llamacpp-mcp

An MCP (Model Context Protocol) wrapper for running local LLMs using llama-cpp-python. This project provides a framework for integrating local language models as MCP tools with built-in support for specialized models like SmileyLlama.

SmileyLlama Integration

Generate SMILES strings (chemical notation) for drug-like molecules with fine-grained constraints:

• Lipinski's Rule of Five validation

• Hydrogen bond donor/acceptor limits

• Molecular weight and LogP constraints

• Warhead SMARTS pattern matching

• Macrocycle detection and filtering

• And more...

Installation

Prerequisites

• Python ≥ 3.13

• uv (recommended) or pip

Setup

Clone the repository and install dependencies:

git clone <repository-url>
cd llamacpp-mcp
uv sync

Backend Configuration

The llama-cpp-python library requires compilation with hardware acceleration support. Choose the appropriate backend for your system:

CUDA (NVIDIA GPUs):

CMAKE_ARGS="-DGGML_CUDA=on" uv pip install llama-cpp-python --force-reinstall --no-cache-dir

ROCm (AMD GPUs):

CMAKE_ARGS="-DGGML_HIPBLAS=on" uv pip install llama-cpp-python --force-reinstall --no-cache-dir

Metal (Apple Silicon):

CMAKE_ARGS="-DGGML_METAL=on" uv pip install llama-cpp-python --force-reinstall --no-cache-dir

CPU-only (no GPU acceleration):

uv sync

Usage

Run the agent example

Setup your example/fastagent.secrets.yaml:

anthropic:
  api_key: your-api-key-here

Then run the agent interface in the terminal:

cd example/
uv run --extra agent agent.py

Running the MCP Server

Start the MCP server with a GGUF model:

uv run llamacpp-mcp -i /path/to/model.gguf

Additional parameters can be passed as command-line arguments:

uv run llamacpp-mcp --input model.gguf -n_gpu_layers -1 -n_threads 8

Common parameters:

• -n_gpu_layers: Number of model layers to offload to GPU (-1 for all)

• -n_threads: Number of CPU threads to use

• -n_ctx: Context window size

• -verbose: Verbosity level

Available Tools

generate_smiles

Generate SMILES strings for drug-like molecules with optional constraints.

Parameters:

• max_hbond_donors: Maximum hydrogen bond donors

• max_hbond_acceptors: Maximum hydrogen bond acceptors

• max_molecular_weight: Maximum molecular weight

• max_clogp: Maximum calculated LogP

• lipinski_rule_of_five: Enforce Lipinski's Rule of Five

• rule_of_three: Enforce Rule-of-Three for fragment-like molecules

• And additional constraint options...

Dependencies

Core:

• fastmcp>=2.13.1 - MCP server framework

• llama-cpp-python>=0.3.16 - LLM inference engine

Optional:

• fast-agent-mcp>=0.2.25 - For agent-based integrations

Development

Project Setup

The project uses uv for dependency management. After installing uv, run:

uv sync

This installs all dependencies in a local virtual environment.

Adding New Models

To add a new model type:

1. Create a subdirectory under src/llamacpp_mcp/models/

2. Implement models.py with Pydantic constraint definitions

3. Implement tools.py with tool registration function

4. Import and register tools in the main __init__.py

Configuration

Model parameters can be configured via:

1. Command-line arguments - Pass directly to llamacpp-mcp

2. Environment variables - Set before running the server

3. Agent Tool Configuration - See example/fastagent.config.yaml for reference

License

MIT License

Author

Lukas Kim