GitHub Copilot

AI pair programmer and coding agent inside GitHub and major IDEs; reads .github/copilot-instructions.md and AGENTS.md.

Best for: Teams already on GitHub
Pricing: Free + paid
Official site: https://github.com/features/copilot

Using GitHub Copilot? Give it rules for your stack.

Coding agents follow AGENTS.md / rules files. Generate one tuned to your project.

Alternatives to GitHub Copilot

CursorFree + paid

AI code editor with agent mode, tab completion and project rules (.cursor/rules, AGENTS.md).

Best for: Daily AI-first coding in a VS Code–style editor

Claude CodePaid (Claude plans/API)

Anthropic's agentic coding tool for the terminal and IDEs; reads CLAUDE.md.

Best for: Terminal-first agentic coding

OpenAI CodexIncluded in ChatGPT plans

OpenAI's coding agent (CLI, IDE and cloud); reads AGENTS.md.

Best for: Delegating tasks to a cloud/CLI agent

The Windsurf editor, now under Cognition as Devin Desktop (windsurf.com redirects here).

Best for: Agentic IDE with Cognition models · NEW

📬 The AgentRules Weekly

New AI coding & agent tools, one email a week. Free starter AGENTS.md template on signup.