plan

plan is a skill for Claude Code, Codex from whieet/harness-kit. It costs 62 tokens per session (391 once invoked), scanned A, original, MIT.

A planning workflow for larger coding changes, organized as Plan, Build, Verify, and Done. It uses a project template and records approved plans in the configured plan directory.

In plain words
What is it for?
Use it before changes larger than 20 lines or changes to planned code paths, including investigation, affected-file planning, verification steps, and a definition of done.
Why use it?
It turns a broad change into checkable steps and makes verification and completion criteria explicit before implementation begins.

Skill for Claude CodeCodex

Part of the harness-kit plugin — 6 skills, 6 commands, 1 agent, 8 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/whieet/harness-kit/plan
Any agent
npx skills add whieet/harness-kit --skill plan
Clone the repo
git clone --depth 1 https://github.com/whieet/harness-kit

Made for: Claude Code, Codex.

Or install harness-kit, the plugin that ships this one along with the rest of its 6 skills, 6 commands, 1 agent, 8 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

README.md
[![agentmods](https://agentmods.dev/badge/skills/whieet/harness-kit/plan.svg)](https://agentmods.dev/skills/whieet/harness-kit/plan)
Your own site
<a href="https://agentmods.dev/skills/whieet/harness-kit/plan"><img src="https://agentmods.dev/badge/skills/whieet/harness-kit/plan.svg" alt="Measured on agentmods" height="20"></a>
Per session 62 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 391 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 $0.00062 $0.00391
Opus 5 $0.00031 $0.00196
Sonnet 5 $0.00012 $0.00078
Haiku 4.5 $0.00006 $0.00039

Measured 4d ago against content hash 4b1b03e9757f, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

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 4d 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.

skills/plan/SKILL.md · 25 lines

What it actually says

/harness-kit:plan

Drive a disciplined plan for the requested change.

Steps

  1. Read .harness/config.json first and follow its language preference for AI interaction and generated plan content. Do not translate file/directory names, command names, or config keys.

  2. Read the project plan template (<plan.dir>/_template.md, where plan.dir comes from .harness/config.json) so your plan matches the project's expected structure and Definition-of-Done format.

  3. Investigate enough to plan well: search for existing utilities/patterns to reuse, identify the files to change, and consider edge cases (empty/error states, performance, regressions).

  4. Enter plan mode and present a plan with: Context (why), the approach, the affected files, step-by-step actions with their verification method, and a Definition of Done whose items are checkable.

  5. On approval, the on-plan-approved hook automatically writes the plan into <plan.dir>/active/. As you implement, check off the DoD items — the Stop-hook gate verifies them before you can finish, and harness-check-plan-dod reminds you to archive the plan to completed/ when done.

Notes

  • For changes ≤ ~20 lines with no interface change, a full plan is optional — but still run /harness-kit:verify before declaring done.
  • If you edit planned code (plan.codeGlob) with no covering plan, the plan-gate hook auto-scaffolds one for you to fill in.
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. 4d ago First seen · 25 lines · 62 tokens per session scan A 4b1b03e9757f

Subscribe to this mod's changes

plan is a skill published in the GitHub repository whieet/harness-kit (5 stars, last pushed 1mo ago), licensed MIT. It adds 62 tokens to every session and 391 once invoked, about $0.0003 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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