# Implementation variants

Millrace has two public implementation surfaces:

- the production Python implementation
- the public Rust implementation

## Python implementation

The Python implementation is the main production runtime today.

Public identifiers:

- package name: `millrace-ai`
- import namespace: `millrace_ai`
- installed CLI: `millrace`
- module entrypoint: `python -m millrace_ai`
- repository: `https://github.com/tim-osterhus/millrace`

This implementation is the current release source of truth for the full local runtime: workspace baseline init and upgrade, CLI and TUI surfaces, compiled runtime plans, planning and execution planes, optional learning modes, usage-governance gates, durable state, diagnostics, and restart-safe control.

## Rust implementation

The Rust implementation is public at:

```text
https://github.com/tim-osterhus/millrace-rs
```

Public Rust identifiers:

- Cargo package: `millrace-ai`
- library crate: `millrace_ai`
- CLI binary: `millrace`
- repository: `https://github.com/tim-osterhus/millrace-rs`

The Rust implementation is not the production runtime line today. It is a public implementation that tracks the Python runtime contract as the Python release line evolves.

## Release automation

The Rust implementation is automatically updated after every version release of the main Python implementation.

That update path is handled by a live Millrace instance and documented publicly at:

```text
https://live.millrace.ai
```

Safe wording:

- Millrace currently ships first as the Python runtime.
- The Rust implementation is public and automatically updated after Python version releases.
- The Rust implementation should be described as tracking the Python runtime contract, not as replacing the Python production implementation.

Avoid saying that the Rust implementation is feature-complete unless current Rust release notes explicitly say so.

See also:

- `/ai/millrace-summary.md`
- `/ai/install.md`
- `/ai/architecture.md`
- `/ai/faq.md`