Research
Why Stale CLAUDE.md and AGENTS.md Files Override Working Code in 90.1% of Runs (And the One-Sentence Fix)
The Brief
- Instruction files such as CLAUDE.md and AGENTS.md are usually written once when a repository sets up a coding agent and are rarely touched again.
- A study of 441 company repositories by Denisov-Blanch et al. (2026) found that 73.8% of AI configuration files were committed once and never updated.
- The source's headline claims stale instruction files override working code in 90.1% of runs; the excerpt does not detail how that figure was measured.
Why it matters
If coding agents follow instruction files that no longer match the codebase, they may act on outdated guidance, so these files need to be maintained alongside the code.
Who’s affected
- Teams using coding agents that read CLAUDE.md or AGENTS.md
What to do
- Review CLAUDE.md and AGENTS.md when the codebase or workflow changes so agents do not follow outdated instructions.
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Instruction files like CLAUDE.md and AGENTS.md are usually written once when a repository sets up a coding agent and rarely touched again. Across 441 company repositories analyzed by Denisov-Blanch et al. (2026), 73.8% of AI configuration files were committed once and never…