opencode-mobile/docs/analytics.md

Activation Analytics — Design Record

Design record for the PostHog-based activation-funnel analytics added to OpenCode Mobile, and how it is disclosed and consent-gated. Companion to docs/playstore.md (Data safety) and distribution/privacy-policy.md (user-facing policy). GitHub issue: #63.

Note: the same consent flag also gates a third, separate data flow not covered by this doc: delivery of user-shared diagnostic reports to our self-hosted Chatwoot support inbox (src/lib/chatwoot.ts, src/lib/diagnostics.ts, issue #85/#88). That flow is triggered manually ("Share Report"), not automatic like Sentry/PostHog. It is disclosed alongside Sentry and PostHog in every surface in the table below; see distribution/privacy-policy.md §3b for the full description.

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Goal

Answer one product question: do new users successfully connect to their opencode server and reach first value (message sent → response received)? Nothing else is tracked.

SDK and destination

Item	Value
SDK	posthog-react-native, self-instantiated (no PostHogProvider, no autocapture)
Destination	PostHog EU region — https://eu.i.posthog.com (override: EXPO_PUBLIC_POSTHOG_HOST)
API key	EXPO_PUBLIC_POSTHOG_KEY (CI secret; unset ⇒ analytics is a strict no-op)
Identity	PostHog's random app-generated anonymous ID only; no identify() calls, no user IDs
Code	src/lib/analytics.ts (wrapper), src/lib/analytics-classify.ts (error bucketing), src/lib/telemetry.ts (consent gate)

Event schema

Keep this table in 1:1 sync with AnalyticsEvent in src/lib/analytics.ts and with section 3a of distribution/privacy-policy.md.

Event	Fired when	Properties	Call site
app_opened	Once per JS session, as soon as analytics is enabled (cold start with prior consent, or immediately after consent grant)	is_first_open: boolean	app/_layout.tsx, src/lib/telemetry.ts
connection_form_submitted	User taps Connect/Save with a non-empty server URL	mode: "quick" | "advanced"	app/connection/add.tsx
connection_attempted	A real connection test starts (advanced mode: fired on save, no pre-flight check)	source: "onboarding" | "edit_test"	src/stores/connections.ts, app/connection/add.tsx
connection_succeeded	Health check responds OK	source	src/stores/connections.ts
connection_failed	Health check fails	source, error_class	src/stores/connections.ts
message_sent	User sends a prompt to an agent session (excludes slash commands)	—	src/stores/sessions.ts
response_received	Agent response finishes streaming (busy → idle), excluding user-aborted runs	—	src/stores/events.ts

error_class is one of a fixed enum — malformed-url, no-internet, server-unreachable, unauthorized, tls-error, timeout, unknown (src/lib/analytics-classify.ts). The raw error string is never sent (it can embed hostnames/IPs/tokens).

PII rule: properties are flat primitives only (AnalyticsProps). Never add server URLs, hostnames, ports, prompts, message/file content, tokens, or raw error text. Adding any new event or property requires updating the privacy policy (section 3a) and the consent modal copy in the same PR.

Consent gating

Single consent flag (opencode_telemetry_consent in expo-secure-store) gates both Sentry and PostHog — there is no separate analytics toggle. Managed by src/lib/telemetry.ts.

• Off by default. First launch shows TelemetryConsentModal (discloses crash reports AND usage analytics). No SDK is initialised before a "granted" decision.
• Grant: initSentry() + initAnalytics(); app_opened fires (once-per-session guard).
• Decline / never asked: track() is a strict no-op; the PostHog client is never created; nothing is written locally (the first-open flag is only touched post-consent).
• Revoke (Settings → Privacy → Crash Reports & Usage Analytics):
  • Sentry client closed.
  • PostHog: buffered-but-unsent events are DROPPED, not flushed. ConsentGatedPostHog overrides the SDK fetch() transport; after revocation every request short-circuits to a synthetic 200, so shutdown() drains the queue with zero bytes leaving the device. SDK optOut() is persisted first so a re-created client can't capture either.
• Re-grant mid-session: optIn() clears the persisted opt-out; the app_opened session guard prevents double-counting.

Disclosure surfaces (must stay in sync)

Surface	File
First-launch consent modal	src/components/TelemetryConsentModal.tsx
Settings toggle label/description	app/(tabs)/settings.tsx
Privacy policy (canonical md)	distribution/privacy-policy.md §3a, §3b, §4, §5
Privacy policy (store/site html)	distribution/privacy-policy.html, docs/privacy/index.html (live gh-pages)
Play Data safety draft	distribution/play-listing.md
Play ops checklist	docs/playstore.md item 7
Apple nutrition label	Apple addendum in distribution/privacy-policy.md (Usage Data → Product Interaction: Yes)

Verification checklist — TODO

Not yet verified end-to-end. Each item needs a real device/emulator run with a network sniffer or PostHog live-events view:

• TODO: Fresh install → decline consent → exercise full app flow → confirm zero requests to eu.i.posthog.com and sentry.io.
• TODO: Fresh install → allow consent → confirm app_opened arrives with is_first_open=true; second launch sends is_first_open=false.
• TODO: Onboarding quick-connect success path emits connection_form_submitted(mode=quick) → connection_attempted(source=onboarding) → connection_succeeded.
• TODO: Failure path emits connection_failed with a coarse error_class and no raw error text/hostname in the payload.
• TODO: Send message + receive response emits message_sent and response_received; aborted run emits no response_received.
• TODO: Revoke mid-session while offline (events buffered) → go online → confirm buffered events are dropped (no PostHog traffic after revoke).
• TODO: Revoke → re-grant in same session → app_opened not double-counted.
• TODO: Build without EXPO_PUBLIC_POSTHOG_KEY → analytics is a complete no-op (no init log, no network).
• TODO: Inspect one real payload of every event type in PostHog and confirm property allowlist matches the schema table above.
• TODO: Play Console Data safety form re-submitted to match distribution/play-listing.md draft before next release.