Simon Willison’s Weblog

30th May 2024

Codestral: Hello, World! Mistral's first code-specific model, trained to be "fluent" in 80 different programming languages.

The weights are released under a new Mistral AI Non-Production License, which is extremely restrictive:

3.2. Usage Limitation

• You shall only use the Mistral Models and Derivatives (whether or not created by Mistral AI) for testing, research, Personal, or evaluation purposes in Non-Production Environments;
• Subject to the foregoing, You shall not supply the Mistral Models or Derivatives in the course of a commercial activity, whether in return for payment or free of charge, in any medium or form, including but not limited to through a hosted or managed service (e.g. SaaS, cloud instances, etc.), or behind a software layer.

To Mistral's credit at least they don't misapply the term "open source" in their marketing around this model - they consistently use the term "open-weights" instead. They also state that they plan to continue using Apache 2 for other model releases.

Codestral can be used commercially when accessed via their paid API.