[2025-08-28] Document support for AGENTS.md custom instructions in Copilot coding agent (#57252)

Co-authored-by: hubwriter <[email protected]>
Co-authored-by: Joe Clark <[email protected]>

Author: 3 people

content/copilot/how-tos/configure-custom-instructions/add-repository-instructions.md

@@ -1,7 +1,7 @@
 ---
 title: Adding repository custom instructions for GitHub Copilot
 shortTitle: Add repository instructions
-intro: 'Create a file in a repository that gives {% data variables.product.prodname_copilot_short %} additional context for the work it does in that repository.'
+intro: 'Create repository custom instructions files that give {% data variables.product.prodname_copilot_short %} additional context on how to understand your project and how to build, test and validate its changes.'
 redirect_from:
   - /copilot/customizing-copilot/adding-custom-instructions-for-github-copilot
   - /copilot/customizing-copilot/adding-repository-custom-instructions-for-github-copilot
@@ -239,7 +239,11 @@ Once saved, these instructions will apply to the current project in Eclipse that
 
 **{% data variables.copilot.copilot_chat_short %}** on the {% data variables.product.github %} website, **{% data variables.copilot.copilot_coding_agent %}** and **{% data variables.copilot.copilot_code-review_short %}** support a single `.github/copilot-instructions.md` custom instructions file stored in the repository.
 
-In addition, **{% data variables.copilot.copilot_coding_agent %}** supports one or more `.instructions.md` files stored within `.github/instructions` in the repository. Each file can specify `applyTo` frontmatter to define what files or directories its instructions apply to.
+In addition, **{% data variables.copilot.copilot_coding_agent %}** supports:
+
+* One or more `.instructions.md` files stored within `.github/instructions` in the repository. Each file can specify `applyTo` frontmatter to define what files or directories its instructions apply to.
+* One or more `AGENTS.md` files stored anywhere within the repository. When {% data variables.product.prodname_copilot_short %} is working, the nearest `AGENTS.md` file in the directory tree will take precedence.
+* A single `CLAUDE.md` or `GEMINI.md` file stored in the root of the repository.
 
 ### Using a single `.github/copilot-instructions.md` file
 

content/copilot/tutorials/coding-agent/get-the-best-results.md

@@ -77,7 +77,13 @@ By adding custom instructions to your repository, you can guide {% data variable
 
 If {% data variables.product.prodname_copilot_short %} is able to build, test and validate its changes in its own development environment, it is more likely to produce good pull requests which can be merged quickly.
 
-You can add instructions in a single `.github/copilot-instructions.md` file in the repository, or create one or more `.github/instructions/**/*.instructions.md` files applying to different files or directories in your repository.
+{% data variables.copilot.copilot_coding_agent %} supports a number of different types of custom instructions files:
+
+* `/.github/copilot-instructions.md`
+* `/.github/instructions/**/*.instructions.md`
+* `**/AGENTS.md`
+* `/CLAUDE.md`
+* `/GEMINI.md`
 
 For more information, see [AUTOTITLE](/copilot/customizing-copilot/adding-repository-custom-instructions-for-github-copilot?tool=webui).