Aider
Aider is an open-source command-line tool for AI-assisted coding, built by Paul Gauthier (independent) (released 2023-06). Aider integrates with 8 verified models, including Claude Sonnet 4.6, Claude Opus 4.6, and Mistral Large 3 675B Instruct. It's free and open source. Engineers run it from a terminal, where it can inspect repositories, edit files, call tools, and drive repeatable agentic coding workflows across local projects.
Overview
Open-source CLI tool for AI-driven code editing via natural language, with deep Git integration that automatically commits changes with descriptive messages.
Featured Model Specs
| Model | Lab | Released | Context | Reasoning | Open source |
|---|---|---|---|---|---|
| Claude Sonnet 4.6 | Anthropic | 2026-02-17 | 1M | Yes | No |
| Claude Opus 4.6 | Anthropic | 2026-02-05 | 1M | Yes | No |
| Mistral Large 3 675B Instruct | MistralAI | 2025-12-01 | 128K | No | No |
| Gemini 2.5 Pro | Google DeepMind | 2025-06-17 | 1M | No | No |
| GPT-4.1 | OpenAI | 2025-04-01 | 1M | No | No |
Model Compatibility Matrix
| Model | Lab | Default | Access tier | Notes |
|---|---|---|---|---|
| Claude Sonnet 4.6 | Anthropic | Yes | Free | Recommended default, via Anthropic API key |
| Claude Opus 4.6 | Anthropic | No | Free | Via Anthropic API key |
| Mistral Large 3 675B Instruct | MistralAI | No | Free | Via Mistral API key |
| Gemini 2.5 Pro | Google DeepMind | No | Free | Via Google API key |
| GPT-4.1 | OpenAI | No | Free | Via OpenAI API key |
| DeepSeek R1 | DeepSeek | No | Free | Via DeepSeek API key |
| DeepSeek V3 | DeepSeek | No | Free | Via DeepSeek API key |
| GPT-4o (2024-11-20) | OpenAI | No | Free | Via OpenAI API key |
Underlying Models
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FAQ
What is Aider?
Aider is an open-source command-line tool for AI-assisted coding, built by Paul Gauthier (independent) (released 2023-06). Engineers run it from a terminal, where it can inspect repositories, edit files, call tools, and drive repeatable agentic coding workflows across local projects. It is primarily used for agentic coding from a local shell.
What models does Aider support?
Aider runs Claude Sonnet 4.6, Claude Opus 4.6, Mistral Large 3 675B Instruct, Gemini 2.5 Pro, GPT-4.1, and 3 more.
How much does Aider cost?
Aider is free and open source. You pay only for the underlying model API usage.
Is Aider open source?
Yes, Aider is open-source software.
What are alternatives to Aider?
Alternatives include Warp, Pi, and Claude Code.
When was Aider released?
Aider was released in 2023-06.