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GitHub Copilot

Overview

GitHub Copilot reads .github/copilot-instructions.md as custom instructions applied across the entire repository. It applies consistently in all environments where Copilot is enabled, such as VS Code, JetBrains, and GitHub.com. The scope is repository-level.

If open source policy is written in this file, Copilot automatically recognizes license and security policy while suggesting code, regardless of which editor team members use. Since most repositories already have a .github/ directory, it can be applied immediately without creating additional directories. It is recommended to copy a base template including this file whenever creating a new repository.

Configuration File Location

  • .github/copilot-instructions.md — single file, applied to the whole repository
  • .github/instructions/*.instructions.md — path-scoped via the applyTo frontmatter pattern (good for per-language or per-folder rules)
  • AGENTS.md — common rules file at the root (nearest file wins)

How to Apply

  1. If .github/ does not exist, create it and add copilot-instructions.md.
  2. Paste content from the Common Rules Template.
  3. Update the allow/deny license list to match internal policy.

Configuration Example

Markdown
## Open Source Policy

### License Management

**Allowed Licenses**: MIT, Apache-2.0, BSD-2-Clause, BSD-3-Clause, ISC

**Review Required Licenses** (legal review required): LGPL, MPL

**Prohibited Licenses** (cannot be used without prior approval): GPL, AGPL, SSPL, Commons Clause

<!-- Copy the full rules (including the Security, SBOM, and Copyright sections) from the Common Rules Template -->

Copy the full text from the Common Rules Template. When the allow/deny lists change, update only the canonical template and paste it into each tool file again.

Verifying the Rules Are Applied

To check whether the rules are applied, ask the tool.

"Can I add a GPL-3.0 licensed package to this project?"

If the rules are recognized, the tool answers that it is a prohibited license and suggests an alternative. If it does not recognize the rules, re-check the configuration file location and how to apply the rules. For linkage to the standard requirements, see ISO Standards Linkage.

Notes

Good to know

Organization settings support organization-wide custom instructions. Their scope is limited to Copilot Chat, code review, and the coding agent on GitHub.com, so to stay consistent across IDEs, also manage per-repository instruction files from a shared template. Custom instructions apply to Chat, code review, and the coding agent; application to inline code completion is not guaranteed. There may be a short delay after changes.