Libraries and SDKs

# pip install openai
import os
from openai import OpenAI

client = OpenAI(
    api_key=os.environ["ACACUS_API_KEY"],
    base_url="https://acacus.ly/v1",
)

response = client.chat.completions.create(
    model="deepseek-v4-flash",
    messages=[
        {"role": "system", "content": "Answer in one sentence."},
        {"role": "user", "content": "What is the capital of Libya?"},
    ],
    # DeepSeek's fields are not OpenAI parameters: send them in extra_body.
    extra_body={"thinking": {"type": "disabled"}},
)
print(response.choices[0].message.content)

export OPENAI_API_KEY="$ACACUS_API_KEY"
export OPENAI_BASE_URL="https://acacus.ly/v1"

from openai import OpenAI

client = OpenAI()  # reads OPENAI_API_KEY and OPENAI_BASE_URL

response = client.chat.completions.create(
    model="deepseek-v4-flash",
    messages=[{"role": "user", "content": "Say hello."}],
    extra_body={"thinking": {"type": "disabled"}},
)
print(response.choices[0].message.content)

import os
import openai
from openai import OpenAI

client = OpenAI(
    api_key=os.environ["ACACUS_API_KEY"],
    base_url="https://acacus.ly/v1",
)

try:
    client.chat.completions.create(
        model="deepseek-chat",  # DeepSeek's own name: not a model id here
        messages=[{"role": "user", "content": "Say hello."}],
    )
except openai.APIStatusError as e:
    print(e.status_code, e.code, e.param)
    print(e.body["message"])  # e.body is the "error" object of the reply
    print(e.request_id)  # quote it if you write to support

400 MODEL_NOT_FOUND model
Unknown model: deepseek-chat. Model ids are exact. GET /v1/models, sent with this key, lists the models it can use: deepseek-v4-flash, deepseek-v4-pro and any others your account has.
2931faea-c596-4c25-8310-5fc23b7d1fbb

// npm install openai
// Save as client.mjs, then run: node client.mjs
import OpenAI from "openai";

const client = new OpenAI({
  apiKey: process.env.ACACUS_API_KEY,
  baseURL: "https://acacus.ly/v1",
});

const response = await client.chat.completions.create({
  model: "deepseek-v4-flash",
  messages: [
    { role: "system", content: "Answer in one sentence." },
    { role: "user", content: "What is the capital of Libya?" },
  ],
  // DeepSeek's fields are not OpenAI parameters: add them to the object.
  thinking: { type: "disabled" },
});
console.log(response.choices[0].message.content);

// npm install openai
// Save as client.mts, then run: node client.mts
import OpenAI from "openai";

// DeepSeek's thinking field is not in the SDK's types: add it to the request type.
type AcacusChatParams = OpenAI.ChatCompletionCreateParamsNonStreaming & {
  thinking?: { type: "enabled" | "adaptive" | "disabled" };
};

const client = new OpenAI({
  apiKey: process.env.ACACUS_API_KEY,
  baseURL: "https://acacus.ly/v1",
});

const params: AcacusChatParams = {
  model: "deepseek-v4-flash",
  messages: [{ role: "user", content: "What is the capital of Libya?" }],
  thinking: { type: "disabled" },
};

const response = await client.chat.completions.create(params);
console.log(response.choices[0].message.content);

import OpenAI from "openai";

const client = new OpenAI({
  apiKey: process.env.ACACUS_API_KEY,
  baseURL: "https://acacus.ly/v1",
});

try {
  await client.chat.completions.create({
    model: "deepseek-chat", // DeepSeek's own name: not a model id here
    messages: [{ role: "user", content: "Say hello." }],
  });
} catch (err) {
  if (!(err instanceof OpenAI.APIError)) throw err;
  console.log(err.status, err.code, err.param);
  console.log(err.error.message); // err.error is the "error" object of the reply
  console.log(err.requestID); // quote it if you write to support
}

400 MODEL_NOT_FOUND model
Unknown model: deepseek-chat. Model ids are exact. GET /v1/models, sent with this key, lists the models it can use: deepseek-v4-flash, deepseek-v4-pro and any others your account has.
59acaf58-3d6b-4aff-a70c-8ed6f252eb85

# pip install langchain-openai
import os
from langchain_openai import ChatOpenAI
from pydantic import BaseModel

llm = ChatOpenAI(
    model="deepseek-v4-flash",
    api_key=os.environ["ACACUS_API_KEY"],
    base_url="https://acacus.ly/v1",
    extra_body={"thinking": {"type": "disabled"}},  # DeepSeek's field
)

print(llm.invoke("What is the capital of Libya? Answer in one sentence.").content)


class City(BaseModel):
    name: str
    country: str


# The default method (json_schema) is refused: use function calling.
structured = llm.with_structured_output(City, method="function_calling")
print(structured.invoke("Tripoli is the capital of which country?"))

The capital of Libya is Tripoli.
name='Tripoli' country='Libya'

# pip install llama-index-llms-openai-like
import os
from llama_index.llms.openai_like import OpenAILike

llm = OpenAILike(
    model="deepseek-v4-flash",
    api_base="https://acacus.ly/v1",
    api_key=os.environ["ACACUS_API_KEY"],
    is_chat_model=True,  # send requests to /v1/chat/completions
    is_function_calling_model=True,  # the models can call tools
    additional_kwargs={"extra_body": {"thinking": {"type": "disabled"}}},  # DeepSeek's field
)

print(llm.complete("What is the capital of Libya? Answer in one sentence."))

The capital of Libya is Tripoli.

curl https://acacus.ly/v1/chat/completions \
  -H "Authorization: Bearer $ACACUS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "deepseek-v4-flash",
    "messages": [
      {"role": "system", "content": "Answer in one sentence."},
      {"role": "user", "content": "What is the capital of Libya?"}
    ],
    "thinking": {"type": "disabled"}
  }'