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PostHog Funnel Analytics

Goal

Track core funnel behavior reliably in PostHog:

  1. page view
  2. signup/auth
  3. project create
  4. checkout start / success / fail

Configuration

Required env vars:

  • POSTHOG_API_KEY — PostHog project API key (phc_...) for capture
  • POSTHOG_HOST — ingest host (https://us.i.posthog.com or https://eu.i.posthog.com)

Djass wires both frontend and backend capture through these settings. No PostHog secret is hardcoded in source.

Event mapping

Funnel Step Event Name Where Emitted Key Properties
Page view $pageview PostHog JS snippet (capture_pageview: true) in base_landing.html / base_app.html standard PostHog page properties
Signup user_signed_up apps/pages/views.py (SignupTrackingMixin._track_signup) signup_method, funnel_step=signup_completed
Auth/login user_authenticated apps/core/signals.py (track_user_login) auth_method, funnel_step=auth_completed, entrypoint=ui
Auth failure user_auth_failed apps/core/signals.py (track_user_login_failed), apps/api/views.py (create_project_v1 insufficient scope) reason, auth_method (UI only), required_scope (API scope fail), funnel_step=auth_failed, entrypoint
Project create project_created apps/core/views.py (create_project), apps/api/views.py (create_project_v1) project_id, project_name, project_slug, funnel_step=project_created, entrypoint
Project create fail project_create_failed apps/core/views.py (subscription/validation), apps/api/views.py (subscription, quota, slug, queue/internal failures) reason, optional validation_fields, optional error_type, funnel_step=project_create_failed, entrypoint
Checkout start checkout_started apps/core/views.py (create_checkout_session) plan, price_id, checkout_id, funnel_step=checkout_started, entrypoint=ui
Checkout success checkout_succeeded apps/core/stripe_webhooks.py (handle_checkout_completed) checkout_id, payment_intent, amount, currency, price_id, plan, funnel_step=checkout_succeeded, entrypoint=api, stripe_event_id
Checkout fail checkout_failed apps/pages/views.py (canceled/failed return), apps/core/views.py (Stripe setup/session exceptions), apps/core/stripe_webhooks.py (unpaid webhook) reason, optional error_type, plan, funnel_step=checkout_failed, entrypoint, optional stripe_event_id

Verification checklist

  1. Start app with valid POSTHOG_API_KEY + POSTHOG_HOST.
  2. Complete one test funnel flow in local or staging:
  3. open landing/home (page view)
  4. sign up or log in
  5. create a project
  6. start checkout (and either cancel or complete with Stripe test card)
  7. In PostHog UI, filter recent events by your test user distinct_id and confirm all expected event names appear.
  8. Confirm checkout success is only emitted on Stripe webhook checkout.session.completed with paid status.

Local validation evidence (automated)

Run targeted tests:

pytest apps/pages/tests.py apps/core/tests/test_checkout_session.py apps/core/tests/test_projects.py apps/core/tests/test_stripe_webhooks.py apps/core/tests/test_signals.py apps/api/test_spec_001_contract.py

These tests assert event names/properties for signup, auth success/failure, project creation success/failure (UI + API), checkout start, checkout success, and checkout failure paths.

Known gaps

  • API requests that fail before principal resolution (missing/invalid API key) cannot be attributed to a user profile_id, so they are audited in ProjectAPIAuditLog but are not emitted as PostHog user events.

Verification evidence (2026-03-11)

PostHog project djass (id=339080) was validated via API by emitting test funnel events and then reading event definitions.

Observed last_seen_at values:

  • user_signed_up — 2026-03-11T14:17:31.782029Z
  • user_authenticated — 2026-03-11T14:17:34.027492Z
  • project_created — 2026-03-11T14:17:31.782029Z
  • checkout_started — 2026-03-11T14:17:32.933335Z
  • checkout_failed — 2026-03-11T14:17:30.706677Z
  • checkout_succeeded — 2026-03-11T14:17:34.457525Z