using-xskill

A guide for installing and operating XSkill, a system that turns coding-agent work records into reusable skills. It covers the command-line tool, background service, team connections, and skill rebuilding.

In plain words
What is it for?
Use it to install XSkill, configure its service, register work folders, join or host a team server, backfill records, or rebuild the skill library after changing models.
Why use it?
It explains how to keep the service running and how recorded agent work becomes reusable instructions.

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/skillnerds/xskill/using-xskill
Any agent
npx skills add SkillNerds/xskill --skill using-xskill
Clone the repo
git clone --depth 1 https://github.com/SkillNerds/xskill

Made for: Claude Code, Codex.

Per session 61 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 854 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 $0.00061 $0.00854
Opus 5 $0.00030 $0.00427
Sonnet 5 $0.00012 $0.00171
Haiku 4.5 $0.00006 $0.00085

Measured 2d ago against content hash 4a496e5ac644, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

using-xskill 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.

skills/using-xskill/SKILL.md · 65 lines

How it starts

The opening of the file, as written. The whole thing — 65 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Using xskill

Overview

xskill distills reusable Skills (SKILL.md folders) out of the real execution trajectories of coding agents (Claude Code, Codex, OpenCode, Cursor, …). A background daemon watches each agent's session logs, slices them into single-intent atoms, clusters atoms into skills, and writes/versions each skill in its own git folder. New skill versions only replace old ones when real traffic shows they serve users better (canary A/B by UX score) — not by an LLM grading itself.

Core mental model: raw trajectory → atoms → candidate routing → SKILL.md → canary A/B → installed into every agent's skill dir. You operate the daemon; the daemon does the distilling.

When to Use

  • Installing xskill or filling in ~/.xskill/config.yaml (LLM + embedding endpoints)
  • Starting/keeping the daemon running (xskill serve), or backfilling old trajectories
  • Joining or hosting a team server (xskill serve --server / xskill connect)
  • Understanding the agent pipeline, atoms, canary/UX scoring, or deployment modes
  • Re-distilling the whole skill library (e.g. after switching to a stronger model)

Quick Reference

Command What it does
pip install xskill Install (Python 3.9+)
xskill serve Standalone daemon: FastAPI + watcher; first run writes ~/.xskill/config.yaml then exits
xskill serve --server Team server: owns all LLM calls + git; prints a join token
xskill connect <host:port> --token <t> Join a team server as a thin client
xskill registry add <path> Backfill / watch an extra trajectory directory
xskill traj search <query> / xskill search <query> Search trajectories or skills
xskill read <path> --eco <eco> Batch-ingest db trajectories (ngagent/opencode)
xskill rebuild [--force] Re-distill from existing raw trajectories (see reference)
xskill stats Token usage & estimated cost

The daemon is the engine: most commands only change state in the DB; nothing is distilled unless xskill serve (or the team server) is running.

Read the full file on GitHub · 65 lines

Files

What ships with it

3 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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 · 65 lines · 61 tokens per session scan A 4a496e5ac644

Subscribe to this mod's changes

using-xskill is a skill published in the GitHub repository SkillNerds/xskill (121 stars, last pushed 3d ago), licensed MIT. It adds 61 tokens to every session and 854 once invoked, about $0.0003 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 2026-08-30.