Product Analytics for Pro 2

[Sancus]

Objective

Continue Product Analytics / Metrics for Pro: ship the remaining Pro-wide telemetry so PostHog answers usage and health questions per service, with the same privacy model (hashed distinct_id, no content, gated on POSTHOG_API_KEY).

🟢 In Scope (carryover)

• Aggregate daily snapshot metrics (subscription counts, waitlist, mail provisioning) not yet instrumented or surfaced in PostHog
• Per-user activity signals (boolean flags and byte counts only)
• PostHog dashboards and alerts for new signal areas
• Instrumentation in Appointment and Send services (not started in prior milestone)

🔴 Out of Scope

• Reading or indexing email/file/calendar content
• Building custom analytics UI inside the accounts app

Technical and/or Business Requirements

• All distinct_id values must be SHA-256 hashed; no raw UUIDs or emails reach PostHog
• All collection gated behind POSTHOG_API_KEY — zero events without it
• Test accounts excluded from all counts

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Remaining proposed metrics (from milestone 1 checklist)

Pro General

Metric	Source	Cadence
Total active (paying) subscribers	Subscription model, status=active	Daily
Remaining waitlist users	AllowListEntry where user is null	Daily
Waitlist conversion rate	Converted / total AllowListEntry	Daily

Accounts / sign-up flow (PostHog)

Tracked in thunderbird-accounts#164.

Metric / signal	Source	Cadence
Sign-up and onboarding usage in Accounts	Accounts app UI / API (PostHog events)	Per-event / derived
Sign-up and auth-flow usage in Keycloak	Keycloak (events forwarded or mirrored into PostHog where applicable)	Per-event / derived

Thundermail

Metric	Source	Cadence
Quota usage per user (bytes + %)	Stalwart API usedQuota	Daily
Users at storage extremes (<1%, >90%)	Derived from quota data	Daily
Active mail accounts provisioned	Account model, active=True	Daily

Appointment

Metric	Source	Cadence
Weekly active users (page views)	Appointment service	Per-event
% of users with availability configured	Appointment service	Daily
Bookings created by clients	Appointment service	Per-event
% of users receiving bookings	Appointment service	Weekly

Send

Metric	Source	Cadence
MAU / WAU	Send service	Per-event
Median storage usage	Send service	Daily
Users at storage extremes	Send service	Daily
File downloads by recipients	Send service	Per-event
Files reported (abuse)	Send service	Per-event

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Sub-issues: thunderbird-accounts#164 (sign-up flow metrics — Accounts + Keycloak), thunderbird-accounts#802 (subscription trends in PostHog), thunderbird-accounts#815 (activity split by account status), thunderbird-accounts#816 (invite → subscriber conversion: invites sent vs subscriptions).