feat(cursor): trace subagent summaries

bt-daemon/src/hook.rs

@@ -110,10 +110,10 @@ pub async fn run_hook(args: HookArgs, route: SessionRoute, host: HostInfo) -> an
 }
 
 fn cursor_hook_response_for_event(event: Option<&str>) -> &'static str {
-    if event == Some("beforeSubmitPrompt") {
-        r#"{"continue":true}"#
-    } else {
-        "{}"
+    match event {
+        Some("beforeSubmitPrompt") => r#"{"continue":true}"#,
+        Some("preToolUse" | "subagentStart") => r#"{"permission":"allow"}"#,
+        _ => "{}",
     }
 }
 
@@ -331,6 +331,16 @@ mod tests {
         args: HookArgs,
     }
 
+    #[test]
+    fn cursor_permission_hooks_allow_actions_after_capture() {
+        for event in ["preToolUse", "subagentStart"] {
+            assert_eq!(
+                cursor_hook_response_for_event(Some(event)),
+                r#"{"permission":"allow"}"#
+            );
+        }
+    }
+
     #[test]
     fn hook_plugin_version_reaches_envelope_and_every_initialize_attempt() {
         let args = HookCli::try_parse_from([

bt-daemon/src/managed_run/cursor.rs

@@ -108,6 +108,7 @@ fn write_cursor_managed_plugin_for_platform(
         }))?,
     )?;
     let script_path = hook_dir.join(if windows { "trace.ps1" } else { "trace.sh" });
+    let source_manifest: serde_json::Value = serde_json::from_str(CURSOR_HOOKS_MANIFEST)?;
     let hooks = cursor_hook_events()?
         .iter()
         .map(|event| {
@@ -119,14 +120,15 @@ fn write_cursor_managed_plugin_for_platform(
             } else {
                 format!("\"${{CURSOR_PLUGIN_ROOT}}/hooks/trace.sh\" {event}")
             };
-            (
-                event.clone(),
-                serde_json::json!([{
-                    "command": command,
-                    "timeout": 10,
-                    "failClosed": false
-                }]),
-            )
+            let mut registration = serde_json::json!({
+                "command": command,
+                "timeout": 10,
+                "failClosed": false
+            });
+            if let Some(matcher) = source_manifest["hooks"][event][0]["matcher"].as_str() {
+                registration["matcher"] = serde_json::json!(matcher);
+            }
+            (event.clone(), serde_json::json!([registration]))
         })
         .collect::<serde_json::Map<_, _>>();
     std::fs::write(
@@ -156,7 +158,7 @@ fn write_cursor_managed_plugin_for_platform(
             command.push_str(&quote_unix_shell_arg(arg));
         }
         let script = format!(
-            "#!/bin/sh\n# Keep Cursor's prompt response valid even when tracing fails.\nif ! {command} >/dev/null 2>/dev/null; then\n  :\nfi\ncase \"${{1-}}\" in\n  beforeSubmitPrompt) printf '%s\\n' '{{\"continue\":true}}' ;;\n  *) printf '%s\\n' '{{}}' ;;\nesac\nexit 0\n"
+            "#!/bin/sh\n# Keep Cursor's hook response valid even when tracing fails.\nif ! {command} >/dev/null 2>/dev/null; then\n  :\nfi\ncase \"${{1-}}\" in\n  beforeSubmitPrompt) printf '%s\\n' '{{\"continue\":true}}' ;;\n  preToolUse|subagentStart) printf '%s\\n' '{{\"permission\":\"allow\"}}' ;;\n  *) printf '%s\\n' '{{}}' ;;\nesac\nexit 0\n"
         );
         std::fs::write(&script_path, script)?;
         #[cfg(unix)]
@@ -202,7 +204,7 @@ fn cursor_managed_powershell_script(hook_command: &RunHookCommand) -> anyhow::Re
         .collect::<Vec<_>>()
         .join(", ");
     Ok(format!(
-        "$bt = {}\n$hookArgs = @({})\ntry {{ & $bt @hookArgs *> $null }} catch {{}}\nif ($args.Count -gt 0 -and $args[0] -eq 'beforeSubmitPrompt') {{\n  [Console]::Out.WriteLine('{{\"continue\":true}}')\n}} else {{\n  [Console]::Out.WriteLine('{{}}')\n}}\nexit 0\n",
+        "$bt = {}\n$hookArgs = @({})\ntry {{ & $bt @hookArgs *> $null }} catch {{}}\nif ($args.Count -gt 0 -and $args[0] -eq 'beforeSubmitPrompt') {{\n  [Console]::Out.WriteLine('{{\"continue\":true}}')\n}} elseif ($args.Count -gt 0 -and ($args[0] -eq 'preToolUse' -or $args[0] -eq 'subagentStart')) {{\n  [Console]::Out.WriteLine('{{\"permission\":\"allow\"}}')\n}} else {{\n  [Console]::Out.WriteLine('{{}}')\n}}\nexit 0\n",
         powershell_literal(executable),
         rendered_args
     ))
@@ -236,6 +238,7 @@ mod tests {
         )
         .unwrap();
         assert_eq!(plugin_manifest["hooks"], "hooks/hooks.json");
+        assert_eq!(manifest["hooks"]["preToolUse"][0]["matcher"], "Task");
         for event in cursor_hook_events().unwrap() {
             let entry = &manifest["hooks"][event][0];
             assert_eq!(entry["failClosed"], false);
@@ -253,14 +256,14 @@ mod tests {
             assert!(script.contains("'--managed-run-hook'"));
             assert!(script.contains("'--session-id-field'"));
             assert!(script.contains("'conversation_id'"));
-            assert!(!script.contains("permission\":\"allow"));
+            assert!(script.contains("permission\":\"allow\""));
             assert!(script.contains("{\"continue\":true}"));
             assert!(!script.contains("--dangerously-bypass"));
         } else {
             let script = std::fs::read_to_string(plugin.join("hooks/trace.sh")).unwrap();
             assert!(script.contains("'--source' 'cursor' '--managed-run-hook'"));
             assert!(script.contains("'--session-id-field' 'conversation_id'"));
-            assert!(!script.contains("\"permission\":\"allow\""));
+            assert!(script.contains("\"permission\":\"allow\""));
             assert!(script.contains("\"continue\":true"));
             assert!(!script.contains("--dangerously-bypass"));
         }
@@ -319,7 +322,7 @@ mod tests {
         assert!(script.contains("--session-id-field"));
         assert!(script.contains("[Console]::Out.WriteLine('{}')"));
         assert!(script.contains("{\"continue\":true}"));
-        assert!(!script.contains("permission\":\"allow"));
+        assert!(script.contains("permission\":\"allow\""));
         assert!(!script.contains("/bin/sh"));
     }
 }

bt-daemon/src/setup/cursor/mod.rs

@@ -27,6 +27,8 @@ $hookArgs = @('trace', 'hook', '--source', 'cursor', '--session-id-field', 'conv
 try { & $bt @hookArgs *> $null } catch {}
 if ($args.Count -gt 0 -and $args[0] -eq 'beforeSubmitPrompt') {
   [Console]::Out.WriteLine('{"continue":true}')
+} elseif ($args.Count -gt 0 -and ($args[0] -eq 'preToolUse' -or $args[0] -eq 'subagentStart')) {
+  [Console]::Out.WriteLine('{"permission":"allow"}')
 } else {
   [Console]::Out.WriteLine('{}')
 }
@@ -414,6 +416,7 @@ mod tests {
         assert!(script.contains("'--source', 'cursor'"));
         assert!(script.contains("'--event-field', 'hook_event_name'"));
         assert!(script.contains("'{\"continue\":true}'") || script.contains("\"continue\":true"));
+        assert!(script.contains("permission\":\"allow\""));
         assert!(script.contains("[Console]::Out.WriteLine('{}')"));
     }
 

bt-daemon/src/translate/cursor/mod.rs

@@ -56,6 +56,8 @@ const CURSOR_METADATA_FIELDS: &[&str] = &[
     "is_interrupt",
     "tool_approval",
     "subagent_type",
+    "subagent_id",
+    "spawning_tool_call_id",
     "recursive_activity_verified",
     "observation_only",
     "completion_observed",
@@ -1129,16 +1131,20 @@ impl CursorTranslator {
         }
         self.ensure_turn(e.ts_ms, None, None, "hook_order", ops);
         let spawn = hook.tool_call_id.as_deref();
-        let parent = spawn
+        let (parent, turn) = spawn
             .and_then(|s| self.tools.get(s).or_else(|| self.completed.get(s)))
-            .map(|t| t.turn.clone())
-            .unwrap_or_else(|| self.turn.as_ref().unwrap().id.clone());
+            .map(|t| (t.row.span_id.clone(), t.turn.clone()))
+            .unwrap_or_else(|| {
+                let turn = self.turn.as_ref().unwrap().id.clone();
+                (turn.clone(), turn)
+            });
         let mut row = self.row(
             ids::span_id(&self.namespace, &format!("subagent:{id}")),
             parent,
             "Cursor subagent",
             SpanType::Task,
         );
+        row.turn_span_id = Some(turn);
         row.start_ms = Some(e.ts_ms);
         row.input = Some(json!(hook.task));
         row.metadata = Some(

bt-daemon/tests/cursor_translator.rs

@@ -1063,7 +1063,7 @@ fn synthetic_usage_without_verified_prompt_generation_stays_unavailable() {
 }
 
 #[test]
-fn synthetic_subagents_parent_to_spawning_turn_and_unmatched_stop_stays_incomplete() {
+fn synthetic_subagents_parent_to_spawning_tool_and_unmatched_stop_stays_incomplete() {
     let mut h = Harness::new("test-session");
     h.handle(&event(
         "beforeSubmitPrompt",
@@ -1075,13 +1075,20 @@ fn synthetic_subagents_parent_to_spawning_turn_and_unmatched_stop_stays_incomple
         110,
         json!({"tool_name":"Task","tool_use_id":"spawn","tool_input":{"task":"explore"}}),
     ));
-    for (ts, id) in [(120, "child-a"), (130, "child-b")] {
-        h.handle(&event("subagentStart", ts, json!({"subagent_id":id,"tool_call_id":"spawn","subagent_type":"explore","subagent_model":"auto","task":"explore"})));
-    }
+    h.handle(&event(
+        "subagentStart",
+        120,
+        json!({"subagent_id":"child-a","tool_call_id":"spawn","subagent_type":"explore","subagent_model":"auto","task":"inspect the code"}),
+    ));
+    h.handle(&event(
+        "subagentStart",
+        130,
+        json!({"subagent_id":"child-b","tool_call_id":"spawn","subagent_type":"explore","subagent_model":"auto","task":"explore"}),
+    ));
     h.handle(&event(
         "subagentStop",
         140,
-        json!({"subagent_id":"child-a","subagent_type":"explore","status":"completed","summary":"available summary"}),
+        json!({"subagent_id":"child-a","subagent_type":"explore","status":"completed","summary":"found the issue"}),
     ));
     h.handle(&event(
         "sessionEnd",
@@ -1096,21 +1103,29 @@ fn synthetic_subagents_parent_to_spawning_turn_and_unmatched_stop_stays_incomple
         .collect();
     assert_eq!(children.len(), 2);
     let rows = h.rows();
+    let spawn_tool_id = h
+        .inserted(SpanType::Tool)
+        .into_iter()
+        .find(|row| row.name == "Task")
+        .unwrap()
+        .span_id
+        .clone();
     for child in children {
-        assert_eq!(child.parent_span_ids, vec![h.turns()[0].span_id.clone()]);
-        assert!(child
-            .metadata
-            .as_ref()
-            .unwrap()
-            .get("spawning_tool_call_id")
-            .is_none());
+        assert_eq!(child.parent_span_ids, vec![spawn_tool_id.clone()]);
+        assert_eq!(child.turn_span_id, Some(h.turns()[0].span_id.clone()));
+        assert_eq!(
+            child.metadata.as_ref().unwrap()["spawning_tool_call_id"],
+            "spawn"
+        );
         assert_eq!(
             child.metadata.as_ref().unwrap()["recursive_activity_verified"],
             false
         );
         let row = &rows[&child.span_id];
         if child.start_ms == Some(120) {
-            assert_eq!(row["output"], "available summary");
+            assert_eq!(row["end_ms"], 140);
+            assert_eq!(child.input, Some(json!("inspect the code")));
+            assert_eq!(row["output"], "found the issue");
             assert_eq!(row["metadata"]["status"], "completed");
         } else {
             assert!(row.get("output").is_none());

src/plugins/cursor/content/hooks/hooks.json

@@ -22,6 +22,14 @@
         "failClosed": false
       }
     ],
+    "preToolUse": [
+      {
+        "command": "bt trace hook --source cursor --event preToolUse --session-id-field conversation_id --event-field hook_event_name --transcript-path-field transcript_path --flush-on-turn-end --capture-timeout-ms 8000",
+        "timeout": 10,
+        "failClosed": false,
+        "matcher": "Task"
+      }
+    ],
     "postToolUse": [
       {
         "command": "bt trace hook --source cursor --event postToolUse --session-id-field conversation_id --event-field hook_event_name --transcript-path-field transcript_path --flush-on-turn-end --capture-timeout-ms 8000",
@@ -36,6 +44,13 @@
         "failClosed": false
       }
     ],
+    "subagentStart": [
+      {
+        "command": "bt trace hook --source cursor --event subagentStart --session-id-field conversation_id --event-field hook_event_name --transcript-path-field transcript_path --flush-on-turn-end --capture-timeout-ms 8000",
+        "timeout": 10,
+        "failClosed": false
+      }
+    ],
     "subagentStop": [
       {
         "command": "bt trace hook --source cursor --event subagentStop --session-id-field conversation_id --event-field hook_event_name --transcript-path-field transcript_path --flush-on-turn-end --capture-timeout-ms 8000",

src/plugins/cursor/content/hooks/trace.sh

@@ -13,10 +13,12 @@ if command -v "$BT_BIN" >/dev/null 2>&1; then
   fi
 fi
 
-# beforeSubmitPrompt is a continuation hook, not a permission decision.
+# beforeSubmitPrompt is a continuation hook; the others below are permission hooks.
 case "${1-}" in
   beforeSubmitPrompt)
     printf '%s\n' '{"continue":true}' ;;
+  preToolUse|subagentStart)
+    printf '%s\n' '{"permission":"allow"}' ;;
   *)
     printf '%s\n' '{}' ;;
 esac

src/plugins/cursor/test/test_capture.sh

@@ -22,6 +22,7 @@ printf '%s\\n' "$*" >> "$CAPTURE_DIR/args"
 /bin/cat > "$CAPTURE_DIR/payload"
 case " $* " in
   *" --event beforeSubmitPrompt "*) printf '%s\\n' '{"continue":true}' ;;
+  *" --event preToolUse "*|*" --event subagentStart "*) printf '%s\\n' '{"permission":"allow"}' ;;
   *) printf '%s\\n' '{}' ;;
 esac
 exit "${BT_EXIT_CODE:-0}"
@@ -39,8 +40,11 @@ exit "${BT_EXIT_CODE:-0}"
                                     input=payload, env=environment,
                                     capture_output=True, executable='/bin/sh')
             assert result.returncode == int(exit_code), (event, result.returncode)
-            expected_output = (b'{"continue":true}\n' if event == 'beforeSubmitPrompt'
-                               else b'{}\n')
+            expected_output = {
+                'beforeSubmitPrompt': b'{"continue":true}\n',
+                'preToolUse': b'{"permission":"allow"}\n',
+                'subagentStart': b'{"permission":"allow"}\n',
+            }.get(event, b'{}\n')
             assert result.stdout == expected_output, (event, result.stdout)
             assert (root / 'payload').read_bytes() == payload
             args = (root / 'args').read_text().splitlines()[-1]
@@ -51,6 +55,16 @@ exit "${BT_EXIT_CODE:-0}"
                             '--capture-timeout-ms 8000'), args
             assert registration['failClosed'] is False
             assert registration['timeout'] * 1000 > 8000
+    for event, expected in (
+        ('beforeSubmitPrompt', b'{"continue":true}\n'),
+        ('preToolUse', b'{"permission":"allow"}\n'),
+        ('subagentStart', b'{"permission":"allow"}\n'),
+    ):
+        result = subprocess.run([str(source / 'hooks/trace.sh'), event],
+                                input=payload, env=environment,
+                                capture_output=True)
+        assert result.returncode == 0, (event, result.returncode)
+        assert result.stdout == expected, (event, result.stdout)
     fake_bt.unlink()
     for event, registrations in config['hooks'].items():
         result = subprocess.run(registrations[0]['command'], shell=True,

src/plugins/cursor/validate.sh

@@ -43,21 +43,24 @@ assert 'MIT License' in (root / 'LICENSE').read_text()
 config = json.loads((root / manifest['hooks']).read_text())
 assert config['version'] == 1
 expected = {
-    'sessionStart', 'sessionEnd', 'beforeSubmitPrompt',
-    'postToolUse', 'postToolUseFailure', 'subagentStop',
+    'sessionStart', 'sessionEnd', 'beforeSubmitPrompt', 'preToolUse',
+    'postToolUse', 'postToolUseFailure', 'subagentStart', 'subagentStop',
     'afterShellExecution', 'afterMCPExecution', 'afterFileEdit', 'preCompact',
     'stop', 'afterAgentResponse',
 }
 assert set(config['hooks']) == expected
 for event, registrations in config['hooks'].items():
-    assert registrations == [{
+    expected_registration = {
         'command': ('bt trace hook --source cursor '
                     f'--event {event} --session-id-field conversation_id '
                     '--event-field hook_event_name --transcript-path-field transcript_path '
                     '--flush-on-turn-end --capture-timeout-ms 8000'),
         'timeout': 10,
         'failClosed': False,
-    }]
+    }
+    if event == 'preToolUse':
+        expected_registration['matcher'] = 'Task'
+    assert registrations == [expected_registration]
 PY
 
 "$SRC_DIR/test/test_capture.sh" "$TARGET_DIR"