Aider

Aider is an open-source AI pair programmer that runs in a terminal and edits files in a local Git repository. A developer starts it in a project, adds specific files or lets Aider identify likely files, and requests changes in natural language. Aider shows diffs and integrates with Git so its edits can be tracked and undone. It can also build a repository map to supply structural context without placing every file into the active chat. The code is published under Apache License 2.0.

Aider is free software, but model access is separate: users supply credentials for supported hosted providers or connect a local model, including through Ollama or an OpenAI-compatible endpoint. Official installation paths cover macOS, Linux, and Windows, with a Python package on PyPI and installer scripts documented by the project. Results and inference costs therefore depend on the model and provider selected rather than an Aider subscription.

Top features

• Terminal-based file editing for existing repositories and new projects.
• Multi-file changes with visible diffs and automatic Git commits that remain reviewable and reversible.
• Repository mapping that helps the model reason about names and relationships beyond the files explicitly added to a chat.
• Broad model connectivity across hosted APIs, local models, Ollama, and OpenAI-compatible services.
• Chat modes for coding, architecture, questions, and help, plus in-chat commands for adding files and changing models.
• Optional voice-to-code, image and web-page context, test execution, linting, and editor watch workflows.
• Apache-2.0 source and a public issue tracker for inspection and contribution.

Use cases

• Implement a scoped feature that requires coordinated edits in source files, tests, and documentation.
• Diagnose a failing test, apply a patch, rerun project commands, and inspect the resulting Git history.
• Refactor call sites across several files while keeping each generated change easy to diff or undo.
• Explore an unfamiliar repository by asking architecture questions informed by its repository map.
• Use a local model for development environments where code should not be sent to a hosted model provider.