create-implementation-plan

A format for writing detailed implementation plans for features, refactoring, package upgrades, design, architecture, or infrastructure work. The plans use discrete phases, executable tasks, dependencies, and measurable completion criteria.

In plain words
What is it for?
Creating self-contained plans for software changes, with parallel work where possible and explicit criteria for knowing when each phase is complete.
Why use it?
It turns a broad coding request into clear steps that another developer or coding agent can follow without filling in missing decisions.

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/thangchung/agent-engineering-experiment/create-implementation-plan
Any agent
npx skills add thangchung/agent-engineering-experiment --skill create-implementation-plan
Clone the repo
git clone --depth 1 https://github.com/thangchung/agent-engineering-experiment

Made for: Claude Code, Codex.

Per session 29 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,021 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 84% copy Near-identical to another mod 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 $0.00029 $0.02021
Opus 5 $0.00015 $0.01010
Sonnet 5 $0.00006 $0.00404
Haiku 4.5 $0.00003 $0.00202

Measured 2d ago against content hash 5501088e57ff, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

create-implementation-plan 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.

Origin

This is a copy

84% identical to create-implementation-plan — 39 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

agentgateway-entraid-obo/.claude/skills/create-implementation-plan/SKILL.md · 185 lines

How it starts

The opening of the file, as written. The whole thing — 185 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Create Implementation Plan

Primary Directive

Your goal is to create a new implementation plan file for ${input:PlanPurpose}. Your output must be machine-readable, deterministic, and structured for autonomous execution by other AI systems or humans.

Execution Context

This prompt is designed for AI-to-AI communication and automated processing. All instructions must be interpreted literally and executed systematically without human interpretation or clarification.

Core Requirements

  • Generate implementation plans that are fully executable by AI agents or humans
  • Use deterministic language with zero ambiguity
  • Structure all content for automated parsing and execution
  • Ensure complete self-containment with no external dependencies for understanding

Plan Structure Requirements

Plans must consist of discrete, atomic phases containing executable tasks. Each phase must be independently processable by AI agents or humans without cross-phase dependencies unless explicitly declared.

Phase Architecture

  • Each phase must have measurable completion criteria
  • Tasks within phases must be executable in parallel unless dependencies are specified
  • All task descriptions must include specific file paths, function names, and exact implementation details
  • No task should require human interpretation or decision-making

AI-Optimized Implementation Standards

  • Use explicit, unambiguous language with zero interpretation required
  • Structure all content as machine-parseable formats (tables, lists, structured data)
  • Include specific file paths, line numbers, and exact code references where applicable
  • Define all variables, constants, and configuration values explicitly
  • Provide complete context within each task description
  • Use standardized prefixes for all identifiers (REQ-, TASK-, etc.)
  • Include validation criteria that can be automatically verified

Output File Specifications

  • Save implementation plan files in /plan/ directory
  • Use naming convention: [purpose]-[component]-[version].md
  • Purpose prefixes: upgrade|refactor|feature|data|infrastructure|process|architecture|design
  • Example: upgrade-system-command-4.md, feature-auth-module-1.md
  • File must be valid Markdown with proper front matter structure

Read the full file on GitHub · 185 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. 2d ago First seen · 185 lines · 29 tokens per session scan A 5501088e57ff

Subscribe to this mod's changes

create-implementation-plan is a skill published in the GitHub repository thangchung/agent-engineering-experiment (24 stars, last pushed 1mo ago), licensed MIT. It adds 29 tokens to every session and 2,021 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. It is 84% identical to create-implementation-plan, differing in 39 lines, and is treated as a copy.

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