Surfaces the GEPA (genetic-evolution prompt-adaptation) library exports
from @metaharness/darwin/gepa. Unlike the other skills in this plugin
there is no CLI binary behind this — the script dynamic-imports the library
(local resolution first, versioned cache install as fallback) and calls the
subprocess-safe subset.
When to use
- Adopting an evolved policy:
--op rendershows the actual system prompt a genome compiles to — read THAT, not the raw JSON, before wiring a genome into a harness. - Auditing a promotion:
--op genomeloads + validates the shipped cand-6 genome (first holdout-confirmed cheap-tier promotion; provenance ships in the package) or any genome file you point at. - CI gate on genome edits:
--op validate --alert-on-invalidexits 1 on structural errors. - Debugging a bad run:
--op analyze --transcript run.jsonclassifies failure modes (GEPA's failure-class taxonomy) from a transcript array.
What is deliberately NOT here
gepaOptimize — the optimization loop takes an in-process
evaluate(candidate) callback ("bring your own evaluator") that cannot
cross a subprocess boundary. Two supported paths instead:
- Library consumers:
import { gepaOptimize, loadCand6Genome } from '@metaharness/darwin/gepa' - Sandbox-scored evolution:
harness-evolve(darwin CLIevolve), which pairs GEPA with its own sandbox evaluators.
Algorithm
Implementation: scripts/gepa.mjs.
import('@metaharness/darwin/gepa'); on MODULE_NOT_FOUND fall back to a one-timenpm install --prefix ~/.ruflo/darwin-cache-0.8.0and import the cacheddist/gepa/index.js(versioned dir → pin bumps invalidate).- Dispatch
--op:genome→loadGenome(fs, path)orloadCand6Genome()+validateGenomevalidate→validateGenome(rawJson)(raw parse so broken files reach the validator instead of throwing in the loader)render→buildSystemFromGenome(genome, ext?, glob?)analyze→analyzeTranscript(entries)
- Emit one JSON object; exit 0 (or 1 under
--alert-on-invalid, 2 on bad input).
Examples
node scripts/gepa.mjs --op genome # cand-6 + validation
node scripts/gepa.mjs --op render | jq -r .system # what does cand-6 SAY?
node scripts/gepa.mjs --op validate --path my-genome.json --alert-on-invalid
node scripts/gepa.mjs --op analyze --transcript run.json
Exit codes
0— op completed (or degraded — darwin not installable)1—--alert-on-invalidand validation found errors2— config error (unknown op, missing/broken input file)
Source: ruvnet/ruflo → plugins/ruflo-metaharness/skills/harness-gepa/SKILL.md