
-    /// The association does not cross `tokio::spawn`, so use the task manager
-    /// for long-running work.
+    /// client request; see [`OriginatingRequestId`].
     #[cfg(feature = "elicitation")]
     pub async fn elicit_url_with_timeout(
         &self,