skill-extract

A command that creates or updates a skill by studying patterns in a codebase and its project instructions. A skill is a reusable set of guidance for a coding agent.

In plain words
What is it for?
Use it to create or update a named skill from a specified project path, optionally reviewing the proposed content before writing it.
Why use it?
Useful project practices can be scattered across source files and instructions. Extracting them turns those patterns into guidance that can be reused.

Command

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 commands/xonovex/platform/skill-extract
Clone the repo
git clone --depth 1 https://github.com/xonovex/platform
Per session 14 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 263 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 $0.00014 $0.00263
Opus 5 $0.00007 $0.00131
Sonnet 5 $0.00003 $0.00053
Haiku 4.5 $0.00001 $0.00026

Measured 2d ago against content hash 38e044337e89, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

skill-extract 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 2d 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.

packages/command/command-utility/commands/skill-extract.md · 34 lines

What it actually says

/xonovex-utility:skill-extract - Extract Skill from Codebase

Arguments

  • skill-name (required): Name for skill (e.g., example-guide)
  • source-path (required): Path to analyze (e.g., packages/example)
  • --update (optional): Update existing skill instead of creating new
  • --interactive (optional): Ask which patterns to include before writing
  • --dry-run (optional): Preview without writing files

Delegation

Load the skill-guide skill (plugin xonovex-skill-skill) and perform its extract-from-codebase operation with these arguments. The skill is the source of truth for the procedure, output format, and gotchas. Do not restate them.

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. 2d ago First seen · 34 lines · 14 tokens per session scan A 38e044337e89

Subscribe to this mod's changes

skill-extract is a command published in the GitHub repository xonovex/platform (5 stars, last pushed 2d ago), licensed MIT. It adds 14 tokens to every session and 263 once invoked, about $0.0001 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.