diff --git a/cli/src/commands/onboard.ts b/cli/src/commands/onboard.ts
index cd7b6fe88b..c6bc08c899 100644
--- a/cli/src/commands/onboard.ts
+++ b/cli/src/commands/onboard.ts
@@ -359,7 +359,7 @@ export async function onboard(opts: OnboardOptions): Promise<void> {
   }
 
   const tc = getTelemetryClient();
-  if (tc) trackInstallStarted(tc, { setupMode });
+  if (tc) trackInstallStarted(tc);
 
   let llm: PaperclipConfig["llm"] | undefined;
   const { defaults: derivedDefaults, usedEnvKeys, ignoredEnvKeys } = quickstartDefaultsFromEnv();
@@ -510,9 +510,7 @@ export async function onboard(opts: OnboardOptions): Promise<void> {
   writeConfig(config, opts.config);
 
   if (tc) trackInstallCompleted(tc, {
-    setupMode,
-    dbMode: database.mode,
-    deploymentMode: server.deploymentMode,
+    adapterType: server.deploymentMode,
   });
 
   p.note(
diff --git a/packages/shared/src/telemetry/client.ts b/packages/shared/src/telemetry/client.ts
index e4503c4fde..939a32ed05 100644
--- a/packages/shared/src/telemetry/client.ts
+++ b/packages/shared/src/telemetry/client.ts
@@ -1,8 +1,7 @@
-import os from "node:os";
 import { createHash } from "node:crypto";
 import type {
   TelemetryConfig,
-  TelemetryEventEnvelope,
+  TelemetryEvent,
   TelemetryEventName,
   TelemetryState,
 } from "./types.js";
@@ -12,11 +11,10 @@ const BATCH_SIZE = 50;
 const SEND_TIMEOUT_MS = 5_000;
 
 export class TelemetryClient {
-  private queue: TelemetryEventEnvelope[] = [];
+  private queue: TelemetryEvent[] = [];
   private readonly config: TelemetryConfig;
   private readonly stateFactory: () => TelemetryState;
   private readonly version: string;
-  private readonly sessionId: string;
   private state: TelemetryState | null = null;
   private flushInterval: ReturnType<typeof setInterval> | null = null;
 
@@ -24,22 +22,16 @@ export class TelemetryClient {
     this.config = config;
     this.stateFactory = stateFactory;
     this.version = version;
-    this.sessionId = `${Date.now()}-${Math.random().toString(36).slice(2, 8)}`;
   }
 
   track(eventName: TelemetryEventName, dimensions?: Record<string, string | number | boolean>): void {
     if (!this.config.enabled) return;
-    const state = this.getState();
+    this.getState(); // ensure state is initialised (side-effect: creates state file on first call)
 
     this.queue.push({
-      installId: state.installId,
-      sessionId: this.sessionId,
-      event: eventName,
+      name: eventName,
+      occurredAt: new Date().toISOString(),
       dimensions: dimensions ?? {},
-      timestamp: new Date().toISOString(),
-      version: this.version,
-      os: os.platform(),
-      arch: os.arch(),
     });
 
     if (this.queue.length >= BATCH_SIZE) {
@@ -51,7 +43,10 @@ export class TelemetryClient {
     if (!this.config.enabled || this.queue.length === 0) return;
 
     const events = this.queue.splice(0);
+    const state = this.getState();
     const endpoint = this.config.endpoint ?? DEFAULT_ENDPOINT;
+    const app = this.config.app ?? "paperclip";
+    const schemaVersion = this.config.schemaVersion ?? "1";
 
     const controller = new AbortController();
     const timer = setTimeout(() => controller.abort(), SEND_TIMEOUT_MS);
@@ -59,7 +54,12 @@ export class TelemetryClient {
       await fetch(endpoint, {
         method: "POST",
         headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({ events }),
+        body: JSON.stringify({
+          app,
+          schemaVersion,
+          installId: state.installId,
+          events,
+        }),
         signal: controller.signal,
       });
     } catch {
diff --git a/packages/shared/src/telemetry/events.ts b/packages/shared/src/telemetry/events.ts
index f44f7908a5..1ed96bb6a6 100644
--- a/packages/shared/src/telemetry/events.ts
+++ b/packages/shared/src/telemetry/events.ts
@@ -1,14 +1,14 @@
 import type { TelemetryClient } from "./client.js";
 
-export function trackInstallStarted(client: TelemetryClient, dims: { setupMode: string }): void {
-  client.track("install.started", dims);
+export function trackInstallStarted(client: TelemetryClient): void {
+  client.track("install.started");
 }
 
 export function trackInstallCompleted(
   client: TelemetryClient,
-  dims: { setupMode: string; dbMode: string; deploymentMode: string },
+  dims: { adapterType: string },
 ): void {
-  client.track("install.completed", dims);
+  client.track("install.completed", { adapter_type: dims.adapterType });
 }
 
 export function trackCompanyImported(
@@ -17,33 +17,29 @@ export function trackCompanyImported(
 ): void {
   const ref = dims.isPrivate ? client.hashPrivateRef(dims.sourceRef) : dims.sourceRef;
   client.track("company.imported", {
-    sourceType: dims.sourceType,
-    sourceRef: ref,
-    sourceRefHashed: dims.isPrivate,
+    source_type: dims.sourceType,
+    source_ref: ref,
+    source_ref_hashed: dims.isPrivate,
   });
 }
 
 export function trackAgentFirstHeartbeat(
   client: TelemetryClient,
-  dims: { adapterType: string },
+  dims: { agentRole: string },
 ): void {
-  client.track("agent.first_heartbeat", dims);
+  client.track("agent.first_heartbeat", { agent_role: dims.agentRole });
 }
 
 export function trackAgentTaskCompleted(
   client: TelemetryClient,
-  dims: { adapterType: string },
+  dims: { agentRole: string },
 ): void {
-  client.track("agent.task_completed", dims);
+  client.track("agent.task_completed", { agent_role: dims.agentRole });
 }
 
 export function trackErrorHandlerCrash(
   client: TelemetryClient,
-  dims: { errorName: string; route: string; method: string },
+  dims: { errorCode: string },
 ): void {
-  client.track("error.handler_crash", {
-    errorName: dims.errorName,
-    route: dims.route,
-    method: dims.method,
-  });
+  client.track("error.handler_crash", { error_code: dims.errorCode });
 }
diff --git a/packages/shared/src/telemetry/index.ts b/packages/shared/src/telemetry/index.ts
index 520a56af90..1757276ec4 100644
--- a/packages/shared/src/telemetry/index.ts
+++ b/packages/shared/src/telemetry/index.ts
@@ -12,6 +12,7 @@ export {
 export type {
   TelemetryConfig,
   TelemetryState,
+  TelemetryEvent,
   TelemetryEventEnvelope,
   TelemetryEventName,
 } from "./types.js";
diff --git a/packages/shared/src/telemetry/types.ts b/packages/shared/src/telemetry/types.ts
index f5df091495..cb0fed735f 100644
--- a/packages/shared/src/telemetry/types.ts
+++ b/packages/shared/src/telemetry/types.ts
@@ -8,17 +8,23 @@ export interface TelemetryState {
 export interface TelemetryConfig {
   enabled: boolean;
   endpoint?: string;
+  app?: string;
+  schemaVersion?: string;
 }
 
-export interface TelemetryEventEnvelope {
-  installId: string;
-  sessionId: string;
-  event: string;
+/** Per-event object inside the backend envelope */
+export interface TelemetryEvent {
+  name: string;
+  occurredAt: string;
   dimensions: Record<string, string | number | boolean>;
-  timestamp: string;
-  version: string;
-  os: string;
-  arch: string;
+}
+
+/** Full payload sent to the backend ingest endpoint */
+export interface TelemetryEventEnvelope {
+  app: string;
+  schemaVersion: string;
+  installId: string;
+  events: TelemetryEvent[];
 }
 
 export type TelemetryEventName =
diff --git a/server/src/__tests__/issue-telemetry-routes.test.ts b/server/src/__tests__/issue-telemetry-routes.test.ts
index 9e6b5fb6dd..ff51f722de 100644
--- a/server/src/__tests__/issue-telemetry-routes.test.ts
+++ b/server/src/__tests__/issue-telemetry-routes.test.ts
@@ -100,7 +100,7 @@ describe("issue telemetry routes", () => {
 
     expect(res.status).toBe(200);
     expect(mockTrackAgentTaskCompleted).toHaveBeenCalledWith(expect.anything(), {
-      adapterType: "codex_local",
+      agentRole: "codex_local",
     });
   });
 
diff --git a/server/src/middleware/error-handler.ts b/server/src/middleware/error-handler.ts
index d68789ef31..032b5e1f19 100644
--- a/server/src/middleware/error-handler.ts
+++ b/server/src/middleware/error-handler.ts
@@ -47,7 +47,7 @@ export function errorHandler(
         err,
       );
       const tc = getTelemetryClient();
-      if (tc) trackErrorHandlerCrash(tc, { errorName: err.name, route: req.route?.path ?? req.path, method: req.method });
+      if (tc) trackErrorHandlerCrash(tc, { errorCode: err.name });
     }
     res.status(err.status).json({
       error: err.message,
@@ -72,7 +72,7 @@ export function errorHandler(
   );
 
   const tc = getTelemetryClient();
-  if (tc) trackErrorHandlerCrash(tc, { errorName: rootError.name, route: req.route?.path ?? req.path, method: req.method });
+  if (tc) trackErrorHandlerCrash(tc, { errorCode: rootError.name });
 
   res.status(500).json({ error: "Internal server error" });
 }
diff --git a/server/src/routes/issues.ts b/server/src/routes/issues.ts
index 7c031c8b13..e815f8aec3 100644
--- a/server/src/routes/issues.ts
+++ b/server/src/routes/issues.ts
@@ -1184,7 +1184,7 @@ export function issueRoutes(db: Db, storage: StorageService) {
       if (tc && actor.agentId) {
         const actorAgent = await agentsSvc.getById(actor.agentId);
         if (actorAgent) {
-          trackAgentTaskCompleted(tc, { adapterType: actorAgent.adapterType });
+          trackAgentTaskCompleted(tc, { agentRole: actorAgent.adapterType });
         }
       }
     }
diff --git a/server/src/services/heartbeat.ts b/server/src/services/heartbeat.ts
index e64c216c9f..507bf66396 100644
--- a/server/src/services/heartbeat.ts
+++ b/server/src/services/heartbeat.ts
@@ -1832,7 +1832,7 @@ export function heartbeatService(db: Db) {
 
     if (isFirstHeartbeat && updated) {
       const tc = getTelemetryClient();
-      if (tc) trackAgentFirstHeartbeat(tc, { adapterType: updated.adapterType });
+      if (tc) trackAgentFirstHeartbeat(tc, { agentRole: updated.adapterType });
     }
 
     if (updated) {