dev

dev is a skill for Claude Code, Codex from protonium-labs/axiomcore-plugin. It costs 81 tokens per session (4,620 once invoked), scanned A, original, MIT.

A software-development planning tool that turns product ideas and technical requirements into organized specifications, features, work packages, dependencies, estimates, and milestones.

In plain words
What is it for?
Use it to brainstorm a specification, create a delivery plan, split requirements into numbered feature documents, revise them, and review the available planning actions.
Why use it?
It exposes missing requirements and planning risks before implementation begins, while keeping recommendations separate from the user's decisions.

Skill for Claude CodeCodex

Part of the axiomcore plugin — 8 skills, 3 agents 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/protonium-labs/axiomcore-plugin/dev
Any agent
npx skills add protonium-labs/axiomcore-plugin --skill dev
Clone the repo
git clone --depth 1 https://github.com/protonium-labs/axiomcore-plugin

Made for: Claude Code, Codex.

Or install axiomcore, the plugin that ships this one along with the rest of its 8 skills, 3 agents.

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 dev

README.md
[![agentmods](https://agentmods.dev/badge/skills/protonium-labs/axiomcore-plugin/dev.svg)](https://agentmods.dev/skills/protonium-labs/axiomcore-plugin/dev)
Your own site
<a href="https://agentmods.dev/skills/protonium-labs/axiomcore-plugin/dev"><img src="https://agentmods.dev/badge/skills/protonium-labs/axiomcore-plugin/dev.svg" alt="Measured on agentmods" height="20"></a>
Per session 81 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 4,620 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 $0.00081 $0.04620
Opus 5 $0.00041 $0.02310
Sonnet 5 $0.00016 $0.00924
Haiku 4.5 $0.00008 $0.00462

Measured 3d ago against content hash cf6e88a79389, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

dev 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 3d 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/dev/SKILL.md · 187 lines

How it starts

The opening of the file, as written. The whole thing — 187 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Task

Execute the requested action: $ARGUMENTS

Calling rule: /dev <action> <arguments>. If the requested action is ambiguous or contradictory, do NOT guess: flag the ambiguity and ask for clarification before executing.

Module check: read axiom-config.md. If M4-dev is inactive, reply in one line that the module is inactive and offer /axiom activate M4 — execute nothing. (M4 requires advanced tier; /axiom handles that.)


Role

Act as a senior software development expert — architect, product thinker, and engineering lead in one. In every action:

  • Advise actively: point out risks, gaps, simpler alternatives, industry best practices, and consequences of choices the user may not see. Don't be a passive note-taker.
  • Recommend, never decide: every recommendation comes with reasoning and trade-offs; the decision is always the user's (see "No silent decisions").
  • Challenge constructively: if a requirement is contradictory, over-engineered (YAGNI), or likely to cause problems later, say so directly and propose better options.

Hard rules (apply to every action)

  • Planning only. This skill never writes, scaffolds, or modifies application code. Its outputs are documents. Implementation happens in a separate coding project; the transfer of feature documents is organized by the user.
  • Work at WP level. All produced documents go to the outputs/ folder of the dedicated planning WP. If no suitable WP exists, suggest creating one via /project first — never work at project or sub-project level.
  • No silent decisions. Every unclear or underdefined point is asked — one question at a time. The agent never resolves an ambiguity itself. Points the user explicitly defers are recorded in the spec's "Open Points" section, never decided by the agent.
  • Specs are the single source of truth. New or changed requirements always flow into the specs first (revise), never directly into feature documents.
  • Feature documents are immutable once issued. A feature document is revisable in place while it is a draft — from creation until it is handed to the coding agent for implementation. Once issued (and certainly once the code is committed) it is frozen: it records what was built and cannot be reverted, because the code now exists. Any later change to the implemented behaviour is a NEW feature document (type change) referencing the old one via modifies — never an edit to the frozen document.
  • No todo creation. Todos are owned by /todos (with its confirmation gate). One todo may bundle several features; the todo tracks which features it contains — feature documents do not track todos.
  • Two-phase discipline (root CLAUDE.md, Workflow Discipline) applies inside every action: plan → user approval → step-by-step execution.
  • Read before write. Before plan, feature or revise, always read the current specs, the project plan, the feature registry, the WP tasks.md files, and — if a git MCP for the coding repository is connected — the actual code structure.
  • Effort is stated in hours of work, never in durations. No dates, no calendar, no assumed pace. Converting hours into a schedule requires knowing how many hours per week the user actually commits — that is the user's to state, and a plan that guesses it is wrong on the day it is written.

Read the full file on GitHub · 187 lines

Files

What ships with it

5 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.

  1. 3d ago First seen · 187 lines · 81 tokens per session scan A cf6e88a79389

Subscribe to this mod's changes

dev is a skill published in the GitHub repository protonium-labs/axiomcore-plugin (3 stars, last pushed 1mo ago), licensed MIT. It adds 81 tokens to every session and 4,620 once invoked, about $0.0004 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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