This page may contain stale information. Last updated: 2026-06-12

Overview

SkillOpt is an MIT-licensed open-source framework from microsoft Research Asia that optimizes AI agent skill markdown documents via validation-gated text-space training — without modifying underlying model weights.

Key Capabilities

  • Treats .md skill files as trainable external state of frozen LLMs
  • Propose-and-test loop with held-out validation gates
  • Exports compact best_skill.md (~920 tokens median, max 2,000)
  • Zero additional inference-time model calls at deployment

Benchmark Results (Microsoft Research)

  • +23.5 average absolute points on GPT-5.5 vs no-skill baseline
  • Best or tied on all 52 (model, benchmark, harness) cells
  • Cross-harness transfer: Codex → Claude Code (+59.7 on spreadsheet skill)
  • SpreadsheetBench: 41.8% → 80.7% on GPT-5.5
  • Training cost: ~$1–5 per single-task skill (GBrain community framework)

Release

  • 2026-06-11: Open-source release (MIT)
  • GitHub: github.com/microsoft/SkillOpt
  • Paper: arXiv:2605.23904
  • PyPI: pip install skillopt

Sources