feat(telemetry): person profiles on lifecycle events to unlock retention/cohort analytics

PostHog cannot compute retention, stickiness, lifecycle, or cohort
insights on profile-less events — exactly the charts growth reporting
needs. Lifecycle events (install_*, uninstall_completed, worker_started;
~1-2/day/install) now build a person profile keyed to the anonymous
install UUID with $set restricted to whitelisted enums. High-volume
operational events stay $process_person_profile:false for cost.

Adds plans/2026-06-09-telemetry-metrics-spec.md mapping every event to
the growth/retention/activation/reliability metric it powers.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

docs/public/telemetry.mdx

@@ -17,7 +17,9 @@ The standard [`DO_NOT_TRACK`](https://consoledonottrack.com) environment variabl
 
 ## What is collected
 
-When enabled, events are anonymous and identified only by a random install UUID (`crypto.randomUUID()`, generated locally on first use). Events are sent with `$process_person_profile: false`, so PostHog never builds a person profile.
+When enabled, events are anonymous and identified only by a random install UUID (`crypto.randomUUID()`, generated locally on first use).
+
+Low-volume lifecycle events (`install_*`, `uninstall_completed`, `worker_started`) build an analytics profile keyed to that random UUID so aggregate retention and cohort statistics are computable — the profile contains nothing beyond the whitelisted fields below (platform, version, IDE/provider choice). It is not, and cannot be, connected to you: there is no name, email, IP, hardware ID, or any other identifier. All high-volume events (`session_compressed`, `search_performed`, `context_injected`, `error_occurred`) are sent with `$process_person_profile: false` and build no profile at all.
 
 Every event property passes through a strict whitelist scrubber — any key not in this table is silently dropped before sending:
 

plans/2026-06-09-telemetry-metrics-spec.md

@@ -0,0 +1,89 @@
+# Telemetry Metrics Spec — the story the data must tell
+
+Audience: us, when building the PostHog dashboard and the fundraise narrative.
+Premise: 82k GitHub stars, zero analytics history. The dataset starts the day
+this ships, so every chart below is designed to be meaningful within 4–8 weeks
+of data and to compound from there.
+
+## The narrative arc (what a deck slide needs to say)
+
+1. **Reach** — "X installs/week and growing N% w/w, across 12 IDEs."
+2. **Habit** — "Installs come back: D30 retention X%, DAU/MAU X%."
+3. **Value loop** — "Memory isn't shelfware: X% of installs reach the aha
+   moment, and active installs read memory back X times/day."
+4. **Reliability** — "Core pipeline succeeds X% of the time at scale."
+
+Everything below maps an event to one of those four sentences. If a metric
+doesn't feed a sentence, it doesn't go on the dashboard.
+
+## Unit of measure — be precise with VCs
+
+The `distinct_id` is an **install** (one machine + one `~/.claude-mem`), not a
+human. Quote "active installs", never "users". This is the honest dev-tool
+convention (Homebrew, VS Code extensions count the same way) and diligence
+will check. Reinstalls keep the same ID (uninstall preserves the data dir), so
+returning installs are not double-counted.
+
+Always filter `is_ci = false` on every insight. CI noise inflates everything.
+
+## Event → metric map
+
+### Reach (growth accounting)
+| Metric | Definition |
+|---|---|
+| New installs/week | unique `distinct_id` on `install_completed` where `is_update = false` |
+| Upgrade adoption | `install_completed` where `is_update = true`, broken down by `version` |
+| Active installs (WAU/MAU) | unique `distinct_id` on `worker_started` (start + daily heartbeat = presence signal) |
+| Churn | `uninstall_completed` count; net growth = new − uninstalls |
+| Surface mix | `install_completed` breakdown by `ide`, `provider`, `runtime_mode` |
+
+### Habit (retention — the slide that raises the round)
+| Metric | Definition |
+|---|---|
+| D1/D7/D30 retention | PostHog Retention insight: first `install_completed` → returning on `worker_started`. Requires person profiles — that's why lifecycle events set them. |
+| Stickiness (DAU/MAU) | PostHog Stickiness insight on `worker_started` |
+| Lifecycle | PostHog Lifecycle insight on `worker_started` (new / returning / resurrecting / dormant) |
+| Retention by segment | same retention insight broken down by person property `ide` or `provider` — "Cursor installs retain 2×" is a fundable sentence |
+
+### Value loop (activation + engagement)
+| Metric | Definition |
+|---|---|
+| Activation funnel | Funnel: `install_completed` → first `session_compressed` → first `context_injected`. The third step is the aha moment: stored memory actually used. |
+| Time-to-value | median time from `install_completed` to first `context_injected` |
+| Engagement depth | `session_compressed` count per active install per day; `context_injected` per active install per day |
+| Read/write ratio | `context_injected` ÷ `session_compressed` — memory being consumed, not hoarded |
+| Feature adoption | `search_performed` breakdown by `endpoint` |
+
+### Reliability (diligence armor)
+| Metric | Definition |
+|---|---|
+| Compression success rate | `session_compressed` outcome ok ÷ all, by `version` and `provider` |
+| Error rate | `error_occurred` per active install, by `error_category` and `version` |
+| Latency health | p50/p95 `duration_ms` on `session_compressed`, `search_performed`, `context_injected` |
+| Install success rate | `install_completed` ÷ (`install_completed` + `install_failed`), failures by `error_category` |
+
+## Person-profile design (cost control)
+
+Only lifecycle events (`install_*`, `uninstall_completed`, `worker_started`)
+carry person profiles — ~1–2 events/day/install, so profile-priced ingestion
+stays bounded even at 100k installs. High-volume operational events are
+profile-less (cheaper tier). Person properties are the whitelisted enums only:
+`version`, `os`, `arch`, `runtime`, `locale`, `ide`, `provider`, `runtime_mode`.
+
+## Caveats to state proactively in diligence
+
+- Telemetry is opt-out (`DO_NOT_TRACK` honored, one-command disable); numbers
+  undercount by the opt-out rate. That's the credible direction to undercount.
+- Data starts <date this ships>; star history is the pre-telemetry proxy.
+- One human can be several installs (work + home). Quote installs.
+
+## Dashboard build order (PostHog UI, ~30 min)
+
+1. Trends: weekly unique `worker_started` (active installs) + weekly
+   `install_completed` where `is_update=false` (new installs).
+2. Retention: `install_completed` → `worker_started`, weekly, breakdown `ide`.
+3. Funnel: `install_completed` → `session_compressed` → `context_injected`,
+   14-day window.
+4. Stickiness + Lifecycle on `worker_started`.
+5. Trends: `session_compressed` outcome error ÷ total (reliability), p95
+   `duration_ms` (latency).

src/npx-cli/commands/install.ts

@@ -1374,7 +1374,7 @@ export async function runInstallCommand(options: InstallOptions = {}): Promise<v
   } catch (error: unknown) {
     if (error instanceof InstallAbortError) {
       // error.category.id is OUR taxonomy id (error-taxonomy.ts), never a message.
-      await captureCliEvent('install_failed', { error_category: error.category.id });
+      await captureCliEvent('install_failed', { error_category: error.category.id }, { person: true });
       // Flush whatever warnings accrued before the abort, then print the
       // remediation headline and exit non-zero. ABORT must never reach the
       // "Installation Complete" path.
@@ -1816,7 +1816,7 @@ async function runInstallCommandInner(options: InstallOptions, summary: InstallS
     is_update: alreadyInstalled,
     outcome: failedIDEs.length > 0 ? 'partial' : 'ok',
     duration_ms: Date.now() - installStartedAt,
-  });
+  }, { person: true });
 }
 
 export async function runRepairCommand(): Promise<void> {

src/npx-cli/commands/uninstall.ts

@@ -400,7 +400,7 @@ export async function runUninstallCommand(): Promise<void> {
 
   // Capture BEFORE the data dir note becomes stale advice: consent and the
   // install ID still live in ~/.claude-mem, which uninstall preserves.
-  await captureCliEvent('uninstall_completed');
+  await captureCliEvent('uninstall_completed', {}, { person: true });
 
   p.outro(pc.green('claude-mem has been uninstalled.'));
 }

src/services/telemetry/cli-telemetry.ts

@@ -10,7 +10,7 @@
 
 import { resolveTelemetryConsent, loadTelemetryConfig, getOrCreateInstallId } from './consent.js';
 import { scrubProperties } from './scrub.js';
-import { getTelemetryApiKey, getTelemetryHost, buildBaseProperties } from './common.js';
+import { getTelemetryApiKey, getTelemetryHost, buildBaseProperties, buildPersonSet } from './common.js';
 
 const CAPTURE_TIMEOUT_MS = 2000;
 
@@ -21,7 +21,8 @@ const CAPTURE_TIMEOUT_MS = 2000;
  */
 export async function captureCliEvent(
   event: string,
-  props?: Record<string, unknown>
+  props?: Record<string, unknown>,
+  opts?: { person?: boolean }
 ): Promise<void> {
   try {
     if (!resolveTelemetryConsent(process.env, loadTelemetryConfig())) {
@@ -32,7 +33,13 @@ export async function captureCliEvent(
       ...buildBaseProperties(),
       ...(props ?? {}),
     });
-    properties.$process_person_profile = false;
+    // Lifecycle events (install_* / uninstall) build the anonymous person
+    // profile that powers retention and cohort insights; see telemetry.ts.
+    if (opts?.person) {
+      properties.$set = buildPersonSet(properties);
+    } else {
+      properties.$process_person_profile = false;
+    }
 
     if (process.env.CLAUDE_MEM_TELEMETRY_DEBUG === '1') {
       process.stderr.write('[telemetry] ' + JSON.stringify({ event, properties }) + '\n');

src/services/telemetry/common.ts

@@ -25,6 +25,39 @@ export function getTelemetryHost(): string {
   return process.env.CLAUDE_MEM_TELEMETRY_HOST || DEFAULT_TELEMETRY_HOST;
 }
 
+/**
+ * Whitelisted properties that may also be set as PostHog person properties on
+ * lifecycle events (install_*, worker_started). The "person" is the anonymous
+ * install UUID — these traits make retention/cohort insights sliceable by
+ * platform and product choices. Strict subset of the scrub whitelist.
+ */
+export const PERSON_PROPERTY_KEYS = [
+  'version',
+  'os',
+  'arch',
+  'runtime',
+  'locale',
+  'ide',
+  'provider',
+  'runtime_mode',
+] as const;
+
+/**
+ * Splits already-scrubbed properties into a $set object for person-profile
+ * events. Lifecycle events are low-volume (~1-2/day/install), so the
+ * person-profile ingestion cost is bounded while unlocking PostHog's native
+ * retention, stickiness, lifecycle, and cohort insights.
+ */
+export function buildPersonSet(
+  scrubbed: Record<string, unknown>
+): Record<string, unknown> {
+  const set: Record<string, unknown> = {};
+  for (const key of PERSON_PROPERTY_KEYS) {
+    if (scrubbed[key] !== undefined) set[key] = scrubbed[key];
+  }
+  return set;
+}
+
 export function buildBaseProperties(): Record<string, unknown> {
   return {
     version: packageVersion,

src/services/telemetry/telemetry.ts

@@ -5,7 +5,7 @@ import {
   getOrCreateInstallId,
 } from './consent.js';
 import { scrubProperties } from './scrub.js';
-import { getTelemetryApiKey, getTelemetryHost, buildBaseProperties } from './common.js';
+import { getTelemetryApiKey, getTelemetryHost, buildBaseProperties, buildPersonSet } from './common.js';
 
 let client: PostHog | null = null;
 let isShutdown = false;
@@ -51,8 +51,20 @@ function getClient(): PostHog {
  *   4. No API key configured — no-op (telemetry ships dark until the
  *      publishable token lands).
  *   5. posthog.capture() — SDK queues in memory and batches in background.
+ *
+ * Two event classes (opts.person):
+ *   - Lifecycle events (worker_started, install_*) pass person: true. They are
+ *     low-volume and build an anonymous person profile keyed to the random
+ *     install UUID, which is what makes PostHog's retention / stickiness /
+ *     lifecycle / cohort insights work. Person properties are restricted to
+ *     PERSON_PROPERTY_KEYS — the same whitelisted enums as event properties.
+ *   - Everything else (high-volume operational events) stays profile-less.
  */
-export function captureEvent(event: string, props?: Record<string, unknown>): void {
+export function captureEvent(
+  event: string,
+  props?: Record<string, unknown>,
+  opts?: { person?: boolean }
+): void {
   try {
     // Once shutdown has flushed the client, late events (e.g. a request that
     // raced graceful stop) are dropped rather than queued in a new client
@@ -65,9 +77,13 @@ export function captureEvent(event: string, props?: Record<string, unknown>): vo
       ...buildBaseProperties(),
       ...(props ?? {}),
     });
-    // Anonymous events: no person profile processing. Added AFTER scrubbing —
-    // $-prefixed PostHog directives are not user data and bypass the whitelist.
-    properties.$process_person_profile = false;
+    // $-prefixed PostHog directives are not user data and bypass the whitelist;
+    // they are added AFTER scrubbing.
+    if (opts?.person) {
+      properties.$set = buildPersonSet(properties);
+    } else {
+      properties.$process_person_profile = false;
+    }
 
     if (process.env.CLAUDE_MEM_TELEMETRY_DEBUG === '1') {
       // Direct stderr write (not console.*): debug mode is a human running the

src/services/worker-service.ts

@@ -298,13 +298,13 @@ export class WorkerService implements WorkerRef {
     captureEvent('worker_started', {
       trigger: 'start',
       duration_ms: Date.now() - this.startTime,
-    });
+    }, { person: true });
 
     // Long-lived workers would otherwise look like a single day of activity.
     // A daily heartbeat makes DAU/WAU/retention computable from distinct_id.
     // unref() so the timer never keeps a stopping process alive.
     this.telemetryHeartbeat = setInterval(() => {
-      captureEvent('worker_started', { trigger: 'heartbeat' });
+      captureEvent('worker_started', { trigger: 'heartbeat' }, { person: true });
     }, 24 * 60 * 60 * 1000);
     this.telemetryHeartbeat.unref?.();