plan-change

plan-change is a skill for Claude Code, Codex from Jed-Tech/spar-kit. It costs 121 tokens per session (1,239 once invoked), scanned A, original, Apache-2.0.

A planning workflow that turns a proposed software change into a written specification and an actionable implementation plan.

In plain words
What is it for?
Use it to discuss a change, settle its name and boundaries, and create the related spec and plan documents under the project’s documentation structure.
Why use it?
It helps resolve the goal and scope before work begins, so the resulting files describe an agreed change rather than an assumption.

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/jed-tech/spar-kit/specify_and_plan
Any agent
npx skills add Jed-Tech/spar-kit --skill specify_and_plan
Clone the repo
git clone --depth 1 https://github.com/Jed-Tech/spar-kit

Made for: Claude Code, Codex.

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-change

README.md
[![agentmods](https://agentmods.dev/badge/skills/jed-tech/spar-kit/specify_and_plan.svg)](https://agentmods.dev/skills/jed-tech/spar-kit/specify_and_plan)
Your own site
<a href="https://agentmods.dev/skills/jed-tech/spar-kit/specify_and_plan"><img src="https://agentmods.dev/badge/skills/jed-tech/spar-kit/specify_and_plan.svg" alt="Measured on agentmods" height="20"></a>
Per session 121 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,239 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 $0.00121 $0.01239
Opus 5 $0.00060 $0.00620
Sonnet 5 $0.00024 $0.00248
Haiku 4.5 $0.00012 $0.00124

Measured 4d ago against content hash acc000c1bc92, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

plan-change 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.

Research/research/example skills/specify_and_plan/SKILL.md · 167 lines

How it starts

The opening of the file, as written. The whole thing — 167 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Plan change

Mandatory first turn

Start by asking — use this wording (or trivially equivalent):

I see you would like to start ideation and planning for a change. Can you provide me with some context or your goals for the change?

If the user already dropped hints in the same thread (e.g. a working title), add at most one short acknowledging clause, then still use the prompt above so goals stay explicit.

Do not create files, do not draft <change-name>_spec.md or plan.md, and do not interrogate for scope, folder name, or success criteria in full — save that for after they reply.

Until scope and change name are confirmed or clearly settled: do not create Docs/<scope>/Specs/<change-name>/ or write <change-name>_spec.md / plan.md. A response that creates files or fabricates spec or Implementation Plan content before that does not follow this skill.

Voice

Be concise, cheerful, and inquisitive — like a helpful teammate, not a form or checklist read aloud.

Convert discussion into durable context and a clear execution plan.

Conversation flow

After the user responds

  1. Clarify intent and naming (workflow §1): refine <change-name> as needed through dialogue.
  2. Resolve scope (workflow §2): conversationally confirm xp_stream | saturation_regen | _Repo if still unclear; only ask what is missing.
  3. Then proceed sequentially through workflow §3 onward (create folder → context → ideate → spec → …). Do not skip ahead (e.g. no plan.md before <change-name>_spec.md is stable).

Outputs

Create:

Docs/<scope>/Specs/<change-name>/

  • <change-name>_spec.md — intent, constraints, decisions (not step-by-step)
  • plan.md (Implementation Plan) — ordered, concrete, verifiable execution steps

Scope must be one of: xp_stream, saturation_regen, _Repo. If unclear, stop and ask.


Workflow

1. Clarify intent and naming

  • Understand the goal from discussion; help refine <change-name>.
  • Do not create files yet. (See Mandatory first turn and Conversation flow for opener and sequencing.)

Read the full file on GitHub · 167 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. 4d ago First seen · 167 lines · 121 tokens per session scan A acc000c1bc92

Subscribe to this mod's changes

plan-change is a skill published in the GitHub repository Jed-Tech/spar-kit (17 stars, last pushed 4mo ago), licensed Apache-2.0. It adds 121 tokens to every session and 1,239 once invoked, about $0.0006 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 2026-08-30.

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