Aider

What is Aider?

Aider is an open-source command-line tool that acts as an AI pair programmer. It works inside a local Git repository and directly edits source code based on natural-language instructions. The documentation describes it as a "AI pair programming in your terminal" that can work with multiple large language models, including GPT-4, Claude, and local models via Ollama or other providers. The tool reads the repository context, suggests changes, and applies them as commits. It is written in Python and distributed via PyPI or can be run from source. The GitHub repository shows 47,733 stars, indicating a large community following. Aider is designed for developers who prefer a terminal-based workflow and want to keep their code under version control without switching to a separate IDE or web interface.

Who is Aider for?

Aider targets developers who are comfortable with the command line and Git. It is suited for those who want to integrate AI code generation and modification directly into their existing terminal workflow, rather than using a plugin or web-based chat. The tool assumes the user has access to one or more AI model APIs (e.g., OpenAI, Anthropic, or a local model) and is willing to configure API keys. It works best on projects already under Git, because it uses the repository history to understand context and can undo changes automatically. Aider is less appropriate for non-developers or for teams that require a graphical interface or a hosted, zero-configuration product. The documentation emphasizes that Aider "edits code in your local git repo" and provides commands for adding files to context, asking questions, and committing changes. It is a power-user tool for programmers who want fine-grained control over AI-assisted edits.

How much does Aider cost?

The pricing page lists Aider as free. There is no subscription fee or usage charge for the tool itself. The starting price is $0 per month. However, running Aider typically requires API keys to third-party language model providers. Those services may charge per token or per request. Aider itself is open-source, so anyone can inspect, modify, or self-host it without paying. The repository contains no paid tiers, premium features, or telemetry-based monetization. The cost to the user is only the time spent setting up API credentials and any fees charged by the chosen model provider. For users running local models with tools like Ollama or llama.cpp, there is no per-request cost beyond hardware electricity. Aider does not impose any artificial limits on the number of requests, projects, or users.