Argus is a VSCode extension that analyzes Claude Code sessions from the .claude directory and gives you:
- Step-by-step breakdown of what Claude did - Cost analysis (which tools burned the most tokens) - Performance insights (retry loops, duplicate reads, context pressure) - Token usage visualization (cache hits, compaction events) - Flow diagrams showing file dependencies
Extension: https://marketplace.visualstudio.com/items?itemName=argus-cl...
It's basically a "time machine debugger" for your Claude Code sessions. You can click through each step, see tool inputs/outputs, and understand exactly what went wrong (or right).
Tech stack: TypeScript, React 19, Chart.js, Vite
Some interesting findings from my own sessions: - 40% of cost was from reading the same files repeatedly - Retry loops cost ~$0.15 per loop on average - Cache hit ratio varies wildly (10% to 80%)
Limitations: - Only works with local .claude directories (not remote sessions) - Session format is undocumented, might break in future - Analysis rules are heuristic-based
GitHub: https://github.com/yessGlory17/argus
Would love feedback, especially from other Claude Code users!