OpenAI SDK base URL for KeepRouter: Python, Node, and Go

Use https://keeprouter.com/v1 as the OpenAI SDK base URL. In Python the option is base_url; in Node it is baseURL; in the official Go SDK it is option.WithBaseURL. All three SDKs can also read OPENAI_BASE_URL. Replace the API key and select an exact chat-compatible model from the live KeepRouter catalog.

Before changing configuration, use the local API migration checker to review credential-free JSON, exact model IDs and unsupported routing assumptions. Download the Python and Node starter pack for controlled tests in your own environment.

Copy the exact value

The SDK appends /chat/completions. Do not pass the complete operation URL as the base URL and do not remove /v1.

Python

from openai import OpenAI

client = OpenAI(
    base_url="https://keeprouter.com/v1",   # KeepRouter endpoint
    api_key="sk-kr-your-key",               # KeepRouter key
)

r = client.chat.completions.create(
    model="claude-fable-5-1",               # choose a supported catalog model
    messages=[{"role": "user", "content": "Hello"}],
)

Environment-only configuration:

export OPENAI_BASE_URL=https://keeprouter.com/v1
export OPENAI_API_KEY=sk-kr-your-key

Node and TypeScript

import OpenAI from "openai";

const client = new OpenAI({
  baseURL: "https://keeprouter.com/v1", // KeepRouter endpoint
  apiKey: process.env.KEEPROUTER_KEY,   // KeepRouter key
});

const r = await client.chat.completions.create({
  model: "gemini-3.8-flash",            // choose a supported catalog model
  messages: [{ role: "user", content: "Hello" }],
});

Keep paid API keys server-side. A browser bundle can expose the credential.

Go

client := openai.NewClient(
    option.WithBaseURL("https://keeprouter.com/v1"),
    option.WithAPIKey(os.Getenv("KEEPROUTER_KEY")),
)

One codebase, compatible chat models

Set model to a compatible chat id from the catalog — no provider-specific chat SDK per maker:

See every model and price on Models & pricing.

Chat Completions is not every OpenAI route

The public OpenAPI document is the route-level contract.

Base URL migration map

Changing URL and key does not translate model IDs or product-specific routing fields. See the OpenRouter Python SDK guide for the native and OpenAI SDK paths.

Troubleshooting

Production verification

Start with a deterministic non-streaming prompt. Record returned model, request ID, token usage, HTTP status, and billed amount. Then test streaming, cancellation, one real tool round trip, and a bounded error.

Frequently asked questions

What is the KeepRouter OpenAI SDK base URL?

Use https://keeprouter.com/v1 exactly.

Is Python base_url the same as Node baseURL?

They configure the same concept, but the option spelling follows each SDK.

Can I use OPENAI_BASE_URL instead?

Yes. Current official Python, Node, and Go SDKs read it when an explicit constructor option is not supplied.

Can I copy an OpenRouter model slug?

No. Use an exact model ID from the live KeepRouter catalog; catalog namespaces are not shared.

Does the base URL enable Responses automatically?

No. The selected model needs a configured Responses route, and the application must use the Responses request and event contract.

How do I get a key?

Create a scoped KeepRouter key, then verify the exact model endpoint before calling it.

Sources reviewed 2026-09-11

• OpenAI Python client
• OpenAI Node client
• OpenAI Go base URL option

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