What goes into CLAUDE.md, AGENTS.md and Cursor rules for an iOS project?
Essence
Agents read the project rules file at the start of every session: Claude Code reads CLAUDE.md, Codex and a number of other tools read AGENTS.md, Cursor reads rules in .cursor/rules/. It's essentially onboarding for a new developer, except the reader is a model and it reads it every time. A good file saves dozens of repetitions in prompts and prevents typical mistakes.
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