Spark-X2.5-4B-GGUF

[!NOTE] This repository provides a BF16 GGUF conversion of Spark-X2.5-4B.

Spark-X2.5 is a compact, general-purpose language model for conversation, writing, translation, reasoning, coding, tool use, and agentic workflows. It uses a hybrid attention architecture, supports a native context length of up to 1M tokens, and covers more than 200 languages. For its architecture, training methods, benchmark results, fine-tuning, and citation, see the Spark-X2.5-4B.

Local Deployment

The GGUF file can be used for local inference with Ollama and LM Studio. Spark-X2.5 support is provided by XHToken/llama.cpp, so the Quick Starts below use this compatible implementation.

Ollama Quick Start

Build

git clone https://github.com/XHToken/llama.cpp.git llama.cpp-spark
git clone https://github.com/ollama/ollama.git ollama-spark
cd ollama-spark
export OLLAMA_LLAMA_CPP_SOURCE="$(cd ../llama.cpp-spark && pwd)"
cmake -S . -B build
cmake --build build --parallel 8

Import the GGUF

Replace the model path below with the absolute path to the downloaded GGUF file:

printf 'FROM /absolute/path/to/Spark-X2.5-4B.gguf\n' > ./Modelfile.spark

Create and Run

Start the Ollama server in the first terminal:

./ollama serve

Open a second terminal in the same ollama-spark directory:

./ollama create Spark-X2.5-4B -f ./Modelfile.spark
./ollama run Spark-X2.5-4B --think=false

--think=false disables thinking mode for faster, direct responses.

LM Studio Quick Start

Build the Compatible llama.cpp Runtime

git clone https://github.com/XHToken/llama.cpp.git llama.cpp-spark
cd llama.cpp-spark
cmake -S . -B build
cmake --build build --parallel 8

Configure LM Studio

1. Close LM Studio.

2. Back up the selected LM Studio runtime directory:

   <LM_STUDIO_HOME>/extensions/backends/<selected-runtime>/
   

3. Copy the llama.cpp-spark build output into the selected runtime directory, replacing the existing runtime files.

4. Place Spark-X2.5-4B.gguf in:

   <LM_STUDIO_HOME>/models/<org>/<name>/
   

Example runtime directory on Apple Silicon:

./build/bin/* -> ~/.lmstudio/extensions/backends/llama.cpp-mac-arm64-apple-metal-advsimd-<version>/

Run

Open LM Studio, select the model under My Models, click Load, and start a new chat.

You can also use the lms CLI:

lms ls
lms load <model>
lms chat <model>

License

Released under the Apache License 2.0.