Add Model Fallback to an OpenAI-Compatible Node.js App

Jinze Wang — Fri, 14 Aug 2026 03:35:25 +0000

A single model can be unavailable, rate-limited, or temporarily slow. If your application already uses an OpenAI-compatible API, a simple fallback can make testing more resilient without introducing another SDK.

This tutorial uses Node.js and the official OpenAI JavaScript package. It tries one model first and switches to a second model only when the first request fails.

1. Install the SDK

npm install openai

2. Store the API key outside your code

On macOS or Linux:

export JINZEAI_API_KEY="your_api_key_here"

On PowerShell:

$env:JINZEAI_API_KEY="your_api_key_here"

Never commit a real API key. Rotate it immediately if it appears in a public repository, screenshot, or support message.

3. Create an OpenAI-compatible client

import OpenAI from "openai";

const client = new OpenAI({
  baseURL: "https://jinzeai.cc/v1",
  apiKey: process.env.JINZEAI_API_KEY,
});

4. Add a small fallback function

const models = ["deepseek-chat", "qwen-flash"];

async function completeWithFallback(messages) {
  let lastError;

  for (const model of models) {
    try {
      const response = await client.chat.completions.create({
        model,
        messages,
      });

      return {
        model,
        text: response.choices[0].message.content,
      };
    } catch (error) {
      lastError = error;
      console.warn(`${model} failed: ${error.status ?? "unknown status"}`);
    }
  }

  throw lastError;
}

const result = await completeWithFallback([
  {
    role: "user",
    content: "Explain model fallback in one sentence.",
  },
]);

console.log(`Model: ${result.model}`);
console.log(result.text);

5. Decide which errors should trigger fallback

The minimal example retries on every error so the control flow is easy to see. A production application should be more selective.

Fallback may be reasonable for:

rate limits;
upstream server errors;
temporary timeouts;
a model that is unavailable to the current account.

Do not silently retry authentication errors. An HTTP 401 usually means the key is missing, inactive, or formatted incorrectly. Fix the key instead of sending the same invalid request to another model.

6. Check model availability first

Available beta models can change. Use your key with GET /v1/models rather than assuming every model is enabled for every account.

curl https://jinzeai.cc/v1/models \
  -H "Authorization: Bearer $JINZEAI_API_KEY"

Try it during the public beta

JinzeAI is testing an OpenAI-compatible endpoint for users outside mainland China. No payment is required during the public beta, and limited free test credit may be available.

Model availability and test limits may change during beta. Feedback about SDK compatibility, latency, and failure handling is especially useful.

Use DeepSeek with the OpenAI Python SDK by Changing One URL

Jinze Wang — Thu, 13 Aug 2026 06:52:10 +0000

If your application already uses the OpenAI Python SDK, testing another model does not have to mean rewriting the integration. An OpenAI-compatible endpoint lets you keep the familiar client, messages format, and response handling.

This tutorial shows a minimal DeepSeek request through JinzeAI's public beta endpoint.

1. Install the SDK

python -m pip install openai

2. Store the API key safely

Do not hard-code an API key or commit it to Git.

On macOS or Linux:

export JINZEAI_API_KEY="your_api_key_here"

On PowerShell:

$env:JINZEAI_API_KEY="your_api_key_here"

3. Create the client

import os

from openai import OpenAI

client = OpenAI(
    base_url="https://jinzeai.cc/v1",
    api_key=os.environ["JINZEAI_API_KEY"],
)

The important change is base_url. The rest of the SDK remains familiar.

4. Send a request

response = client.chat.completions.create(
    model="deepseek-chat",
    messages=[
        {
            "role": "user",
            "content": "Explain API gateways in one sentence.",
        }
    ],
)

print(response.choices[0].message.content)

Common errors

HTTP 401

Confirm that the API key is active and that your client sends it as a bearer token. If a key was ever exposed publicly, rotate it instead of continuing to use it.

HTTP 404

Confirm that the base URL is exactly:

https://jinzeai.cc/v1

Chat requests must use POST /chat/completions.

Slow first test

Start with a short prompt and a new conversation. Large message histories can add substantial input tokens and latency.

Try the public beta

JinzeAI is inviting early beta testers outside mainland China. The beta may include a limited free test credit, and no payment is required to test it.

Model availability and usage limits may change during beta. I would especially value feedback about setup clarity, latency, and SDK compatibility.

DEV Community: Jinze Wang

Add Model Fallback to an OpenAI-Compatible Node.js App

1. Install the SDK

2. Store the API key outside your code

3. Create an OpenAI-compatible client

4. Add a small fallback function

5. Decide which errors should trigger fallback

6. Check model availability first

Try it during the public beta

Use DeepSeek with the OpenAI Python SDK by Changing One URL

1. Install the SDK

2. Store the API key safely

3. Create the client

4. Send a request

Common errors

HTTP 401

HTTP 404

Slow first test

Try the public beta