offeryn

Overview

Offeryn is a Rust implementation of the Model Context Protocol that allows developers to easily create and expose tools to AI agents. It features a procedural macro for automatic tool generation from Rust code, handles JSON schema creation based on Rust types, and supports both stdio and SSE transport methods. The project demonstrates clean code structure with clear examples showing how to implement and register calculator tools.

Try asking AI

After installing, here are 5 things you can ask your AI assistant:

• calculator_add(a: i64, b: i64) -> i64

  Add two numbers

  Try:Add 5 and 3Try:Calculate the sum of 10 and 15
• calculator_subtract(a: i64, b: i64) -> i64

  Subtract two numbers

  Try:Subtract 3 from 5Try:Calculate 10 minus 15
• calculator_multiply(a: i64, b: i64) -> i64

  Multiply two numbers

  Try:Multiply 5 by 3Try:Calculate 10 times 15
• calculator_divide(a: i64, b: i64) -> Result<f64, String>

  Divide two numbers

  Try:Divide 10 by 2Try:Calculate 15 divided by 3

Comparable tools

Installation

[dependencies]
offeryn = "0.1.0"

{
  "mcpServers": {
    "offeryn-calculator": {
      "command": "path/to/your/calculator-binary",
      "args": []
    }
  }
}

FAQ

What is the purpose of the #[mcp_tool] macro?

The #[mcp_tool] procedural macro automatically generates MCP-compatible tool methods from Rust functions, including JSON schema generation and proper error handling.

Which transport methods are supported?

Currently supports stdio and Server-Sent Events (SSE) transports. WebSocket transport is planned for future releases.

On Hacker News

Recent discussion from the developer community.

• Show HN: Offeryn – Build Tools for LLMs in Rust, with Model Context Protocol▲ 7
  Story by avhwl · 2025-01-24

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