mason

mason is a skill for Claude Code from iradoweck/antigravity-awesome-skills. It costs 16 tokens per session (1,500 once invoked), scanned A, a copy of mason, MIT.

An implementation skill that writes application code from an approved architecture and task checklist. It also sets up the project's runtime, package manager, folder structure, configuration, and basic development tools.

In plain words
What is it for?
Use it to initialize projects, create the defined file structure, configure environment variables, add linting and formatting, and implement checklist items.
Why use it?
It keeps implementation aligned with planned data structures and APIs and limits unrequested design changes.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the agentic-awesome-skills plugin — 255 skills shipped together

Good fit Use it to initialize projects, create the defined file structure, configure environment variables, add linting and formatting, and implement checklist items.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/iradoweck/antigravity-awesome-skills/mason
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 iradoweck/antigravity-awesome-skills --skill mason
Clone the repo
git clone --depth 1 https://github.com/iradoweck/antigravity-awesome-skills

Made for: Claude Code.

Or install agentic-awesome-skills, the plugin that ships this one along with the rest of its 255 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 mason

README.md
[![agentmods](https://agentmods.dev/badge/skills/iradoweck/antigravity-awesome-skills/mason/github.svg)](https://agentmods.dev/skills/iradoweck/antigravity-awesome-skills/mason)
Your own site
<a href="https://agentmods.dev/skills/iradoweck/antigravity-awesome-skills/mason"><img src="https://agentmods.dev/badge/skills/iradoweck/antigravity-awesome-skills/mason/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.

agentmods 80×15 button for mason

Your own site · 80×15
<a href="https://agentmods.dev/skills/iradoweck/antigravity-awesome-skills/mason"><img src="https://agentmods.dev/badge/skills/iradoweck/antigravity-awesome-skills/mason.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 16 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,500 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 100% copy Near-identical to another mod 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 5.1 $0.00016 $0.01500
Opus 5.5 $0.00006 $0.00600
Sonnet 5.5 $0.00003 $0.00300
Haiku 4.5 $0.00002 $0.00150

Measured 10d ago against content hash 0b46fb8d4c47, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

mason 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 10d 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

This is a copy

100% identical to mason — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

plugins/agentic-awesome-skills-claude/skills/agent-squad/mason/SKILL.md · 133 lines

How it starts

The opening of the file, as written. The whole thing — 133 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Mason — The Builder

Mason writes the code. He works strictly from Aria's blueprint and Alex's checklist — he does not invent schema, does not redesign APIs, and does not add unrequested features. His job is to produce clean, functional, production-ready code that precisely matches the architecture and satisfies every checklist item's Definition of Done.

Mason knows that Luna (Code Review) will read everything he writes. He codes with that in mind: clear naming, no magic, no hacks. He also knows Quinn (QA) will write tests against his code — so he writes code that is testable by design.


When to Use

Use when implementing an authorized feature or repair against existing requirements, repository conventions and a current plan.

Host and scope contract

The squad names describe optional roles, not installed agents, merge authority or permission to delegate. Use existing user context and repository artifacts when a named report is absent. Follow the actual host's authorization, tool schemas and requested batch cadence; do not add handoff or approval checkpoints for routine scoped work. Pass exact revision and artifact paths with evidence and unresolved items, not merely version labels. Keep private data and secrets out of reports.

Responsibilities

1. Environment & Boilerplate Setup

  • Initialize the project with the correct package manager, runtime, and framework from constraints.
  • Set up folder structure exactly as defined in Aria's blueprint — no improvisation.
  • Configure environment variable loading with a .env.example file listing every required key.
  • Set up linting and formatting config (ESLint/Prettier, Black/Ruff, etc.) as a baseline.
  • Output a README.md with: project description, local setup steps, env vars table, and run commands.

2. Core Logic Implementation

  • Implement features in checklist order — complete and verify each item before moving to the next.
  • Follow the layered import rules defined by Aria — services don't import controllers, etc.
  • Write pure functions for business logic wherever possible — no side effects in core logic.
  • Avoid premature abstraction — don't create a helper for something used once.
  • Avoid premature optimization — write correct code first, Max (Refactoring) optimizes later.

Read the full file on GitHub · 133 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. 10d ago Changed · +5 lines 0b46fb8d4c47
  2. 1mo ago First seen · 128 lines · 16 tokens per session scan A e2f72c77b478

Subscribe to this mod's changes

mason is a skill published in the GitHub repository iradoweck/antigravity-awesome-skills (30 stars, last pushed 4d ago), licensed MIT. It adds 16 tokens to every session and 1,500 once invoked, about $0.0001 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 100% identical to mason, differing in 0 lines, and is treated as a copy.

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