simon-dev

simon-dev is a skill for Claude Code, Codex from SW-in-beta/simon-skills. It costs 170 tokens per session (12,339 once invoked), scanned A, original, MIT.

A 19-step workflow for planning, building, and checking software features. It can also use expert review, parallel Git worktrees, and strict verification before a pull request.

In plain words
What is it for?
Use it to build new features, create a structured implementation plan, run parallel work in Git worktrees, and perform a full pre-pull-request code check.
Why use it?
It gives feature work a defined path from plan to implementation and checks, reducing the risk of missing important steps. It also separates vague requests from work that is ready to plan.

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/sw-in-beta/simon-skills/simon-dev
Any agent
npx skills add SW-in-beta/simon-skills --skill simon-dev
Clone the repo
git clone --depth 1 https://github.com/SW-in-beta/simon-skills

Made for: Claude Code, Codex.

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 simon-dev

README.md
[![agentmods](https://agentmods.dev/badge/skills/sw-in-beta/simon-skills/simon-dev.svg)](https://agentmods.dev/skills/sw-in-beta/simon-skills/simon-dev)
Your own site
<a href="https://agentmods.dev/skills/sw-in-beta/simon-skills/simon-dev"><img src="https://agentmods.dev/badge/skills/sw-in-beta/simon-skills/simon-dev.svg" alt="Measured on agentmods" height="20"></a>
Per session 170 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 12,339 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 5.1 $0.00170 $0.12339
Opus 5 $0.00085 $0.06169
Sonnet 5 $0.00034 $0.02468
Haiku 4.5 $0.00017 $0.01234

Measured 5d ago against content hash 5d95a0cb3c17, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-05, from the pricing page.

Security

Grade A, and why

simon-dev 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 5d ago.

The scan reads SKILL.md. This mod also ships 3 executable files (scripts/create-branch.sh, scripts/create-unit-worktree.sh, scripts/merge-units.sh), 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.

skills/simon-dev/SKILL.md · 494 lines

How it starts

The opening of the file, as written. The whole thing — 494 lines — stays where its author put it; the contents beside it link to each section on GitHub.

simon-dev

Deep workflow skill with 19-step quality pipeline.

Instructions

You are executing the simon-dev deep workflow. This is a 19-step quality pipeline that plans, implements, and verifies code with maximum rigor.

요청이 심하게 막연하여 해석 자체가 갈리는 경우(목표·대상·형태가 모두 불특정), Phase A에 진입하지 말고 simon-resolve-unknowns 스킬로 발산 단계를 먼저 제안한다 (파이프라인: resolve-unknowns → plan → dev).

State-Driven Execution

매 턴(응답) 시작 시 반드시 실행하는 루틴 — compaction, 세션 재개, 작업 전환 후 복귀 등 어떤 상황에서도 적용된다. 이 루틴이 없으면 compaction 후 현재 위치를 잃고 이전 Step을 반복하거나 건너뛸 수 있다:

  1. {SESSION_DIR}/memory/workflow-state.json 읽기

  2. current_step에 해당하는 Phase의 reference 목록 확인 (Reference Loading Policy 테이블)

  3. references_loaded 필드에 해당 reference가 없거나, 있더라도 loaded_at이 현재 session_id 이전이면 → 재로딩. 그 외에는 → 스킵. Compaction 감지는 결정론적 JSON 비교로 수행한다 — 아래 보조 조건 중 하나라도 해당하면 재로딩 트리거:

    • 조건 1: 세션 재개 (session_id 불일치 또는 없음)
    • 조건 2: /compact 명령 직후
    • 조건 3: loaded_at이 현재 session_id(ISO-8601) 이전인 Tier 1 항목이 존재 (compaction 소실 의심)
    • 조건 4: 매 턴 시작 시 Tier 1 파일 하나라도 references_loaded에 없음 (방어적 재로딩)

    Compaction 감지 시 Tier별 선택적 초기화: Tier 1은 강제 재로딩, Tier 2는 현재 Phase에 해당하는 것만 재로딩, Tier 3는 초기화하지 않음 (on-demand 트리거로 자연스럽게 재로딩). "이전에 읽었으니 알고 있다"가 LLM 기억이 아닌 JSON 기록에 기반해야 핵심 규칙 소실을 방지한다.

    원칙: "기억 판단 비용 > 1개 파일 재로딩 비용" — 의심스러우면 재로딩한다. 3-B. 이전 Step 산출물 로딩 (세션 독립성 핵심): step_outputs[prev_step]에 기록된 파일들을 로딩한다.

  • 새 세션 감지 시 (workflow-state.json의 session_id가 현재 Startup에서 설정한 값과 다르거나 없으면): 반드시 로딩
  • 동일 세션 내: 이미 컨텍스트에 있으면 스킵
  • Why: 새 세션에서 Step N을 시작할 때 Step N-1의 산출물 파일이 컨텍스트에 없으면 잘못된 판단이나 중복 작업이 발생한다. step_outputs는 Step 완료 시 기록되므로, 이 파일들을 로딩하면 이전 Step의 결과를 즉시 복원할 수 있다.
  1. 해당 Step 실행
  2. Step 완료 즉시 workflow-state.json 갱신 (references_loaded + step_outputs 포함)

workflow-state.json이 없으면 Startup부터 시작한다.

갱신 규칙: Step 시작 시 current_step, 완료 시 completed_steps+next_step, Phase 전환 시 current_phase+phase_timestamps 갱신. 중단/에러: blocked: true. Step skip 시 skipped_steps 기록. Phase A 완료 시 Done-When Checks → done_when_checks 배열 추출 (verified: false 초기값). Step 5d/6/17 검증 통과 시 verified: true 갱신. Step 17에서 verified: false 잔존 시 FAIL — JSON boolean은 명시적 갱신이 필요하므로 LLM의 임의 체크 방지.

Read the full file on GitHub · 494 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. 5d ago First seen · 494 lines · 170 tokens per session scan A 5d95a0cb3c17

Subscribe to this mod's changes

simon-dev is a skill published in the GitHub repository SW-in-beta/simon-skills (2 stars, last pushed 1mo ago), licensed MIT. It adds 170 tokens to every session and 12,339 once invoked, about $0.0009 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.

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