gate-check

gate-check is a skill for Claude Code from bullish0x/GameStudio. It costs 64 tokens per session (7,151 once invoked), scanned A, a copy of gate-check, MIT.

A readiness check for moving a game project from one development phase to the next. It checks required documents, quality standards, and blockers, then gives a pass, concerns, or fail result.

In plain words
What is it for?
Use it to check transitions such as pre-production to production, production to polish, or polish to release.
Why use it?
It prevents a project from advancing while important work or required artifacts are still missing.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter. Also seen: mentions subagents; names the AskUserQuestion tool; installed under .agents/ (shared by several agents).

Good fit Use it to check transitions such as pre-production to production, production to polish, or polish to release.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/bullish0x/gamestudio/gate-check
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 bullish0x/GameStudio --skill gate-check
Clone the repo
git clone --depth 1 https://github.com/bullish0x/GameStudio

Made for: Claude Code.

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 gate-check

README.md
[![agentmods](https://agentmods.dev/badge/skills/bullish0x/gamestudio/gate-check/github.svg)](https://agentmods.dev/skills/bullish0x/gamestudio/gate-check)
Your own site
<a href="https://agentmods.dev/skills/bullish0x/gamestudio/gate-check"><img src="https://agentmods.dev/badge/skills/bullish0x/gamestudio/gate-check/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 gate-check

Your own site · 80×15
<a href="https://agentmods.dev/skills/bullish0x/gamestudio/gate-check"><img src="https://agentmods.dev/badge/skills/bullish0x/gamestudio/gate-check.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 64 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 7,151 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 92% 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 $0.00064 $0.07151
Opus 5 $0.00032 $0.03576
Sonnet 5 $0.00013 $0.01430
Haiku 4.5 $0.00006 $0.00715

Measured 5d ago against content hash 663aa9699078, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

gate-check 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 5d 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

92% identical to gate-check — 19 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.

.agents/skills/gate-check/SKILL.md · 542 lines

How it starts

The opening of the file, as written. The whole thing — 542 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Phase Gate Validation

This skill validates whether the project is ready to advance to the next development phase. It checks for required artifacts, quality standards, and blockers.

Distinct from /project-stage-detect: That skill is diagnostic ("where are we?"). This skill is prescriptive ("are we ready to advance?" with a formal verdict).

Production Stages (7)

The project progresses through these stages:

  1. Concept — Brainstorming, game concept document
  2. Systems Design — Mapping systems, writing GDDs
  3. Technical Setup — Engine config, architecture decisions
  4. Pre-Production — Prototyping, vertical slice validation
  5. Production — Feature development (Epic/Feature/Task tracking active)
  6. Polish — Performance, playtesting, bug fixing
  7. Release — Launch prep, certification

When a gate passes, write the new stage name to production/stage.txt (single line, e.g. Production). This updates the status line immediately.


1. Parse Arguments

Target phase: $ARGUMENTS[0] (blank = auto-detect current stage, then validate next transition)

Also resolve the review mode (once, store for all gate spawns this run):

  1. If --review [full|lean|solo] was passed → use that
  2. Else read production/review-mode.txt → use that value
  3. Else → default to lean

Note: in solo mode, director spawns (CD-PHASE-GATE, TD-PHASE-GATE, PR-PHASE-GATE, AD-PHASE-GATE) are skipped — gate-check becomes artifact-existence checks only. In lean mode, all four directors still run (phase gates are the purpose of lean mode).

  • With argument: /gate-check production — validate readiness for that specific phase

  • No argument: Auto-detect current stage using the same heuristics as /project-stage-detect, then confirm with the user before running:

    Use AskUserQuestion:

    • Prompt: "Detected stage: [current stage]. Running gate for [Current] → [Next] transition. Is this correct?"
    • Options:
      • [A] Yes — run this gate
      • [B] No — pick a different gate (if selected, show a second widget listing all gate options: Concept → Systems Design, Systems Design → Technical Setup, Technical Setup → Pre-Production, Pre-Production → Production, Production → Polish, Polish → Release)

Read the full file on GitHub · 542 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. 5d ago First seen · 542 lines · 64 tokens per session scan A 663aa9699078

Subscribe to this mod's changes

gate-check is a skill published in the GitHub repository bullish0x/GameStudio (10 stars, last pushed 2mo ago), licensed MIT. It adds 64 tokens to every session and 7,151 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. It is 92% identical to gate-check, differing in 19 lines, and is treated as a copy.

Related

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