Aider
Free & Open SourceAI pair programming in your terminal. Edit code with natural language commands and get intelligent suggestions.
About Aider
Free, open-source AI pair programming tool that runs in your terminal. Edit code with natural language commands and get intelligent suggestions.
Key Features
- ✓Terminal-first pair programming: Work with the assistant directly from the command line without switching to a separate web UI.
- ✓Git-aware changes: Aider can create descriptive commits for AI-assisted edits, making changes easier to inspect and roll back.
- ✓Repository context: Uses project context to reason about code relationships instead of treating every prompt as an isolated snippet.
- ✓Multi-file editing: Apply coordinated changes across several files for refactors, feature work, and bug fixes.
- ✓Flexible model access: Use supported hosted model APIs or compatible local-model workflows depending on your setup and privacy needs.
Pricing
Aider itself is open source under the Apache 2.0 license. Any model or API charges are billed separately by the provider you connect.
Official pricing sources: aider.chat · aider.chat
Pros & Cons
✅ Pros
- ✅ Completely free and open source
- ✅ Perfect for terminal-first workflows
- ✅ Automatic git commits with every change
- ✅ Understands entire codebase
- ✅ Can edit multiple files simultaneously
⚠️ Cons
- ⚠️ Terminal-based, requires CLI comfort
- ⚠️ Requires API key (or local model)
- ⚠️ No GUI for visual developers
- ⚠️ Setup requires technical knowledge
Use Cases
Code Refactoring
Use AI to refactor code across multiple files in your git repository.
Feature Development
Build new features with AI pair programming in the terminal.
Bug Fixing
Get AI assistance to identify and fix bugs in your codebase.
Alternatives
Frequently Asked Questions
Is Aider free?
Yes, Aider is completely free and open source. You'll need to provide your own API key for an LLM provider like OpenAI or Anthropic, or you can run it with local models. There's no subscription fee.
How does Aider work with git?
Aider automatically creates git commits for each set of changes it makes. Each commit includes a descriptive message explaining what was changed, making it easy to review history, roll back changes, or understand the evolution of your code.
Can I use Aider without leaving my terminal?
Absolutely! Aider is designed to be used entirely from the command line. You can run it in any terminal, work with your preferred text editor, and never need to switch to a web browser or GUI application.
What's the difference between Aider and Mentat?
Both are terminal-based AI coding assistants. Aider has deeper git integration and automatic commits, while Mentat focuses on showing diffs and giving you more control over the review process. Both are excellent choices for terminal workflows.