feature-development-prepare

feature-development-prepare is a skill for Claude Code, Codex from protect-my-hair/nucleus-marketplace. It costs 26 tokens per session (2,687 once invoked), scanned A, original, MIT.

A preparation workflow for creating an implementation plan that can be reviewed before development starts.

In plain words
What is it for?
Use it when one clearly defined feature has its requirements and feature document ready, and you need a reviewable development plan.
Why use it?
It ties the plan to the feature requirements, project rules, and any relevant interface designs, while making missing information visible.

Skill for Claude CodeCodex

Written for Claude Code and Codex: SessionStart hook event, but also agents/openai.yaml present. Also seen: mentions subagents; names the TodoWrite tool; mentions Claude Code.

Part of the nucleus plugin — 27 skills, 1 agent, 1 hook shipped together

Good fit Use it when one clearly defined feature has its requirements and feature document ready, and you need a reviewable development plan.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/protect-my-hair/nucleus-marketplace/feature-development-prepare
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add protect-my-hair/nucleus-marketplace --skill feature-development-prepare
Clone the repo
git clone --depth 1 https://github.com/protect-my-hair/nucleus-marketplace

Made for: Claude Code, Codex.

Or install nucleus, the plugin that ships this one along with the rest of its 27 skills, 1 agent, 1 hook.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for feature-development-prepare

README.md
[![agentmods](https://agentmods.dev/badge/skills/protect-my-hair/nucleus-marketplace/feature-development-prepare/github.svg)](https://agentmods.dev/skills/protect-my-hair/nucleus-marketplace/feature-development-prepare)
Your own site
<a href="https://agentmods.dev/skills/protect-my-hair/nucleus-marketplace/feature-development-prepare"><img src="https://agentmods.dev/badge/skills/protect-my-hair/nucleus-marketplace/feature-development-prepare/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for feature-development-prepare

Your own site · 80×15
<a href="https://agentmods.dev/skills/protect-my-hair/nucleus-marketplace/feature-development-prepare"><img src="https://agentmods.dev/badge/skills/protect-my-hair/nucleus-marketplace/feature-development-prepare.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 26 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,687 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00026 $0.02687
Opus 5 $0.00013 $0.01344
Sonnet 5 $0.00005 $0.00537
Haiku 4.5 $0.00003 $0.00269

Measured 13d ago against content hash 58a7f8596f32, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

feature-development-prepare scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 13d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/feature_development_prepare.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

plugins/nucleus/skills/feature-development-prepare/SKILL.md · 129 lines

How it starts

The opening of the file, as written. The whole thing — 129 lines — stays where its author put it; the contents beside it link to each section on GitHub.

特性开发准备

前置:使用本 Skill 前,先按 using-nucleus 完成 Nucleus 入口识别(Claude Code 会话由插件 SessionStart hook 自动注入该纪律)。

核心原则

实施计划必须绑定当前阶段真实依赖;它不是脱离 primary feature、特性文档、需求输入和已存在 UI 设计源的普通任务清单。

生成实施计划前必须扫描目标仓库 docs/specs/** 规范事实源,并把适用 rules、缺失 rules 或 setup gap 写入 developmentSpecs;缺失规范不得被静默当作“无要求”。

生成实施计划前必须把 primary feature、需求输入、docs/specs/** 和 UI 设计源发现结果固化为 .nucleus/runs/<workflowRunId>/spec-anchor.json;实施计划必须包含 specAnchor,声明 facts manifest hash、reload policy、pre-edit gate 和 completion gate,供上下文压缩 / 恢复 / 阶段切换后重读。

发现 docs/ui-design/**/*.pendocs/ui-design/**/ui-prototype.md 或用户 / context 明确提供 UI 设计源时,实施计划必须先区分“当前特性相关设计源”和“仓库候选设计源”;相关设计源必须把 UI 设计源、Pencil frame / UI 状态映射、公共组件 / 公共样式契约和视觉证据路径写成阻塞型验收项;候选设计源必须进入人工计划确认,未确认相关性前不得写 UI 源码。

请求开发计划人工评审前,必须先按 _shared/references/subagent-precheck-protocol.md 执行 subagentPreReview 子代理预审;未取得“材料可提交人工审查”预审结论时,不得请求人工批准计划。

什么时候使用

使用本 Skill:

  • 在当前阶段 context 中已有恰好一个 primary feature,且 docs/features/**/feature.md 与需求 / 拆解输入可读时,为该特性准备实施计划。
  • 生成回链到 primary feature、特性文档和需求 / 拆解输入的可评审实施计划:Markdown 是人工计划主入口,JSON 是机器事实源和下游输入。

不要使用本 Skill:

  • 当前特性文档缺失、需求 / 拆解输入缺失、没有明确单一 primary feature 时。
  • 改源码、测试、特性文档、需求文档,或提交、推送、创建 PR/MR、关闭缺陷。
  • 把计划写成脱离特性文档的独立 coding checklist。

Checklist

启动本 Skill 后,必须先为每一项创建宿主 todo/task,并按顺序逐项推进、逐项更新状态;Claude Code 用 TodoWrite 或等价宿主 todo,Codex 用计划 / 任务工具。.nucleus/runs/**summary.mdresult.json 只能记录事实,不能替代宿主任务、人工计划确认或人工评审事实。

  1. 读取 context 和输入 完成证据:已读 .nucleus/context/<workflowRunId>.json,以及声明 read-only 的需求方案 artifact。 STOP:未读 context 或需求拆解输入时,不得生成任何计划。

  2. 校验恰好一个 primary feature 且 feature.md 存在 完成证据:context 中恰好一个 features[].role=primary,且其 docs/features/**/feature.md 已存在。 STOP:缺 primary、多于一个 primary,或 primary feature 文件不存在时,返回 FAILED_BLOCKED

  3. 校验需求 / 拆解输入可读 完成证据:需求 / 拆解输入 artifact 存在、路径合法、read-only 且已记录 hash。 STOP:输入缺失、不可读、路径越界或写策略不符合边界时,ALERT_AND_BLOCK

Read the full file on GitHub · 129 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 13d ago First seen · 129 lines · 26 tokens per session scan A 58a7f8596f32

Subscribe to this mod's changes

feature-development-prepare is a skill published in the GitHub repository protect-my-hair/nucleus-marketplace (162 stars, last pushed 1mo ago), licensed MIT. It adds 26 tokens to every session and 2,687 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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