feat: migrate analytics from ClickHouse to PostHog

.env.example

@@ -10,11 +10,13 @@ DIFFBOT_API_KEY=
 UPSTASH_REDIS_REST_URL=
 UPSTASH_REDIS_REST_TOKEN=
 
-# Analytics (required)
-CLICKHOUSE_URL=http://localhost:8123
-CLICKHOUSE_USER=default
-CLICKHOUSE_PASSWORD=clickhouse
-CLICKHOUSE_DATABASE=smry_analytics
+# Analytics - PostHog (required)
+POSTHOG_API_KEY=phc_xxx
+POSTHOG_HOST=https://us.i.posthog.com
+POSTHOG_PROJECT_ID=12345
+POSTHOG_PERSONAL_API_KEY=phx_xxx
+NEXT_PUBLIC_POSTHOG_KEY=phc_xxx
+NEXT_PUBLIC_POSTHOG_HOST=https://us.i.posthog.com
 
 # Alerting
 ALERT_EMAIL=

CLAUDE.md

@@ -9,7 +9,8 @@ Article reader and summarizer with AI chat.
 - **Backend**: Elysia (Bun-native web framework)
 - **AI/LLM**: OpenRouter (Vercel AI SDK for streaming)
 - **Auth**: Clerk (billing + JWT)
-- **Database**: ClickHouse (analytics), Upstash Redis (rate limiting, chat thread storage)
+- **Analytics**: PostHog (product analytics, session recording, heatmaps, LLM analytics)
+- **Database**: Upstash Redis (rate limiting, chat thread storage)
 - **Client Storage**: IndexedDB (offline-first chat threads), localStorage (article history, preferences)
 
 ## Project Structure
@@ -27,7 +28,7 @@ types/            Zod schemas and shared types
 ## Key Commands
 
 ```bash
-bun dev           # Start dev server (Next.js + Elysia + ClickHouse)
+bun dev           # Start dev server (Next.js + Elysia)
 bun run build     # Production build
 bun run lint      # ESLint
 bun run typecheck # TypeScript check

ONBOARDING.md

@@ -11,7 +11,7 @@ Welcome to SMRY (internally "13ft") - an AI-powered article summarizer that bypa
 bun install
 
 # Start development environment
-bun run dev  # Starts ClickHouse + Elysia server + Next.js
+bun run dev  # Starts Elysia server + Next.js
 
 # Or with full Docker stack
 bun run dev:docker
@@ -58,7 +58,7 @@ SMRY fetches articles from behind paywalls using multiple extraction sources and
          │                  │                    │
          ▼                  ▼                    ▼
     ┌─────────┐       ┌──────────┐         ┌──────────┐
-    │ Diffbot │       │OpenRouter│         │ClickHouse│
+    │ Diffbot │       │OpenRouter│         │ PostHog  │
     │  (API)  │       │  (AI)    │         │(Analytics)│
     └─────────┘       └──────────┘         └──────────┘
          │
@@ -98,7 +98,7 @@ SMRY/
 │   └── validation/         # Zod schemas
 ├── types/                  # TypeScript type definitions
 ├── tests/                  # Unit and integration tests
-├── docker/                 # Docker and ClickHouse setup
+├── docker/                 # Docker setup
 ├── messages/               # i18n translation files
 └── docs/                   # Additional documentation
 ```
@@ -124,7 +124,7 @@ SMRY/
 | Elysia | Lightweight TypeScript HTTP framework |
 | Clerk | Authentication and billing |
 | Upstash Redis | Serverless caching (with zlib compression) |
-| ClickHouse | Analytics database |
+| PostHog | Product analytics, session recording, heatmaps |
 | OpenRouter | AI model access (300+ models) |
 | Diffbot | AI-powered article extraction |
 
@@ -185,11 +185,13 @@ NEXT_PUBLIC_CLERK_PUBLISHABLE_KEY=
 CLERK_SECRET_KEY=
 CLERK_WEBHOOK_SECRET=
 
-# Analytics
-CLICKHOUSE_HOST=         # ClickHouse for analytics
-CLICKHOUSE_DATABASE=
-CLICKHOUSE_USERNAME=
-CLICKHOUSE_PASSWORD=
+# Analytics (PostHog)
+POSTHOG_API_KEY=                  # Server-side PostHog key
+POSTHOG_HOST=                     # PostHog instance URL
+POSTHOG_PROJECT_ID=               # Project ID for HogQL queries
+POSTHOG_PERSONAL_API_KEY=         # Personal key for analytics dashboard
+NEXT_PUBLIC_POSTHOG_KEY=          # Client-side PostHog key
+NEXT_PUBLIC_POSTHOG_HOST=         # Client-side PostHog host
 
 # Optional
 NEXT_PUBLIC_API_URL=     # API URL for client (default: /api)
@@ -427,7 +429,6 @@ bun run pages:deploy  # Deploy to Cloudflare Pages
 - [README.md](./README.md) - Project overview and motivation
 - [DESIGN_PHILOSOPHY.md](./DESIGN_PHILOSOPHY.md) - UI/UX guidelines
 - [MIGRATION_PLAN.md](./MIGRATION_PLAN.md) - Deployment guide
-- [docs/clickhouse-schema.sql](./docs/clickhouse-schema.sql) - Analytics schema
 - [docs/MEMORY_LEAK_FIX.md](./docs/MEMORY_LEAK_FIX.md) - Performance optimizations
 
 ---

README.md

@@ -225,11 +225,13 @@ DIFFBOT_API_KEY=           # https://diffbot.com
 UPSTASH_REDIS_REST_URL=
 UPSTASH_REDIS_REST_TOKEN=
 
-# Analytics - ClickHouse (use docker-compose for local dev)
-CLICKHOUSE_URL=http://localhost:8123
-CLICKHOUSE_USER=default
-CLICKHOUSE_PASSWORD=
-CLICKHOUSE_DATABASE=smry_analytics
+# Analytics - PostHog
+POSTHOG_API_KEY=
+POSTHOG_HOST=
+POSTHOG_PROJECT_ID=
+POSTHOG_PERSONAL_API_KEY=
+NEXT_PUBLIC_POSTHOG_KEY=
+NEXT_PUBLIC_POSTHOG_HOST=
 
 # Alerting - https://resend.com
 RESEND_API_KEY=
@@ -250,7 +252,7 @@ pnpm install
 2. **Set up environment variables**:
    - Copy `.env.example` to `.env.local`
    - Get API keys from: Clerk, OpenRouter, Diffbot, Upstash, Resend
-   - Run `docker-compose up -d clickhouse` for local analytics
+   - PostHog analytics is cloud-hosted (no local setup needed)
 
 3. **Run development server**:
 ```bash

app/layout.tsx

@@ -44,6 +44,7 @@ import { ClerkProvider } from "@clerk/nextjs";
 import { Toaster } from "@/components/ui/sonner";
 import { getLocale } from 'next-intl/server';
 import { JsonLd, organizationSchema, websiteSchema } from "@/components/seo/json-ld";
+import { PostHogProvider } from "@/components/providers/posthog-provider";
 
 // Root metadata - OG images are handled by file-based convention (opengraph-image.tsx)
 // in each route segment for proper caching and to avoid robots.txt blocking issues
@@ -105,6 +106,7 @@ export default async function RootLayout({
         <body
           className={`${GeistSans.className} ${GeistSans.variable} ${syne.variable} ${literata.variable} ${atkinson.variable} ${merriweather.variable} bg-background text-foreground`}
         >
+          <PostHogProvider>
           <Databuddy
             clientId="638f8e5f-f436-4d00-a459-66dee9152e3c"
             trackPerformance
@@ -130,6 +132,7 @@ export default async function RootLayout({
               </QueryProvider>
             </NuqsAdapter>
           </ThemeProvider>
+          </PostHogProvider>
         </body>
       </html>
     </ClerkProvider>