Testing 7 models across Claude Code, Codex and Pi: native harness isn't always best
CShorten30 · x · 2026-09-17
An evaluation ran 7 models inside Claude Code, Codex and Pi, with three surprising findings:
- Harness choice has little effect on task success rate but can significantly affect cost.
- A simple harness can be competitive.
- The native harness isn't always the best.
With millions using coding agents, harness selection is an overlooked variable; the authors argue "harness-routing" deserves attention.
Related event: 7 Models × 3 Coding Harnesses: Harness Choice Drives Cost, Not Success(7 posts)→
More from coding & agent
- awa-video-reel: free Claude Code skill auto-edits shorts and records website B-roll — TawohAwa · 2026-11-02
- Econ PhD Job Market Database Hits 900+ Candidates, Open to Codex and Claude Code — aniketapanjwani · 2026-11-02
- Cron works by hand, fails on schedule: a 7-point debugging checklist — petrusenko_max · 2026-11-02
- Local quants vs Claude on 9 real private bugs: 3-bit costs thinking time, not score — FeydRowan · 2026-11-02
- Build products for AI, not humans: MCP lets Claude Code run everything — gefei55 · 2026-11-02
- Solo dev launches hosted MCP server with 31 tools scheduling to 20+ social networks — troyizzle · 2026-11-02