V-Sekai-fire's Minizinc
Solve constraint programming problems with MiniZinc.
Ask AI about V-Sekai-fire's Minizinc
Powered by Claude · Grounded in docs
I know everything about V-Sekai-fire's Minizinc. Ask me about installation, configuration, usage, or troubleshooting.
0/500
Reviews
Documentation
MiniZinc MCP Server
A Model Context Protocol (MCP) server that provides MiniZinc constraint programming capabilities.
Features
- Solve MiniZinc models using HiGHS solver (LP/MIP with float support)
- Validate MiniZinc models for syntax and type errors without solving
- Support for both MZN (model) and DZN (data) content as strings
- Automatic standard library inclusion (e.g.,
alldifferent.mzn) when not present in models - Comprehensive output format: Parses DZN format for variable extraction, passthroughs output_text from explicit output statements
- JSON-RPC 2.0 protocol support via STDIO or HTTP transports
- Server-Sent Events (SSE) support for streaming responses
Quick Start
Prerequisites
- Elixir 1.18+
- MiniZinc installed and available in PATH
Note: MiniZinc is automatically installed in the Docker image.
Installation
git clone <repository-url>
cd minizinc-mcp
mix deps.get
mix compile
Usage
STDIO Transport (Default)
For local development:
mix mcp.server
Or using release:
./_build/prod/rel/minizinc_mcp/bin/minizinc_mcp start
HTTP Transport
For web deployments (e.g., Smithery):
PORT=8081 MIX_ENV=prod ./_build/prod/rel/minizinc_mcp/bin/minizinc_mcp start
Endpoints:
POST /- JSON-RPC 2.0 MCP requestsGET /sse- Server-Sent Events for streamingGET /health- Health check
Docker
docker build -t minizinc-mcp .
docker run -d -p 8081:8081 --name minizinc-mcp minizinc-mcp
Tools
The server provides the following MCP tools:
minizinc_solve
Solve a MiniZinc model using the HiGHS solver (LP/MIP with float support).
Parameters
model_content(string, required): MiniZinc model content (.mzn) as stringdata_content(string, optional): DZN data content as string (e.g.,"n = 8;"). Must be valid DZN format. Parsed and included in response asinput_datafield.timeout(integer, optional): Optional timeout in milliseconds (default: 30000, i.e., 30 seconds). Maximum allowed is 30000 ms (30 seconds); values exceeding this will be capped at 30 seconds.auto_include_stdlib(boolean, optional): Automatically include standard MiniZinc libraries (e.g.,alldifferent.mzn) if not present (default:true)
Output Format Details
The minizinc_solve tool returns solutions as JSON in the following format:
- DZN format parsing: When MiniZinc provides DZN format output (models without explicit
outputstatements), variables are parsed and returned as structured data (e.g.,{"x": 10, "y": [1, 2, 3]}) - Output text passthrough: When models include explicit
outputstatements, the output text is passthrough'd in theoutput_textfield (e.g.,{"output_text": "x = 10\n"}) - Both formats: When both DZN and explicit output are available, both are included in the response
- Input data: When
data_contentis provided, the parsed DZN data is included in theinput_datafield - Status: Solution status (e.g.,
"SATISFIED","OPTIMAL_SOLUTION","UNSATISFIABLE") is included when available
The response is always returned as a JSON string in the MCP content field.
Standard Library Support
The minizinc_solve tool automatically includes common MiniZinc standard libraries (e.g., alldifferent.mzn)
if they are not already present in the model (when auto_include_stdlib is true). This means you can use
standard functions like all_different without needing to add explicit include statements.
Solve Tool Examples
STDIO:
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "minizinc_solve",
"arguments": {
"model_content": "var int: x; constraint x > 0; solve satisfy;"
}
}
}
HTTP:
curl -X POST http://localhost:8081/ \
-H "Content-Type: application/json" \
-H "mcp-protocol-version: 2025-06-18" \
-d '{"jsonrpc": "2.0", "id": 1, "method": "tools/call", "params": {"name": "minizinc_solve", "arguments": {"model_content": "var int: x; constraint x > 0; solve satisfy;"}}}'
With data content:
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "minizinc_solve",
"arguments": {
"model_content": "var int: n; array[1..n] of var int: x; constraint all_different(x); solve satisfy;",
"data_content": "n = 8;",
"timeout": 30000
}
}
}
minizinc_validate
Validate a MiniZinc model by checking syntax and type checking without solving. Useful for debugging models before attempting to solve them.
Parameters
model_content(string, required): MiniZinc model content (.mzn) as stringdata_content(string, optional): DZN data content as string (e.g.,"n = 8;"). Must be valid DZN format.auto_include_stdlib(boolean, optional): Automatically include standard MiniZinc libraries (e.g.,alldifferent.mzn) if not present (default:true)
Response Format
Returns a JSON object with:
valid(boolean): Whether the model is validerrors(array): List of error messages (if any)warnings(array): List of warning messages (if any)message(string): Human-readable message (when valid)raw_output(string): Raw MiniZinc validation output (when invalid)
Validate Tool Examples
Validate a valid model:
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "minizinc_validate",
"arguments": {
"model_content": "var int: x; constraint x > 0; solve satisfy;"
}
}
}
Response for valid model:
{
"valid": true,
"errors": [],
"warnings": [],
"message": "Model is valid"
}
Validate a model with syntax errors:
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "minizinc_validate",
"arguments": {
"model_content": "var int: x; constraint x > 0 solve satisfy;"
}
}
}
Response for invalid model:
{
"valid": false,
"errors": [
"Error: syntax error, unexpected solve, expecting ';'"
],
"warnings": [],
"raw_output": "..."
}
Configuration
Environment Variables:
PORT- HTTP server port (default: 8081)HOST- HTTP server host (default:0.0.0.0if PORT set, elselocalhost)MIX_ENV- Environment (prod,dev,test)ELIXIR_ERL_OPTIONS- Erlang options (set to"+fnu"for UTF-8)MCP_SSE_ENABLED- Enable/disable Server-Sent Events (default:true, set to"false"to disable)
The server uses HTTP streaming only (no stdio transport).
Troubleshooting
MiniZinc not found: Ensure MiniZinc is installed and available in PATH. For Docker, MiniZinc is included in the image.
Port already in use: Change PORT environment variable or stop conflicting services.
Compilation errors: Run mix deps.get && mix clean && mix compile.
Debug mode: Use MIX_ENV=dev mix mcp.server for verbose logging.
Version
Current version: 1.0.0-dev2 (see mix.exs for latest version)
Requirements
- Elixir 1.18+
- Erlang/OTP 26+
- MiniZinc 2.9.3+ installed and available in PATH (or use Docker image which includes MiniZinc)
Development
Building
mix deps.get
mix compile
Testing
mix test
Building Release
MIX_ENV=prod mix release
Running Locally
For STDIO transport (default):
mix mcp.server
PORT=8081 mix run --no-halt
License
MIT License - see LICENSE.md for details.
Copyright
Copyright (c) 2025-present K. S. Ernest (iFire) Lee