ZBS Index What actually exists in applied AI, with the source next to it

skill

arbor

Autonomously improve a real artifact (code, training recipe, agent harness, data pipeline, prompt) against an objective and an evaluator, using Hypothesis Tree Refinement (HTR) from the Arbor paper. Use this whenever someone wants to iteratively optimize something over many experiments without overfitting — e.g. "get my model's eval score up", "improve this agent/harness", "tune this pipeline", "beat the baseline on this benchmark", "run a search over approaches and keep the best", "do an MLE-bench / Kaggle-style optimization", or any long-horizon "make this artifact better and don't just memorize the dev set" task. Trigger it even when the user doesn't say "Arbor" or "hypothesis tree" but describes repeated experiment-and-evaluate loops, branching exploration of competing ideas, or worries about a dev/test gap. Runs Claude itself as the coordinator with subagent executors in isolated git worktrees; for the standalone `arbor` CLI tool see references/arbor-upstream.md.

Description as published by the maintainer. Source

  • active

active — Most recent push to the repository was 2026-08-03.

Signals

These are separate measurements of different things. They are deliberately not combined into one score, because a popularity number that mixes website traffic with saves and stars cannot be checked or acted on.

Signal Value What it measures Window Observed Source
GitHub stars 32,829 Stars on the repository that contains this skill, not on the skill itself. A collection of fifty skills shares one number, so it says nothing about this particular skill. cumulative, all time GitHub
Last commit 2026-08-03 Most recent push to the containing repository. It may reflect work on a different skill in the same collection. point in time GitHub
repository status active The repository holding this skill exists and is not archived. as of fetch GitHub

Will this work with your setup?

No harness stated by the author and no install path convention detected. Compatibility is untested.

We have not run this skill against a task with and without it enabled, so we cannot tell you whether it improves anything, what it costs in tokens, or whether it duplicates behaviour your harness already has. When we have run that test, the result will appear on this page with the task, the versions and the budget it used.

The skill definition lives at skills/arbor/SKILL.md in https://github.com/K-Dense-AI/scientific-agent-skills.

Where to get it

Also from k-dense-ai

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Sources

  1. K-Dense-AI/scientific-agent-skills on GitHub — GitHub, observed , trust tier 3.