Crate turbomcp_protocol 

MCP Protocol Implementation

This crate provides a complete implementation of the Model Context Protocol (MCP) specification version 2025-06-18. It includes all protocol types, JSON-RPC integration, and capability negotiation.

Features

Core Protocol Support

• Complete MCP 2025-06-18 protocol implementation
• JSON-RPC 2.0 support with batching and notifications
• Type-safe capability negotiation and compatibility checking
• Protocol versioning with backward compatibility
• Fast serialization with SIMD acceleration

Advanced Protocol Features (New in 1.0.3)

• Elicitation Protocol - Server-initiated user input requests with rich schema validation
• Sampling Support - Bidirectional LLM sampling message types
• Roots Protocol - Filesystem boundaries with roots/list support
• Comprehensive Schema Builders - Type-safe builders for all schema types

Validation & Security

• Comprehensive validation constraints (min/max, patterns, required fields)
• Type-safe schema builders with fluent API
• Protocol method validation and error handling
• Security-focused design with proper boundary checking

Usage Examples

Basic Protocol Types

use turbomcp_protocol::types::{Tool, ToolInputSchema, CallToolRequest, CallToolResult};
use std::collections::HashMap;

// Define a tool schema
let tool = Tool {
    name: "calculate".to_string(),
    title: Some("Calculator".to_string()),
    description: Some("Perform mathematical calculations".to_string()),
    input_schema: ToolInputSchema {
        schema_type: "object".to_string(),
        properties: Some({
            let mut props = HashMap::new();
            props.insert("operation".to_string(), serde_json::json!({
                "type": "string",
                "enum": ["add", "subtract", "multiply", "divide"]
            }));
            props
        }),
        required: Some(vec!["operation".to_string()]),
        additional_properties: Some(false),
    },
    output_schema: None,
    annotations: None,
    meta: None,
};

Elicitation Schema Building

use turbomcp_protocol::elicitation::{ElicitationSchema, EnumSchema, BooleanSchema, PrimitiveSchemaDefinition};

// Build an elicitation schema with validation
let schema = ElicitationSchema::new()
    .add_property("theme".to_string(), PrimitiveSchemaDefinition::Enum(EnumSchema {
        schema_type: "string".to_string(),
        title: Some("Theme".to_string()),
        description: Some("UI color theme".to_string()),
        enum_values: vec!["light".to_string(), "dark".to_string(), "auto".to_string()],
        enum_names: None,
    }))
    .add_property("notifications".to_string(), PrimitiveSchemaDefinition::Boolean(BooleanSchema {
        schema_type: "boolean".to_string(),
        title: Some("Notifications".to_string()),
        description: Some("Enable push notifications".to_string()),
        default: Some(true),
    }))
    .require(vec!["theme".to_string()]);

Re-exports

pub use types::ArgumentInfo;

pub use types::CallToolRequest;

pub use types::CallToolResult;

pub use types::ClientCapabilities;

pub use types::ClientNotification;

pub use types::ClientRequest;

pub use types::CompleteRequestParams;

pub use types::CompletionReference;

pub use types::CompletionResponse;

pub use types::Content;

pub use types::CreateMessageRequest;

pub use types::CreateMessageResult;

pub use types::ElicitRequest;

pub use types::ElicitRequestParams;

pub use types::ElicitResult;

pub use types::ElicitationAction;

pub use types::ElicitationSchema;

pub use types::EmbeddedResource;

pub use types::GetPromptRequest;

pub use types::GetPromptResult;

pub use types::ImageContent;

pub use types::Implementation;

pub use types::InitializeRequest;

pub use types::InitializeResult;

pub use types::InitializedNotification;

pub use types::ListPromptsRequest;

pub use types::ListPromptsResult;

pub use types::ListResourceTemplatesRequest;

pub use types::ListResourceTemplatesResult;

pub use types::ListResourcesRequest;

pub use types::ListResourcesResult;

pub use types::ListRootsRequest;

pub use types::ListRootsResult;

pub use types::ListToolsRequest;

pub use types::ListToolsResult;

pub use types::LogLevel;

pub use types::LoggingNotification;

pub use types::PingParams;

pub use types::PingRequest;

pub use types::PingResult;

pub use types::ProgressNotification;

pub use types::ProgressToken;

pub use types::Prompt;

pub use types::PromptInput;

pub use types::ProtocolVersion;

pub use types::ReadResourceRequest;

pub use types::ReadResourceResult;

pub use types::RequestId;

pub use types::Resource;

pub use types::ResourceContents;

pub use types::ResourceTemplate;

pub use types::ResourceUpdatedNotification;

pub use types::Root;

pub use types::RootsListChangedNotification;

pub use types::SamplingMessage;

pub use types::ServerCapabilities;

pub use types::ServerNotification;

pub use types::ServerRequest;

pub use types::SetLevelRequest;

pub use types::SetLevelResult;

pub use types::SubscribeRequest;

pub use types::TextContent;

pub use types::Tool;

pub use types::ToolInputSchema;

pub use types::ToolOutputSchema;

pub use types::UnsubscribeRequest;

pub use jsonrpc::JsonRpcBatch;

pub use jsonrpc::JsonRpcError;

pub use jsonrpc::JsonRpcErrorCode;

pub use jsonrpc::JsonRpcNotification;

pub use jsonrpc::JsonRpcRequest;

pub use jsonrpc::JsonRpcResponse;

pub use jsonrpc::JsonRpcVersion;

pub use capabilities::CapabilityMatcher;

pub use capabilities::CapabilityNegotiator;

pub use capabilities::CapabilitySet;

pub use versioning::VersionCompatibility;

pub use versioning::VersionManager;

pub use versioning::VersionRequirement;

Modules

capabilities

Capability Negotiation

elicitation

MCP Protocol Elicitation Types (Spec-Compliant)

error_codes

Protocol error codes (JSON-RPC standard + MCP extensions)

features

Protocol feature flags

jsonrpc

JSON-RPC 2.0 Implementation

methods

Protocol method names

types

MCP Protocol Types

validation

Protocol Validation

versioning

Protocol Versioning and Compatibility

Structs

Error

Comprehensive error type with rich context information

Constants

PROTOCOL_VERSION

Current MCP protocol version

SUPPORTED_VERSIONS

Supported MCP protocol versions

Type Aliases

Result

Result type alias for MCP operations