# Build Contract Design

> Build Contract Design

- Skill: `onfire7777/build-contract-design` (Agent Skill)
- Install (CLI): `npx skillmds@latest add onfire7777/build-contract-design`
- Raw SKILL.md: https://api.skillmd.com/api/skills/onfire7777/build-contract-design/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: onfire7777 (https://skillmd.com/u/onfire7777)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/onfire7777/build-contract-design

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# Build Contract Design

Purpose: Give frontend and backend agents a stable implementation boundary.

1. Define data shapes, endpoints, and UI states.
2. Mark assumptions and non-goals.
3. Specify validation and rollback expectations.
4. Keep the contract small enough to build in one loop.

Checklist:

- Frontend and backend responsibilities are separated.
- Acceptance criteria map to checks.
- Risks have owners.
- Contract changes require a new handoff.

Positive example: endpoint schema plus dashboard state map.
Negative example: leave API shape to builder preference.

Failure modes: ambiguous boundary, missing tests, contract drift.