unbiased ai

Developers

Pareto API docs

Pareto is Unbiased’s blended AI model: it selects frontier and open models for each request and blends their outputs into one answer. It is one model string built so AI providers compete for every request. It speaks the OpenAI and Anthropic API formats, so you can keep the client you already use: change the base URL, the key and the model string, then validate your client’s streaming, tools and error handling. Scores are on the model card, rates on the pricing page, release notes on the Pareto 26.10 hub. Setting up a coding agent? See vibe coding with Pareto.

Quickstart

curl https://api.unbiased.ai/v1/chat/completions \
  -H "Authorization: Bearer $UNBIASED_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model": "pareto", "messages": [{"role": "user", "content": "Hello"}]}'

Rather have your agent do the setup? Hand it start/agent.md.

Already on OpenRouter? Use Pareto on OpenRouter.

Authentication

Send your API key as Authorization: Bearer <api-key> or in the x-api-key header. Keep it in an environment variable or your OS keychain, never in a repo.

Endpoints

EndpointFormatUse it from
POST /v1/chat/completionsOpenAI Chat CompletionsOpenAI SDKs and any OpenAI-compatible tool
POST /v1/messagesAnthropic MessagesAnthropic SDKs and Anthropic-compatible tools

Both accept stream: true for server-sent events in their own format. Anthropic-format example:

curl https://api.unbiased.ai/v1/messages \
  -H "x-api-key: $UNBIASED_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model": "pareto", "max_tokens": 1024, "messages": [{"role": "user", "content": "Hello"}]}'

OpenAI and Anthropic SDKs

Keep the SDK you already use. Point it at Pareto with a base URL, your key and the model string pareto; the rest of your code stays the same.

OpenAI 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 SDK (Python). The SDK adds /v1/messages itself, so the base URL stops at the domain:

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)

Coding agents and other tools that take an OpenAI- or Anthropic-compatible base URL connect the same way. Works with has the exact settings for each one, from Claude Code, Codex and OpenCode to Cursor, Cline and Open WebUI.

Rate limits

PlanRequests per minuteTokens
Personal2050M a week
Personal Max60600M a week
Team300No weekly cap; prepaid credits

Requests over the limit return HTTP 429. Back off and retry. Plans and token rates are on the pricing page.

Errors

Errors come back as JSON in the format of the endpoint you called. A missing key on /v1/chat/completions:

{"error": {"message": "Missing API key. ...", "type": "invalid_request_error", "code": "invalid_api_key"}}

The same on /v1/messages:

{"type": "error", "error": {"type": "authentication_error", "message": "Missing API key. ..."}, "request_id": "req_..."}

Status codes: 400 invalid request, 401 missing or invalid key, 429 rate limit reached, 500 server error. Include the request ID (in the error body on /v1/messages, in the x-request-id response header on /v1/chat/completions) when you write to info@unbiased.ai, never the key.

Versioning and known gaps

For agents and tools