urd

Urd

Your AI agent hit a gap in the spec — so it guessed, and shipped. Urd makes it stop and ask instead.

The moment the agent moves from a plan into code and the plan runs out, Urd makes it consult the source of truth or ask you — instead of inventing an answer and burying the decision in the diff.

/plugin marketplace add krzysztofdudek/UrdSkill
/plugin install urd@urd-marketplace

Run both, then /reload-plugins to activate it in this session (or restart Claude Code). No config, no API key. The skill activates on its own the moment the agent moves from a plan, design doc, or spec into implementation.

MIT licensed · single markdown file · works with any agent that reads skills · part of the Yggdrasil family · full skill body

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See it

Step 4 of the plan: implement the retry logic. The plan says, verbatim:

"On 5xx response, retry up to 3 times with exponential backoff."

Mid-implementation the agent hits a 429 (rate-limited) — not a 5xx, but retryable. The spec is silent on it. The default agent picks something and moves on. Urd makes it stop:

Question — retry logic, step 4. The plan covers 5xx, but I've hit 429 (rate-limited): not 5xx, yet retryable. The spec doesn't say how to treat it. Three options:

1. Treat 429 like 5xx — retry with backoff.
2. Honor the Retry-After header if present, otherwise back off.
3. Leave 429 to the caller — don't retry it here.

I'd go with (2). Proceed?

Note what it did: it didn't resolve the ambiguity silently. Ten seconds on a decision now, instead of finding it in the diff an hour later. That's the whole skill — at the moment of doubt, ask, don't guess.

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When it fires

The skill activates the moment the agent moves from a plan/spec into implementation. Once active, it pushes toward asking rather than guessing whenever:

• the spec is silent on a case the agent hit
• the spec contradicts itself
• the agent is about to add a fallback, exception, or TODO the spec didn't sanction
• a test would have to be weakened or skipped to make the code pass
• a framework or type-system constraint is forcing a workaround
• the agent catches itself thinking "this is probably fine" without certainty

Well-written plans trigger few stops. Sparse plans trigger many. That's the point.

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How it asks

When Urd asks, it gives you enough to decide in seconds — never an open-ended "what should I do?":

It tells you	Example
Where it is in the plan	"Step 4, retry logic"
What the spec says, verbatim	"On 5xx, retry 3× with backoff"
What it found that doesn't fit	"hit a 429, not covered"
The options, with trade-offs	the numbered list above
Its recommendation	"I'd go with (2)"

It also distinguishes verified from believed: it states as fact only what it has checked against the source. An unverified inference — a cause, a mechanism, how an API behaves — it labels as a guess or verifies before you rely on it. Challenge a claim and it re-reads the source and corrects itself, instead of defending an answer it never confirmed.

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Install

Claude Code plugin (recommended)

Two slash commands. The first registers this repo as a marketplace; the second installs the plugin from it.

/plugin marketplace add krzysztofdudek/UrdSkill
/plugin install urd@urd-marketplace

Then run /reload-plugins to activate it in the current session (or restart Claude Code). No config, no API key.

To upgrade later, refresh the marketplace and reinstall:

/plugin marketplace update urd-marketplace
/plugin install urd@urd-marketplace

GitHub Copilot CLI plugin

The same repo is also a GitHub Copilot CLI marketplace. Register it, then install the plugin:

copilot plugin marketplace add krzysztofdudek/UrdSkill
copilot plugin install urd@urd-marketplace

To upgrade later: copilot plugin update urd. The same skill body powers both Claude Code and Copilot — nothing changes in how it behaves.

Codex CLI plugin

Codex reads the same skill. Register this repo as a marketplace, then install:

codex plugin marketplace add krzysztofdudek/UrdSkill
codex plugin install urd@urd-marketplace

To upgrade later: codex plugin marketplace upgrade urd-marketplace. Or drop the single file into ~/.agents/skills/urd/SKILL.md (user-level) or .agents/skills/urd/SKILL.md (project-level).

Cursor plugin

Cursor auto-discovers the skill from the plugin manifest at the repo root. Install it locally: