skillify

skillify is a skill for Claude Code, Codex from cynthiajones34/GBrain. It costs 68 tokens per session (3,164 once invoked), scanned A, a copy of skillify, MIT.

A framework for turning a rough feature into a complete, testable agent skill. It defines the skill's instructions, code, checks, tests, and entry trigger.

In plain words
What is it for?
Use it to package features as skills, add unit, integration, and AI-quality tests, review behavior with multiple AI models, and make the skill discoverable.
Why use it?
It prevents useful behavior from remaining undocumented or difficult to run reliably. It also checks the feature across different kinds of evaluation.

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/cynthiajones34/gbrain/skillify
Any agent
npx skills add cynthiajones34/GBrain --skill skillify
Clone the repo
git clone --depth 1 https://github.com/cynthiajones34/GBrain

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 skillify

README.md
[![agentmods](https://agentmods.dev/badge/skills/cynthiajones34/gbrain/skillify.svg)](https://agentmods.dev/skills/cynthiajones34/gbrain/skillify)
Your own site
<a href="https://agentmods.dev/skills/cynthiajones34/gbrain/skillify"><img src="https://agentmods.dev/badge/skills/cynthiajones34/gbrain/skillify.svg" alt="Measured on agentmods" height="20"></a>
Per session 68 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,164 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 88% 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 $0.00068 $0.03164
Opus 5 $0.00034 $0.01582
Sonnet 5 $0.00014 $0.00633
Haiku 4.5 $0.00007 $0.00316

Measured 4d ago against content hash a154e4340945, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

skillify 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.

Origin

This is a copy

88% identical to skillify — 13 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.

skills/skillify/SKILL.md · 318 lines

How it starts

The opening of the file, as written. The whole thing — 318 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Skillify — The Meta Skill

Relationship to /cross-modal-review: That skill is the manual mid-flow "second opinion" gate (one model reviews work product before commit). This skill's Phase 3 below uses gbrain eval cross-modal instead — three different-provider frontier models score-and-iterate on a documented dimension list before tests cement behavior. Use /cross-modal-review for ad-hoc second opinions; use Phase 3 here when skillifying a feature.

Contract

A feature is "properly skilled" when all 11 checklist items pass. Item 3 (cross-modal eval) is informational in v1.1.0 — it does not gate the skillpack-check audit, but a missing or stale receipt is surfaced so the user knows where the gate stands.

The Checklist

□ 1.  SKILL.md           — skill file with frontmatter + contract + phases
□ 2.  Code               — deterministic script if applicable
□ 3.  Cross-modal eval   — 3 frontier models from 3 providers; informational
□ 4.  Unit tests         — cover every branch of deterministic logic
□ 5.  Integration tests  — exercise live endpoints
□ 6.  LLM evals          — quality/correctness cases for LLM-involving steps
□ 7.  Resolver trigger   — entry in skills/RESOLVER.md with real user trigger phrases
□ 8.  Resolver eval      — test that triggers route to this skill
□ 9.  Check-resolvable   — DRY + MECE audit, no orphans
□ 10. E2E test           — smoke test: trigger → side effect
□ 11. Brain filing       — if it writes pages, entry in brain/RESOLVER.md

Phase 0: Should This Be a Skill?

Before skillifying, check:

  • Will this be invoked 2+ times? (One-off work ≠ skill)
  • Is there >20 lines of logic? (Trivial helpers don't need full infrastructure)
  • Does it have a clear trigger phrase a user would actually say?

If ANY answer is no, it's a script, not a skill — stop here. Do not scaffold, write a SKILL.md, run evals, or write tests for it. Tell the user why and move on.

Scope check (upper bound): one skill = one capability = one coherent trigger family. If the target spans multiple distinct intents users would invoke separately ("run the build" / "roll back the deploy" / "notify the team" are three intents, not one), do NOT build one skill covering them all. Stop, propose splitting into separate skillify targets, and ask the user which one to skillify first.

Read the full file on GitHub · 318 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 · 318 lines · 68 tokens per session scan A a154e4340945

Subscribe to this mod's changes

skillify is a skill published in the GitHub repository cynthiajones34/GBrain (0 stars, last pushed 28d ago), licensed MIT. It adds 68 tokens to every session and 3,164 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. It is 88% identical to skillify, differing in 13 lines, and is treated as a copy.