Using OpenAI SDKs

Square1 speaks the OpenAI wire format, so the official SDKs (and any tool built on them) work with two settings:

Base URL — https://inference.square1.dev/v1
API key — your sq-arca-... key

Setup

from openai import OpenAI

client = OpenAI(
    base_url="https://inference.square1.dev/v1",
    api_key="sq-arca-...",
)

import OpenAI from "openai";

const client = new OpenAI({
  baseURL: "https://inference.square1.dev/v1",
  apiKey: "sq-arca-...",
});

Streaming

stream = client.chat.completions.create(
    model="deepseek-v4-pro",
    messages=[{"role": "user", "content": "Explain quicksort."}],
    stream=True,
)
for chunk in stream:
    delta = chunk.choices[0].delta
    if delta.content:
        print(delta.content, end="", flush=True)

const stream = await client.chat.completions.create({
  model: "deepseek-v4-pro",
  messages: [{ role: "user", content: "Explain quicksort." }],
  stream: true,
});
for await (const chunk of stream) {
  process.stdout.write(chunk.choices[0]?.delta?.content ?? "");
}

Reasoning models also emit a delta.reasoning channel the SDK types don’t know about. It’s carried in the raw chunk object — read it as an untyped field if you want to display thinking text, or ignore it.

Reasoning effort

On models with supports_reasoning, pass reasoning_effort. The Python and Node SDKs both forward it natively:

completion = client.chat.completions.create(
    model="kimi-k2.6",
    reasoning_effort="high",
    messages=[{"role": "user", "content": "Prove it."}],
)

Allowed values are per-model. Sending a value the model doesn’t accept returns 400 invalid_reasoning_effort with the allowed list in the message.

Tool calling

Models with supports_tools accept the standard tools / tool_choice / parallel_tool_calls fields and answer with tool_calls (ids always look like call_<32 hex>). Send tool results back as role: "tool" messages, exactly as with OpenAI.

What to expect that’s different

The response carries a wellspring quota receipt — SDKs preserve it as an extra field on the response object.
Unsupported request fields (n, presence_penalty, seed, response_format, …) are not part of the contract — don’t rely on them.
max_tokens is clamped to the model’s max_output_tokens; input is capped by max_input_tokens (both visible in GET /v1/models).
Errors follow the OpenAI envelope with Square1-specific codes — see Errors, and note HTTP 529 (model_overloaded) is retryable.

Getting started

Core concepts

Guides

Public data

Using OpenAI SDKs

Setup

Streaming

Reasoning effort

Tool calling

What to expect that’s different

​Setup

​Streaming

​Reasoning effort

​Tool calling

​What to expect that’s different

Setup

Streaming

Reasoning effort

Tool calling

What to expect that’s different