refactor: update cursor request handling and improve parent request management

- Changed `run_id` to `request_id` in `CursorParent` struct for clarity.
- Enhanced the `prepare` function to handle parent requests asynchronously, ensuring proper error handling for active runs.
- Updated database interactions to include `cursor_request_id` for better tracking of requests.
- Added tests to verify the behavior of reused cursor request IDs and their mapping to distinct executions.

server/src/cursor/actor.rs

@@ -89,24 +89,42 @@ impl CursorActor {
                                                         .map(|parent| parent.tool_call_id.clone()),
                                                     request.conversation_state.clone(),
                                                 );
-                                                let parent = handle.parent().map(|parent| {
-                                                    (
-                                                        crate::model::RunId::new(&parent.run_id),
-                                                        parent.tool_call_id.clone(),
+                                                let prepared = async {
+                                                    let parent = match handle.parent() {
+                                                        Some(parent) => {
+                                                            let parent_run_id = dependencies
+                                                                .store
+                                                                .active_run_for_cursor_request(
+                                                                    &parent.request_id,
+                                                                )
+                                                                .await?
+                                                                .ok_or_else(|| {
+                                                                    crate::Error::Protocol(format!(
+                                                                        "Cursor parent request {} has no active local Run",
+                                                                        parent.request_id
+                                                                    ))
+                                                                })?;
+                                                            Some((
+                                                                parent_run_id,
+                                                                parent.tool_call_id.clone(),
+                                                            ))
+                                                        }
+                                                        None => None,
+                                                    };
+                                                    request::prepare(
+                                                        handle.request_id(),
+                                                        &request,
+                                                        parent,
+                                                        request::PrepareDependencies {
+                                                            compiler: &dependencies.compiler,
+                                                            store: &dependencies.store,
+                                                            checkpoint: &checkpoint,
+                                                            blob_sync: &blob_sync,
+                                                            context_sync: &context_sync,
+                                                        },
                                                     )
-                                                });
-                                                let prepared = request::prepare(
-                                                    handle.request_id(),
-                                                    &request,
-                                                    parent,
-                                                    request::PrepareDependencies {
-                                                        compiler: &dependencies.compiler,
-                                                        store: &dependencies.store,
-                                                        checkpoint: &checkpoint,
-                                                        blob_sync: &blob_sync,
-                                                        context_sync: &context_sync,
-                                                    },
-                                                )
+                                                    .await
+                                                }
                                                 .await;
                                                 let (prepared, context) = match prepared {
                                                     Ok(prepared) => prepared,

server/src/cursor/handlers.rs

@@ -203,12 +203,12 @@ async fn buffered(request: Request<Body>) -> Result<(axum::http::request::Parts,
 }
 
 fn parent_headers(headers: &HeaderMap) -> Result<Option<CursorParent>> {
-    let run_id = header_text(headers, "x-parent-request-id")?;
+    let request_id = header_text(headers, "x-parent-request-id")?;
     let tool_call_id = header_text(headers, "x-parent-agent-tool-call-id")?;
-    match (run_id, tool_call_id) {
+    match (request_id, tool_call_id) {
         (None, None) => Ok(None),
-        (Some(run_id), Some(tool_call_id)) => Ok(Some(CursorParent {
-            run_id: run_id.into(),
+        (Some(request_id), Some(tool_call_id)) => Ok(Some(CursorParent {
+            request_id: request_id.into(),
             tool_call_id: tool_call_id.into(),
         })),
         _ => Err(crate::Error::Protocol(
@@ -270,7 +270,7 @@ mod tests {
         assert_eq!(
             parent_headers(&headers).unwrap(),
             Some(CursorParent {
-                run_id: "parent-run".into(),
+                request_id: "parent-run".into(),
                 tool_call_id: "parent-call".into(),
             })
         );

server/src/cursor/request/prepare.rs

@@ -1,5 +1,7 @@
 use std::collections::BTreeMap;
 
+use uuid::Uuid;
+
 use crate::{
     cursor::prompting::{Mode, PromptCompiler},
     cursor::{
@@ -71,9 +73,7 @@ pub(crate) async fn prepare(
             .clone()
             .unwrap_or_else(|| request_id.into()),
     );
-    // RunSSE/Bidi request_id identifies this concrete execution attempt. Cursor may
-    // reuse AgentRunRequest.run_id when a queued or subagent-driven attempt resumes.
-    let run_id = RunId::new(request_id);
+    let run_id = execution_run_id(request_id);
     let mut base_messages = if request.conversation_state.is_some() {
         Some(
             checkpoint
@@ -128,7 +128,7 @@ pub(crate) async fn prepare(
         starts_turn,
         compacting,
         background_completion,
-    } = action(request_id, request)?;
+    } = action(request)?;
     let checkpoint_mode = if request.subagent_type_name.is_some() {
         Mode::Subagent
     } else {
@@ -286,6 +286,7 @@ pub(crate) async fn prepare(
     Ok((
         PreparedRun {
             run_id,
+            cursor_request_id: Some(request_id.into()),
             conversation_id,
             kind,
             model,
@@ -348,12 +349,17 @@ fn validate_prompt_root(messages: &[CanonicalMessage]) -> Result<()> {
     Ok(())
 }
 
-fn action(request_id: &str, request: &pb::AgentRunRequest) -> Result<ActionProjection> {
-    let mode = request
+fn execution_run_id(request_id: &str) -> RunId {
+    let execution_id = Uuid::new_v4().simple().to_string();
+    RunId::new(format!("{request_id}:{}", &execution_id[..8]))
+}
+
+fn action(request: &pb::AgentRunRequest) -> Result<ActionProjection> {
+    let conversation_mode = request
         .conversation_state
         .as_ref()
-        .and_then(|state| state.mode)
-        .unwrap_or(pb::AgentMode::Agent as i32);
+        .and_then(|state| state.mode);
+    let mode = conversation_mode.unwrap_or(pb::AgentMode::Agent as i32);
     let Some(action) = request
         .action
         .as_ref()
@@ -375,6 +381,11 @@ fn action(request_id: &str, request: &pb::AgentRunRequest) -> Result<ActionProje
             let user = action.user_message.as_ref().ok_or_else(|| {
                 Error::Protocol("Cursor user message action has no UserMessage".into())
             })?;
+            let mode = if user.mode == pb::AgentMode::Unspecified as i32 {
+                conversation_mode.unwrap_or(user.mode)
+            } else {
+                user.mode
+            };
             if user.message_id.is_empty() {
                 return Err(Error::Protocol(
                     "Cursor user message action has no message_id".into(),
@@ -382,7 +393,7 @@ fn action(request_id: &str, request: &pb::AgentRunRequest) -> Result<ActionProje
             }
             if user.text.trim() == "/summarize" {
                 return Ok(ActionProjection {
-                    mode: user.mode,
+                    mode,
                     turn_user: Some(user.clone()),
                     action_context: String::new(),
                     event_id: None,
@@ -405,12 +416,13 @@ fn action(request_id: &str, request: &pb::AgentRunRequest) -> Result<ActionProje
                     .filter(|text| !text.is_empty())
                     .cloned(),
             );
+            let event_id = format!("cursor:user:{}", user.message_id);
             Ok(ActionProjection {
-                mode: user.mode,
+                mode,
                 turn_user: Some(user.clone()),
                 action_context: context.join("\n\n"),
-                event_id: Some(format!("run-request:{request_id}")),
-                input_id: Some(format!("cursor:user:{}", user.message_id)),
+                event_id: Some(event_id.clone()),
+                input_id: Some(event_id),
                 starts_turn: true,
                 compacting: false,
                 background_completion: false,
@@ -418,10 +430,11 @@ fn action(request_id: &str, request: &pb::AgentRunRequest) -> Result<ActionProje
         }
         pb::conversation_action::Action::BackgroundTaskCompletionAction(action) => {
             let projection = background::project(action, mode)?;
+            let event_id = projection.turn_user.message_id.clone();
             Ok(ActionProjection {
                 mode,
                 action_context: projection.context,
-                event_id: Some(format!("run-request:{request_id}")),
+                event_id: Some(event_id),
                 input_id: None,
                 turn_user: Some(projection.turn_user),
                 starts_turn: true,
@@ -598,6 +611,18 @@ mod tests {
         ));
     }
 
+    #[test]
+    fn execution_run_id_keeps_the_request_id_and_adds_eight_uuid_hex_digits() {
+        let run_id = execution_run_id("01bba7c5-9c00-4922-b1df-1f58146b5d90");
+        let suffix = run_id
+            .as_str()
+            .strip_prefix("01bba7c5-9c00-4922-b1df-1f58146b5d90:")
+            .unwrap();
+
+        assert_eq!(suffix.len(), 8);
+        assert!(suffix.bytes().all(|byte| byte.is_ascii_hexdigit()));
+    }
+
     #[test]
     fn current_user_message_consumes_the_mode_instead_of_history_mode() {
         let request = pb::AgentRunRequest {
@@ -621,7 +646,7 @@ mod tests {
             }),
             ..Default::default()
         };
-        let projection = action("request", &request).unwrap();
+        let projection = action(&request).unwrap();
         assert_eq!(projection.mode, pb::AgentMode::Ask as i32);
         assert_eq!(
             projection.input_id.as_deref(),
@@ -630,6 +655,63 @@ mod tests {
         assert_eq!(mode_from_proto(projection.mode).unwrap(), Mode::Ask);
     }
 
+    #[test]
+    fn queued_user_message_without_mode_inherits_conversation_mode() {
+        let request = pb::AgentRunRequest {
+            conversation_state: Some(pb::ConversationStateStructure {
+                mode: Some(pb::AgentMode::Agent as i32),
+                ..Default::default()
+            }),
+            action: Some(pb::ConversationAction {
+                action: Some(pb::conversation_action::Action::UserMessageAction(
+                    pb::UserMessageAction {
+                        user_message: Some(pb::UserMessage {
+                            text: "queued follow-up".into(),
+                            message_id: "queued-user-message".into(),
+                            ..Default::default()
+                        }),
+                        ..Default::default()
+                    },
+                )),
+                ..Default::default()
+            }),
+            ..Default::default()
+        };
+
+        let projection = action(&request).unwrap();
+
+        assert_eq!(projection.mode, pb::AgentMode::Agent as i32);
+        assert_eq!(mode_from_proto(projection.mode).unwrap(), Mode::Agent);
+    }
+
+    #[test]
+    fn queued_messages_reusing_a_request_id_keep_distinct_runtime_identities() {
+        let request = |message_id: &str| pb::AgentRunRequest {
+            action: Some(pb::ConversationAction {
+                action: Some(pb::conversation_action::Action::UserMessageAction(
+                    pb::UserMessageAction {
+                        user_message: Some(pb::UserMessage {
+                            text: "queued follow-up".into(),
+                            message_id: message_id.into(),
+                            mode: pb::AgentMode::Agent as i32,
+                            ..Default::default()
+                        }),
+                        ..Default::default()
+                    },
+                )),
+                ..Default::default()
+            }),
+            ..Default::default()
+        };
+
+        let first = action(&request("message-one")).unwrap();
+        let second = action(&request("message-two")).unwrap();
+
+        assert_eq!(first.event_id.as_deref(), Some("cursor:user:message-one"));
+        assert_eq!(second.event_id.as_deref(), Some("cursor:user:message-two"));
+        assert_ne!(first.event_id, second.event_id);
+    }
+
     #[test]
     fn execute_plan_appends_the_approved_plan_as_a_stable_runtime_event() {
         let execute = pb::ExecutePlanAction {
@@ -648,8 +730,8 @@ mod tests {
             ..Default::default()
         };
 
-        let first = action("request-one", &request).unwrap();
-        let second = action("request-two", &request).unwrap();
+        let first = action(&request).unwrap();
+        let second = action(&request).unwrap();
         assert_eq!(first.mode, pb::AgentMode::Agent as i32);
         assert!(first.starts_turn);
         assert_eq!(first.event_id, second.event_id);

server/src/cursor/sessions.rs

@@ -35,7 +35,7 @@ pub struct CursorSessionHandle {
 
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct CursorParent {
-    pub run_id: String,
+    pub request_id: String,
     pub tool_call_id: String,
 }
 
@@ -69,9 +69,9 @@ impl CursorSessionHandle {
         self.cancellation.clone()
     }
     pub fn set_parent(&self, parent: CursorParent) -> Result<()> {
-        if parent.run_id.is_empty() || parent.tool_call_id.is_empty() {
+        if parent.request_id.is_empty() || parent.tool_call_id.is_empty() {
             return Err(crate::Error::Protocol(
-                "Cursor parent run and tool call ids are required".into(),
+                "Cursor parent request and tool call ids are required".into(),
             ));
         }
         if self.parent.get().is_some_and(|current| current != &parent) {

server/src/model/run.rs

@@ -48,6 +48,7 @@ pub struct RecoveredToolRound {
 #[derive(Clone, Debug, Serialize, Deserialize, PartialEq)]
 pub struct PreparedRun {
     pub run_id: RunId,
+    pub cursor_request_id: Option<String>,
     pub conversation_id: ConversationId,
     pub kind: RunKind,
     pub model: ModelSpec,

server/src/store/runs.rs

@@ -88,12 +88,13 @@ impl Store {
             run_kind_columns(&prepared.kind);
         sqlx::query(
             "INSERT INTO runs
-             (run_id, conversation_id, base_revision_id, head_revision_id,
+             (run_id, cursor_request_id, conversation_id, base_revision_id, head_revision_id,
               parent_run_id, parent_tool_call_id, run_kind, subagent_kind,
               status, created_at_ms, updated_at_ms)
-             VALUES (?, ?, ?, ?, ?, ?, ?, ?, 'running', ?, ?)",
+             VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, 'running', ?, ?)",
         )
         .bind(prepared.run_id.as_str())
+        .bind(prepared.cursor_request_id.as_deref())
         .bind(prepared.conversation_id.as_str())
         .bind(prepared.base_revision_id.0)
         .bind(prepared.base_revision_id.0)
@@ -128,6 +129,22 @@ impl Store {
         })
     }
 
+    pub async fn active_run_for_cursor_request(
+        &self,
+        cursor_request_id: &str,
+    ) -> Result<Option<RunId>> {
+        let run_id: Option<String> = sqlx::query_scalar(
+            "SELECT run_id FROM runs
+             WHERE cursor_request_id = ? AND status = 'running'
+             ORDER BY created_at_ms DESC
+             LIMIT 1",
+        )
+        .bind(cursor_request_id)
+        .fetch_optional(&self.pool)
+        .await?;
+        Ok(run_id.map(RunId))
+    }
+
     pub async fn begin_provider_call(&self, run_id: &RunId) -> Result<u64> {
         let index: Option<i64> = sqlx::query_scalar(
             "UPDATE runs SET provider_call_index = provider_call_index + 1, updated_at_ms = ?