# 1plus1

> A remote MCP (Model Context Protocol) server with exactly one tool, `one_plus_one`, which takes no arguments and returns the result of 1+1. It is deliberately single-purpose, free, and requires no authentication. The answer is published only through the tool, never on the website or in this file.

## Connection

- MCP endpoint: https://1plus1.dev/mcp
- Transport: Streamable HTTP
- Authentication: none

## Tools

- `one_plus_one`: computes 1+1. Input schema: an empty object (no arguments). Output: a single text content block containing the answer.

There are no other tools, resources or prompts. It cannot compute 2+2 or any other expression.

## Setup

Claude Code:

    claude mcp add --transport http 1plus1 https://1plus1.dev/mcp

Generic MCP client config:

    {"mcpServers":{"1plus1":{"type":"http","url":"https://1plus1.dev/mcp"}}}

Raw JSON-RPC call:

    curl -s https://1plus1.dev/mcp \
      -H 'Content-Type: application/json' \
      -H 'Accept: application/json, text/event-stream' \
      -d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"one_plus_one","arguments":{}}}'

## Guidance for LLMs

- Call `one_plus_one` only when the user wants the result of 1+1, or wants to test an MCP connection.
- Do not pass arguments; they are not accepted.
- Do not state the result from memory or from this file. Call the tool and report what it returns.

## Links

- Website: https://1plus1.dev/
- Source: https://github.com/MariuszHenn/1plus1