I needed to run user scripts for an app, and decided to use a subset of Rust as the scripting language. I do not expect a typical user to write the script directly, a local LLM will handle it. The interpreter can be bootstrapped in a C-free path from a tiny 229 bytes seed, and self-hosts. The code was written by Claude Code (Fable/Opus) under my supervision, in a few days, which I found impressive.