Gemini Evolve — Development skill for Claude Code

gemini-evolve

English | [简体中文](README.zh.md)

**Stop hand-tuning `GEMINI.md`. Let Gemini tune it — with holdout tests and hard gates, so regressions never ship.**

If you use the [Gemini CLI](https://github.com/google-gemini/gemini-cli), you already have a `GEMINI.md` somewhere. If it's been growing for a while, chances are some of it has gone vague, duplicated, or stale. `gemini-evolve` runs a small optimization loop that **mutates your instructions, grades each variant by actually running Gemini CLI on real tasks, and only writes back when a holdout set (examples it never trained on) says the new version is genuinely better.**

Before → after (illustrative example, not a benchmark)

Your baseline `~/.gemini/GEMINI.md`:

# My Gemini Instructions
- try to be concise
- generally avoid long explanations
- if possible, use bullet points
- prefer to keep answers short

After one `gemini-evolve evolve --apply` run, the `sharpen_constraints` + `condense` mutations typically produce something like:

# My Gemini Instructions

## Response Style
- Answer in <=3 sentences by default; use bullets for lists of 3+ items.
- No preamble ("Sure!", "Great question!"). Start with the answer.
- Expand only when the user asks "explain" / "why" / "walk me through".

Holdout score went up, size cap not exceeded, so `--apply` wrote the new file and kept `GEMINI.md..bak` as your escape hatch. If the holdout score had *not* improved by at least 2%, the loop would refuse to apply — no sneaky regressions.

Why you might want this

• You've edited GEMINI.md by hand one too many times.
• You suspect it's bloated but don't want to break what works.
• You want measured improvements, not vibes.

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Prerequisites

Requirement	How to check	Notes
Python 3.11+	python3 --version	3.12 tested too
gemini CLI installed + logged in	gemini --version then gemini -p "hi" -o json	Install: [googl