spec

Define contract-level behavior specifications before execution planning.

3|Updated Apr 19, 2026
One-click install
npx skills add https://github.com/xiongxianfei/rigorloop --skill spec-xiongxianfei
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: spec
Source: https://github.com/xiongxianfei/rigorloop/tree/main/.codex/skills/spec
Command: npx skills add https://github.com/xiongxianfei/rigorloop --skill spec-xiongxianfei

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

Writing contract-level specifications before execution planning ensures that system behavior, APIs, UI, data contracts, error handling, and security requirements are clearly defined and verifiable.

Core Features & Use Cases

  • Establishes observable contracts before changes, reducing ambiguity and rework.
  • Serves as the canonical reference for APIs, UI flows, and data formats across teams.
  • Use Case: when starting a new feature, draft a spec that captures goals, success criteria, and acceptance tests to guide design and implementation.

Quick Start

Create a new spec document under specs/slug.md to begin detailing the contract before planning.

Frequently Asked Questions about spec

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I write a contract-level specification before execution planning?

To write a contract-level specification, define externally observable behavior, APIs, UI, data contracts, and error handling. Include status, goals, inputs/outputs, constraints, acceptance criteria, and risks to ensure clear, testable expectations before execution planning.

What should a specification artifact include for API and UI changes?

A specification artifact for API and UI changes should include status, goals, inputs/outputs, constraints, acceptance criteria, risks, and follow-on artifacts. This ensures clear, testable expectations for externally observable behavior and data formats.

When do I need a contract-level spec for software development?

You need a contract-level spec when making changes affecting externally observable behavior, APIs, UI, config, data contracts, error handling, compatibility, security, or safety-sensitive logic across software systems to reduce ambiguity and rework.

How do I start drafting a new feature specification?

To start drafting a new feature specification, create a document to capture goals, success criteria, and acceptance tests. This guides design and implementation by establishing observable contracts before changes are made.

What is the best way to define testable expectations for system behavior?

The best way to define testable expectations for system behavior is to draft a contract-level specification that captures inputs, outputs, constraints, and acceptance criteria, serving as a canonical reference for APIs and data formats.

Does writing specifications before planning reduce rework?

Writing specifications before planning reduces rework by establishing observable contracts early. This defines clear, verifiable expectations for system behavior, APIs, and UI flows across teams.