Label Codex collaboration groups as subagents

Read canonical tool metadata in the grouped conversation header so Codex spawn batches no longer fall back to the generic Other label.

Generated-By: PostHog Code
Task-Id: 971044c5-e622-4f07-b1b5-dca9b06d040c

Author: richardsolomou

packages/ui/src/features/sessions/components/chat-thread/ToolGroup.test.tsx

@@ -0,0 +1,41 @@
+import { posthogToolMeta } from "@posthog/shared";
+import type { ConversationItem } from "@posthog/ui/features/sessions/components/buildConversationItems";
+import { Theme } from "@radix-ui/themes";
+import { render, screen } from "@testing-library/react";
+import { describe, expect, it } from "vitest";
+import { ToolGroup } from "./ToolGroup";
+
+function subagentItem(
+  id: string,
+): Extract<ConversationItem, { type: "session_update" }> {
+  return {
+    type: "session_update",
+    id,
+    update: {
+      sessionUpdate: "tool_call",
+      toolCallId: id,
+      title: "Subagent",
+      kind: "other",
+      status: "completed",
+      _meta: posthogToolMeta({ toolName: "spawn_agent" }),
+    },
+    turnContext: {
+      toolCalls: new Map(),
+      childItems: new Map(),
+      turnCancelled: false,
+      turnComplete: true,
+    },
+  } as Extract<ConversationItem, { type: "session_update" }>;
+}
+
+describe("ToolGroup", () => {
+  it("labels Codex spawn batches as subagents", () => {
+    render(
+      <Theme>
+        <ToolGroup tools={[subagentItem("spawn-1"), subagentItem("spawn-2")]} />
+      </Theme>,
+    );
+
+    expect(screen.getByText("Used Subagents")).toBeInTheDocument();
+  });
+});

packages/ui/src/features/sessions/components/chat-thread/ToolGroup.tsx

@@ -6,9 +6,11 @@ import {
   cn,
   Spinner,
 } from "@posthog/quill";
+import { readAgentToolName } from "@posthog/shared";
 import type { ToolCall } from "@posthog/ui/features/sessions/types";
 import { memo } from "react";
 import type { ConversationItem } from "../buildConversationItems";
+import { grouping } from "../new-thread/conversationThreadConfig";
 import { SessionUpdateView } from "../session-update/SessionUpdateView";
 import { iconForToolCall } from "../session-update/toolCallUtils";
 
@@ -38,10 +40,10 @@ function resolveTool(item: ToolGroupItem["tools"][number]): {
     ...(update as unknown as ToolCall),
     status: (update as unknown as ToolCall).status ?? "in_progress",
   };
-  const meta = fromMap._meta as
-    | { claudeCode?: { toolName?: string } }
-    | undefined;
-  return { toolCall: fromMap, toolName: meta?.claudeCode?.toolName };
+  return {
+    toolCall: fromMap,
+    toolName: readAgentToolName(fromMap._meta),
+  };
 }
 
 /** Identity used to decide if a group is "all the same tool". */
@@ -52,9 +54,12 @@ function toolKey(item: ToolGroupItem["tools"][number]): string {
 
 /** Human label for a uniform group, e.g. `ToolSearch` → "Tool search", `mcp__x__run` → "Run". */
 function friendlyName(key: string): string {
+  if (grouping.subagentToolNames.has(key)) return "Subagents";
   const last = key.includes("__") ? (key.split("__").pop() ?? key) : key;
-  // Split PascalCase/camelCase into words so `ToolSearch` reads "Tool search" rather than "Toolsearch".
-  const spaced = last.replace(/([a-z\d])([A-Z])/g, "$1 $2");
+  // Split separators and PascalCase/camelCase so tool identifiers read naturally.
+  const spaced = last
+    .replace(/[_-]+/g, " ")
+    .replace(/([a-z\d])([A-Z])/g, "$1 $2");
   return spaced.charAt(0).toUpperCase() + spaced.slice(1).toLowerCase();
 }