OpenAI-Compatible APIs: What They Are and Why They Matter

What "OpenAI-Compatible" Means

An OpenAI-compatible API uses the same request format, same response format, and same SDKs as OpenAI. The only difference: the base URL and API key.

If your code works with OpenAI, it works with any compatible provider. No rewrite needed.

Why This Matters

• •No vendor lock-in. Switch providers without touching application code.
• •Use any SDK. Python openai, JavaScript OpenAI library, LangChain, Vercel AI SDK, cURL. All work.
• •Access open-source models. Models like DeepSeek V3, Qwen 3.6, and Gemma 4 are competitive with GPT-4 at a fraction of the cost.

The 2-Line Migration

Moving from OpenAI to an open-source model through Kyma takes exactly 2 changes:

from openai import OpenAI

client = OpenAI()  # uses api.openai.com

response = client.chat.completions.create(
    model="gpt-4o",
    messages=[{"role": "user", "content": "Hello"}],
)

from openai import OpenAI

client = OpenAI(
    base_url="https://kymaapi.com/v1",  # ← change 1
    api_key="ky-your-key",               # ← change 2
)

response = client.chat.completions.create(
    model="qwen-3.6-plus",  # open-source, GPT-4 class
    messages=[{"role": "user", "content": "Hello"}],
)

Same code structure. Same SDK. Same response format. Different model, different price.

What Tools Support This

Any tool that lets you set a custom base URL works with OpenAI-compatible APIs:

Active Models, One Endpoint

Through Kyma API, you get access to Kyma's active open models from Google, Meta, Alibaba, DeepSeek, Moonshot, MiniMax, and more. All through https://kymaapi.com/v1.

Switch models by changing the model parameter. No new SDK, no new API key, no new billing account.

Get Started

Head to kymaapi.com, sign up for free credits, and try it with your existing OpenAI code. The quickstart guide takes 2 minutes.