A Model Context Protocol (MCP) server that provides constraint solving capabilities using MiniZinc. This server exposes a single powerful tool for solving constraint satisfaction and optimization problems.

The server provides one core tool:

• solve_constraint - General purpose constraint solver that accepts any MiniZinc model with optional data parameters, solver selection, and timeout configuration

The easiest way to get started is using our free hosted version at:

https://minizinc-mcp.up.railway.app/sse

Build and run locally:

git clone <repository-url>
cd ccake
docker build -t minizinc-mcp .
docker run -p 8000:8000 minizinc-mcp

Prerequisites:

• Python 3.11+
• MiniZinc 2.8+ (install from https://www.minizinc.org/software.html)

git clone https://github.com/r33drichards/minizinc-mcp
cd minizinc-mcp
pip install -r requirements.txt
python main.py

got to the connectors settings page

click Add Custom Connector button

for name use "minizinc mcp"

for url use:

https://minizinc-mcp.up.railway.app/sse

Once configured, you can ask Claude to solve constraint problems:

"Solve the 4-Queens problem where 4 queens must be placed on a 4x4 chessboard so that no two queens attack each other"

"Find the optimal solution to a knapsack problem with items having weights [2,3,4,5] and values [3,4,5,6] and capacity 7"

"Solve this custom constraint: I need two variables x and y between 1 and 10 where x + y = 15 and x < y"

The solve_constraint tool returns a SolveResult object containing:

• solutions: List of solutions found
• status: Solving status (SATISFIED, OPTIMAL, UNSATISFIABLE, etc.)
• solve_time: Time taken to solve in seconds
• num_solutions: Number of solutions found
• error: Error message if solving failed

Each solution contains:

• variables: Dictionary of variable names to values
• objective: Objective value for optimization problems
• is_optimal: Whether the solution is optimal

MIT License - see LICENSE file for details.

claude mcp add minizinc -t sse   https://minizinc-mcp.up.railway.app/sse

then to test run the command

claude

in the input window prompt:

Solve the 4-Queens problem where 4 queens must be placed on a 4x4 chessboard so that no two queens attack each other

and you should see an output similar to this: