oni-comb-rs: Skill for Codex

.agents/skills/skill-forge/SKILL.md

skill-forge is a skill for Codex from j5ik2o/oni-comb-rs. It costs 208 tokens per session (8,379 once invoked), scanned A, a copy of skill-creator, Apache-2.0.

A skill for creating or improving skills used by Claude Code and Codex, which are coding agents. It covers drafting, testing, evaluating, and refining skill instruction files.

In plain words
What is it for?
Use it to create, test, debug, and refine skills in agent projects.
Why use it?
It provides a repeatable process for checking whether an agent skill works as intended and improving it from test results.

Skill for Codex

Written for Codex: runs codex exec. Also seen: reads .claude/ paths; mentions subagents; mentions Claude Code.

This is j5ik2o/oni-comb-rs's own configuration. It tells Codex how to work on oni-comb-rs itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything oni-comb-rs configures →

Reuse

Borrowing it

Nothing to install: this file belongs to j5ik2o/oni-comb-rs. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/j5ik2o/oni-comb-rs/main/.agents/skills/skill-forge/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/j5ik2o/oni-comb-rs

Made for: 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 skill-forge

README.md
[![agentmods](https://agentmods.dev/badge/skills/j5ik2o/oni-comb-rs/skill-forge.svg)](https://agentmods.dev/skills/j5ik2o/oni-comb-rs/skill-forge)
Your own site
<a href="https://agentmods.dev/skills/j5ik2o/oni-comb-rs/skill-forge"><img src="https://agentmods.dev/badge/skills/j5ik2o/oni-comb-rs/skill-forge.svg" alt="Measured on agentmods" height="20"></a>
Per session 208 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 8,379 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 86% 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 $0.00208 $0.08379
Opus 5 $0.00104 $0.04189
Sonnet 5 $0.00042 $0.01676
Haiku 4.5 $0.00021 $0.00838

Measured 6d ago against content hash 85add02361b0, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

skill-forge 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 6d ago.

The scan reads SKILL.md. This mod also ships 22 executable files (eval-viewer/generate_review.py, scripts/__init__.py, scripts/aggregate_benchmark.py, …), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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

86% identical to skill-creator — 180 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/skill-forge/SKILL.md · 567 lines

How it starts

The opening of the file, as written. The whole thing — 567 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Skill Forge

A skill for creating new skills and iteratively improving them.

At a high level, the process of creating a skill goes like this:

  • Decide what you want the skill to do and roughly how it should do it
  • Write a draft of the skill
  • Create a few test prompts and run claude-with-access-to-the-skill on them
  • Help the user evaluate the results both qualitatively and quantitatively
    • While the runs happen in the background, draft some quantitative evals if there aren't any (if there are some, you can either use as is or modify if you feel something needs to change about them). Then explain them to the user (or if they already existed, explain the ones that already exist)
    • Use the eval-viewer/generate_review.py script to show the user the results for them to look at, and also let them look at the quantitative metrics
  • Rewrite the skill based on feedback from the user's evaluation of the results (and also if there are any glaring flaws that become apparent from the quantitative benchmarks)
  • Repeat until you're satisfied
  • Expand the test set and try again at larger scale

Your job when using this skill is to figure out where the user is in this process and then jump in and help them progress through these stages. So for instance, maybe they're like "I want to make a skill for X". You can help narrow down what they mean, write a draft, write the test cases, figure out how they want to evaluate, run all the prompts, and repeat.

On the other hand, maybe they already have a draft of the skill. In this case you can go straight to the eval/iterate part of the loop.

Of course, you should always be flexible and if the user is like "I don't need to run a bunch of evaluations, just vibe with me", you can do that instead.

Then after the skill is done (but again, the order is flexible), you can also run the skill description improver, which we have a whole separate script for, to optimize the triggering of the skill.

Cool? Cool.

Communicating with the user

Read the full file on GitHub · 567 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. 6d ago First seen · 567 lines · 208 tokens per session scan A 85add02361b0

Subscribe to this mod's changes

skill-forge is a skill published in the GitHub repository j5ik2o/oni-comb-rs (41 stars, last pushed 3mo ago), licensed Apache-2.0. It adds 208 tokens to every session and 8,379 once invoked, about $0.0010 per session on Opus 5. A static security scan graded it A with 0 findings. It is 86% identical to skill-creator, differing in 180 lines, and is treated as a copy.

Related

Other skills, from other repositories

migrate-oxfmt

Guide for migrating a project from Prettier or Biome to Oxfmt. Use when asked to migrate, convert, or switch a JavaScript/TypeScript project's formatter from Prettier or Biome to Oxfmt.

oxc-project/oxc · 53 tokens

migrate-oxlint

Guide for migrating a project from ESLint to Oxlint. Use when asked to migrate, convert, or switch a JavaScript/TypeScript project's linter from ESLint to Oxlint.

oxc-project/oxc · 44 tokens

insta-snapshots

Guide for working with and updating insta snapshot tests in Oxc without terminal interaction.

oxc-project/oxc · 22 tokens

performance-lint-rules

Performance review guidance for Oxc linter rule implementations. Use only when reviewing Rust rule code under crates/oxclinter/src/rules/ or when explicitly auditing those rules for performance improvements.

oxc-project/oxc · 45 tokens

vera-language

Write programs in the Vera programming language. Use when asked to write, edit, debug, or review Vera code (.vera files). Vera is a statically typed, purely functional language with algebraic effects, mandatory contracts, and typed slot references (@T.n) instead of variable names.

aallan/vera · 61 tokens

pcl-expert

Expert in Persona Control Language (PCL) - language design, compiler architecture, runtime systems, and ecosystem development. Use when the user mentions persona control language, compiler design, language design, DSL, runtime systems, or lexer, or when the task involves Language Design & Specification, Compiler…

personamanagmentlayer/pcl · 73 tokens