# Compare Maps

> Compare two reviewed Modbus maps and report added, removed, moved, changed, and unresolved points. Use when the user compares firmware/map revisions or asks what changed between two validated maps.

- Skill: `studioxvii/compare-maps` (Agent Skill, multi-file: 3 files)
- Install (CLI): `npx skillmds@latest add studioxvii/compare-maps`
- Raw SKILL.md: https://api.skillmd.com/api/skills/studioxvii/compare-maps/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Docs & Writing
- License: Apache-2.0
- Author: studioxvii (https://skillmd.com/u/studioxvii)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/studioxvii/compare-maps

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# Compare Maps

Compare normalized maps while preserving evidence from both sides.

Follow `../../references/interaction-contract.md`.

## Process

1. Normalize both inputs without changing unresolved engineering values.
2. Run `python3 <skill-dir>/scripts/run.py --before <old.json> --after <new.json> --output <diff.json>`.
3. Report added, removed, moved, changed, and unresolved points.
4. Treat route, unit, area, or protocol-offset changes as moves when logical identity remains stable.
5. Highlight address, datatype, width, access, scale, byte-order, enum, and evidence changes.

## Output files

- `diff.json` - Open this comparison. It lists added, removed, moved, changed, and unresolved points without changing either input map.

Completion requires every point from both inputs to have a disposition.

## Stop

- Stop on schema mismatch or unresolved composite identity.
- Do not treat numeric address alone as identity.
- Do not collapse points from different routes, areas, or unit identifiers.

## Handoff

- The new source still needs review: suggest `review-map`.
- The requested change is only address notation: suggest `remap-addresses`.

Use composite identity. Numeric address alone is not an identity.