Merge pull request #371 from edwardcqian/in-memory-client-example

Add an example of an in process client

Author: pottekkat

examples/in_process/main.go

@@ -0,0 +1,100 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"time"
+
+	"github.com/mark3labs/mcp-go/client"
+	"github.com/mark3labs/mcp-go/mcp"
+	"github.com/mark3labs/mcp-go/server"
+)
+
+// handleDummyTool is a simple tool that returns "foo bar"
+func handleDummyTool(
+	ctx context.Context,
+	request mcp.CallToolRequest,
+) (*mcp.CallToolResult, error) {
+	return mcp.NewToolResultText("foo bar"), nil
+}
+
+func NewMCPServer() *server.MCPServer {
+	mcpServer := server.NewMCPServer(
+		"example-server",
+		"1.0.0",
+		server.WithResourceCapabilities(true, true),
+		server.WithPromptCapabilities(true),
+		server.WithToolCapabilities(true),
+	)
+	mcpServer.AddTool(mcp.NewTool("dummy_tool",
+		mcp.WithDescription("A dummy tool that returns foo bar"),
+	), handleDummyTool)
+
+	return mcpServer
+}
+
+type MCPClient struct {
+	client     *client.Client
+	serverInfo *mcp.InitializeResult
+}
+
+// NewMCPClient creates a new MCP client with an in-process MCP server.
+func NewMCPClient(ctx context.Context) (*MCPClient, error) {
+	srv := NewMCPServer()
+	client, err := client.NewInProcessClient(srv)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create in-process client: %w", err)
+	}
+
+	// Start the client with timeout context
+	ctxWithTimeout, cancel := context.WithTimeout(ctx, 5*time.Second)
+	defer cancel()
+
+	if err := client.Start(ctxWithTimeout); err != nil {
+		return nil, fmt.Errorf("failed to start client: %w", err)
+	}
+
+	// Initialize the client
+	initRequest := mcp.InitializeRequest{}
+	initRequest.Params.ProtocolVersion = mcp.LATEST_PROTOCOL_VERSION
+	initRequest.Params.ClientInfo = mcp.Implementation{
+		Name:    "Example MCP Client",
+		Version: "1.0.0",
+	}
+	initRequest.Params.Capabilities = mcp.ClientCapabilities{}
+
+	serverInfo, err := client.Initialize(ctx, initRequest)
+	if err != nil {
+		return nil, fmt.Errorf("failed to initialize MCP client: %w", err)
+	}
+
+	return &MCPClient{
+		client:     client,
+		serverInfo: serverInfo,
+	}, nil
+}
+
+func main() {
+	ctx := context.Background()
+	client, err := NewMCPClient(ctx)
+	if err != nil {
+		log.Fatalf("Failed to create MCP client: %v", err)
+	}
+
+	toolsRequest := mcp.ListToolsRequest{}
+	toolsResult, err := client.client.ListTools(ctx, toolsRequest)
+	if err != nil {
+		log.Fatalf("Failed to list tools: %v", err)
+	}
+	fmt.Println(toolsResult.Tools)
+
+	request := mcp.CallToolRequest{}
+	request.Params.Name = "dummy_tool"
+
+	result, err := client.client.CallTool(ctx, request)
+	if err != nil {
+		log.Fatalf("Failed to call tool: %v", err)
+	}
+	fmt.Println(result.Content)
+}