Trial
Aider is an open-source AI pair programming tool for the terminal. It integrates tightly with Git, committing changes automatically as you work with it. With Claude Sonnet as the backend, it scores ~72% on SWE-Bench Verified as of early 2026.
Why It's in Trial
Aider has been around longer than most agentic coding tools and has earned a reputation for reliability and a thoughtful workflow:
- Git-native: Every change Aider makes is committed to Git with a descriptive message, giving you a full history of what the AI did and easy rollback.
- Model agnostic: Works with Claude Sonnet 4.6, GPT-5.4, o3-mini, DeepSeek R1/V3, Gemini, and local models via Ollama. DeepSeek has become popular for cost-effective use.
- Architect + Editor mode: A two-model workflow where an "architect" model (e.g., DeepSeek R1) plans changes and an "editor" model (e.g., Claude Sonnet) implements them — a major capability for complex tasks.
- Diff-based editing: Aider shows you exactly what it's changing before it changes it.
- Multi-file awareness: Add any files to the context and Aider can edit across all of them, with an internal repo map for large codebases.
- Automated linting and testing: Aider can run linters and tests after each change and self-correct on failures.
Getting Started
# Recommended: install script (no Python required)
curl https://aider.chat/install.sh | sh
# Or via pip installer
pip install aider-install && aider-install
# Use with Claude (requires ANTHROPIC_API_KEY)
aider --model sonnet
# Or with GPT-5.4 (requires OPENAI_API_KEY)
aider --model gpt-5.4
# Add files to context
/add src/main.py tests/test_main.py
Compared to Claude Code
Both are terminal-based agentic tools. Aider's Git integration, open-source nature, and model flexibility are strengths; Claude Code's deeper integration with Anthropic's models and its interactive permission model feel more polished for many workflows.
Key Characteristics
| Property | Value |
|---|---|
| Interface | Terminal / CLI |
| License | Open source (Apache 2.0) |
| Underlying model | Claude, GPT-5.4, o3-mini, DeepSeek, Gemini, local |
| SWE-bench Verified | ~72% (Claude Sonnet) |
| Pricing | Free (BYOK) |
| Sandbox | Host terminal (no built-in isolation) |
| Provider | Community / Paul Gauthier |
| Website | aider.chat |
| GitHub | Aider-AI/aider |