K-EXAONE#

K-EXAONE is a large-scale multilingual language model developed by LG AI Research. It is an auto-regressive Mixture-of-Experts (MoE) transformer with 236B total parameters and 23B active per token (128 experts, 8 activated plus 1 shared), using a hybrid attention scheme that interleaves sliding-window and global attention layers. It covers six languages — Korean, English, Spanish, German, Japanese, and Vietnamese — and supports both reasoning and non-reasoning chat.

Furiosa-LLM runs K-EXAONE in NVFP4A16 (NVFP4 weights with 16-bit activations and KV cache). FuriosaAI publishes pre-compiled NVFP4A16 builds under the furiosa-ai organization on the Hugging Face Hub, each shipping a Furiosa Executable Bundle (FXB) for running it on FuriosaAI RNGD with Furiosa-LLM. The upstream weights also run on other frameworks (such as vLLM, SGLang, and Transformers); for usage with those, see the upstream model card linked below.

Variants#

Model

Quantization

RNGD cards

Notes

furiosa-ai/K-EXAONE-236B-A23B-NVFP4A16

NVFP4A16

4

236B total / 23B active; thinking by default

  • Architecture: ExaoneMoE (Mixture-of-Experts), ExaoneMoEForCausalLM

  • Input / Output: Text / Text

  • Quantization: The weights are quantized to NVFP4 (4-bit floating point), while activations and the KV cache remain in 16-bit precision (NVFP4A16).

Usage#

To run this model with Furiosa-LLM, follow the example commands below after installing Furiosa-LLM and its prerequisites.

Launch the server#

The simplest way to serve the model is:

# Launch the server, listening on port 8000 by default
furiosa-llm serve furiosa-ai/K-EXAONE-236B-A23B-NVFP4A16 \
  --reasoning-parser deepseek_v3 \
  --default-chat-template-kwargs '{"enable_thinking": true}'

The --reasoning-parser deepseek_v3 flag separates the model’s chain of thought from the final answer (see Reasoning below). The --default-chat-template-kwargs '{"enable_thinking": true}' flag keeps the chat template and the reasoning parser aligned: K-EXAONE’s chat template enables thinking by default, but deepseek_v3 treats reasoning as disabled unless enable_thinking is set, so without this flag a request that omits enable_thinking would leak the raw <think>...</think> text into the response.

When the server is ready, you will see:

INFO:     Started server process [27507]
INFO:     Waiting for application startup.
INFO:     Application startup complete.
INFO:     Uvicorn running on http://0.0.0.0:8000 (Press CTRL+C to quit)

Launch the server with tool calling#

To enable tool (function) calling, start the server with the hermes tool-call parser:

furiosa-llm serve furiosa-ai/K-EXAONE-236B-A23B-NVFP4A16 \
  --reasoning-parser deepseek_v3 \
  --default-chat-template-kwargs '{"enable_thinking": true}' \
  --enable-auto-tool-choice \
  --tool-call-parser hermes

Query the server#

The server exposes an OpenAI-compatible API. You can send a request with curl:

curl http://localhost:8000/v1/chat/completions \
    -H "Content-Type: application/json" \
    -d '{
    "model": "furiosa-ai/K-EXAONE-236B-A23B-NVFP4A16",
    "messages": [{"role": "user", "content": "What is the capital of France?"}]
    }' \
    | python -m json.tool

Reasoning#

With --reasoning-parser deepseek_v3, K-EXAONE returns its reasoning separately from the final answer:

  • response.choices[].message.reasoning (non-streaming)

  • response.choices[].delta.reasoning (streaming)

K-EXAONE thinks by default, so a normal request returns both the reasoning and the final answer:

from openai import OpenAI

client = OpenAI(base_url="http://localhost:8000/v1", api_key="EMPTY")

response = client.chat.completions.create(
    model="furiosa-ai/K-EXAONE-236B-A23B-NVFP4A16",
    messages=[{"role": "user", "content": "How many r's are in 'strawberry'?"}],
)

print("Reasoning:", response.choices[0].message.reasoning)
print("Answer:", response.choices[0].message.content)

For latency-sensitive tasks you can turn thinking off per request by passing extra_body={"chat_template_kwargs": {"enable_thinking": False}}. The response then carries no reasoning content, so read only message.content (accessing message.reasoning would raise AttributeError, as noted below).

Note: The reasoning field is not part of the OpenAI API specification, but it is the convention OpenAI recommends for returning the chain-of-thought (CoT) in Chat Completions-compatible APIs. The OpenAI Agents SDK uses reasoning as its primary property for the CoT, and many LLM serving frameworks (such as vLLM) follow the same convention. It appears only in responses that contain reasoning content; accessing it on a response without reasoning content raises an AttributeError.

Tool calling#

With the server launched using --enable-auto-tool-choice --tool-call-parser hermes, you can pass tools and let the model decide when to call them. See the Tool Calling guide for a complete client example and details on tool-choice options.

Learn more#