GitHub Copilot June 18 Changelog: MAI-Code-1-Flash Expands and AGENTS.md Lands in Code Review
GitHub
GitHub's June 18, 2026 changelog includes: MAI-Code-1-Flash (Microsoft's 5B-parameter coding model) now available on Copilot CLI, GitHub Copilot app, and Copilot Chat beyond its Build 2026 debut surfaces. Code review gains support for repository-level AGENTS.md files, letting teams document agent conventions and have review tools respect them. Duplicate issue detection entered public preview. Copilot-authored PRs are now discoverable via `author:` search.
Why it matters
AGENTS.md support in code review establishes a repository-level convention for documenting agent behavior, likely to become a standard pattern across tools. MAI-Code-1-Flash expansion gives Copilot users a fast Microsoft-owned model across more surfaces.
Importance: 2/5
Incremental changelog update; AGENTS.md in code review is a small but notable standardization step.