Table of Contents
📖 Overview
SkillX is a fully automated framework that constructs a reusable, plug-and-play skill knowledge base for LLM agents from experience.
Instead of storing raw trajectories, workflows, or loosely structured reflections, SkillX distills agent experience into a three-level skill hierarchy:
- Planning Skills for high-level task organization
- Functional Skills for reusable tool-based subroutines
- Atomic Skills for execution-oriented tool usage patterns
Built with a strong backbone agent, SkillX produces a transferable skill library that can be directly plugged into weaker base agents and new environments. Across challenging long-horizon, user-interactive benchmarks such as AppWorld, BFCL-v3, and τ2-Bench, SkillX consistently improves both task success and execution efficiency.
Data Formats
Trajectory Input (JSONL)
SkillX expects trajectories in the following schema:
{
"trajectory_id": "traj_001",
"task_id": "task_001",
"user_task": "How many songs are in my Spotify library?",
"task_history": [
{"role": "system", "content": "You are a helpful assistant..."},
{"role": "assistant", "content": "I'll help you count..."},
{"role": "user", "content": "Output:\n```\n{\"songs\": 150}\n```"}
],
"reward": 1.0,
"metadata": {}
}
🤖 Key Features
Hierarchical Multi-Level Skill Design
SkillX transforms raw trajectories into a structured three-tier skill space:
- Planning Skills capture high-level decomposition and ordering
- Functional Skills represent reusable multi-step tool subroutines
- Atomic Skills encode practical tool usage constraints and patterns
Fully Automated Skill KB Construction
SkillX provides an end-to-end automated pipeline that:
- rolls out agents on training tasks,
- extracts reusable skills from successful trajectories,
- consolidates and filters low-quality skills,
- and builds a reusable plug-and-play skill knowledge base.
Iterative Skill Refinement
SkillX continuously improves the skill library through:
- skill merging for consolidating redundant behaviors,
- quality filtering for removing brittle or hallucinated skills,
- and iterative updates that add, modify, or keep skills based on execution feedback.
Exploratory Skill Expansion
Beyond seed demonstrations, SkillX proactively discovers new skills by:
- identifying under-used and failure-prone tools,
- guiding environment exploration,
- synthesizing new tasks from exploratory trajectories,
- and expanding skill coverage beyond the original training distribution.
Plug-and-Play Transfer Across Agents
The resulting skill library can be directly injected into different base agents, enabling strong-to-weak transfer without retraining the underlying model.
Better Performance and Efficiency
SkillX consistently improves:
- task success rate on challenging benchmarks,
- execution efficiency by reducing unne