CodeBurn is a local-first, cross-platform observability and cost management tool for AI coding assistants. It reads session logs from 40+ AI tools (Claude Code, Cursor, Copilot, Codex, Gemini, etc.) directly from the user's local disk, parses them, and attributes costs using a bundled pricing engine with fallbacks. The architecture is a modular monolith with a core TypeScript CLI engine and multiple platform-specific frontends (Electron desktop, Swift macOS menubar, Tauri Windows/Linux tray, VS Code extension, MCP server, and GNOME extension). The codebase demonstrates exceptional engineering discipline. It features a sophisticated versioned cache with cross-process locks and progressive hydration, a clean provider adapter pattern for ingesting heterogeneous data sources, and a robust quota monitoring system with strict error handling and credential safety. The test suite is extensive, covering parser edge cases, cache correctness, and cross-platform parity. The project is actively maintained with frequent releases and a large community (11k+ stars). The primary risk is the volatility of the external AI tool APIs it depends on for quota tracking and log formats, but the code is structured to handle this through its adapter pattern and comprehensive testing. It requires Node.js 22.13+.