fix: support current Codex subagent activity events

plugins/tracing/dist/index.mjs

@@ -46661,6 +46661,10 @@ function newTurn(startTime) {
 		aborted: false
 	};
 }
+/** Record a spawned subagent once across Codex rollout schema versions. */
+function addSubagentThreadId(turn, threadId) {
+	if (typeof threadId === "string" && !turn.subagentThreadIds.includes(threadId)) turn.subagentThreadIds.push(threadId);
+}
 /**
 * Parse a Codex rollout into session metadata and a list of fully assembled
 * turns.
@@ -46835,7 +46839,8 @@ function parseSession(lines) {
 				aborted: true
 			});
 			else {
-				if (et === "collab_agent_spawn_end" && typeof p.new_thread_id === "string") turn.subagentThreadIds.push(p.new_thread_id);
+				if (et === "collab_agent_spawn_end") addSubagentThreadId(turn, p.new_thread_id);
+				else if (et === "sub_agent_activity" && p.kind === "started") addSubagentThreadId(turn, p.agent_thread_id);
 				if ((et === "mcp_tool_call_begin" || et === "mcp_tool_call_end") && typeof p.call_id === "string") {
 					const tc = toolCallsById.get(p.call_id);
 					const inv = p.invocation;

plugins/tracing/src/parse.ts

@@ -96,6 +96,13 @@ function newTurn(startTime: number): MutableTurn {
   };
 }
 
+/** Record a spawned subagent once across Codex rollout schema versions. */
+function addSubagentThreadId(turn: MutableTurn, threadId: unknown): void {
+  if (typeof threadId === "string" && !turn.subagentThreadIds.includes(threadId)) {
+    turn.subagentThreadIds.push(threadId);
+  }
+}
+
 /**
  * Parse a Codex rollout into session metadata and a list of fully assembled
  * turns.
@@ -305,10 +312,12 @@ export function parseSession(lines: RolloutLine[]): {
       } else if (et === "turn_aborted") {
         finishTurn(ts, { completed: true, aborted: true });
       } else {
-        // A subagent spawn records the child thread *and* (since it carries a
-        // call_id ending in "_end") enriches the spawning tool call below.
-        if (et === "collab_agent_spawn_end" && typeof p.new_thread_id === "string") {
-          turn!.subagentThreadIds.push(p.new_thread_id);
+        // Codex has used two lifecycle schemas for successful subagent spawns.
+        // Accept both and deduplicate in case a rollout contains both forms.
+        if (et === "collab_agent_spawn_end") {
+          addSubagentThreadId(turn!, p.new_thread_id);
+        } else if (et === "sub_agent_activity" && p.kind === "started") {
+          addSubagentThreadId(turn!, p.agent_thread_id);
         }
         // MCP tool calls are function calls with a mangled name
         // (`server__tool`); the begin/end events carry the clean server/tool

plugins/tracing/src/types.ts

@@ -131,6 +131,9 @@ export type EventMsgPayload = {
   } | null;
   /** collab_agent_spawn_end */
   new_thread_id?: string | null;
+  /** sub_agent_activity */
+  agent_thread_id?: string | null;
+  kind?: string | null;
   /** mcp_tool_call_begin / mcp_tool_call_end */
   invocation?: { server?: string; tool?: string; arguments?: unknown } | null;
   /** web_search_end */

plugins/tracing/test/fixtures/sessions/2026/06/03/rollout-child-thread-child-current.jsonl

@@ -0,0 +1,12 @@
+{"timestamp":"2026-06-03T13:00:03.000Z","type":"session_meta","payload":{"id":"thread-child-current","cli_version":"0.147.0","model_provider":"openai","parent_thread_id":"sess-parent-current","thread_source":"subagent"}}
+{"timestamp":"2026-06-03T13:00:03.100Z","type":"event_msg","payload":{"type":"task_started","turn_id":"turn-child-current"}}
+{"timestamp":"2026-06-03T13:00:03.200Z","type":"turn_context","payload":{"model":"gpt-5.4"}}
+{"timestamp":"2026-06-03T13:00:03.300Z","type":"event_msg","payload":{"type":"user_message","message":"run a command"}}
+{"timestamp":"2026-06-03T13:00:03.400Z","type":"response_item","payload":{"type":"function_call","name":"exec_command","call_id":"call-child-exec","arguments":"{\"command\":[\"echo\",\"child action\"]}"}}
+{"timestamp":"2026-06-03T13:00:03.600Z","type":"event_msg","payload":{"type":"exec_command_end","call_id":"call-child-exec","status":"completed","exit_code":0,"stdout":"child action\n","stderr":"","aggregated_output":"child action\n"}}
+{"timestamp":"2026-06-03T13:00:03.700Z","type":"response_item","payload":{"type":"function_call_output","call_id":"call-child-exec","output":"child action\n"}}
+{"timestamp":"2026-06-03T13:00:03.800Z","type":"event_msg","payload":{"type":"token_count","info":{"last_token_usage":{"input_tokens":40,"output_tokens":8,"total_tokens":48,"cached_input_tokens":0,"reasoning_output_tokens":0},"total_token_usage":{"input_tokens":40,"output_tokens":8,"total_tokens":48,"cached_input_tokens":0,"reasoning_output_tokens":0}}}}
+{"timestamp":"2026-06-03T13:00:04.000Z","type":"response_item","payload":{"type":"message","role":"assistant","content":[{"type":"output_text","text":"The child command completed."}]}}
+{"timestamp":"2026-06-03T13:00:04.100Z","type":"event_msg","payload":{"type":"agent_message","message":"The child command completed."}}
+{"timestamp":"2026-06-03T13:00:04.200Z","type":"event_msg","payload":{"type":"token_count","info":{"last_token_usage":{"input_tokens":50,"output_tokens":10,"total_tokens":60,"cached_input_tokens":0,"reasoning_output_tokens":0},"total_token_usage":{"input_tokens":90,"output_tokens":18,"total_tokens":108,"cached_input_tokens":0,"reasoning_output_tokens":0}}}}
+{"timestamp":"2026-06-03T13:00:04.300Z","type":"event_msg","payload":{"type":"task_complete","turn_id":"turn-child-current"}}

plugins/tracing/test/fixtures/sessions/2026/06/03/rollout-parent-sub-agent-activity.jsonl

@@ -0,0 +1,13 @@
+{"timestamp":"2026-06-03T13:00:00.000Z","type":"session_meta","payload":{"id":"sess-parent-current","cli_version":"0.147.0","model_provider":"openai"}}
+{"timestamp":"2026-06-03T13:00:01.000Z","type":"event_msg","payload":{"type":"task_started","turn_id":"turn-parent-current"}}
+{"timestamp":"2026-06-03T13:00:01.200Z","type":"turn_context","payload":{"model":"gpt-5.4"}}
+{"timestamp":"2026-06-03T13:00:01.300Z","type":"event_msg","payload":{"type":"user_message","message":"Spawn a subagent to run a command"}}
+{"timestamp":"2026-06-03T13:00:02.000Z","type":"response_item","payload":{"type":"function_call","name":"spawn_agent","call_id":"call-spawn-current","arguments":"{\"message\":\"run a command\"}"}}
+{"timestamp":"2026-06-03T13:00:02.500Z","type":"event_msg","payload":{"type":"sub_agent_activity","event_id":"call-spawn-current","agent_thread_id":"thread-child-current","agent_path":"/root/current-child","kind":"started"}}
+{"timestamp":"2026-06-03T13:00:02.600Z","type":"event_msg","payload":{"type":"sub_agent_activity","event_id":"call-spawn-current","agent_thread_id":"thread-child-current","agent_path":"/root/current-child","kind":"started"}}
+{"timestamp":"2026-06-03T13:00:02.700Z","type":"response_item","payload":{"type":"function_call_output","call_id":"call-spawn-current","output":"started"}}
+{"timestamp":"2026-06-03T13:00:02.800Z","type":"event_msg","payload":{"type":"token_count","info":{"last_token_usage":{"input_tokens":80,"output_tokens":10,"total_tokens":90,"cached_input_tokens":0,"reasoning_output_tokens":0},"total_token_usage":{"input_tokens":80,"output_tokens":10,"total_tokens":90,"cached_input_tokens":0,"reasoning_output_tokens":0}}}}
+{"timestamp":"2026-06-03T13:00:05.000Z","type":"response_item","payload":{"type":"message","role":"assistant","content":[{"type":"output_text","text":"Subagent completed."}]}}
+{"timestamp":"2026-06-03T13:00:05.100Z","type":"event_msg","payload":{"type":"agent_message","message":"Subagent completed."}}
+{"timestamp":"2026-06-03T13:00:05.200Z","type":"event_msg","payload":{"type":"token_count","info":{"last_token_usage":{"input_tokens":90,"output_tokens":12,"total_tokens":102,"cached_input_tokens":0,"reasoning_output_tokens":0},"total_token_usage":{"input_tokens":170,"output_tokens":22,"total_tokens":192,"cached_input_tokens":0,"reasoning_output_tokens":0}}}}
+{"timestamp":"2026-06-03T13:00:05.300Z","type":"event_msg","payload":{"type":"task_complete","turn_id":"turn-parent-current"}}

plugins/tracing/test/parse.test.ts

@@ -81,6 +81,13 @@ describe("parseSession", () => {
     expect(turn.endTime).toBe(Date.parse("2026-06-03T11:00:05.000Z"));
   });
 
+  it("captures and deduplicates current sub_agent_activity thread ids", () => {
+    const { turns } = parseSession(loadFixture("rollout-parent-sub-agent-activity.jsonl"));
+
+    expect(turns).toHaveLength(1);
+    expect(turns[0].subagentThreadIds).toEqual(["thread-child-current"]);
+  });
+
   it("treats a trailing, never-completed turn as not completed", () => {
     const lines: RolloutLine[] = [
       { timestamp: "2026-06-03T12:00:00.000Z", type: "session_meta", payload: { id: "s" } },

plugins/tracing/test/trace.test.ts

@@ -159,6 +159,42 @@ describe("convertRollout", () => {
     expect(attr(failedTool!, "langfuse.observation.status_message")).toContain("command failed");
   });
 
+  it("nests current sub_agent_activity rollouts with their execution actions", async () => {
+    const dir = stageFixtures();
+    await convertRollout(path.join(dir, "rollout-parent-sub-agent-activity.jsonl"), {
+      config: baseConfig,
+    });
+
+    const spans = exporter.getFinishedSpans();
+    const parent = spans.find((s) => s.name === "Codex Turn" && obsType(s) === "agent");
+    const childAgents = spans.filter(
+      (s) => s.name === "Codex Subagent Turn" && obsType(s) === "agent",
+    );
+
+    expect(parent).toBeDefined();
+    expect(childAgents).toHaveLength(1);
+    const child = childAgents[0];
+    expect(parentId(child)).toBe(parent!.spanContext().spanId);
+    expect(child.spanContext().traceId).toBe(parent!.spanContext().traceId);
+
+    const childGeneration = spans.find(
+      (s) =>
+        s.name === "LLM Subagent" &&
+        obsType(s) === "generation" &&
+        parentId(s) === child.spanContext().spanId,
+    );
+    expect(childGeneration).toBeDefined();
+
+    const childTool = spans.find(
+      (s) =>
+        s.name === "exec_command" &&
+        obsType(s) === "tool" &&
+        parentId(s) === childGeneration!.spanContext().spanId,
+    );
+    expect(childTool).toBeDefined();
+    expect(attr(childTool!, "langfuse.observation.output")).toContain("child action");
+  });
+
   it("captures web search, local shell, and MCP tool calls with specific names", async () => {
     const dir = stageFixtures();
     await convertRollout(path.join(dir, "rollout-tools-main.jsonl"), { config: baseConfig });