Gasoline v4.0.0 Released
What’s New in v4.0.0
Section titled “What’s New in v4.0.0”Gasoline v4.0.0 is the refinement phase. The core architecture from v3 works well—this version focuses on making it robust and adding missing developer-focused features.
Major Features
Section titled “Major Features”- User Action Recording — Record clicks, typing, navigation with smart selectors
- Web Vitals Capture — LCP, CLS, INP, FCP tracking
- API Schema Inference — Auto-detect OpenAPI patterns from network traffic
- Error Aggregation — Group and deduplicate similar errors
- Session Checkpoints — Save browser state, diff changes, detect regressions
Performance
Section titled “Performance”- Optimized ring buffers — 2000-event cap prevents unbounded memory growth
- Efficient filtering — Skip irrelevant logs (ads, tracking, etc.)
- Smart deduplication — Collapse repeated identical events
- Rate limiting — Respect browser and extension quotas
Developer Experience
Section titled “Developer Experience”- Better error messages — Clear explanations of what went wrong and why
- Command-line flags —
--port,--server,--api-keyfor flexibility - Health check endpoint —
/healthfor verifying setup - Example integration — Claude Code, Cursor, Copilot configs included
Stability
Section titled “Stability”- Comprehensive testing — 80+ unit and integration tests
- Error recovery — Graceful handling of extension crashes/restarts
- Logging improvements — Debug mode for troubleshooting
- TypeScript strict mode — Zero implicit any
Known Limitations
Section titled “Known Limitations”- Recording still in alpha (no video yet)
- No Safari/Firefox support (MV3 requirement)
- Replay system not yet implemented
- Limited to Chrome 120+
Status: This version proved the concept could handle real-world usage. Ready for broader testing.
Next: Production-grade recording system, broader browser support research, performance benchmarking.
See [GitHub](https://github.com/brennhill/gasoline-agentic-browser-devtools-mcp for source.