The files are not available in the local file system as this is a PR evaluation. I'll proceed to evaluate the PR based on the diff provided.

PR Evaluation Report

Summary

This PR integrates PostHog analytics into a Next.js 15 App Router SaaS application. It adds both client-side (posthog-js) and server-side (posthog-node) tracking, implements a reverse proxy for ad-blocker circumvention, and captures events across authentication, subscription management, and team management flows.

Confidence score: 4/5 👍

• User identification uses email as distinct ID: Using email directly as the distinct ID can cause issues when users change their email. Consider using a stable user ID instead. [MEDIUM]
• onClick event timing issue: Several posthog.capture() calls are attached to onClick handlers on form submit buttons. These fire before form validation and before the action succeeds, potentially capturing events that fail. [MEDIUM]
• Server-side client singleton with shutdown: The posthog-server.ts creates a singleton but calls shutdown() after each request, which would invalidate the singleton pattern and could cause issues with concurrent requests. [MEDIUM]

File changes

App sanity check: 4/5 ✅

Issues

• Server-side client singleton pattern conflict: The getPostHogClient() creates a singleton, but shutdown() is called after each request in route handlers. After shutdown, the singleton reference remains but the client is invalidated. This could cause issues with concurrent requests or subsequent requests reusing a shutdown client. Consider either creating a new client per request or using a proper request-scoped pattern. [MEDIUM]

PostHog implementation: 4/5 ✅

Issues

• Inconsistent distinct ID strategy: Client-side uses email for identify(), server-side checkout uses email, but webhook handler uses Stripe customer ID. This creates fragmented user profiles in PostHog. All events should use a consistent identifier (preferably a stable internal user ID). [MEDIUM]
• onClick timing captures premature events: Events like account_updated, password_updated, team_member_invited fire on button click before the server action completes. If the action fails, the event is still captured, leading to inaccurate analytics. Consider tracking on successful action completion instead. [MEDIUM]
• Missing pageview tracking: No explicit pageview tracking setup. While capture_pageview defaults may handle this, it's not explicitly configured. [LOW]

PostHog insights and events: 4/5 ✅

Issues

• Webhook events lack user context: Subscription events use Stripe customer ID but don't link to the internal user identity used elsewhere. This breaks funnel analysis connecting checkout_started → checkout_completed → subscription_updated. [MEDIUM]
• Team member events capture PII: team_member_invited captures invited_email which may be considered PII depending on compliance requirements. [LOW]

Reviewed by wizard workbench PR evaluator