OpenRouter alternative? Try Pareto direct.

One real request

A rate-limit retry helper, written and checked.

import time

def call_with_retry(fn, max_attempts=4):
    for attempt in range(max_attempts):
        try:
            return fn()
        except RateLimited as e:
            if attempt == max_attempts - 1:
                raise
            time.sleep(e.retry_after)

The checks (test_retry.py, in full)

import time

class RateLimited(Exception):
    def __init__(self, retry_after):
        self.retry_after = retry_after

slept = []
time.sleep = slept.append  # record waits instead of sleeping

def flaky(failures, result="ok"):
    calls = []
    def fn():
        calls.append(1)
        if len(calls) <= failures:
            raise RateLimited(2)
        return result
    return fn, calls

fn, calls = flaky(2)
assert call_with_retry(fn) == "ok" and len(calls) == 3 and slept == [2, 2]

slept.clear(); fn, calls = flaky(9)
try:
    call_with_retry(fn, max_attempts=3); assert False, "should re-raise"
except RateLimited:
    assert len(calls) == 3 and slept == [2, 2]

def broken():
    raise ValueError("bad request")
slept.clear()
try:
    call_with_retry(broken); assert False, "should propagate"
except ValueError:
    assert slept == []

print("all checks passed")

Result

$ python3 test_retry.py
all checks passed

We put the answer’s function right after the RateLimited class and the sleep stub, then ran the checks with Python 3. The stub records each wait instead of sleeping. The checks cover a call that succeeds on the third try, one that runs out of attempts, and an unrelated error that must not be retried.

Captured October 20, 2026 from the Unbiased API (model pareto, served as Pareto 26.10). 410 tokens (92 prompt, 318 answer), as reported by the API. On pay-as-you-go credits this call cost $0.0011 at the published rates. Raw capture.

Going direct

Change the base URL, key and model string.

The Unbiased API speaks the OpenAI Chat Completions and Anthropic Messages formats (API spec). Keep the SDK you already use. These are the quickstart examples:

OpenAI-format SDK (Python)

import os
from openai import OpenAI

client = OpenAI(
    base_url="https://api.unbiased.ai/v1",
    api_key=os.environ["UNBIASED_API_KEY"],
)
reply = client.chat.completions.create(
    model="pareto",
    messages=[{"role": "user", "content": "Hello"}],
)
print(reply.choices[0].message.content)

Anthropic-format SDK (Python)

import os
import anthropic

client = anthropic.Anthropic(
    base_url="https://api.unbiased.ai",
    api_key=os.environ["UNBIASED_API_KEY"],
)
message = client.messages.create(
    model="pareto",
    max_tokens=1024,
    messages=[{"role": "user", "content": "Hello"}],
)
print(message.content[0].text)

Model listing (GET /v1/models) isn’t implemented yet, so set the model string pareto yourself. Validate your client’s streaming, tools and error handling before you move live traffic.