# Does GitHub Copilot Read CLAUDE.md? Support Matrix by Surface

GitHub Copilot support for CLAUDE.md is surface-specific. Use the GitHub support matrix before relying on it, and keep .github/copilot-instructions.md as the broad Copilot baseline.

## Quick Answer

GitHub Copilot does not have one universal answer for CLAUDE.md. GitHub documents instruction-file support by Copilot surface, so CLAUDE.md should be treated as a surface-specific input. For broad Copilot repository guidance, use .github/copilot-instructions.md and keep CLAUDE.md for Claude Code.

## Best for

Maintainers standardizing Copilot, Claude Code, and Codex repository instruction files.

## Use this guide to

Developers want a direct answer about whether GitHub Copilot reads CLAUDE.md in Chat, cloud-agent, code-review, CLI, or IDE workflows.

## Recommended play

1. Use .github/copilot-instructions.md as the broad Copilot repository baseline.
2. Keep CLAUDE.md for Claude Code, and treat Copilot CLAUDE.md support as surface-specific.
3. Verify each Copilot surface your team uses before deleting or consolidating instruction files.
4. Update adapters together when setup commands, test commands, or security boundaries change.

## CLAUDE.md support decision table

Use this table before deciding where Copilot-facing repository guidance should live.

| Area | Question | Safe answer | Action |
| --- | --- | --- | --- |
| Need broad Copilot coverage? | Use .github/copilot-instructions.md as the baseline | CLAUDE.md support is not the broad default across every Copilot surface | Keep Copilot rules in the GitHub instructions path |
| Using Claude Code? | Use CLAUDE.md for Claude Code memory | Do not remove it just because Copilot has its own instructions file | Synchronize shared commands and safety boundaries |
| Using Codex? | Use AGENTS.md for Codex repository instructions | Do not expect AGENTS.md, CLAUDE.md, and Copilot paths to be interchangeable | Keep one maintained policy and concise adapters |
| Unsure about a Copilot surface? | Check the current GitHub support matrix | Avoid global yes-or-no claims | Run a small controlled task and record what was followed |

## Execution steps

1. **List active Copilot surfaces** — Write down whether the team uses IDE Chat, GitHub web tasks, coding agent flows, code review, CLI, or organization-level instructions.
2. **Map files to each surface** — Compare AGENTS.md, CLAUDE.md, .github/copilot-instructions.md, and path-specific instructions against the current support matrix.
3. **Set the broad baseline** — Put Copilot-wide repository rules in .github/copilot-instructions.md, then keep Claude-specific memory in CLAUDE.md.
4. **Run a tiny behavior check** — Ask each surface to perform a small task that depends on one instruction, then record whether it followed the expected rule.

## Common pitfalls

- **Using CLAUDE.md as the only Copilot file**: Keep .github/copilot-instructions.md for broad Copilot repository coverage.
- **Saying Copilot never reads CLAUDE.md**: Use surface-specific wording and point readers to the current GitHub support matrix.
- **Letting adapters drift**: Choose one maintained policy and update AGENTS.md, CLAUDE.md, Copilot instructions, and Cursor rules together.

## Implementation checklist

- [ ] Confirm which Copilot surfaces the team uses.
- [ ] Check the current GitHub support matrix before relying on CLAUDE.md.
- [ ] Keep .github/copilot-instructions.md for broad Copilot guidance.
- [ ] Keep CLAUDE.md for Claude Code memory and workflows.
- [ ] Synchronize shared commands, safety boundaries, and verification rules.
- [ ] Record the verification date because support can change.

## FAQ

**Q: What should you do first?**

Use .github/copilot-instructions.md as the broad Copilot repository baseline.

**Q: Who is this guide for?**

Maintainers standardizing Copilot, Claude Code, and Codex repository instruction files.

**Q: What evidence supports this guide?**

This guide uses listed source material from GitHub, Anthropic. Source links and scope notes are available on this page.

## Evidence sources

- [Custom instructions support in GitHub Copilot](https://docs.github.com/en/copilot/reference/custom-instructions-support) — GitHub. Official matrix for which Copilot surfaces support which instruction files.
- [Add repository custom instructions for GitHub Copilot](https://docs.github.com/en/copilot/how-tos/copilot-on-github/customize-copilot/add-custom-instructions/add-repository-instructions) — GitHub. Official repository-wide Copilot instructions path and setup guidance.
- [Claude Code memory](https://code.claude.com/docs/en/memory) — Anthropic. Official CLAUDE.md project memory behavior for Claude Code.

## Related guides

- [AGENTS.md vs CLAUDE.md vs Copilot instructions](/guides/agents-md-vs-claude-md-cursorrules-copilot-instructions) — The main comparison explains how all instruction-file adapters fit together.
- [View the AGENTS.md template for monorepos](/guides/agents-md-template-for-ai-coding-agents) — Teams using Codex need a parallel AGENTS.md adapter beside Copilot and Claude files.
- [agent governance checklist for software teams](/guides/agent-governance-checklist-for-software-teams) — Instruction files should carry the same permission and approval language as the governance checklist.
- [MCP security checklist](/guides/secure-mcp-servers-ai-coding-agents) — Tool and credential rules belong in both Copilot instructions and MCP security planning.

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Canonical: https://www.kyenai.com/guides/does-github-copilot-read-claude-md-support-matrix