Where coding-agent rule files live
A map of AGENTS.md, CLAUDE.md, GEMINI.md, Copilot instructions, Cursor rules, Windsurf, and Cline paths.
One concern, several filenames
The policy is usually the same: stack, commands, and bans. The path depends on the tool. AGENTS.md and CLAUDE.md and GEMINI.md sit at the repository root. Copilot uses `.github/copilot-instructions.md`. Cursor uses `.cursor/rules/*.mdc`. Windsurf uses `.windsurf/rules`. Cline uses `.clinerules`.
Commit the files for the tools your team runs. Generating all of them from one set of options keeps the commands from drifting. You do not need a file for an editor nobody has installed.
Do not hide them
A rule that lives only in a chat is not a project rule. Check the file into git, and start a new agent session after it changes. Nested files are for exceptions, not for the only copy of the test command.
Do it in this order
01
List the tools
Write down Cursor, Claude Code, Copilot, Windsurf, Gemini, Cline, or whichever subset you use.
02
Generate one file per tool
Use the same stack and strictness for each.
03
Put each file on its real path
Do not rename them. The tools look for specific filenames.
04
Link them from the README only if humans need the map
The agents do not need the README to find their own file.
Questions
Can one file serve every agent?
AGENTS.md is the closest thing to a shared file. Several tools still look for their own filename. If a tool is important to you, give it the file it reads.
Where do system prompts fit?
A system prompt is for an agent that does not read the repo. Paste it into that product. You can also commit `system-prompt.md` and point the agent at it.