For the most complete CLI agent: [Aider](/en/avis/aider) is more mature and active. For VS Code: [Cline](/en/avis/cline) or [Continue](/en/avis/continue). For advanced agentic work: [Claude Code](/...

Mentat, Joute's Review

The Essentials

Python CLI agent to edit code files in natural language
Free and open source, BYOK
Can modify multiple files simultaneously in a single prompt
Direct competition with Aider in the CLI agent segment

What is Mentat?

Mentat is a command-line code assistant that, like Aider, lets you describe in natural language what you want to change in your codebase, and the tool makes the changes directly in the files. The main difference from Aider: Mentat natively handles modifications across multiple files in a single instruction without requiring you to specify them explicitly.

Strengths

Native multi-file

You can ask "refactor this architecture" and Mentat identifies and modifies all relevant files. Aider often requires explicitly specifying files.

Free BYOK

No subscription. You provide your OpenAI API key or other compatible model.

Open source

Code is available, auditable and modifiable.

Limits

Less active development than Aider

The GitHub repo shows less recent activity. Aider and Cline have more sustained release cycles.

Fewer advanced features

No git integration as clean as Aider (automatic commits, clean diffs).

Pricing

Free (BYOK: you provide your own LLM API key).

Alternatives

For the most complete CLI agent: Aider is more mature and active. For VS Code: Cline or Continue. For advanced agentic work: Claude Code.

Verdict

Mentat is a valid option for anyone wanting a free open source CLI agent. But Aider is overall more mature, better documented and more actively developed. Test both to see which fits better in your workflow.

FAQ

Does Mentat support Claude or only OpenAI?

Mentat supports multiple providers via API keys. Check documentation for supported models.

How to install Mentat?

Via pip: pip install mentat. Check the GitHub repo for up-to-date instructions.

Can Mentat be used on Windows?

Python being cross-platform, Mentat theoretically works on Windows but the experience is optimized for Unix/macOS.

Mentat vs Aider, which to choose in 2026?

Aider. More development activity, better community support, more features.

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