A planning guide for non-trivial software changes. It requires a written implementation plan covering the goal, scope, files, steps, success conditions, and risks before coding begins.

Planning new commands, workflows, structural changes, or template updates, with the plan saved as a dated Markdown file.

It helps clarify a multi-file change in advance and gives the person implementing it a shared checklist to follow.

create-plan — Skill for Claude Code by mishahanin/heading-os

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.

Any agent

npx skills add mishahanin/heading-os --skill create-plan

Clone the repo

git clone --depth 1 https://github.com/mishahanin/heading-os

Made for: Claude Code.

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/mishahanin/heading-os/create-plan/github.svg)](https://agentmods.dev/skills/mishahanin/heading-os/create-plan)

Your own site

<a href="https://agentmods.dev/skills/mishahanin/heading-os/create-plan"><img src="https://agentmods.dev/badge/skills/mishahanin/heading-os/create-plan/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/skills/mishahanin/heading-os/create-plan"><img src="https://agentmods.dev/badge/skills/mishahanin/heading-os/create-plan.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 79 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,444 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

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.

Model	Per session	Once invoked
Fable 5.1	$0.00079	$0.01444
Opus 5.5	$0.00032	$0.00578
Sonnet 5.5	$0.00016	$0.00289
Haiku 4.5	$0.00008	$0.00144

Measured 1mo ago against content hash 79d6c6bb4c47, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

create-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 1mo 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

Copies of this mod

1 near-identical copy found in the catalogue:

create-plan — 100% identical, 13 lines differ

.claude/skills/create-plan/SKILL.md · 129 lines

How it starts

The opening of the file, as written. The whole thing — 129 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Plan

Create a detailed implementation plan for changes to this workspace. Plans are thorough documents that capture the full context, rationale, and step-by-step tasks needed to execute a change with complete alignment across the project.

Variables

request: $ARGUMENTS (describe what you want to plan — new command, new workflow, structural change, template update, etc.)

Instructions

IMPORTANT: You are creating a PLAN, not implementing changes. Research thoroughly, think deeply, then output a comprehensive plan document.
Use your reasoning capabilities to think hard about the request, workspace structure, and best approach.
Research the workspace to understand existing patterns, conventions, and how this change fits.
Create the plan in the build/spec/plans/ directory with filename: YYYY-MM-DD-{descriptive-name}.md
- Use today's date
- Replace {descriptive-name} with a short, kebab-case name (e.g., "add-guest-research-command", "restructure-outputs", "create-outreach-workflow")
Fill out every section of the Plan Format below. Replace all <placeholders> with specific, actionable content.
Be thorough — this plan will be executed by /implement and needs enough detail to execute without ambiguity.
Follow existing patterns. Study similar files in the workspace before proposing new structures.

Research Phase

Before writing the plan, investigate:

Read core reference files:
- CLAUDE.md — workspace overview
- The five context homes: canon/position/context/, canon/reference/context/, status/entity/context/, status/matter/context/, ledger/measurement/context/ — background on the user and project
Explore relevant areas:
- If creating a skill: read existing skills in .claude/skills/
- If modifying outputs: explore outputs/ structure and examples
- If updating templates: check reference/ for existing patterns
- If adding scripts: review scripts/ for conventions
Understand connections:
- How does this change relate to existing workflows?
- What files reference or depend on areas being changed?
- Are there naming conventions to follow?

Read the full file on GitHub · 129 lines

Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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.

1mo ago Changed 79d6c6bb4c47
1mo ago Changed · +1 lines 8b9f74b1799a
1mo ago First seen · 128 lines · 79 tokens per session scan A 101a6ed114cf

Subscribe to this mod's changes

create-plan is a skill published in the GitHub repository mishahanin/heading-os (11 stars, last pushed 1mo ago), licensed Apache-2.0. It adds 79 tokens to every session and 1,444 once invoked, about $0.0003 per session on Opus 5.5. 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 2026-08-30.

Claude Code LLM Planning Security ai-agent anthropic automation

create-plan

Getting it into your agent

Wrote this? Show the measurements

What it costs to keep this loaded

Grade A, and why

Nothing flagged

Copies of this mod

How it starts

Plan

Variables

Instructions

Research Phase

What ships with it

What this file has done since we first saw it

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