Aider

About Aider

Aider is an open-source AI pair programming tool for the terminal, created by Paul Gauthier in 2023 and growing to 25,000+ GitHub stars by 2025. Aider's design is git-native and terminal-first — it runs in the command line, reads your codebase, and makes changes that are automatically committed to git with descriptive messages. Unlike IDE-integrated tools (Cursor, Copilot, Continue), Aider works in any development environment without editor plugins, making it the preferred AI coding tool for Vim/Emacs power users, remote development over SSH, and automation pipelines. Aider's benchmark performance is exceptional — it consistently ranks #1 or #2 on SWE-bench (a benchmark measuring ability to solve real GitHub issues), outperforming most commercial AI coding tools including early versions of Cursor. Aider supports 60+ LLMs: Claude 3.7 Sonnet, GPT-4o, DeepSeek, Gemini, and local models via Ollama. Aider's architect mode uses a separate 'reasoning' model to plan changes before a cheaper 'editor' model writes the code — combining Claude's reasoning with DeepSeek for cost efficiency. Aider's /add command adds files to the context window; /run executes shell commands and adds output to context; /test runs tests and feeds failures back to the AI for self-correction. Aider handles large multi-file refactors by applying unified diffs rather than rewriting entire files. Aider's cost efficiency (works with cheap models like DeepSeek V3 at $0.014/1M tokens) makes it the choice for automated issue resolution, nightly coding pipelines, and cost-sensitive teams running AI coding at scale.