stabilize cursor request context and release workflow

server/src/cursor/projection/decode.rs

@@ -30,17 +30,15 @@ pub fn decode(data: &[u8], internal_id: String) -> Result<CanonicalMessage> {
         .and_then(Value::as_str)
         .unwrap_or_default()
         .to_string();
+    let is_request_context = role == Role::User && wire_id.starts_with("request-context:");
+    let is_prompt_context =
+        is_request_context || role == Role::User && wire_id.starts_with("selected-context:");
     let origin = match role {
         Role::System => Origin::Prompt,
         Role::Assistant => Origin::Assistant,
         Role::Tool => Origin::Tool,
         Role::User if wire_id.starts_with("runtime:") => Origin::Runtime,
-        Role::User
-            if wire_id.starts_with("request-context:")
-                || wire_id.starts_with("selected-context:") =>
-        {
-            Origin::Prompt
-        }
+        Role::User if is_prompt_context => Origin::Prompt,
         Role::User => Origin::User,
     };
     let runtime_event_id = wire_id.strip_prefix("runtime:").map(str::to_string);
@@ -49,7 +47,7 @@ pub fn decode(data: &[u8], internal_id: String) -> Result<CanonicalMessage> {
         Role::Tool => MessageContent::ToolResult(decode_tool_result(&value)?),
         _ => decode_text(&value)?,
     };
-    let message_id = if runtime_event_id.is_some() {
+    let message_id = if runtime_event_id.is_some() || is_request_context {
         wire_id
     } else {
         internal_id

server/src/cursor/projection/tests.rs

@@ -131,6 +131,23 @@ fn runtime_wire_identity_survives_checkpoint_hydration() {
     );
 }
 
+#[test]
+fn request_context_identity_survives_checkpoint_hydration() {
+    let wire = json!({
+        "role": "user",
+        "id": "request-context:digest",
+        "content": "<rules>current rules</rules>",
+    });
+    let message = decode(
+        serde_json::to_vec(&wire).unwrap().as_slice(),
+        "cursor-root:blob-id:20".into(),
+    )
+    .unwrap();
+
+    assert_eq!(message.message_id, "request-context:digest");
+    assert_eq!(message.origin, crate::model::Origin::Prompt);
+}
+
 #[test]
 fn cursor_user_image_uses_image_field() {
     let wire = json!({

server/src/cursor/prompting/assets.rs

@@ -134,7 +134,6 @@ impl PromptAssets {
 }
 
 const RUNTIME_VARIABLES: &[&str] = &[
-    "REQUEST_CONTEXT",
     "OPEN_FILES",
     "SELECTED_CONTEXT",
     "ACTION_CONTEXT",

server/src/cursor/request/prepare.rs

@@ -192,6 +192,20 @@ pub(crate) async fn prepare(
         }
         _ => None,
     };
+    let request_context_message = match event_id.as_deref() {
+        Some(event_id) if !compacting && !background_completion => {
+            let message_id = format!("request-context:{event_id}");
+            match store.message(&conversation_id, &message_id).await? {
+                Some(message) => Some(message),
+                None => runtime::compile_request_context(
+                    event_id,
+                    &request_context,
+                    base_messages.as_deref().unwrap_or_default(),
+                )?,
+            }
+        }
+        _ => None,
+    };
     let initial_messages = if compacting {
         Vec::new()
     } else {
@@ -209,21 +223,27 @@ pub(crate) async fn prepare(
                 turn_user = Some(user);
                 vec![message]
             }
-            (Some(user), Some(event_id)) => match existing_runtime {
-                Some(message) => vec![message],
-                None => vec![
-                    runtime::compile(
-                        event_id,
-                        checkpoint_mode,
-                        &user,
-                        &request_context,
-                        &action_context,
-                        compiler,
-                        blob_sync,
-                    )
-                    .await?,
-                ],
-            },
+            (Some(user), Some(event_id)) => {
+                let runtime = match existing_runtime {
+                    Some(message) => message,
+                    None => {
+                        runtime::compile(
+                            event_id,
+                            checkpoint_mode,
+                            &user,
+                            &request_context,
+                            &action_context,
+                            compiler,
+                            blob_sync,
+                        )
+                        .await?
+                    }
+                };
+                request_context_message
+                    .into_iter()
+                    .chain(std::iter::once(runtime))
+                    .collect()
+            }
             (None, None) => Vec::new(),
             _ => {
                 return Err(Error::Protocol(

server/src/cursor/request/runtime.rs

@@ -87,10 +87,6 @@ pub async fn compile(
             .map(|env| env.time_zone.as_str()),
     )?;
     let mut values = BTreeMap::from([
-        (
-            "REQUEST_CONTEXT",
-            section(context::compile_context(request_context, &time.today)),
-        ),
         ("OPEN_FILES", section(open_files(user))),
         (
             "SELECTED_CONTEXT",
@@ -122,6 +118,41 @@ pub async fn compile(
     .await
 }
 
+pub(super) fn compile_request_context(
+    event_id: &str,
+    request_context: &pb::RequestContext,
+    history: &[CanonicalMessage],
+) -> Result<Option<CanonicalMessage>> {
+    let time = Time::now(
+        request_context
+            .env
+            .as_ref()
+            .map(|env| env.time_zone.as_str()),
+    )?;
+    let text = context::compile_context(request_context, &time.today);
+    if text.is_empty() {
+        return Ok(None);
+    }
+    let message = CanonicalMessage::text(
+        format!("request-context:{event_id}"),
+        Role::User,
+        Origin::Prompt,
+        text,
+    );
+    Ok(should_project_request_context(history, &message).then_some(message))
+}
+
+fn should_project_request_context(
+    history: &[CanonicalMessage],
+    current: &CanonicalMessage,
+) -> bool {
+    history
+        .iter()
+        .rev()
+        .find(|message| message.message_id.starts_with("request-context:"))
+        .is_none_or(|previous| previous.content != current.content)
+}
+
 pub async fn compile_background(
     event_id: String,
     user: &pb::UserMessage,
@@ -252,3 +283,55 @@ impl Time {
         })
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn request_context_is_only_projected_when_its_content_changes() {
+        let first = CanonicalMessage::text(
+            "request-context:first",
+            Role::User,
+            Origin::Prompt,
+            "<rules>same</rules>",
+        );
+        let duplicate = CanonicalMessage::text(
+            "request-context:second",
+            Role::User,
+            Origin::Prompt,
+            "<rules>same</rules>",
+        );
+        let changed = CanonicalMessage::text(
+            "request-context:third",
+            Role::User,
+            Origin::Prompt,
+            "<rules>changed</rules>",
+        );
+        let runtime = CanonicalMessage::text(
+            "runtime:turn",
+            Role::User,
+            Origin::Runtime,
+            "<user_query>next</user_query>",
+        );
+
+        assert!(should_project_request_context(&[], &first));
+        assert!(!should_project_request_context(
+            &[first.clone(), runtime.clone()],
+            &duplicate
+        ));
+        assert!(should_project_request_context(
+            &[first.clone(), runtime.clone()],
+            &changed
+        ));
+        assert!(should_project_request_context(
+            &[first.clone(), changed, runtime],
+            &CanonicalMessage::text(
+                "request-context:fourth",
+                Role::User,
+                Origin::Prompt,
+                "<rules>same</rules>",
+            )
+        ));
+    }
+}

server/src/run/engine.rs

@@ -460,11 +460,8 @@ impl RunEngine {
             .iter()
             .map(|message| message.message_id.as_str())
             .collect::<HashSet<_>>();
-        let compactable = messages
-            .iter()
-            .filter(|message| !current_ids.contains(message.message_id.as_str()))
-            .cloned()
-            .collect::<Vec<_>>();
+        let (compactable, retained_request_context) =
+            auto_compaction_partition(messages, &current_ids);
         if compactable.is_empty() {
             return Ok((revision, None));
         }
@@ -533,7 +530,8 @@ impl RunEngine {
             },
             runtime_event_id: Some(event_id),
         };
-        let mut replacement = vec![summary_message];
+        let mut replacement = retained_request_context.into_iter().collect::<Vec<_>>();
+        replacement.push(summary_message);
         replacement.extend(prepared.initial_messages.iter().cloned());
         let revision = self
             .store
@@ -565,6 +563,29 @@ impl RunEngine {
     }
 }
 
+fn auto_compaction_partition(
+    messages: &[CanonicalMessage],
+    current_ids: &HashSet<&str>,
+) -> (Vec<CanonicalMessage>, Option<CanonicalMessage>) {
+    let latest_request_context = messages
+        .iter()
+        .rposition(|message| message.message_id.starts_with("request-context:"));
+    let compactable = messages
+        .iter()
+        .enumerate()
+        .filter(|(index, message)| {
+            Some(*index) != latest_request_context
+                && !current_ids.contains(message.message_id.as_str())
+        })
+        .map(|(_, message)| message.clone())
+        .collect();
+    let retained = latest_request_context
+        .and_then(|index| messages.get(index))
+        .filter(|message| !current_ids.contains(message.message_id.as_str()))
+        .cloned();
+    (compactable, retained)
+}
+
 fn should_auto_compact(prepared: &PreparedRun, messages: &[CanonicalMessage]) -> bool {
     if prepared.action != RunAction::Start {
         return false;
@@ -724,7 +745,7 @@ fn failure_message(failure: &RunFailure) -> String {
 
 #[cfg(test)]
 mod tests {
-    use super::{estimate_context_tokens, hydrate_tool_images};
+    use super::{auto_compaction_partition, estimate_context_tokens, hydrate_tool_images};
     use crate::{
         model::{
             CanonicalMessage, ContentPart, Origin, ProjectedContent, ProjectedMessage, PromptSpec,
@@ -732,6 +753,7 @@ mod tests {
         },
         store::Store,
     };
+    use std::collections::HashSet;
 
     #[test]
     fn context_estimate_grows_with_prompt_history() {
@@ -756,6 +778,42 @@ mod tests {
         assert!(estimate_context_tokens(&prompt, &long) > estimate_context_tokens(&prompt, &short));
     }
 
+    #[test]
+    fn auto_compaction_preserves_only_the_latest_request_context() {
+        let first_context = CanonicalMessage::text(
+            "request-context:first",
+            Role::User,
+            Origin::Prompt,
+            "old rules",
+        );
+        let old_runtime =
+            CanonicalMessage::text("runtime:first", Role::User, Origin::Runtime, "old query");
+        let latest_context = CanonicalMessage::text(
+            "request-context:second",
+            Role::User,
+            Origin::Prompt,
+            "new rules",
+        );
+        let current_runtime = CanonicalMessage::text(
+            "runtime:current",
+            Role::User,
+            Origin::Runtime,
+            "current query",
+        );
+        let messages = vec![
+            first_context.clone(),
+            old_runtime.clone(),
+            latest_context.clone(),
+            current_runtime,
+        ];
+        let current_ids = HashSet::from(["runtime:current"]);
+
+        let (compactable, retained) = auto_compaction_partition(&messages, &current_ids);
+
+        assert_eq!(compactable, vec![first_context, old_runtime]);
+        assert_eq!(retained, Some(latest_context));
+    }
+
     #[tokio::test]
     async fn read_image_is_loaded_only_for_the_provider_projection() {
         let directory = tempfile::tempdir().unwrap();