← All skills
Coding
🔧

Aider

Open-source terminal pair programmer

What it is

Open-source CLI tool that connects to any model (GPT-5.5, Claude, Llama) and works directly in your terminal and Git repo. Every change is proposed as a diff and applied only after confirmation. Supports whole-codebase maps to keep context on large projects. Free and completely local.

How to use it, step by step

  1. 1

    Install Aider with: python -m pip install aider-install && aider-install (needs Python 3.8+).

  2. 2

    Set the API key for your chosen model as an environment variable (e.g. OPENAI_API_KEY or ANTHROPIC_API_KEY).

  3. 3

    Enter your Git project folder and run: aider (or aider --model sonnet to pick the model).

  4. 4

    Type your request in plain language: Aider shows the diff, asks for confirmation, and even makes the Git commit automatically.

  5. 5

    Add specific files to context with /add filename for targeted edits.

💡Practical tips

  • →Aider auto-commits to Git: you can always roll back, so experiment freely.
  • →On large projects use /add only on relevant files: you save tokens and get sharper answers.
  • →Works with local models via Ollama, if you want everything free and offline.

💰Pricing

The tool is free and open-source. You only pay for your chosen model's usage (API), or nothing if you use local models.

Go to Aider

The official site opens in a new tab.