xskill 0.5.1

Distill reusable Skills from AI Agent execution trajectories

xskill

Your coding agent, self-evolving.

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News

• 2026-05-23 — Officially open-source, v0.5.0 released: team mode (client-server), trajectory redaction, Python 3.9 support, no git binary needed at runtime. See the release notes.
• 2026-05-20 — MIT-licensed open source; on PyPI: pip install xskill.
• 2026-05-12 — Claude Code, Codex, OpenCode supported; OpenClaw and Cursor connected.

What problem it solves

Your coding agent re-derives the same solution every time it bumps into a familiar problem. You either re-explain it, or hand-maintain a prompt library that quietly rots when no one is looking.

With xskill running, that work goes away:

• Patterns that actually worked get distilled into Skill files your agent loads automatically.
• The library grows itself as you keep using your agent — no review queue, no one curating "best practices."
• When you edit a Skill by hand, xskill picks up your edit immediately and learns from it.
• A new Skill version only replaces the old one if it measurably serves users better (UX-driven evolution, not naive LLM self-grading).

Get started

pip install xskill          # Python 3.9+
xskill serve                # writes ~/.xskill/config.yaml, then exits

Open ~/.xskill/config.yaml and fill in two model endpoints:

skill_dir: ~/.xskill/skill

llm:
  base_url: https://api.deepseek.com
  model:    deepseek-v4-flash
  api_key:  YOUR_KEY

embedding:
  base_url: https://api.deepseek.com
  model:    deepseek-embedding
  api_key:  YOUR_KEY
  dim:      0

Run xskill serve again — it auto-detects every supported agent on your machine (Claude Code, Codex, OpenCode, OpenClaw, Cursor) and starts watching. To also index an archive of older trajectories:

xskill registry add /path/to/trajectories

Rate limiting (cloud-plan users)

Default watcher.max_concurrent: 4 is conservative and OK for accounts without a hard concurrency cap. If your provider has RPM/TPM quotas (OpenAI Tier-1, Azure 60 RPM, OneAPI, etc.) add rate_limit under llm:

llm:
  base_url: https://api.deepseek.com
  model:    deepseek-v4-flash
  api_key:  YOUR_KEY
  rate_limit:
    rpm: 60          # match your provider plan
    tpm: 100000      # optional within rate_limit
    burst: 10        # optional; default = ceil(rate/6)

Buckets are shared per base_url across utils/llm and agno_factory paths, so the same key is never double-debited. Self-hosted vLLM / high-tier accounts should leave rate_limit out and raise max_concurrent to 20-30.

Design rationale: docs/adr/0001-rate-limit-diy-not-litellm.md.

Team mode: the killer use case

The way xskill really wants to be deployed in an organization is team mode: one machine is the server, everyone else joins as a thin client, and the whole team works against the same evolving Skill library.

xskill serve --server                        # prints a join token
xskill connect <host:port> --token <token>

• Silently distill your top performers. When one person solves something in their own work, the rest of the team gets that solution automatically — nobody has to write it down. (Capability democratized.)
• Any coding workflow plugs in. Codex, Claude Code, Cursor IDE — pick whatever; everyone joins the same library, synced across tools.
• Trajectories stay private. Sessions are redacted before upload; agent privacy built in.
• A/B-driven evolution. A Skill change is measured per person before it spreads — the more people in the team, the faster and sharper the evolution.
• Experts can teach manually. When an expert edits a Skill locally, the change is pulled into the server as user-staging/<client_id> and feeds the next round of evolution.

Architecture

How it works

A few narrow LLM agents do the work. One splits a trajectory into single-intent Atoms; one routes each Atom to a Skill; one rewrites the SKILL.md once a Skill has enough material; one A/B-tests new versions on live traffic and keeps the winner. Every Skill is its own git repository, so every change is versioned and reversible. Details: docs/agent.md.

Works with your agents

Agent	Status	Trajectory ingest	Skill install
Claude Code	✅ verified	auto-detects ~/.claude/projects/	symlink → ~/.claude/skills/<name>/
Codex CLI	✅ verified	auto-detects ~/.codex/sessions/	symlink → ~/.agents/skills/<name>/
OpenCode	✅ verified	SQLite ~/.local/share/opencode/opencode.db	symlink → ~/.agents/skills/<name>/
OpenClaw	🟡 implemented, not well tested	auto-detects ~/.openclaw/agents/	copy → ~/.agents/skills/<name>/
Cursor	🟡 implemented, not well tested	auto-detects ~/.cursor/projects/*/agent-transcripts/	symlink → ~/.cursor/skills/<name>/
Any other agent	manual	SDK: xskill.adapters.submit_trajectory	copy or symlink the SKILL.md directory

Concepts

Term	Meaning
Trajectory	One agent run — the transcript of a session. Stored as traj_*.md.
Atom	The smallest single-intent slice of a trajectory. Routing happens at this level.
Skill	A SKILL.md plus optional scripts, in its own versioned git directory.
Canary	A live-traffic A/B test of the current Skill against a new candidate.
UX score	How well a Skill served the user on a given Atom, scored 1–10 from the interaction itself. The canary keeps whichever version scores higher.

Roadmap

• More agent adapters — Trae, Goose, OpenHands, Aider
• More mature user profiling and recommendation
• Native MCP server interface (Skills exposed as tools)
• Web UI for browsing the library and viewing canary stats
• Skill marketplace — import / export portable bundles
• Multi-tenant libraries (per-team skill_dir)

License

MIT © 370025263. See LICENSE.