Universal Tool Calling Protocol (UTCP)

Introduction

The Universal Tool Calling Protocol (UTCP) is a secure, scalable standard for defining and interacting with tools across a wide variety of communication protocols. UTCP 1.0.0 introduces a modular core with a plugin-based architecture, making it more extensible, testable, and easier to package.

In contrast to other protocols, UTCP places a strong emphasis on:

• Scalability: UTCP is designed to handle a large number of tools and providers without compromising performance.
• Extensibility: A pluggable architecture allows developers to easily add new communication protocols, tool storage mechanisms, and search strategies without modifying the core library.
• Interoperability: With a growing ecosystem of protocol plugins (including HTTP, SSE, CLI, and more), UTCP can integrate with almost any existing service or infrastructure.
• Ease of Use: The protocol is built on simple, well-defined Pydantic models, making it easy for developers to implement and use.

Repository Structure

This repository contains the complete UTCP Python implementation:

• core/ - Core utcp package with foundational components (README)
• plugins/communication_protocols/ - Protocol-specific plugins:
  • http/ - HTTP/REST, SSE, streaming, OpenAPI (README)
  • cli/ - Command-line tools (README)
  • mcp/ - Model Context Protocol (README)
  • text/ - File-based tools (README)
  • socket/ - TCP/UDP (🚧 In Progress)
  • gql/ - GraphQL (🚧 In Progress)

Architecture Overview

UTCP uses a modular architecture with a core library and protocol plugins:

Core Package (utcp)

The core/ directory contains the foundational components:

• Data Models: Pydantic models for Tool, CallTemplate, UtcpManual, and Auth
• Client Interface: Main UtcpClient for tool interaction
• Plugin System: Extensible interfaces for protocols, repositories, and search
• Default Implementations: Built-in tool storage and search strategies

Quick Start

Installation

Install the core library and any required protocol plugins:

# Install core + HTTP plugin (most common)
pip install utcp utcp-http

# Install additional plugins as needed
pip install utcp-cli utcp-mcp utcp-text

Basic Usage

from utcp.utcp_client import UtcpClient

# Create client with HTTP API
client = await UtcpClient.create(config={
    "manual_call_templates": [{
        "name": "my_api",
        "call_template_type": "http",
        "url": "https://api.example.com/utcp"
    }]
})

# Call a tool
result = await client.call_tool("my_api.get_data", {"id": "123"})

# Release the connections this client opened
await client.close()

Protocol Lifetime: Shared vs. Per-Client Instances

A protocol plugin registers itself in one of two registries, and the choice decides who its state belongs to.