PostHog · adboio · Apr 1, 2026
diff --git a/apps/code/src/main/services/agent/schemas.ts b/apps/code/src/main/services/agent/schemas.ts
@@ -209,6 +209,7 @@ export const AgentServiceEvent = {
   PermissionRequest: "permission-request",
   SessionsIdle: "sessions-idle",
   SessionIdleKilled: "session-idle-killed",
+  AgentFileActivity: "agent-file-activity",
 } as const;
 
 export interface AgentSessionEventPayload {
@@ -229,11 +230,17 @@ export interface SessionIdleKilledPayload {
   taskId: string;
 }
 
+export interface AgentFileActivityPayload {
+  taskId: string;
+  branchName: string | null;
+}
+
 export interface AgentServiceEvents {
   [AgentServiceEvent.SessionEvent]: AgentSessionEventPayload;
   [AgentServiceEvent.PermissionRequest]: PermissionRequestPayload;
   [AgentServiceEvent.SessionsIdle]: undefined;
   [AgentServiceEvent.SessionIdleKilled]: SessionIdleKilledPayload;
+  [AgentServiceEvent.AgentFileActivity]: AgentFileActivityPayload;
 }
 
 // Permission response input for tRPC

diff --git a/apps/code/src/main/services/agent/service.ts b/apps/code/src/main/services/agent/service.ts
@@ -22,6 +22,7 @@ import {
 } from "@posthog/agent/gateway-models";
 import { getLlmGatewayUrl } from "@posthog/agent/posthog-api";
 import type { OnLogCallback } from "@posthog/agent/types";
+import { getCurrentBranch } from "@posthog/git/queries";
 import { isAuthError } from "@shared/errors";
 import type { AcpMessage } from "@shared/types/session-events";
 import { app, powerMonitor } from "electron";
@@ -1124,8 +1125,8 @@ For git operations while detached:
       };
       emitToRenderer(acpMessage);
 
-      // Detect PR URLs in bash tool results and attach to task
-      this.detectAndAttachPrUrl(taskRunId, message as AcpMessage["message"]);
+      // Inspect tool call updates for PR URLs and file activity
+      this.handleToolCallUpdate(taskRunId, message as AcpMessage["message"]);
     };
 
     const tappedReadable = createTappedReadableStream(
@@ -1404,11 +1405,7 @@ For git operations while detached:
     };
   }
 
-  /**
-   * Detect GitHub PR URLs in bash tool results and attach to task.
-   * This enables webhook tracking by populating the pr_url in TaskRun output.
-   */
-  private detectAndAttachPrUrl(taskRunId: string, message: unknown): void {
+  private handleToolCallUpdate(taskRunId: string, message: unknown): void {
     try {
       const msg = message as {
         method?: string;
@@ -1430,86 +1427,136 @@ For git operations while detached:
       if (msg.method !== "session/update") return;
       if (msg.params?.update?.sessionUpdate !== "tool_call_update") return;
 
-      const toolMeta = msg.params.update._meta?.claudeCode;
+      const update = msg.params.update;
+      const toolMeta = update._meta?.claudeCode;
       const toolName = toolMeta?.toolName;
+      if (!toolName) return;
 
-      // Only process Bash tool results
-      if (
-        !toolName ||
-        (!toolName.includes("Bash") && !toolName.includes("bash"))
-      ) {
-        return;
+      const session = this.sessions.get(taskRunId);
+
+      // PR URLs only appear in Bash tool output
+      if (toolName.includes("Bash") || toolName.includes("bash")) {
+        this.detectAndAttachPrUrl(taskRunId, session, toolMeta, update.content);
       }
 
-      // Extract text content from tool response or update content
-      let textToSearch = "";
-
-      // Check toolResponse (hook response with raw output)
-      const toolResponse = toolMeta?.toolResponse;
-      if (toolResponse) {
-        if (typeof toolResponse === "string") {
-          textToSearch = toolResponse;
-        } else if (typeof toolResponse === "object" && toolResponse !== null) {
-          // May be { stdout?: string, stderr?: string } or similar
-          const respObj = toolResponse as Record<string, unknown>;
-          textToSearch =
-            String(respObj.stdout || "") + String(respObj.stderr || "");
-          if (!textToSearch && respObj.output) {
-            textToSearch = String(respObj.output);
-          }
+      this.trackAgentFileActivity(taskRunId, session, toolName);
+    } catch (err) {
+      log.debug("Error in tool call update handling", {
+        taskRunId,
+        error: err,
+      });
+    }
+  }
+
+  /**
+   * Detect GitHub PR URLs in bash tool results and attach to task.
+   * This enables webhook tracking by populating the pr_url in TaskRun output.
+   */
+  private detectAndAttachPrUrl(
+    taskRunId: string,
+    session: ManagedSession | undefined,
+    toolMeta: { toolName?: string; toolResponse?: unknown },
+    content?: Array<{ type?: string; text?: string }>,
+  ): void {
+    let textToSearch = "";
+
+    // Check toolResponse (hook response with raw output)
+    const toolResponse = toolMeta?.toolResponse;
+    if (toolResponse) {
+      if (typeof toolResponse === "string") {
+        textToSearch = toolResponse;
+      } else if (typeof toolResponse === "object" && toolResponse !== null) {
+        // May be { stdout?: string, stderr?: string } or similar
+        const respObj = toolResponse as Record<string, unknown>;
+        textToSearch =
+          String(respObj.stdout || "") + String(respObj.stderr || "");
+        if (!textToSearch && respObj.output) {
+          textToSearch = String(respObj.output);
         }
       }
+    }
 
-      // Also check content array
-      const content = msg.params.update.content;
-      if (Array.isArray(content)) {
-        for (const item of content) {
-          if (item.type === "text" && item.text) {
-            textToSearch += ` ${item.text}`;
-          }
+    // Also check content array
+    if (Array.isArray(content)) {
+      for (const item of content) {
+        if (item.type === "text" && item.text) {
+          textToSearch += ` ${item.text}`;
         }
       }
+    }
 
-      if (!textToSearch) return;
+    if (!textToSearch) return;
 
-      // Match GitHub PR URLs
-      const prUrlMatch = textToSearch.match(
-        /https:\/\/github\.com\/[^/]+\/[^/]+\/pull\/\d+/,
-      );
-      if (!prUrlMatch) return;
+    // Match GitHub PR URLs
+    const prUrlMatch = textToSearch.match(
+      /https:\/\/github\.com\/[^/]+\/[^/]+\/pull\/\d+/,
+    );
+    if (!prUrlMatch) return;
 
-      const prUrl = prUrlMatch[0];
-      log.info("Detected PR URL in bash output", { taskRunId, prUrl });
+    const prUrl = prUrlMatch[0];
+    log.info("Detected PR URL in bash output", { taskRunId, prUrl });
 
-      // Find session and attach PR URL
-      const session = this.sessions.get(taskRunId);
-      if (!session) {
-        log.warn("Session not found for PR attachment", { taskRunId });
-        return;
-      }
+    // Attach PR URL
+    if (!session) {
+      log.warn("Session not found for PR attachment", { taskRunId });
+      return;
+    }
 
-      // Attach asynchronously without blocking message flow
-      session.agent
-        .attachPullRequestToTask(session.taskId, prUrl)
-        .then(() => {
-          log.info("PR URL attached to task", {
-            taskRunId,
-            taskId: session.taskId,
-            prUrl,
-          });
-        })
-        .catch((err) => {
-          log.error("Failed to attach PR URL to task", {
-            taskRunId,
-            taskId: session.taskId,
-            prUrl,
-            error: err,
-          });
+    // Attach asynchronously without blocking message flow
+    session.agent
+      .attachPullRequestToTask(session.taskId, prUrl)
+      .then(() => {
+        log.info("PR URL attached to task", {
+          taskRunId,
+          taskId: session.taskId,
+          prUrl,
         });
-    } catch (err) {
-      // Don't let detection errors break message flow
-      log.debug("Error in PR URL detection", { taskRunId, error: err });
-    }
+      })
+      .catch((err) => {
+        log.error("Failed to attach PR URL to task", {
+          taskRunId,
+          taskId: session.taskId,
+          prUrl,
+          error: err,
+        });
+      });
+  }
+
+  /**
+   * Track agent file activity for branch association observability.
+   */
+  private static readonly FILE_MODIFYING_TOOLS = new Set([
+    "Edit",
+    "Write",
+    "FileEditTool",
+    "FileWriteTool",
+    "MultiEdit",
+    "NotebookEdit",
+  ]);
+
+  private trackAgentFileActivity(
+    taskRunId: string,
+    session: ManagedSession | undefined,
+    toolName: string,
+  ): void {
+    if (!session) return;
+    if (!AgentService.FILE_MODIFYING_TOOLS.has(toolName)) return;
+
+    getCurrentBranch(session.repoPath)
+      .then((branchName) => {
+        this.emit(AgentServiceEvent.AgentFileActivity, {
+          taskId: session.taskId,
+          branchName,
+        });
+      })
+      .catch((err) => {
+        log.error("Failed to emit agent file activity event", {
+          taskRunId,
+          taskId: session.taskId,
+          toolName,
+          error: err,
+        });
+      });
   }
 
   async getGatewayModels(apiHost: string) {

diff --git a/apps/code/src/main/trpc/routers/agent.ts b/apps/code/src/main/trpc/routers/agent.ts
@@ -189,6 +189,16 @@ export const agentRouter = router({
     }
   }),
 
+  onAgentFileActivity: publicProcedure.subscription(async function* (opts) {
+    const service = getService();
+    for await (const event of service.toIterable(
+      AgentServiceEvent.AgentFileActivity,
+      { signal: opts.signal },
+    )) {
+      yield event;
+    }
+  }),
+
   getGatewayModels: publicProcedure
     .input(getGatewayModelsInput)
     .output(getGatewayModelsOutput)

diff --git a/apps/code/src/renderer/App.tsx b/apps/code/src/renderer/App.tsx
@@ -14,9 +14,10 @@ import { initializeConnectivityStore } from "@renderer/stores/connectivityStore"
 import { useFocusStore } from "@renderer/stores/focusStore";
 import { useThemeStore } from "@renderer/stores/themeStore";
 import { trpcClient, useTRPC } from "@renderer/trpc/client";
+import { ANALYTICS_EVENTS } from "@shared/types/analytics";
 import { useQueryClient } from "@tanstack/react-query";
 import { useSubscription } from "@trpc/tanstack-react-query";
-import { initializePostHog } from "@utils/analytics";
+import { initializePostHog, track } from "@utils/analytics";
 import { logger } from "@utils/logger";
 import { toast } from "@utils/toast";
 import { AnimatePresence, motion } from "framer-motion";
@@ -108,6 +109,17 @@ function App() {
     }),
   );
 
+  useSubscription(
+    trpcReact.agent.onAgentFileActivity.subscriptionOptions(undefined, {
+      onData: (data) => {
+        track(ANALYTICS_EVENTS.AGENT_FILE_ACTIVITY, {
+          task_id: data.taskId,
+          branch_name: data.branchName,
+        });
+      },
+    }),
+  );
+
   // Auto-unfocus when user manually checks out to a different branch
   useSubscription(
     trpcReact.focus.onForeignBranchCheckout.subscriptionOptions(undefined, {

diff --git a/apps/code/src/renderer/features/git-interaction/hooks/useGitInteraction.ts b/apps/code/src/renderer/features/git-interaction/hooks/useGitInteraction.ts
@@ -1,3 +1,4 @@
+import { getAuthenticatedClient } from "@features/auth/hooks/authClient";
 import { useGitQueries } from "@features/git-interaction/hooks/useGitQueries";
 import { computeGitInteractionState } from "@features/git-interaction/state/gitInteractionLogic";
 import {
@@ -19,6 +20,7 @@ import { getSuggestedBranchName } from "@features/git-interaction/utils/getSugge
 import { invalidateGitBranchQueries } from "@features/git-interaction/utils/gitCacheKeys";
 import { partitionByStaged } from "@features/git-interaction/utils/partitionByStaged";
 import { updateGitCacheFromSnapshot } from "@features/git-interaction/utils/updateGitCache";
+import { useSessionStore } from "@features/sessions/stores/sessionStore";
 import { trpc, trpcClient } from "@renderer/trpc";
 import type { ChangedFile } from "@shared/types";
 import { ANALYTICS_EVENTS } from "@shared/types/analytics";
@@ -115,6 +117,21 @@ function trackGitAction(
   });
 }
 
+function attachPrUrlToTask(taskId: string, prUrl: string) {
+  const taskRunId = useSessionStore.getState().taskIdIndex[taskId];
+  if (!taskRunId) return;
+
+  getAuthenticatedClient()
+    .then((client) =>
+      client?.updateTaskRun(taskId, taskRunId, {
+        output: { pr_url: prUrl },
+      }),
+    )
+    .catch((err) =>
+      log.warn("Failed to attach PR URL to task", { taskId, prUrl, err }),
+    );
+}
+
 export function useGitInteraction(
   taskId: string,
   repoPath?: string,
@@ -255,6 +272,7 @@ export function useGitInteraction(
 
       if (result.prUrl) {
         await trpcClient.os.openExternal.mutate({ url: result.prUrl });
+        attachPrUrlToTask(taskId, result.prUrl);
       }
 
       modal.closeCreatePr();

diff --git a/apps/code/src/shared/types/analytics.ts b/apps/code/src/shared/types/analytics.ts
@@ -111,6 +111,11 @@ export interface PrCreatedProperties {
   success: boolean;
 }
 
+export interface AgentFileActivityProperties {
+  task_id: string;
+  branch_name: string | null;
+}
+
 // File interactions
 export interface FileOpenedProperties {
   file_extension: string;
@@ -224,6 +229,7 @@ export const ANALYTICS_EVENTS = {
   // Git operations
   GIT_ACTION_EXECUTED: "Git action executed",
   PR_CREATED: "PR created",
+  AGENT_FILE_ACTIVITY: "Agent file activity",
 
   // File interactions
   FILE_OPENED: "File opened",
@@ -278,6 +284,7 @@ export type EventPropertyMap = {
   // Git operations
   [ANALYTICS_EVENTS.GIT_ACTION_EXECUTED]: GitActionExecutedProperties;
   [ANALYTICS_EVENTS.PR_CREATED]: PrCreatedProperties;
+  [ANALYTICS_EVENTS.AGENT_FILE_ACTIVITY]: AgentFileActivityProperties;
 
   // File interactions
   [ANALYTICS_EVENTS.FILE_OPENED]: FileOpenedProperties;