OpenAI Compatibility

DOS AI implements the OpenAI API specification. If your application already uses the OpenAI API, you can switch to DOS AI by changing two lines of configuration -- no code rewrite required.

Drop-in replacement

The only changes needed are base_url (or baseURL) and api_key:

Python

from openai import OpenAI

# Before (OpenAI)
# client = OpenAI(api_key="sk-...")

# After (DOS AI)
client = OpenAI(
    base_url="https://api.dos.ai/v1",
    api_key="dos_sk_...",
)

# Everything else stays the same
response = client.chat.completions.create(
    model="dos-ai",
    messages=[{"role": "user", "content": "Hello!"}],
    temperature=0.7,
    max_tokens=256,
)

JavaScript / TypeScript

import OpenAI from "openai";

// Before (OpenAI)
// const client = new OpenAI({ apiKey: "sk-..." });

// After (DOS AI)
const client = new OpenAI({
  baseURL: "https://api.dos.ai/v1",
  apiKey: "dos_sk_...",
});

// Everything else stays the same
const response = await client.chat.completions.create({
  model: "dos-ai",
  messages: [{ role: "user", content: "Hello!" }],
  temperature: 0.7,
  max_tokens: 256,
});

cURL / HTTP

Replace https://api.openai.com with https://api.dos.ai and update your API key:

curl https://api.dos.ai/v1/chat/completions \
  -H "Authorization: Bearer dos_sk_..." \
  -H "Content-Type: application/json" \
  -d '{
    "model": "dos-ai",
    "messages": [{"role": "user", "content": "Hello!"}],
    "temperature": 0.7,
    "max_tokens": 256
  }'

Supported endpoints

Endpoint	Method	Description
/v1/chat/completions	POST	Chat completions (single and streaming)
/v1/models	GET	List available models

Supported parameters

The /v1/chat/completions endpoint supports the following request parameters:

Parameter	Type	Description
model	string	Required. Model ID (e.g., dos-ai)
messages	array	Required. Conversation messages (role + content)
temperature	float	Sampling temperature (0.0 -- 2.0). Default: 1.0
top_p	float	Nucleus sampling threshold. Default: 1.0
max_tokens	integer	Maximum tokens to generate
stream	boolean	Enable server-sent events streaming. Default: false
stop	string or array	Stop sequence(s)
frequency_penalty	float	Penalize repeated tokens (-2.0 -- 2.0). Default: 0.0
presence_penalty	float	Penalize tokens already present (-2.0 -- 2.0). Default: 0.0
n	integer	Number of completions to generate. Default: 1
seed	integer	Seed for deterministic sampling

Framework compatibility

Since DOS AI follows the OpenAI specification, it works out of the box with popular frameworks and libraries:

LangChain

from langchain_openai import ChatOpenAI

llm = ChatOpenAI(
    base_url="https://api.dos.ai/v1",
    api_key="dos_sk_...",
    model="dos-ai",
)

response = llm.invoke("Explain recursion in one sentence.")
print(response.content)

LlamaIndex

from llama_index.llms.openai_like import OpenAILike

llm = OpenAILike(
    api_base="https://api.dos.ai/v1",
    api_key="dos_sk_...",
    model="dos-ai",
    is_chat_model=True,
)

Vercel AI SDK

import { createOpenAI } from "@ai-sdk/openai";
import { generateText } from "ai";

const dosai = createOpenAI({
  baseURL: "https://api.dos.ai/v1",
  apiKey: "dos_sk_...",
});

const { text } = await generateText({
  model: dosai("dos-ai"),
  prompt: "Explain recursion in one sentence.",
});

What's different from OpenAI

While we aim for full compatibility, there are a few differences to be aware of:

Feature	Status	Notes
Chat completions	Supported	Full compatibility including streaming
Model names	Different	Use DOS AI model IDs (e.g., dos-ai instead of gpt-4o)
Function calling / tools	Supported	Works with vLLM tool-calling implementation
JSON mode	Supported	Set response_format: {"type": "json_object"}
Vision (image inputs)	Model-dependent	Supported if the underlying model handles vision
Embeddings	Not yet available	Coming soon
Image generation	Not available	Use a dedicated image generation service
Audio / TTS / STT	Not available	Not on the roadmap
Assistants API	Not available	Use chat completions directly
Batch API	Not yet available	Coming soon

Migration checklist

Switching from OpenAI to DOS AI:

• Sign up at app.dos.ai and create an API key
• Update base_url / baseURL to https://api.dos.ai/v1
• Update api_key / apiKey to your dos_sk_... key
• Update the model parameter to a DOS AI model ID (e.g., dos-ai)
• Test your application -- request/response format is identical
• (Optional) Update environment variable names for clarity:

# .env
# Before
OPENAI_API_KEY=sk-...

# After
DOS_AI_API_KEY=dos_sk_...
DOS_AI_BASE_URL=https://api.dos.ai/v1

Using both OpenAI and DOS AI

You can use both providers in the same application by creating separate client instances:

from openai import OpenAI

openai_client = OpenAI(api_key="sk-...")
dosai_client = OpenAI(base_url="https://api.dos.ai/v1", api_key="dos_sk_...")

# Route requests based on your needs
def get_completion(prompt, provider="dosai"):
    client = dosai_client if provider == "dosai" else openai_client
    model = "dos-ai" if provider == "dosai" else "gpt-4o"

    return client.chat.completions.create(
        model=model,
        messages=[{"role": "user", "content": prompt}],
    )

This makes it easy to evaluate DOS AI side-by-side or use it as a fallback provider.