Python implementation of "WikiSkill: Compiling Agent Experience into Persistent Knowledge for Skill Evolution" (arXiv:2608.27454v1, Tang et al., Google Research).

Docs: see prd.md (requirements), design.md (architecture), plan.md (build plan).

Credits & Attribution

This project is an independent, open-source reimplementation of the research paper:

WikiSkill: Compiling Agent Experience into Persistent Knowledge for Skill Evolution Liyan Tang, Cyrus Rashtchian, Chun-Sung Ferng, Andrew Tomkins, Da-Cheng Juan, Tu Vu — Google Research (and Virginia Tech). arXiv:2608.27454v1 [cs.AI], 27 Aug 2026. License: CC BY 4.0. Paper: https://arxiv.org/abs/2608.27454

All credit for the WikiSkill method, algorithm (Algorithm 1), three-layer knowledge architecture, agent designs, experimental findings, and agent prompts (Appendix E) belongs to the Google Research authors. This repository reimplements the framework in code for study/experimentation purposes and is not an official Google product. Agent system prompts in src/wikiskill/prompts.py are condensed adaptations of those published in the paper (CC BY 4.0); adaptations in this repo are released under the same spirit — please cite the original paper if you use this work:

@article{tang2026wikiskill,
  title   = {WikiSkill: Compiling Agent Experience into Persistent Knowledge
             for Skill Evolution},
  author  = {Tang, Liyan and Rashtchian, Cyrus and Ferng, Chun-Sung and
             Tomkins, Andrew and Juan, Da-Cheng and Vu, Tu},
  journal = {arXiv preprint arXiv:2608.27454},
  year    = {2026},
  note    = {Google Research}
}

What it implements

Three-layer workspace (paper §3.1): immutable raw/ traces, persistent wiki/ (patterns + index + logs + skill-impact tracker), active skills/ (SKILL.md + PURPOSE.md).
Evolutionary loop (paper Algorithm 1, §3.2): Inference Agent rollouts with skill injection but no wiki access; Wiki Maintainer consolidation (create/update pattern pages via append/replace/insert_after patches); a ReAct Skill Proposer that reads the wiki and raw traces on demand and emits one atomic skill proposal.
Gating & rollback (§3.2.4): accept iff validation score strictly improves R_best; otherwise roll back skills only — the wiki is never rolled back. The harness programmatically appends proposal + unified diff + outcome to wiki/skill-impact.md.
Stratified trace sampling (App. C): ≤5 failing + ≤3 passing traces, 15,000-char cap.
Paired bootstrap significance testing (App. C) in metrics.py.
Early stop when R_best == 1.0.

Quickstart

pip install -e ".[dev]"
pytest                                  # 14 tests incl. end-to-end loop
python -m wikiskill.demo                # offline demo with the deterministic MockLLM

Demo output: a wikiskill_demo_workspace/ with raw/, wiki/, skills/ populated, accepted/rejected proposals logged in wiki/skill-impact.md, and run_state.json.

Using a real LLM

wikiskill evolve --tasks tasks.jsonl \
  --train-ids train.txt --val-ids val.txt --test-ids test.txt \
  --model <model-name> --base-url https://your-endpoint/v1

API key is read from --api-key, WIKISKILL_API_KEY, or OPENAI_API_KEY. Any OpenAI-compatible /chat/completions endpoint works (including local vLLM, as in the paper). tasks.jsonl lines: {"id", "x", "y", "meta?"}.

Layout

src/wikiskill/
├── workspace.py    # three layers + patch engine + scoped read_file
├── skills.py       # skills layer, apply_proposal, skills-only snapshot/rollback
├── agents.py       # InferenceAgent, WikiMaintainer, ReAct SkillProposer, stratified_sample
├── orchestrator.py # Algorithm 1 with gating/rollback + audit trail
├── prompts.py      # agent system prompts (adapted from paper Appendix E)
├── llm.py          # LLM protocol, OpenAI-compatible client, MockLLM, extract_json
├── metrics.py      # accuracy + paired bootstrap (1,000 iterations)
├── datasets.py     # dataclasses + synthetic demo dataset
├── demo.py / cli.py
└── tests/…         # unit + end-to-end tests

Notes & limitations (mirroring the paper)

Skills are injected directly into the prompt (no retrieval), matching the paper's setup.
Gating requires strict improvement; neutral proposals are rejected (paper Limitations).
The wiki accumulates without pruning (paper Limitations).