Module protocol 

MCP protocol types — JSON-RPC 2.0 and Model Context Protocol messages.

This module is a functional core: pure data types with serde serialization. No IO, no side effects. All parsing and building happens through serde_json.

Structs

InitializeResult

The result of initialize.

JsonRpcError

The error object inside a JSON-RPC error response.

JsonRpcErrorResponse

A JSON-RPC 2.0 error response.

JsonRpcRequest

A JSON-RPC 2.0 request (or notification when id is None).

JsonRpcResponse

A JSON-RPC 2.0 success response.

ServerCapabilities

Server capabilities advertised during initialization.

ServerInfo

Server info returned during initialization.

ToolCallParams

Parameters for tools/call.

ToolCallResult

The result of tools/call.

ToolDefinition

A tool definition returned by tools/list.

ToolListResult

The result of tools/list.

ToolResultContent

A single content item in a tool result.

ToolsCapability

Indicates the server supports tools.

Constants

INTERNAL_ERROR

INVALID_PARAMS

INVALID_REQUEST

METHOD_NOT_FOUND

PARSE_ERROR

Functions

build_initialize_result

Build the initialize result for this server.

error_response

Build a JSON-RPC error response.

error_response_with_data

Build a JSON-RPC error response with extra data.

parse_request

Parse a raw JSON string into a JsonRpcRequest.

success_response

Build a JSON-RPC success response.

tool_result_error

Build an error tool result.

tool_result_json

Build a JSON tool result (serializes value to pretty-printed text).

tool_result_text

Build a successful text tool result.