diff --git a/packages/agent/src/server/agent-server.test.ts b/packages/agent/src/server/agent-server.test.ts
index 88bae5505..ca2ed2364 100644
--- a/packages/agent/src/server/agent-server.test.ts
+++ b/packages/agent/src/server/agent-server.test.ts
@@ -203,6 +203,247 @@ describe("AgentServer HTTP Mode", () => {
   });
 
   describe("turn completion", () => {
+    function stubSessionCleanup(testServer: unknown): {
+      cleanupSession: (options?: {
+        completeEventStream?: boolean;
+      }) => Promise<void>;
+      eventStreamSender: {
+        enqueue: ReturnType<typeof vi.fn>;
+        stop: ReturnType<typeof vi.fn>;
+      };
+    } {
+      const cleanupServer = testServer as {
+        session: unknown;
+        eventStreamSender: {
+          enqueue: ReturnType<typeof vi.fn>;
+          stop: ReturnType<typeof vi.fn>;
+        };
+        captureCheckpointState: ReturnType<typeof vi.fn>;
+        cleanupSession: (options?: {
+          completeEventStream?: boolean;
+        }) => Promise<void>;
+      };
+      cleanupServer.captureCheckpointState = vi.fn(async () => {});
+      cleanupServer.eventStreamSender = {
+        enqueue: vi.fn(),
+        stop: vi.fn(async () => {}),
+      };
+      cleanupServer.session = {
+        payload: { run_id: "run-1" },
+        pendingHandoffGitState: undefined,
+        logWriter: { flush: vi.fn(async () => {}) },
+        acpConnection: { cleanup: vi.fn(async () => {}) },
+        sseController: { close: vi.fn() },
+      };
+      return cleanupServer;
+    }
+
+    it("keeps event ingest open for non-terminal session cleanup", async () => {
+      const testServer = stubSessionCleanup(createServer());
+
+      await testServer.cleanupSession();
+
+      expect(testServer.eventStreamSender.enqueue).not.toHaveBeenCalled();
+      expect(testServer.eventStreamSender.stop).not.toHaveBeenCalled();
+    });
+
+    it("stops event ingest for terminal session cleanup without fake task completion", async () => {
+      const testServer = stubSessionCleanup(createServer());
+
+      await testServer.cleanupSession({ completeEventStream: true });
+
+      expect(testServer.eventStreamSender.enqueue).not.toHaveBeenCalled();
+      expect(testServer.eventStreamSender.stop).toHaveBeenCalledOnce();
+    });
+
+    it("writes terminal failure status before completing event ingest", async () => {
+      const order: string[] = [];
+      const testServer = new AgentServer({
+        port,
+        jwtPublicKey: TEST_PUBLIC_KEY,
+        repositoryPath: repo.path,
+        apiUrl: "http://localhost:8000",
+        apiKey: "test-api-key",
+        projectId: 1,
+        mode: "interactive",
+        taskId: "test-task-id",
+        runId: "test-run-id",
+      }) as unknown as {
+        eventStreamSender: {
+          enqueue: (event: Record<string, unknown>) => void;
+          stop: () => Promise<void>;
+        };
+        posthogAPI: {
+          updateTaskRun: (
+            taskId: string,
+            runId: string,
+            payload: Record<string, unknown>,
+          ) => Promise<unknown>;
+        };
+        signalTaskComplete(
+          payload: JwtPayload,
+          stopReason: string,
+          errorMessage?: string,
+        ): Promise<void>;
+      };
+      testServer.eventStreamSender = {
+        enqueue: vi.fn(() => {
+          order.push("enqueue");
+        }),
+        stop: vi.fn(async () => {
+          order.push("stop");
+        }),
+      };
+      testServer.posthogAPI = {
+        updateTaskRun: vi.fn(async () => {
+          order.push("update");
+          return {};
+        }),
+      };
+
+      await testServer.signalTaskComplete(
+        {
+          run_id: "run-1",
+          task_id: "task-1",
+          team_id: 1,
+          user_id: 1,
+          distinct_id: "distinct-id",
+          mode: "interactive",
+        },
+        "error",
+        "boom",
+      );
+
+      expect(order).toEqual(["enqueue", "update", "stop"]);
+      expect(testServer.eventStreamSender.enqueue).toHaveBeenCalledWith(
+        expect.objectContaining({
+          type: "notification",
+          notification: expect.objectContaining({
+            method: "_posthog/error",
+            params: expect.objectContaining({ error: "boom" }),
+          }),
+        }),
+      );
+      expect(testServer.posthogAPI.updateTaskRun).toHaveBeenCalledWith(
+        "task-1",
+        "run-1",
+        {
+          status: "failed",
+          error_message: "boom",
+        },
+      );
+    });
+
+    it("still stops event ingest when terminal failure status update fails", async () => {
+      const testServer = new AgentServer({
+        port,
+        jwtPublicKey: TEST_PUBLIC_KEY,
+        repositoryPath: repo.path,
+        apiUrl: "http://localhost:8000",
+        apiKey: "test-api-key",
+        projectId: 1,
+        mode: "interactive",
+        taskId: "test-task-id",
+        runId: "test-run-id",
+      }) as unknown as {
+        eventStreamSender: {
+          enqueue: (event: Record<string, unknown>) => void;
+          stop: () => Promise<void>;
+        };
+        posthogAPI: {
+          updateTaskRun: (
+            taskId: string,
+            runId: string,
+            payload: Record<string, unknown>,
+          ) => Promise<unknown>;
+        };
+        signalTaskComplete(
+          payload: JwtPayload,
+          stopReason: string,
+          errorMessage?: string,
+        ): Promise<void>;
+      };
+      testServer.eventStreamSender = {
+        enqueue: vi.fn(),
+        stop: vi.fn(async () => {}),
+      };
+      testServer.posthogAPI = {
+        updateTaskRun: vi.fn(async () => {
+          throw new Error("update failed");
+        }),
+      };
+
+      await testServer.signalTaskComplete(
+        {
+          run_id: "run-1",
+          task_id: "task-1",
+          team_id: 1,
+          user_id: 1,
+          distinct_id: "distinct-id",
+          mode: "interactive",
+        },
+        "error",
+        "boom",
+      );
+
+      expect(testServer.eventStreamSender.enqueue).toHaveBeenCalledOnce();
+      expect(testServer.posthogAPI.updateTaskRun).toHaveBeenCalledOnce();
+      expect(testServer.eventStreamSender.stop).toHaveBeenCalledOnce();
+    });
+
+    it("leaves event ingest open for non-error stop reasons", async () => {
+      const testServer = new AgentServer({
+        port,
+        jwtPublicKey: TEST_PUBLIC_KEY,
+        repositoryPath: repo.path,
+        apiUrl: "http://localhost:8000",
+        apiKey: "test-api-key",
+        projectId: 1,
+        mode: "interactive",
+        taskId: "test-task-id",
+        runId: "test-run-id",
+      }) as unknown as {
+        eventStreamSender: {
+          enqueue: (event: Record<string, unknown>) => void;
+          stop: () => Promise<void>;
+        };
+        posthogAPI: {
+          updateTaskRun: (
+            taskId: string,
+            runId: string,
+            payload: Record<string, unknown>,
+          ) => Promise<unknown>;
+        };
+        signalTaskComplete(
+          payload: JwtPayload,
+          stopReason: string,
+        ): Promise<void>;
+      };
+      testServer.eventStreamSender = {
+        enqueue: vi.fn(),
+        stop: vi.fn(async () => {}),
+      };
+      testServer.posthogAPI = {
+        updateTaskRun: vi.fn(async () => ({})),
+      };
+
+      await testServer.signalTaskComplete(
+        {
+          run_id: "run-1",
+          task_id: "task-1",
+          team_id: 1,
+          user_id: 1,
+          distinct_id: "distinct-id",
+          mode: "interactive",
+        },
+        "end_turn",
+      );
+
+      expect(testServer.eventStreamSender.enqueue).not.toHaveBeenCalled();
+      expect(testServer.eventStreamSender.stop).not.toHaveBeenCalled();
+      expect(testServer.posthogAPI.updateTaskRun).not.toHaveBeenCalled();
+    });
+
     it("persists structured turn completion notifications", () => {
       const appendRawLine = vi.fn();
       const testServer = new AgentServer({
diff --git a/packages/agent/src/server/agent-server.ts b/packages/agent/src/server/agent-server.ts
index 12ea84c47..dbe7ab794 100644
--- a/packages/agent/src/server/agent-server.ts
+++ b/packages/agent/src/server/agent-server.ts
@@ -54,6 +54,7 @@ import {
   normalizeCloudPromptContent,
   promptBlocksToText,
 } from "./cloud-prompt";
+import { TaskRunEventStreamSender } from "./event-stream-sender";
 import { type JwtPayload, JwtValidationError, validateJwt } from "./jwt";
 import {
   handoffLocalGitStateSchema,
@@ -217,6 +218,7 @@ export class AgentServer {
   private session: ActiveSession | null = null;
   private app: Hono;
   private posthogAPI: PostHogAPIClient;
+  private eventStreamSender: TaskRunEventStreamSender | null = null;
   private questionRelayedToSlack = false;
   private detectedPrUrl: string | null = null;
   private lastReportedBranch: string | null = null;
@@ -281,6 +283,16 @@ export class AgentServer {
       getApiKey: () => config.apiKey,
       userAgent: `posthog/cloud.hog.dev; version: ${config.version ?? packageJson.version}`,
     });
+    if (config.eventIngestToken) {
+      this.eventStreamSender = new TaskRunEventStreamSender({
+        apiUrl: config.apiUrl,
+        projectId: config.projectId,
+        taskId: config.taskId,
+        runId: config.runId,
+        token: config.eventIngestToken,
+        logger: this.logger.child("EventIngest"),
+      });
+    }
     this.app = this.createApp();
   }
 
@@ -544,7 +556,9 @@ export class AgentServer {
     this.logger.debug("Stopping agent server...");
 
     if (this.session) {
-      await this.cleanupSession();
+      await this.cleanupSession({ completeEventStream: true });
+    } else {
+      await this.eventStreamSender?.stop();
     }
 
     if (this.server) {
@@ -1772,6 +1786,12 @@ ${attributionInstructions}
 
     const status = "failed";
 
+    this.enqueueTaskTerminalEvent(POSTHOG_NOTIFICATIONS.ERROR, {
+      source: "agent_server",
+      stopReason,
+      error: errorMessage ?? "Agent error",
+    });
+
     try {
       await this.posthogAPI.updateTaskRun(payload.task_id, payload.run_id, {
         status,
@@ -1780,9 +1800,28 @@ ${attributionInstructions}
       this.logger.debug("Task completion signaled", { status, stopReason });
     } catch (error) {
       this.logger.error("Failed to signal task completion", error);
+    } finally {
+      await this.eventStreamSender?.stop();
     }
   }
 
+  private enqueueTaskTerminalEvent(
+    method:
+      | typeof POSTHOG_NOTIFICATIONS.TASK_COMPLETE
+      | typeof POSTHOG_NOTIFICATIONS.ERROR,
+    params: Record<string, unknown>,
+  ): void {
+    this.eventStreamSender?.enqueue({
+      type: "notification",
+      timestamp: new Date().toISOString(),
+      notification: {
+        jsonrpc: "2.0",
+        method,
+        params,
+      },
+    });
+  }
+
   private configureEnvironment({
     isInternal = false,
   }: {
@@ -2180,7 +2219,11 @@ ${attributionInstructions}
     }
   }
 
-  private async cleanupSession(): Promise<void> {
+  private async cleanupSession({
+    completeEventStream = false,
+  }: {
+    completeEventStream?: boolean;
+  } = {}): Promise<void> {
     if (!this.session) return;
 
     this.logger.debug("Cleaning up session");
@@ -2219,6 +2262,10 @@ ${attributionInstructions}
       this.session.sseController.close();
     }
 
+    if (completeEventStream) {
+      await this.eventStreamSender?.stop();
+    }
+
     this.pendingEvents = [];
     this.lastReportedBranch = null;
     this.session = null;
@@ -2302,9 +2349,13 @@ ${attributionInstructions}
   }
 
   private broadcastEvent(event: Record<string, unknown>): void {
+    if (!this.session) return;
+
+    this.eventStreamSender?.enqueue(event);
+
     if (this.session?.sseController) {
       this.sendSseEvent(this.session.sseController, event);
-    } else if (this.session) {
+    } else {
       // Buffer events during initialization (sseController not yet attached)
       this.pendingEvents.push(event);
     }
diff --git a/packages/agent/src/server/bin.ts b/packages/agent/src/server/bin.ts
index d72a91ba3..d22608828 100644
--- a/packages/agent/src/server/bin.ts
+++ b/packages/agent/src/server/bin.ts
@@ -32,6 +32,7 @@ const envSchema = z.object({
   POSTHOG_CODE_REASONING_EFFORT: z
     .enum(["low", "medium", "high", "xhigh", "max"])
     .optional(),
+  POSTHOG_TASK_RUN_EVENT_INGEST_TOKEN: z.string().min(1).optional(),
 });
 
 const program = new Command();
@@ -148,6 +149,7 @@ program
     const server = new AgentServer({
       port: parseInt(options.port, 10),
       jwtPublicKey: env.JWT_PUBLIC_KEY,
+      eventIngestToken: env.POSTHOG_TASK_RUN_EVENT_INGEST_TOKEN,
       repositoryPath: options.repositoryPath,
       apiUrl: env.POSTHOG_API_URL,
       apiKey: env.POSTHOG_PERSONAL_API_KEY,
diff --git a/packages/agent/src/server/types.ts b/packages/agent/src/server/types.ts
index 10cf96fc7..c982a9854 100644
--- a/packages/agent/src/server/types.ts
+++ b/packages/agent/src/server/types.ts
@@ -15,6 +15,7 @@ export interface AgentServerConfig {
   apiKey: string;
   projectId: number;
   jwtPublicKey: string; // RS256 public key for JWT verification
+  eventIngestToken?: string;
   mode: AgentMode;
   taskId: string;
   runId: string;