EasyEvolve

Give us an evaluator. We'll evolve the code.

EasyEvolve is a hosted API that improves Python code with LLM-driven evolutionary search. You write a function that scores a candidate program; the service generates, mutates and evaluates candidates in isolated sandboxes and returns the best one.

Invite-only beta. You need an invite token from the EasyEvolve team. The API, pricing and limits may change, and data may be reset during the beta.

Install

pip install --pre easyevolve

Python 3.11 or later.

Sign in with your invite token

easyevolve login

Paste the token when prompted. It is stored at ~/.config/easyevolve/credentials.json with owner-only permissions. You can also set EASYEVOLVE_TOKEN instead.

Write an evaluator

Expose evaluate(candidate_path: str) -> dict returning a finite score (higher is better). Use the Python standard library only.

# eval.py
"""Candidate contract: solve(values: list[int]) -> list[int], sorted ascending."""
import importlib.util


def evaluate(candidate_path: str) -> dict:
    spec = importlib.util.spec_from_file_location("candidate", candidate_path)
    candidate = importlib.util.module_from_spec(spec)
    spec.loader.exec_module(candidate)
    cases = [[], [1], [3, 1, 2], [5, -1, 5, 0], list(range(30, 0, -1))]
    passed = sum(candidate.solve(values.copy()) == sorted(values) for values in cases)
    return {"score": passed / len(cases)}

Run

from easyevolve import EasyEvolve

with EasyEvolve(evaluator="eval.py") as client:
    print(client.estimate(iterations=5, level="low", budget=0.5))
    result = client.run(iterations=5, level="low", budget=0.5)
    print(result.best_score, result.cost)
    print(result.best_code)

Or from the terminal:

easyevolve balance
easyevolve run eval.py --iterations 5 --level low --budget 0.5

budget (USD) is a hard cap: the run stops before it would exceed it, and unused budget returns to your balance. A client timeout does not stop the job; use client.resume(job_id) to reconnect or easyevolve cancel <job_id> to stop it.

Documentation: https://easyevolve.dev/docs