MCP Swift SDK

Official Swift SDK for the [Model Context Protocol][mcp] (MCP).

Overview

The Model Context Protocol (MCP) defines a standardized way for applications to communicate with AI and ML models. This Swift SDK implements both client and server components according to the [2025-11-25][mcp-spec-2025-11-25] (latest) version of the MCP specification.

Table of contents

• Requirements
• Installation
• Client Usage
  • Basic Client Setup
  • Transport Options for Clients
  • Tools
  • Resources
  • Prompts
  • Completions
  • Sampling
  • Elicitation
  • Roots
  • Logging
  • Error Handling
  • Cancellation
  • Progress Tracking
  • Advanced Client Features
• Server Usage
  • Basic Server Setup
  • Tools
  • Resources
  • Prompts
  • Completions
  • Sampling
  • Elicitations
  • Roots
  • Logging
  • Progress Tracking
  • Initialize Hook
  • HTTP Request Context in Handlers
  • Graceful Shutdown
• Transports
• Authentication
  • Client: Client Credentials Flow
  • Client: Authorization Code Flow
  • Client: Custom Token Provider
  • Client: Custom Token Storage
  • Client: private_key_jwt Authentication
  • Client: Endpoint Overrides
  • Server: Serving Protected Resource Metadata
  • Server: Validating Bearer Tokens
• Platform Availability
• Debugging and Logging
• Additional Resources
• Changelog
• License

Requirements

• Swift 6.0+ (Xcode 16+)

See the Platform Availability section below for platform-specific requirements.

Installation

Swift Package Manager

Add the following to your Package.swift file:

dependencies: [
    .package(url: "https://github.com/modelcontextprotocol/swift-sdk.git", from: "0.11.0")
]

Then add the dependency to your target:

.target(
    name: "YourTarget",
    dependencies: [
        .product(name: "MCP", package: "swift-sdk")
    ]
)

Client Usage

The client component allows your application to connect to MCP servers.

Basic Client Setup

import MCP

// Initialize the client
let client = Client(name: "MyApp", version: "1.0.0")

// Create a transport and connect
let transport = StdioTransport()
let result = try await client.connect(transport: transport)

// Check server capabilities
if result.capabilities.tools != nil {
    // Server supports tools (implicitly including tool calling if the 'tools' capability object is present)
}