version: "1.0.0" name: parity-setup description: Declare that this repo ports behavior from another codebase — find the original, record the baseline, write seal/parity.md. disable-model-invocation: true

/specseal:parity-setup — turn on parity mode

Writes seal/parity.md, whose presence is the declaration that this repository ports behavior from another codebase. That turns on three-way judgment (policy ↔ original ↔ new code, with the original preserved when the policy is silent) and lets the scribe agent fetch what the original does.

The implement skill asks this question once, when it first bootstraps a repo. Use this command when the answer was no at the time, when the layout predates the question, or when the original repo changes.

Procedure

1. Stop if it already exists. If seal/parity.md is present, show it and

ask what should change instead of overwriting a declaration someone made.

1. Find candidates for the original. Do not ask the user to type a path

from memory when the machine can propose one:

• sibling directories of this repo that are git checkouts — a port usually

sits beside its original

• an upstream or fork relation in git remote -v
• repos whose directory structure overlaps this one's

Present what you found with what each one is, and let the user pick or give a path. Never guess. A comparison against a guessed original proves nothing, which is worse than having no parity mode at all.

1. Read the baseline. git -C <original> rev-parse HEAD. This is the

commit the evidence ledger's coordinates will refer to, so record the SHA and the date you read it.

1. Confirm the module. A port often covers one directory of a larger

original (apps/foo), not the whole repo. Ask when the original has an obvious multi-module layout.

1. Policy root. docs/policies/ if present; otherwise propose it and say

it will be created on first use.

1. Write two files.

• seal/parity.md from templates/parity.md, committed. Coordinate-trust

exceptions start empty.

• ~/.claude/specseal/parity-paths.md — the machine-local checkout path,

keyed by this repo's origin remote URL so worktrees and second checkouts resolve to one entry. This never goes in the committed file: it is wrong for every other machine.

1. Show the result and say what changes now. Name the legacy-parity

skill, the scribe agent, and that divergence from the original now needs grounds rather than preference. Say the consequence they will feel first, too: from this file onward, a commit touching anything outside the document roots stops and asks whether the original was consulted, and it keeps asking until legacy-parity has recorded the compared HEAD in <git-dir>/specseal-parity — .git/ in a plain checkout, but .git/worktrees/<name>/ in a worktree, so write it through git rev-parse --git-dir rather than a literal path. [no-parity] skips one commit as a bare word typed in FRONT of it — : '[no-parity]'; git commit …, quotes included, because after git commit a bare word is a pathspec and git rejects the whole command; inside a longer message it is prose and the prompt still appears. Two cases read as bare anyway, both measured: a message that is nothing but the marker leaves the marker as a bare token once the quotes come off, and a command the gate cannot tokenize falls back to a substring search that finds it anywhere.

What this does not decide

Whether the port is a good idea, what to port, or in what order. It records where the truth lives so that later disagreements have somewhere to appeal.