Deploying a 1-Bit Bonsai-27B Model with PrismML llama.cpp and OpenAI-Compatible Local Inference Workflows

In this tutorial, we deploy the 1-bit Bonsai-27B language model using the PrismML fork of llama.cpp, which provides the specialized CUDA kernels required to decode the model’s Q1_0_g128 GGUF quantization format. We begin by validating the GPU runtime, installing the required Python dependencies, compiling the CUDA-enabled inference binaries, and downloading the compressed model weights from Hugging Face. We then test the model through llama-cli, launch an OpenAI-compatible local inference server, and interact with it through a reusable Python client that supports standard completions, streamed responses, multi-turn conversations, and code generation. We also examine optional configurations for throughput benchmarking, quantized key-value caching, long-context inference, speculative decoding, and multimodal extensions. Copy CodeCopiedUse a different Browserimport os import sys import time import json import shutil import subprocess import multiprocessing WORK_DIR = "/content" REPO_URL = "https://github.com/PrismML-Eng/llama.cpp" REPO_DIR = os.path.join(WORK_DIR, "llama.cpp") BUILD_DIR = os.path.join(REPO_DIR, "build") BIN_DIR = os.path.join(BUILD_DIR, "bin") HF_REPO = "prism-ml/Bonsai-27B-gguf" MODEL_FILE = "Bonsai-27B-Q1_0.gguf" MODEL_PATH = os.path.join(WORK_DIR, MODEL_FILE) SERVER_HOST = "127.0.0.1" SERVER_PORT = 8080 SERVER_URL = f"http://{SERVER_HOST}:{SERVER_PORT}" GEN_PARAMS = {"temperature": 0.7, "top_p": 0.95, "top_k": 20} CTX_SIZE = 8192 N_GPU_LAYERS = 99 USE_KV_Q4 = False def sh(cmd, check=True, **kw): """Run a shell command, streaming output to the notebook.""" print(f"\n$ {cmd}") return subprocess.run(cmd, shell=True, check=check, **kw) print("=" * 70) print("[1/7] Checking environment") print("=" * 70) gpu = subprocess.run("nvidia-smi --query-gpu=name,memory.total --format=csv,noheader", shell=True, capture_output=True, text=True) if gpu.returncode != 0: sys.exit("No GPU detected. In Colab: Runtime -> Change runtime type -> GPU (T4).") print(f"GPU detected: {gpu.stdout.strip()}") print("Bonsai-27B needs only ~5.2 GB peak at 4K context — any Colab GPU works.") sh("pip -q install huggingface_hub requests") We configure the Colab workspace, model repository, server endpoint, inference parameters, context size, and GPU offloading settings required throughout the tutorial. We define a reusable shell-command function and verify that the runtime exposes a compatible NVIDIA GPU before continuing. We then install the Hugging Face Hub and HTTP client dependencies needed for model retrieval and API communication. Copy CodeCopiedUse a different Browserprint("=" * 70) print("[2/7] Building PrismML llama.cpp fork with CUDA (cached after 1st run)") print("=" * 70) if not os.path.isdir(REPO_DIR): sh(f"git clone --depth 1 {REPO_URL} {REPO_DIR}") else: print("Repo already cloned — skipping.") cli_bin = os.path.join(BIN_DIR, "llama-cli") server_bin = os.path.join(BIN_DIR, "llama-server") bench_bin = os.path.join(BIN_DIR, "llama-bench") if not (os.path.exists(cli_bin) and os.path.exists(server_bin)): jobs = multiprocessing.cpu_count() sh(f"cmake -S {REPO_DIR} -B {BUILD_DIR} -DGGML_CUDA=ON -DCMAKE_BUILD_TYPE=Release") sh(f"cmake --build {BUILD_DIR} -j{jobs} --target llama-cli llama-server llama-bench") else: print("Binaries already built — skipping.") We clone the PrismML fork of llama.cpp, which provides the specialized kernels required for the model’s Q1_0_g128 quantization format. We configure a CUDA-enabled release build with CMake and compile the command-line, server, and benchmarking executables. We also reuse previously generated binaries when they already exist, reducing repeated setup time in the same Colab session. Copy CodeCopiedUse a different Browserprint("=" * 70) print("[3/7] Downloading weights from Hugging Face") print("=" * 70) from huggingface_hub import hf_hub_download if not os.path.exist