implementation

An implementation skill helps an agent follow the coding rules and architecture of the part of a project it changes. Architecture means the way a codebase is divided into parts and responsibilities.

In plain words
What is it for?
It is for finding and following relevant project instructions when writing code or changing module structure.
Why use it?
It reduces the risk of adding code that conflicts with local conventions or puts logic in the wrong place.

Skill for Claude CodeCodex

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.

agentmods
npx agentmods add skills/sei-newbear/xp-harness/implementation
Any agent
npx skills add sei-newbear/xp-harness --skill implementation
Clone the repo
git clone --depth 1 https://github.com/sei-newbear/xp-harness

Made for: Claude Code, Codex.

Per session 132 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 587 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00132 $0.00587
Opus 5 $0.00066 $0.00293
Sonnet 5 $0.00026 $0.00117
Haiku 4.5 $0.00013 $0.00059

Measured 2d ago against content hash 588ae0c38644, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

implementation 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 2d ago.

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.

.apm/skills/implementation/SKILL.md · 20 lines

What it actually says

実装の規約とアーキテクチャ

プロジェクト固有のコード規約・アーキテクチャ方針を実装に効かせるためのスキル。「どう進めるか」(リズム・分割) ではなく、「コードが何を満たすか」(規約・構造) を扱う。規約そのものはプロジェクト側にあり、このスキルはそれを探して効かせる入口。

関連する実装の規約・アーキテクチャ方針を探して従う

このスキルが呼ばれるたびに、以下を行う(1 つの作業の中で触る範囲が別の領域に移ったら、その都度やり直す):

  1. 触る範囲を特定する: いま読み書きしようとしているファイルのディレクトリ / 領域を特定する(例: front 配下と api 配下で規約が分かれている場合、どちらの領域の作業かを特定する)
  2. 範囲に対応する規約・アーキテクチャ方針を探す:
    • セッションに登録されているスキル(このスキル自身を除く)にその範囲の実装規約を扱うものがあれば、(参照して読むのではなく)スキルとして呼ぶ
    • スキルでない規約ファイル(その領域のディレクトリ配下の CLAUDE.md / AGENTS.md 等のドキュメント)があれば、読む
  3. 見つけた規約・アーキテクチャ方針に従って作業する
  4. 見つからなければ、規約をでっち上げない: 一般に良いとされる判断で進める
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. 2d ago First seen · 20 lines · 132 tokens per session scan A 588ae0c38644

Subscribe to this mod's changes

implementation is a skill published in the GitHub repository sei-newbear/xp-harness (9 stars, last pushed 25d ago), licensed MIT. It adds 132 tokens to every session and 587 once invoked, about $0.0007 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 2026-08-31.

Related

Other skills, from other repositories

systematic-debugging

Use when encountering any bug, test failure, or unexpected behavior, before proposing fixes.

obra/superpowers · 21 tokens

next-cache-components-adoption

Turn on Cache Components in a Next.js app and resolve the blocking routes it surfaces. Use when the user wants to enable, adopt, or migrate to Cache Components, flip the cacheComponents flag, work through a flood of blocking-prerender / instant validation errors, run the cache-components-instant-false codemod, or…

vercel/next.js · 95 tokens

babysit-pr

Babysit a GitHub pull request after creation by continuously polling review comments, CI checks/workflow runs, and mergeability state until the PR is merged/closed or user help is required. Diagnose failures, retry likely flaky failures up to 3 times, auto-fix/push branch-related issues when appropriate, and keep…

openai/codex · 114 tokens

imagegen

Generate or edit raster images when the task benefits from AI-created bitmap visuals such as photos, illustrations, textures, sprites, mockups, or transparent-background cutouts. Use when Codex should create a brand-new image, transform an existing image, or derive visual variants from references, and the output…

openai/codex · 113 tokens

cpu-profile-analysis

Analyze V8/Chrome CPU profiles (.cpuprofile) and DevTools trace files (Trace-.json). Use when: profiling performance, investigating slow functions, comparing code paths, finding bottlenecks, analyzing timeToRequest, understanding call trees from sampling profiler data, analyzing layout/paint/rendering, investigating…

microsoft/vscode · 71 tokens

next-cache-components-optimizer

Drive a Next.js route to instant navigation by setting up an agentic loop, under Cache Components / PPR, on initial load (hard navigation) and client-side navigation (soft navigation). Encode the goal as a failing @next/playwright instant() e2e and work it to green, one verified route at a time; the shipped test then…

vercel/next.js · 170 tokens