伊格德拉斯

What you install

npm install -g @chrisdudek/yg
cd your-project
yg init

Requires Node.js 22 or newer. yg init asks one question: which reviewer judges the rules that need judgment. "None for now" is a valid answer.

• Does not touch: yg init does not edit your source files, your build or your runtime; it writes the files in the table above. It installs no pre-commit hook and no CI step; you add those yourself (step 5 of Start).
• Needs: Node.js 22 or newer. A reviewer only for rules a script cannot decide: Claude Code, Codex, Gemini CLI or Copilot CLI with no key, Anthropic, OpenAI or Google with a key, Ollama on your machine, or any OpenAI-compatible endpoint.
• Costs: script rules, dependency checks, a plain yg check and the CI gate are free, local and need no key or network. A reviewer rule costs one model call per rule and component when it is first judged, and again only after its inputs change. One call takes roughly 10 to 40 seconds. yg check --approve --dry-run tells you how many paid calls a run will make before it makes them.
• In the agent's context: the rules block in AGENTS.md, and for each file the agent edits, the rules in force on that file only.

<details> <summary>What the words in the reports mean</summary>

A rule is an aspect, a component is a node, and a pair is one rule on one component or file. The graph is the map of components and rules in .yggdrasil/, a verdict is the recorded pass or refusal of one pair, and the lock is the file that holds the verdicts. The full list is in the glossary.

</details>

3. Install it in your own repository

Run the three install commands above.

You see: the reviewer question, then the files from the table written.

2. Run the example with a recorded verdict

Run cd ../failing, then npx @chrisdudek/yg@6.1.0 check.

You see:

yg check: FAIL  1 error   2 nodes · 3/3 files covered · 4 excluded

error[refused] requires-audit — refused on payments
  at:   payments  Both mutation functions in src/payments.ts violate the requirement: charge (line 5) and refund (line 11) mutate state but use only generic console.log() calls instead of calling emitAudit(). The aspect requires structured audit events with operation, timestamp, and entityId fields. No suppression markers found.
  why:  Every mutation must emit an audit event
  fix:  Four exits — the verdict is recorded for this exact code, so re-running the reviewer changes nothing:

(Trimmed; the full report lists the four exits.) That is a model's verdict, recorded once in the lock and replayed with no model call. Change src/payments.ts by one character and check again:

yg check: FAIL  1 error   2 nodes · 3/3 files covered · 4 excluded

error[unverified] 1 pair whose inputs changed since the verdict
  at:   requires-audit @ payments
  why:  A verdict was recorded, but its inputs changed since (a source edit, an aspect edit, or a changed reference), so it no longer counts. It is re-judged over the code as it stands now.
  fix:  yg check --approve  (1 reviewer pair · 1 call · paid)

Questions

How is this different from a rules file? A rules file is flat text in every prompt, with no scope and no check. Here the agent gets only the rules on the file it is editing, and its change is checked against them.

And from dependency-cruiser or ArchUnit? For import rules in one language they are mature, and if that is all you need, use them. Yggdrasil's dependency check is one part of it: one graph across eleven languages, with script rules, reviewer rules and the lock beside it.

And from an AI review bot? A review bot looks for bugs against its own idea of good code and runs again on every pull request. Yggdrasil checks your team's rules and pays for a verdict once per version of the code it judged.