what file am I supposed to be using for the Claude code claude.md equivalent?

[ljmerza]

Reading through the docs it's not very clear if the different between instructions file and agent file in a repo? I want to be able to load custom instructions in every session similar to the claude.md file for Claude code how do I do this?

[classicsc]

From what I've seen, Copilot CLI reads both CLAUDE.md and AGENTS.md. At startup you'll see a message like ● Loaded env: AGENTS.md, 1 MCP server so it's clear that it was picked up.