writing-an-implementation-plan

writing-an-implementation-plan is a skill for Claude Code from redhuntlabs/wizard. It costs 30 tokens per session (1,195 once invoked), scanned A, original, MIT.

A skill that turns a chosen feature specification into a step-by-step implementation plan with file-level changes, dependencies, checks, risks, rollback steps, and acceptance criteria.

In plain words
What is it for?
Use it after a product requirements document or design decision to plan which files change, in what order, how each step is verified, and how the work can be rolled back.
Why use it?
It makes non-trivial work easier to hand to another developer or continue later without repeatedly rediscovering the approach.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the wizard plugin — 37 skills, 6 commands, 1 agent, 1 hook 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/redhuntlabs/wizard/writing-an-implementation-plan
Any agent
npx skills add redhuntlabs/wizard --skill writing-an-implementation-plan
Clone the repo
git clone --depth 1 https://github.com/redhuntlabs/wizard

Made for: Claude Code.

Or install wizard, the plugin that ships this one along with the rest of its 37 skills, 6 commands, 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 writing-an-implementation-plan

README.md
[![agentmods](https://agentmods.dev/badge/skills/redhuntlabs/wizard/writing-an-implementation-plan.svg)](https://agentmods.dev/skills/redhuntlabs/wizard/writing-an-implementation-plan)
Your own site
<a href="https://agentmods.dev/skills/redhuntlabs/wizard/writing-an-implementation-plan"><img src="https://agentmods.dev/badge/skills/redhuntlabs/wizard/writing-an-implementation-plan.svg" alt="Measured on agentmods" height="20"></a>
Per session 30 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,195 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 $0.00030 $0.01195
Opus 5 $0.00015 $0.00598
Sonnet 5 $0.00006 $0.00239
Haiku 4.5 $0.00003 $0.00120

Measured 6d ago against content hash b723096daa0d, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

writing-an-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 6d 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.

spells/dev/writing-an-implementation-plan/SKILL.md · 137 lines

How it starts

The opening of the file, as written. The whole thing — 137 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Writing an Implementation Plan

What this does

Turns a feature spec (output of brainstorming-a-feature, or a written PRD) into an executable implementation plan: file-level changes, ordering, checkpoints, risks, and rollback. Designed so a different person — or future-you in a different session — could execute it without asking clarifying questions.

When to use

  • After a feature has been brainstormed and an approach chosen
  • Before starting to code any non-trivial feature
  • When handing implementation to someone else
  • When the work spans multiple sessions and needs continuity

What you bring (Inputs)

  • The chosen approach (from brainstorming-a-feature or a PRD)
  • Read access to the codebase
  • The acceptance criteria (how will we know it's done)

What you get (Output)

A plan document with: scope, file-level changes (paths + what changes), ordering with dependencies, per-step verification, risks and rollback, and the acceptance criteria.

How it works (Steps)

This is a workflow.

Stages

Stage 1: Restate scope

In one paragraph, restate what's being built and what's explicitly out of scope. Out-of-scope is critical — it prevents drift mid-implementation.

Stage 2: Inventory file-level changes

Walk the codebase and list every file that needs to change. For each: full path + 1-3 line description of what changes there.

If you're adding new files, list them too.

If you're not sure which files need to change for a given concern, that's a discovery task — note it explicitly.

Stage 3: Order the steps

Order is important. Rules of thumb:

  • Foundations first (data model → API → UI)
  • Each step should leave the system in a working state if possible
  • Risky steps early (so you discover unknowns before you've sunk cost)
  • Steps should be independently verifiable

Stage 4: Define per-step verification

For each step: how will you know it worked? Examples:

  • Unit test passes
  • Curl a specific endpoint and see expected response
  • Open the page and see the new component
  • Migration runs without error and rollback also works

Read the full file on GitHub · 137 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. 6d ago First seen · 137 lines · 30 tokens per session scan A b723096daa0d

Subscribe to this mod's changes

writing-an-implementation-plan is a skill published in the GitHub repository redhuntlabs/wizard (9 stars, last pushed 4mo ago), licensed MIT. It adds 30 tokens to every session and 1,195 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.