Skill manifest

A skill is a directory under <data_dir>/skills/<slug>/:

<slug>/
├─ manifest.json      # metadata + test status
├─ skill.rhai         # fn run(input)
├─ test.rhai          # fn test()
└─ history/v<N>/      # archived previous versions

Manifest

{
  name: string;        // slug (lowercase, alphanumerics + single hyphens)
  version: number;     // integer, bumped on every update
  description: string;
  created_at: number;
  updated_at: number;
  test_status: { status: "passed" } | { status: "failed"; detail: string };
}

The contract

• skill.rhai defines fn run(input) — takes one string, returns a value.
• test.rhai defines fn test() — returns true when the skill is correct, and calls run(...) with at least one concrete example.

On every save and re-test, run + test are compiled together and test() is executed. Passed → the skill is runnable. Failed → it’s flagged and run_skill refuses it until it passes.

The language

Skills are written in Rhai — a small, embedded scripting language. Useful string methods: .len(), .to_upper(), .to_lower(), .trim(), .contains(s), .replace(a, b), .split(s), .sub_string(start, len).

The sandbox

Rhai is sandboxed by construction — scripts see only language built-ins (no filesystem, no network). Each execution runs under hard caps: 200,000 operations, bounded call depth, and bounded string/array/map sizes. A runaway loop terminates instead of hanging the assistant.

Versioning & rollback

Updating a skill archives the outgoing skill.rhai / test.rhai to history/v<N>/ and increments the version. A rollback restores the previous version’s sources as a new version (a revert, preserving the chain), or deletes the skill if it’s on v1 with nothing to revert to.