Aider

Overview

Aider is an open-source CLI tool for AI pair programming. Works with any LLM (Claude, GPT, local models), is git-aware, and edits multiple files from the terminal.

Key Strengths

• Open source: Free, transparent, community-driven
• LLM agnostic: Works with Claude, GPT, Gemini, local models, any provider
• Git-aware: Creates commits, works with branches, respects .gitignore
• Multi-file: Edits multiple files in a single conversation
• Terminal native: Perfect for developers who live in the terminal

Usage

# Start aider with Claude
aider --model claude-sonnet-4-6

# Add files to context
/add src/api/users.ts src/lib/auth.ts

# Ask for changes
"Add rate limiting to the users API endpoint. Use a token bucket algorithm with 100 requests per minute per IP."

# Aider edits the files, shows diff, creates git commit

Best Use Cases

Use Case	Quality
Terminal-based coding	Excellent
Quick edits across files	Excellent
Open-source projects	Excellent (model flexibility)
CI/CD integration	Very Good
Large refactors	Good

Access

• Install: pip install aider-chat
• Free (bring your own API key)
• GitHub: github.com/paul-gauthier/aider