spec

Agentic skills based on the standard SDLC workflow. These are the skills I use daily to build software.

インストール
CLI
npx skills add https://github.com/owainlewis/blueprint --skill spec

CLI を使用してこのスキルをインストールし、ワークスペースで SKILL.md ワークフローの使用を開始します。

最終更新日: 4/24/2026

Blueprint

A collection of agent skills for running the software development lifecycle.

Why Blueprint

Good software follows a process: understand what to build, plan the work, build it in small pieces, test it, review it, and ship it. Blueprint encodes that process as a small set of reusable agent skills.

The skills are short, focused, and opinionated. They give the agent clear goals and get out of the way. As models get more capable, that approach gets better — not worse.

Blueprint is agent-agnostic. The same skills can be used from Claude Code, Codex, Cursor, OpenCode, and other agents that support local skills.

9 skills. You can read the entire framework in 15 minutes.

The Flow

flowchart TB
    Brief["Idea / Brief"] --> Spec["Spec"]
    Spec --> Plan["Plan"]
    Plan --> Build["Build"]
    Build --> Review["Review"]
    Review --> Commit["Commit"]
    Commit --> Ship["Ship"]

For each task in the plan:

flowchart TB
    Task["Planned Task"] --> Build["Build"]
    Build --> Test["Test"]
    Test --> Review["Review"]
    Review --> Commit["Commit"]
    Review -. if changes needed .-> Build
Write a spec for user-auth adding OAuth login with Google and GitHub.
Create a plan for user-auth.
Implement Task 1 from user-auth.
Review the current changes.
Commit the current changes.

Writing Specs for Agents

Blueprint generates markdown specs and plans that live in your repo. These are instructions for agents, not design documents for humans.

Your real design thinking happens elsewhere — in Confluence, on a whiteboard, in a conversation with your team. What lands in the repo is the distilled brief an agent needs to build correctly: what we're building, why, how it fits into the existing system, and what order to build it in.

This is why Blueprint uses a single spec rather than separate requirements, architecture, and planning documents. An agent doesn't need hand-offs between phases or sign-off gates between documents. Two docs, two concerns: what are we building (spec) and how to build it and in what order (plan).

Keep specs short. If a spec is getting long, the feature is too big — split the feature, not the document.

Install

npx skills add owainlewis/blueprint

Install Blueprint with the skills CLI. This is the simplest setup and works across agents that support local skills.

Update

npx skills update

Run this to update Blueprint and your installed skills to the latest version.

How you invoke a skill depends on the agent:

  • Some agents expose slash commands
  • Some expose a skill picker
  • Some work best when you ask for a skill by name in natural language

Blueprint itself is just the skill content.

Skills

Planning

Specs and plans are written to docs/<feature>/ — one directory per feature, no collisions.

Skill What it does Example
spec Write a spec: requirements, technical design, and testing strategy Write a spec for user-auth adding OAuth login
plan Break a spec into tasks you can give to an AI coding agent to implement Create a plan for user-auth

Building

Skill What it does Example
build Execute a task — write code, write tests if relevant, verify it works Implement Task 2 from user-auth
tdd Build test-first: failing tests, then implementation, then simplify Use TDD for retry logic in the API client

Use build for most work. Use tdd when you want test-first discipline — the agent must write failing tests before any implementation code.

Quality

Skill What it does Example
review Code review — correctness, security, simplicity, robustness Review the current diff
refactor Simplify code without changing behavior Refactor src/api/routes.py
coverage Fill test gaps with tests that catch realistic bugs Add high-value tests for src/auth/
debug Systematic root-cause debugging: observe, hypothesize, test, fix Debug the API returning 500 on POST

Git

Skill What it does Example
commit Stage and commit with a clear conventional commit message Commit the current changes

Philosophy

Encode the process, not the rules. The value is in the sequence — spec before code, tests alongside implementation, review before ship. Get the sequence right and the agent does the rest.

Specs are for agents. Your design thinking happens in Confluence, on whiteboards, in conversations. What lands in markdown is the minimum an agent needs to build correctly.

Simplicity scales. Short, focused skills that trust the model outperform heavy frameworks full of guardrails. One focused review catches more real bugs than 16 agents generating noise.

Small safe changes win. Preserve contracts, handle failure paths explicitly, and prefer the smallest change that fully solves the problem.

Core SDLC only. Blueprint encodes the development lifecycle — planning, building, testing, reviewing, shipping. Integrations with specific tools (Linear, Jira, Slack) are a separate concern and belong in separate plugins.

Example

The examples/ folder shows the planning output for a Python RAG chatbot API:

  1. input.md — rough project notes
  2. spec.md — the spec
  3. plan.md — ordered tasks

Learn More

https://www.skool.com/aiengineer