just-define

just-define is a skill for Claude Code, Codex from doodledood/manifest-dev. It costs 58 tokens per session (566 once invoked), scanned A, original, MIT.

A goal-based tool for turning a conversation into a Manifest: a written agreement describing what will be delivered, how success will be checked, and which rules must always hold.

In plain words
What is it for?
Use it to define a project, write a lean specification, or amend an existing Manifest while keeping its item IDs stable.
Why use it?
It prevents important decisions from being lost between planning and implementation. The resulting document can guide later work even when the original conversation is unavailable.

Skill for Claude CodeCodex

Part of the manifest-dev plugin — 20 skills 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/doodledood/manifest-dev/just-define
Any agent
npx skills add doodledood/manifest-dev --skill just-define
Clone the repo
git clone --depth 1 https://github.com/doodledood/manifest-dev

Made for: Claude Code, Codex.

Or install manifest-dev, the plugin that ships this one along with the rest of its 20 skills.

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 just-define

README.md
[![agentmods](https://agentmods.dev/badge/skills/doodledood/manifest-dev/just-define.svg)](https://agentmods.dev/skills/doodledood/manifest-dev/just-define)
Your own site
<a href="https://agentmods.dev/skills/doodledood/manifest-dev/just-define"><img src="https://agentmods.dev/badge/skills/doodledood/manifest-dev/just-define.svg" alt="Measured on agentmods" height="20"></a>
Per session 58 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 566 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 $0.00058 $0.00566
Opus 5 $0.00029 $0.00283
Sonnet 5 $0.00012 $0.00113
Haiku 4.5 $0.00006 $0.00057

Measured today against content hash 2ed2702640e1, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

just-define 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 today.

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.

claude-plugins/manifest-dev/skills/just-define/SKILL.md · 45 lines

What it actually says

Encode the conversation's shared understanding as a Manifest at ~/.manifest-dev/manifests/manifest-<ts>.md (create the dir); how you interview is yours. No shared understanding in the transcript → invoke just-figure-out first. A manifest path in the arguments means amend: targeted changes only, IDs stable, no renumbering.

The Manifest is the acceptance contract — what the user accepts as "I'd ship the outcome of executing this" — and /do or /just-do executes it later with none of this conversation's context, so everything binding lives in the gate texts themselves. That gives a floor that isn't ceremony:

  • Follow the schema in this skill's own references/SCHEMA.md exactly — it is what the executor parses.
  • Every Acceptance Criterion and Global Invariant is one text — title, body, optional why — stating what done means, the evidence to inspect, and the threshold between PASS and FAIL, precise enough that two evaluations read the same thing.
  • Every gate declares "Judgment gate." or "Deterministic gate." — never inferred; an executor handed an undeclared kind is broken by it.
  • Anything whose violation would be unsafe or irreversible becomes a Global Invariant — never Process Guidance, never dropped for resisting verification.
  • Every manifest carries the ceiling invariant from the schema, verbatim — the one bound on the other side.
  • A criterion nothing can check is sharpened or dropped with a recorded assumption; only gates bind.

Before finishing, give a plain-language digest — the pain, the plan, what gets built, the guardrails — and wait for a yes unless the caller is /just-auto or an amendment. Then emit the handoff (<manifest-path> is the absolute path you wrote):

Manifest complete: <manifest-path>

To execute: /just-do <manifest-path>
For unattended execution, invoke /just-do <manifest-path> as the execution entrypoint. /just-do reads the manifest and owns the manifest-completion contract: it sets that completion contract when the active harness exposes a goal-setting or continuation capability, or prints the manual copy-paste contract when not. just-define does not set a separate /just-do goal.
Files

What ships with it

1 file 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.

  1. today Changed 2ed2702640e1
  2. 5d ago First seen · 45 lines · 58 tokens per session scan A 68bdfe9f1b9f

Subscribe to this mod's changes

just-define is a skill published in the GitHub repository doodledood/manifest-dev (72 stars, last pushed today), licensed MIT. It adds 58 tokens to every session and 566 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 2026-08-30.

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