feat(acp): route session/setTitle to the new schema types

Cargo.toml

@@ -105,3 +105,7 @@ struct_field_names = "allow"
 too_many_lines = "allow"
 type_complexity = "allow"
 wildcard_imports = "allow"
+
+[patch.crates-io]
+# Temporary: consume session/setTitle schema types before they are released.
+agent-client-protocol-schema = { git = "https://github.com/daniel-agentee/agent-client-protocol", rev = "23977c0193c786d0747464a46b5a561ca15c62e2" }

src/agent-client-protocol/src/schema/client_to_agent/requests.rs

@@ -5,6 +5,7 @@ use crate::schema::{
     LogoutRequest, LogoutResponse, NewSessionRequest, NewSessionResponse, PromptRequest,
     PromptResponse, ResumeSessionRequest, ResumeSessionResponse, SetSessionConfigOptionRequest,
     SetSessionConfigOptionResponse, SetSessionModeRequest, SetSessionModeResponse,
+    SetSessionTitleRequest, SetSessionTitleResponse,
 };
 #[cfg(feature = "unstable_session_fork")]
 use crate::schema::{ForkSessionRequest, ForkSessionResponse};
@@ -31,6 +32,11 @@ impl_jsonrpc_request!(
     SetSessionConfigOptionResponse,
     "session/set_config_option"
 );
+impl_jsonrpc_request!(
+    SetSessionTitleRequest,
+    SetSessionTitleResponse,
+    "session/setTitle"
+);
 
 #[cfg(feature = "unstable_session_fork")]
 impl_jsonrpc_request!(ForkSessionRequest, ForkSessionResponse, "session/fork");

src/agent-client-protocol/src/schema/enum_impls.rs

@@ -24,6 +24,7 @@ impl_jsonrpc_request_enum!(ClientRequest {
     CloseSessionRequest => "session/close",
     SetSessionModeRequest => "session/set_mode",
     SetSessionConfigOptionRequest => "session/set_config_option",
+    SetSessionTitleRequest => "session/setTitle",
     PromptRequest => "session/prompt",
     #[cfg(feature = "unstable_mcp_over_acp")]
     MessageMcpRequest => "mcp/message",

src/agent-client-protocol/tests/protocol_v2.rs

@@ -49,6 +49,13 @@ fn cwd() -> Result<PathBuf, Error> {
     std::env::current_dir().map_err(Error::into_internal_error)
 }
 
+fn v2_initialize_response_with_session(
+    protocol_version: ProtocolVersion,
+) -> v2::InitializeResponse {
+    v2::InitializeResponse::new(protocol_version)
+        .capabilities(v2::AgentCapabilities::new().session(v2::SessionCapabilities::new()))
+}
+
 #[cfg(feature = "unstable_mcp_over_acp")]
 fn json_value(value: impl Serialize) -> Result<Value, Error> {
     serde_json::to_value(value).map_err(Error::into_internal_error)
@@ -215,7 +222,9 @@ async fn role_builder_v1_client_downgrades_initialize_for_v2_agent() -> Result<(
     let agent = Agent.v2().on_receive_request(
         async |initialize: v2::InitializeRequest, responder, _cx| {
             assert_eq!(initialize.protocol_version, ProtocolVersion::V2);
-            responder.respond(v2::InitializeResponse::new(initialize.protocol_version))
+            responder.respond(v2_initialize_response_with_session(
+                initialize.protocol_version,
+            ))
         },
         agent_client_protocol::on_receive_request!(),
     );
@@ -451,7 +460,7 @@ async fn v2_agent_serves_v1_client_with_v2_handlers() -> Result<(), Error> {
             async |initialize: v2::InitializeRequest, responder, _cx| {
                 assert_eq!(initialize.protocol_version, ProtocolVersion::V2);
                 // The compatibility layer should force this back to the negotiated v1 wire version.
-                responder.respond(v2::InitializeResponse::new(ProtocolVersion::V2))
+                responder.respond(v2_initialize_response_with_session(ProtocolVersion::V2))
             },
             agent_client_protocol::on_receive_request!(),
         )
@@ -515,7 +524,9 @@ async fn v2_client_and_agent_negotiate_v2() -> Result<(), Error> {
         .on_receive_request(
             async |initialize: v2::InitializeRequest, responder, _cx| {
                 assert_eq!(initialize.protocol_version, ProtocolVersion::V2);
-                responder.respond(v2::InitializeResponse::new(initialize.protocol_version))
+                responder.respond(v2_initialize_response_with_session(
+                    initialize.protocol_version,
+                ))
             },
             agent_client_protocol::on_receive_request!(),
         )

src/agent-client-protocol/tests/schema_elicitation.rs

@@ -196,7 +196,11 @@ async fn v2_agent_can_elicit_from_v1_client() -> Result<(), Error> {
         .on_receive_request(
             async |initialize: v2::InitializeRequest, responder, _cx| {
                 assert_eq!(initialize.protocol_version, ProtocolVersion::V2);
-                responder.respond(v2::InitializeResponse::new(ProtocolVersion::V2))
+                responder.respond(
+                    v2::InitializeResponse::new(ProtocolVersion::V2).capabilities(
+                        v2::AgentCapabilities::new().session(v2::SessionCapabilities::new()),
+                    ),
+                )
             },
             agent_client_protocol::on_receive_request!(),
         )