Anthropic admits to August 2025 Claude quality regression
After weeks of community complaints about Claude Code ignoring CLAUDE.md guidelines, Anthropic acknowledged a quality regression in August 2025.
What changed
before— removed
Claude reliably honored CLAUDE.md rules
after+ current
Claude began ignoring or violating CLAUDE.md rules; later acknowledged
word-level diff
Claude began ignoring orreliably violatinghonored CLAUDE.md rules; later acknowledged
Context
Throughout August 2025 developers reported Claude Code ignoring previously-honored project instructions. Anthropic confirmed the regression on September 17. Top user comment captured the pain: 'the one thing that was very obvious was the number of times Claude Code would fail to respect guidelines or blatantly ignore rules clearly laid out in the CLAUDE.md file.' This validated the broader silent model swap theory.