btcdata/CLAUDE.md

btcdata

Bitcoin data backend — Clojure Kit application. Fetches BTC prices from Binance WebSocket and Kraken HTTP, stores in PostgreSQL, exposes a JSON API with SSE price stream.

Build & Development Commands

• make run — Start dev server on port 4100
• make repl — Start nREPL
• make test — Run tests
• make uberjar — Build production JAR
• docker compose up -d — Start btcdata container

Docker

Docker runs alongside local dev on different ports and databases:

	Local dev	Docker
Port	localhost:4100	localhost:4101
Database	btcprice	btcprod

REPL Commands

(dev-prep!)   ;; Prepare dev system
(go)          ;; Start system
(reset)       ;; Reload code & restart
(halt)        ;; Stop system
(reset-db)    ;; Drop & re-migrate database
(migrate)     ;; Run pending migrations
(rollback)    ;; Rollback last migration
(query-fn)    ;; Get database query function

Architecture

• Framework: Kit (Integrant-based)
• Server: Undertow
• Routing: Reitit
• Database: PostgreSQL + conman + Migratus
• Port: 4100 (env: BTCDATA_PORT)
• CORS: Configured via CORS_ORIGIN env var

API Endpoints

• GET /api/health — Health check
• GET /api/price/stream — SSE stream with JSON price updates
• GET /api/price/latest — Latest price as JSON

Source Layout

src/clj/pmagnus/btcdata/
├── core.clj              # App entry point
├── config.clj            # System config loader
├── ws/
│   └── binance.clj       # Binance WebSocket client
├── kraken/
│   ├── ohlc.clj          # Hourly OHLC poller
│   └── ohlc_daily.clj    # Daily OHLC poller
└── web/
    ├── handler.clj       # Ring handler + routes
    ├── controllers/
    │   └── health.clj    # Health check
    ├── middleware/
    │   ├── core.clj      # Base middleware + CORS
    │   ├── exception.clj # Exception handling
    │   └── formats.clj   # Content negotiation
    └── routes/
        ├── api.clj       # /api routes (JSON + SSE)
        └── utils.clj     # Route utilities