github-copilot

When a GitHub Actions job goes red, the Fix with Copilot button hands the failure to the Copilot cloud agent: it reads the logs, pushes a fix to your branch, and tags you for review. Here is where the button lives, the May 18 / June 4 2026 rollout, the Approve and run workflows gotcha that stalls re-runs, how billing works per session, and when to reach for the REST API instead.

POST a prompt to /agents/repos/{owner}/{repo}/tasks and Copilot's cloud agent spins up, writes code, and opens a PR. Here is the exact request, the X-GitHub-Api-Version: 2026-03-10 header, the user-to-server token gotcha that breaks GitHub App installs, a polling loop over the eight task states, and a fan-out script that dispatches the same migration across many repos.

As of the June 11, 2026 change, GitHub Agentic Workflows run on the built-in GITHUB_TOKEN. Add copilot-requests: write, drop the PAT, recompile the lock file, and let safe-outputs apply writes from a privileged step. Full issue-triage example, the token fallback chain, and the two cases where you still need a custom token.

At Build 2026 GitHub shipped Copilot SDK 1.0 GA with a first-class .NET package. You can now drive the same planning, tool-calling, and multi-turn agent runtime from C# code, BYOK included.

Claude Code wins on raw agent quality and predictable flat pricing, Cursor wins as the editor you live in with the best multi-model routing, and GitHub Copilot wins when the work starts and ends on GitHub. The June 2026 token-billing shift is the tiebreaker for cost.

Copilot Chat reads your .github/copilot-instructions.md fine, but Agent mode and *.instructions.md files often look ignored. Here is the actual checklist: settings, file locations, applyTo globs, and how to prove the file made it into context.

On May 17, 2026 GitHub flipped the default Copilot model on Business and Enterprise plans from GPT-4.1 to GPT-5.3-Codex. GPT-4.1 stays free until June 1, then it falls under usage-based billing. Here is what changes for pinned models in your repo and CI.

GitHub deprecated claude-sonnet-4 on May 6, 2026 across Copilot Chat, inline edits, ask and agent modes, and code completions. Recommended migration target is Claude Sonnet 4.6. What to grep for in your repo before the next pinned model selection silently breaks.

Turn the unwritten rules in your repo into a SKILL.md that GitHub Copilot loads on demand. Frontmatter, descriptions that route, file references, and how to verify it actually fires.

GitHub Copilot for VS Code shipped Bring Your Own Key on April 22, 2026. Wire your own Anthropic, OpenAI, Gemini, OpenRouter, or Azure account into Chat, or point at a local Ollama or Foundry Local model. Billing skips the Copilot quota and goes straight to the provider.