I made one using Rust predating Gemini-CLI https://github.com/MostlyKIGuess/Yappus-Term , but it's more of a search tool than coding.

Closest you get is https://github.com/opencode-ai/opencode in GO.

OpenAI's Codex has a Rust and Ratatui implementation. I believe it's now the default verison. (Previously the TypeScript implementation was the default.)

https://github.com/openai/codex/tree/main/codex-rs

Amazon's Claude Code clone is in Rust and Apache-2/MIT:

https://github.com/aws/amazon-q-developer-cli