plan-project

plan-project is a skill for Claude Code, Codex from martian56/claude-engineer. It costs 44 tokens per session (606 once invoked), scanned A, original, MIT.

A planning workflow for turning an agreed project brief into a phased implementation plan across multiple files. It requires a person to approve the plan before any building starts.

In plain words
What is it for?
Use it to plan projects involving design, frontend, backend, integrations, testing, and delivery, including work in a monorepo—a repository that contains several related projects.
Why use it?
It prevents coding from beginning before the work, file changes, priorities, and decisions are clear. It also keeps the plan in project files for later reference.

Skill for Claude CodeCodex

Part of the claude-engineer plugin — 13 skills, 1 command, 2 agents, 3 hooks shipped together

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/martian56/claude-engineer/plan-project
Any agent
npx skills add martian56/claude-engineer --skill plan-project
Clone the repo
git clone --depth 1 https://github.com/martian56/claude-engineer

Made for: Claude Code, Codex.

Or install claude-engineer, the plugin that ships this one along with the rest of its 13 skills, 1 command, 2 agents, 3 hooks.

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 plan-project

README.md
[![agentmods](https://agentmods.dev/badge/skills/martian56/claude-engineer/plan-project.svg)](https://agentmods.dev/skills/martian56/claude-engineer/plan-project)
Your own site
<a href="https://agentmods.dev/skills/martian56/claude-engineer/plan-project"><img src="https://agentmods.dev/badge/skills/martian56/claude-engineer/plan-project.svg" alt="Measured on agentmods" height="20"></a>
Per session 44 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 606 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 $0.00044 $0.00606
Opus 5 $0.00022 $0.00303
Sonnet 5 $0.00009 $0.00121
Haiku 4.5 $0.00004 $0.00061

Measured 5d ago against content hash 7c79313a9e83, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

plan-project 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.

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/claude-engineer/skills/plan-project/SKILL.md · 35 lines

How it starts

The opening of the file, as written. The whole thing — 35 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Plan Project

Announce at start: "I'm using claude-engineer:plan-project to produce the phased plan."

Iron Law

NO BUILD WORK BEFORE THE USER SIGNS OFF ON THE PLAN. Violating the letter is violating the spirit.

Procedure (create a task per step)

  1. Decompose with superpowers:writing-plans - turn the agreed brief into bite-sized, testable tasks; map the file structure first; right-size tasks; bake in DRY/YAGNI/TDD.
  2. Impose the customer-experience-first phase order. Default phases:
    • Phase 0 - Conventions & scaffold (project-conventions, monorepo-and-tooling, docker-dev-environment).
    • Phase 1 - Design system (design-system: DESIGN.md is the source of truth).
    • Phase 2 - Frontend shells & components (frontend-development, on-token, WCAG AA).
    • Phase 3 - Backend APIs & data (backend-development).
    • Phase 4 - Integration & end-to-end flows.
    • Phase 5 - Quality, CI/CD, finish (testing-and-quality, ci-cd-pipeline).
  3. Write the plan as multiple files under docs/plan/ - 00-overview.md plus one file per phase (01-design-system.md, 02-frontend.md, …), each with goals, tasks, file targets, and the per-phase "definition of done" (the four quality gates).
  4. Record a decision log at docs/plan/decisions.md (every non-obvious choice + why).
  5. Initialize durable state via claude-engineer:project-memory (creates .claude-engineer/memory.md, progress.md, current-phase.txt).
  6. HARD SIGN-OFF GATE. Present the plan and explicitly ask the user to approve. Do not proceed to claude-engineer:execute-build until they do.

Quality bar baked into every phase's "done"

Tests + coverage · Playwright E2E with zero console errors · WCAG AA · strict types + lint clean. (See claude-engineer:testing-and-quality.)

Red flags - STOP

  • About to scaffold/build code while still "planning" → stop; finish the plan and get sign-off.
  • A phase has no concrete "definition of done" → add the four gates.
  • The plan lives in one giant file → split into docs/plan/* so it survives and stays scannable.

Read the full file on GitHub · 35 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 · 35 lines · 44 tokens per session scan A 7c79313a9e83

Subscribe to this mod's changes

plan-project is a skill published in the GitHub repository martian56/claude-engineer (2 stars, last pushed 2mo ago), licensed MIT. It adds 44 tokens to every session and 606 once invoked, about $0.0002 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.