Free, open-source AI pair programming agent in the terminal.
Aider is a completely free, open-source command-line AI pair programmer. It edits code across multiple files, integrates tightly with git (auto-committing changes), and works with a wide range of models through your own API keys. It is a long-standing favorite for terminal-based agentic coding.
Free and open-source (Apache 2.0). Costs come only from the model API you connect via your own key.
pricing model · as of 2026-11-03