Summary
Exposes a stateful RPN calculator through MCP with two tools: evaluate and clear. The evaluate tool handles standard arithmetic operators (add, subtract, multiply, divide, power, modulo) plus stack commands like dup, swap, and clear. Stack state persists between calls unless you explicitly clear it. Reach for this when you need Claude to chain multi-step calculations without juggling intermediate results in conversation context. The RPN approach means you can build complex expressions incrementally, useful for financial calculations, unit conversions, or any scenario where you're iteratively computing values. Runs over stdio transport and packages cleanly via pip.
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mcp-rpn
MCP server that exposes an RPN calculator
Install
pip install mcp-rpn
Usage
mcp-rpn
The server uses stdio transport for MCP protocol communication.
MCP Tools
evaluate
Evaluate an RPN (Reverse Polish Notation) expression.
{
"name": "evaluate",
"arguments": {
"expression": "3 4 +",
"show_stack": true
}
}
Operators:
+- Add-- Subtract-- Multiply/- Divide**- Power%- Modulo
Commands:
clear- Clear the stackdup- Duplicate top of stackswap- Swap top two elements
Examples:
3 4 +returns710 5 2 + * 2 -returns323 2 /returns1.5
clear
Clear the calculator stack.
{
"name": "clear",
"arguments": {}
}
Development
git clone https://github.com/daedalus/mcp-rpn.git
cd mcp-rpn
pip install -e ".[test]"
# run tests
pytest
# format
ruff format src/ tests/
# lint
ruff check src/ tests/
# type check
mypy src/
MCP Registry
mcp-name: io.github.daedalus/mcp-rpn
Featured
Keep your Mac awake while Claude Code and 40+ AI agents run. Sleeps when they're idle.
One time payment $9 →Integrate web data into your AI product. One API to scrape website & brand data.
Get API Key Now →Agent, run crypto. Access onchain data & trade routes via 1inch.
Install now →On Capafy, your Skill runs online 24/7 as an agent product, and you get paid every time someone uses it.
Start earning →