mcp_client.go

package reference

import (
	"encoding/json"
	"fmt"
)

// MCPRequest represents a JSON-RPC 2.0 request payload to an MCP server.
type MCPRequest struct {
	JSONRPC string      `json:"jsonrpc"`
	ID      int64       `json:"id"`
	Method  string      `json:"method"`
	Params  interface{} `json:"params,omitempty"`
}

// MCPResponse represents a JSON-RPC 2.0 response payload from an MCP server.
type MCPResponse struct {
	JSONRPC string          `json:"jsonrpc"`
	ID      int64           `json:"id"`
	Result  json.RawMessage `json:"result,omitempty"`
	Error   *MCPError       `json:"error,omitempty"`
}

// MCPError represents a JSON-RPC error payload.
type MCPError struct {
	Code    int    `json:"code"`
	Message string `json:"message"`
}

// ToolDescription represents a discovered MCP tool.
type ToolDescription struct {
	Name        string                 `json:"name"`
	Description string                 `json:"description"`
	InputSchema map[string]interface{} `json:"inputSchema"`
}

// FormatMCPToolListRequest creates a JSON-RPC request for listing MCP tools.
func FormatMCPToolListRequest(id int64) ([]byte, error) {
	req := MCPRequest{
		JSONRPC: "2.0",
		ID:      id,
		Method:  "tools/list",
	}
	return json.Marshal(req)
}

// FormatMCPToolCallRequest creates a JSON-RPC request for executing an MCP tool.
func FormatMCPToolCallRequest(id int64, name string, args map[string]interface{}) ([]byte, error) {
	params := map[string]interface{}{
		"name":      name,
		"arguments": args,
	}
	req := MCPRequest{
		JSONRPC: "2.0",
		ID:      id,
		Method:  "tools/call",
		Params:  params,
	}
	return json.Marshal(req)
}