/api-analytics-posthog-analytics

name: api-analytics-posthog-analytics
description: PostHog event tracking, user identification, group analytics for B2B, GDPR consent patterns. Use when implementing product analytics, tracking user behavior, setting up funnels, or configuring privacy-compliant tracking.

PostHog Analytics Patterns

> **Quick Guide:** Use PostHog for product analytics with structured event naming (`category:object_action`), server-side tracking for reliability, and proper user identification integrated with your authentication flow. Client-side for UI interactions, server-side for business events. Always call `reset()` on logout, never store PII in event properties, and use `captureImmediate()` or `await shutdown()` in serverless environments.

**Detailed Resources:**

• [examples/core.md](examples/core.md) - Event naming, user identification, property conventions
• [examples/client-tracking.md](examples/client-tracking.md) - React hooks, provider setup, component tracking
• [examples/server-tracking.md](examples/server-tracking.md) - posthog-node, serverless patterns, auth events
• [examples/group-analytics.md](examples/group-analytics.md) - B2B organization tracking
• [examples/privacy-gdpr.md](examples/privacy-gdpr.md) - GDPR consent, cookieless mode, PII filtering
• [reference.md](reference.md) - Decision frameworks, anti-patterns, event taxonomy

---

<critical_requirements>

CRITICAL: Before Using This Skill

**(You MUST call `posthog.identify()` ONLY when a user signs up or logs in - never on every page load)**

**(You MUST include the user's database ID as `distinct_id` in ALL server-side events)**

**(You MUST call `posthog.reset()` when a user logs out to unlink future events)**

**(You MUST use the `category:object_action` naming convention for all custom events)**

**(You MUST NEVER include PII (email, name, phone) in event properties - use user IDs only)**

</critical_requirements>

---

**Auto-detection:** PostHog, posthog-js, posthog-node, usePostHog, PostHogProvider, capture, identify, group analytics, product analytics, event tracking, funnel analysis

**When to use:**

• Tracking user behavior and product analytics
• Setting up conversion funnels and retention analysis
• Implementing group analytics for B2B multi-tenant apps
• Understanding feature adoption and user journeys
• A/B testing analysis (in conjunction with feature flags)

**When NOT to use:**

• Feature flag implementation (separate concern)
• Error tracking and logging (use dedicated error tracking tools)
• Infrastructure monitoring (use observability tools)

**Key patterns covered:**

• Event naming conventions (`category:object_action`)
• Property naming patterns (`object_adjective`, `is_`/`has_` booleans)
• User identification with authentication flow integration
• Client-side tracking with React hooks
• Server-side tracking with posthog-node
• Group analytics for B2B organizations
• Privacy and GDPR consent patterns
• TypeScript patterns for type-safe events

---

<philosophy>

Philosophy

PostHog analytics follows a **structured taxonomy** approach: consistent naming conventions, meaningful properties, and strategic placement (client vs server). Track what matters for product decisions, not everything.

**Core principles:**

1. **Server-side for business events** - User signups, purchases, subscriptions (reliable, not blocked) 2. **Client-side for UI interactions** - Button clicks, page views, form interactions 3. **Identify once per session** - Not on every page load 4. **Structured naming** - Makes querying and analysis possible at scale

</philosophy>

---

<patterns>

Core Patterns

Pattern 1: Event Naming Conventions

Use the **`category:object_action`** framework for consistent, queryable event names.

// category: Context (signup_flow, settings, dashboard)
// object: Component/location (password_button, pricing_page)
// action: Present-tense verb (click, submit, view)

"signup_flow:email_form_submit";
"dashboard:project_create";
"settings:billing_plan_upgrade";

// Simpler alternative: object_verb
"project_created";
"user_signed_up";

**Why good:** Category prefix groups related events in PostHog UI, enables wildcard queries like `signup_flow:*`, consistent naming makes analysis possible at scale.

**Property naming rules:**

• `object_adjective`: `project_id`, `plan_name`, `item_count`
• `is_` / `has_` for booleans: `is_first_purchase`, `has_completed_onboarding`
• `_date` / `_timestamp` suffix: `trial_end_date`, `last_login_timestamp`

See [examples/core.md](examples/core.md) for complete naming examples.

---

Pattern 2: User Identification with Authentication

Call `identify()` only on auth state change (not every render). Use database user ID as `distinct_id`. Call `reset()` on logout.

// Check _isIdentified() to prevent duplicate calls
useEffect(() => {
  if (session?.user && !posthog._isIdentified()) {
    posthog.identify(session.user.id, {
      plan: session.user.plan ?? "free",
      created_at: session.user.createdAt,
      is_verified: session.user.emailVerified ?? false,
    });
  }
}, [session?.user]);

// Always reset on logout
posthog?.capture("user_logged_out");
posthog?.reset(); // Unlink future events from this user

See [examples/core.md](examples/core.md) for full identification hook and logout handler.

---

Pattern 3: Server-Side Tracking

Track business events reliably from your backend with posthog-node.

// Serverless: use captureImmediate (guarantees HTTP completion)
await posthogServer.captureImmediate({
  distinctId: user.id,
  event: "subscription_created",
  properties: { plan: "pro", is_annual: true },
});

// Always call shutdown before returning in serverless
await posthogServer.shutdown();

**Key rules:**

1. Always include `distinctId` (user's database ID) 2. Use `captureImmediate()` for serverless (guarantees HTTP completion) 3. Always call `shutdown()` before returning in