Core Package

MCP Toolbox Go Core SDK
This SDK allows you to seamlessly integrate the functionalities of Toolbox allowing you to load and use tools defined in the service as standard Go structs within your GenAI applications.
This simplifies integrating external functionalities (like APIs, databases, or custom logic) managed by the Toolbox into your workflows, especially those involving Large Language Models (LLMs).
- MCP Toolbox Core SDK
- Installation
- Quickstart
- Usage
- Transport Protocols
- Loading Tools
- Invoking Tools
- Client to Server Authentication
- Authenticating Tools
- Binding Parameter Values
- Using with Orchestration Frameworks
- Contributing
- License
- Support
Installation
go get github.com/googleapis/mcp-toolbox-sdk-go
This SDK is supported on Go version 1.24.4 and higher.
Note
While the SDK itself is synchronous, you can execute its functions within goroutines to achieve asynchronous behavior.
Quickstart
Here’s a minimal example to get you started. Ensure your Toolbox service is running and accessible.
package main
import (
"context"
"fmt"
"github.com/googleapis/mcp-toolbox-sdk-go/core"
)
func quickstart() string {
ctx := context.Background()
inputs := map[string]any{"location": "London"}
client, err := core.NewToolboxClient("http://localhost:5000")
if err != nil {
return fmt.Sprintln("Could not start Toolbox Client", err)
}
tool, err := client.LoadTool("get_weather", ctx)
if err != nil {
return fmt.Sprintln("Could not load Toolbox Tool", err)
}
result, err := tool.Invoke(ctx, inputs)
if err != nil {
return fmt.Sprintln("Could not invoke tool", err)
}
return fmt.Sprintln(result)
}
func main() {
fmt.Println(quickstart())
}
Usage
Import and initialize a Toolbox client, pointing it to the URL of your running Toolbox service.
import "github.com/googleapis/mcp-toolbox-sdk-go/core"
client, err := core.NewToolboxClient("http://localhost:5000")
All interactions for loading and invoking tools happen through this client.
Note
For advanced use cases, you can provide an external custom http.Client during initialization (e.g., core.NewToolboxClient(URL, core.WithHTTPClient(myClient)).
If you provide your own session, you are responsible for managing its lifecycle; ToolboxClient will not close it.
Info
Closing the ToolboxClient also closes the underlying network session shared by all tools loaded from that client. As a result, any tool instances you have loaded will cease to function and will raise an error if you attempt to invoke them after the client is closed.
Transport Protocols
The SDK supports multiple transport protocols for communicating with the Toolbox server. By default, the client uses the latest supported version of the Model Context Protocol (MCP).
You can explicitly select a protocol using the core.WithProtocol option during client initialization. This is useful if you need to use the native Toolbox HTTP protocol or pin the client to a specific legacy version of MCP.
Note
- Native Toolbox Transport: This uses the service’s native REST over HTTP API.
- MCP Transports: These options use the Model Context Protocol over HTTP.
Supported Protocols
| Constant | Description |
|---|---|
core.MCP | (Default) Alias for the latest supported MCP version (currently v2025-06-18). |
core.Toolbox | The native Toolbox HTTP protocol. |
core.MCPv20250618 | MCP Protocol version 2025-06-18. |
core.MCPv20250326 | MCP Protocol version 2025-03-26. |
core.MCPv20241105 | MCP Protocol version 2024-11-05. |
Example
If you wish to use the native Toolbox protocol:
import "github.com/googleapis/mcp-toolbox-sdk-go/core"
client, err := core.NewToolboxClient(
"http://localhost:5000",
core.WithProtocol(core.Toolbox),
)
If you want to pin the MCP Version 2025-03-26:
import "github.com/googleapis/mcp-toolbox-sdk-go/core"
client, err := core.NewToolboxClient(
"http://localhost:5000",
core.WithProtocol(core.MCPv20250326),
)
Loading Tools
You can load tools individually or in groups (toolsets) as defined in your Toolbox service configuration. Loading a toolset is convenient when working with multiple related functions, while loading a single tool offers more granular control.
Load a toolset
A toolset is a collection of related tools. You can load all tools in a toolset or a specific one:
// Load default toolset by providing an empty string as the name
tools, err := client.LoadToolset("", ctx)
// Load a specific toolset
tools, err := client.LoadToolset("my-toolset", ctx)
Load a single tool
Loads a specific tool by its unique name. This provides fine-grained control.
tool, err = client.LoadTool("my-tool", ctx)
Invoking Tools
Once loaded, tools behave like Go structs. You invoke them using Invoke method
by passing arguments corresponding to the parameters defined in the tool’s
configuration within the Toolbox service.
tool, err = client.LoadTool("my-tool", ctx)
inputs := map[string]any{"location": "London"}
result, err := tool.Invoke(ctx, inputs)
Tip
For a more comprehensive guide on setting up the Toolbox service itself, which you’ll need running to use this SDK, please refer to the Toolbox Quickstart Guide.
Client to Server Authentication
This section describes how to authenticate the ToolboxClient itself when connecting to a Toolbox server instance that requires authentication. This is crucial for securing your Toolbox server endpoint, especially when deployed on platforms like Cloud Run, GKE, or any environment where unauthenticated access is restricted.
This client-to-server authentication ensures that the Toolbox server can verify the identity of the client making the request before any tool is loaded or called. It is different from Authenticating Tools, which deals with providing credentials for specific tools within an already connected Toolbox session.
When is Client-to-Server Authentication Needed?
You’ll need this type of authentication if your Toolbox server is configured to deny unauthenticated requests. For example:
- Your Toolbox server is deployed on Cloud Run and configured to “Require authentication.”
- Your server is behind an Identity-Aware Proxy (IAP) or a similar authentication layer.
- You have custom authentication middleware on your self-hosted Toolbox server.
Without proper client authentication in these scenarios, attempts to connect or
make calls (like LoadTool) will likely fail with Unauthorized errors.
How it works
The ToolboxClient allows you to specify TokenSources that dynamically generate HTTP headers for
every request sent to the Toolbox server. The most common use case is to add an
Authorization header with a bearer token (e.g., a Google ID token).
These header-generating functions are called just before each request, ensuring that fresh credentials or header values can be used.
Configuration
You can configure these dynamic headers as seen below:
import "github.com/googleapis/mcp-toolbox-sdk-go/core"
tokenProvider := func() string {
return "header3_value"
}
staticTokenSource := oauth2.StaticTokenSource(&oauth2.Token{AccessToken: "header2_value"})
dynamicTokenSource := core.NewCustomTokenSource(tokenProvider)
client, err := core.NewToolboxClient(
"toolbox-url",
core.WithClientHeaderString("header1", "header1_value"),
core.WithClientHeaderTokenSource("header2", staticTokenSource),
core.WithClientHeaderTokenSource("header3", dynamicTokenSource),
)
Authenticating with Google Cloud Servers
For Toolbox servers hosted on Google Cloud (e.g., Cloud Run) and requiring
Google ID token authentication, the helper module
auth_methods provides utility functions.
Step by Step Guide for Cloud Run
- Configure Permissions: Grant the
roles/run.invokerIAM role on the Cloud Run service to the principal. This could be youruser account emailor aservice account. - Configure Credentials
- Local Development: Set up ADC.
- Google Cloud Environments: When running within Google Cloud (e.g., Compute Engine, GKE, another Cloud Run service, Cloud Functions), ADC is typically configured automatically, using the environment’s default service account.
- Connect to the Toolbox Server
import "github.com/googleapis/mcp-toolbox-sdk-go/core" import "context" ctx := context.Background() token, err := core.GetGoogleIDToken(ctx, URL) client, err := core.NewToolboxClient( URL, core.WithClientHeaderString("Authorization", token), ) // Now, you can use the client as usual.
Authenticating Tools
Warning
Always use HTTPS to connect your application with the Toolbox service, especially in production environments or whenever the communication involves sensitive data (including scenarios where tools requireauthentication tokens). Using plain HTTP lacks encryption and exposes your application and data to significant security risks, such as eavesdropping and tampering.
Tools can be configured within the Toolbox service to require authentication, ensuring only authorized users or applications can invoke them, especially when accessing sensitive data.
When is Authentication Needed?
Authentication is configured per-tool within the Toolbox service itself. If a tool you intend to use is marked as requiring authentication in the service, you must configure the SDK client to provide the necessary credentials (currently Oauth2 tokens) when invoking that specific tool.
Supported Authentication Mechanisms
The Toolbox service enables secure tool usage through Authenticated Parameters. For detailed information on how these mechanisms work within the Toolbox service and how to configure them, please refer to Toolbox Service Documentation - Authenticated Parameters.
Step 1: Configure Tools in Toolbox Service
First, ensure the target tool(s) are configured correctly in the Toolbox service to require authentication. Refer to the Toolbox Service Documentation - Authenticated Parameters for instructions.
Step 2: Configure SDK Client
Your application needs a way to obtain the required Oauth2 token for the authenticated user. The SDK requires you to provide a function capable of retrieving this token when the tool is invoked.
Provide an ID Token Retriever Function
You must provide the SDK with a function that returns the necessary token when called. The implementation depends on your application’s authentication flow (e.g., retrieving a stored token, initiating an OAuth flow).
Info
The name used when registering the getter function with the SDK (e.g., "my_api_token") must exactly match the name of the corresponding authServices defined in the tool’s configuration within the Toolbox service.
func getAuthToken() string {
// ... Logic to retrieve ID token (e.g., from local storage, OAuth flow)
// This example just returns a placeholder. Replace with your actual token retrieval.
return "YOUR_ID_TOKEN" // Placeholder
}
Tip
Your token retriever function is invoked every time an authenticated parameter requires a token for a tool call. Consider implementing caching logic within this function to avoid redundant token fetching or generation, especially for tokens with longer validity periods or if the retrieval process is resource-intensive.
Option A: Add Default Authentication to a Client
You can add default tool level authentication to a client. Every tool / toolset loaded by the client will contain the auth token.
ctx := context.Background()
client, err := core.NewToolboxClient("http://127.0.0.1:5000",
core.WithDefaultToolOptions(
core.WithAuthTokenString("my-auth-1", "auth-value"),
),
)
AuthTool, err := client.LoadTool("my-tool", ctx)
Option B: Add Authentication to a Loaded Tool
You can add the token retriever function to a tool object after it has been loaded. This modifies the specific tool instance.
ctx := context.Background()
client, err := core.NewToolboxClient("http://127.0.0.1:5000")
tool, err := client.LoadTool("my-tool", ctx)
AuthTool, err := tool.ToolFrom(
core.WithAuthTokenSource("my-auth", headerTokenSource),
core.WithAuthTokenString("my-auth-1", "value"),
)
Option C: Add Authentication While Loading Tools
You can provide the token retriever(s) directly during the LoadTool or
LoadToolset calls. This applies the authentication configuration only to the
tools loaded in that specific call, without modifying the original tool objects
if they were loaded previously.
AuthTool, err := client.LoadTool("my-tool", ctx, core.WithAuthTokenString("my-auth-1", "value"))
// or
AuthTools, err := client.LoadToolset(
"my-toolset",
ctx,
core.WithAuthTokenString("my-auth-1", "value"),
)
Note
Adding auth tokens during loading only affect the tools loaded within that call.
Complete Authentication Example
import "github.com/googleapis/mcp-toolbox-sdk-go/core"
import "fmt"
func getAuthToken() string {
// ... Logic to retrieve ID token (e.g., from local storage, OAuth flow)
// This example just returns a placeholder. Replace with your actual token retrieval.
return "YOUR_ID_TOKEN" // Placeholder
}
func main() {
ctx := context.Background()
inputs := map[string]any{"input": "some input"}
dynamicTokenSource := core.NewCustomTokenSource(getAuthToken)
client, err := core.NewToolboxClient("http://127.0.0.1:5000")
tool, err := client.LoadTool("my-tool", ctx)
AuthTool, err := tool.ToolFrom(core.WithAuthTokenSource("my_auth", dynamicTokenSource))
result, err := AuthTool.Invoke(ctx, inputs)
fmt.Println(result)
}
Note
An auth token getter for a specific name (e.g., “GOOGLE_ID”) will replace any client header with the same name followed by “_token” (e.g., “GOOGLE_ID_token”).
Binding Parameter Values
The SDK allows you to pre-set, or “bind”, values for specific tool parameters before the tool is invoked or even passed to an LLM. These bound values are fixed and will not be requested or modified by the LLM during tool use.
Why Bind Parameters?
- Protecting sensitive information: API keys, secrets, etc.
- Enforcing consistency: Ensuring specific values for certain parameters.
- Pre-filling known data: Providing defaults or context.
Info
The parameter names used for binding (e.g., "api_key") must exactly match the parameter names defined in the tool’s configuration within the Toolbox service.
Note
You do not need to modify the tool’s configuration in the Toolbox service to bind parameter values using the SDK.
Option A: Add Default Bound Parameters to a Client
You can add default tool level bound parameters to a client. Every tool / toolset
loaded by the client will have the bound parameter.
ctx := context.Background()
client, err := core.NewToolboxClient("http://127.0.0.1:5000",
core.WithDefaultToolOptions(
core.WithBindParamString("param1", "value"),
),
)
boundTool, err := client.LoadTool("my-tool", ctx)
Option B: Binding Parameters to a Loaded Tool
Bind values to a tool object after it has been loaded. This modifies the specific tool instance.
client, err := core.NewToolboxClient("http://127.0.0.1:5000")
tool, err := client.LoadTool("my-tool", ctx)
boundTool, err := tool.ToolFrom(
core.WithBindParamString("param1", "value"),
core.WithBindParamString("param2", "value")
)
Option C: Binding Parameters While Loading Tools
Specify bound parameters directly when loading tools. This applies the binding only to the tools loaded in that specific call.
boundTool, err := client.LoadTool("my-tool", ctx, core.WithBindParamString("param", "value"))
// OR
boundTool, err := client.LoadToolset("", ctx, core.WithBindParamString("param", "value"))
Note
Bound values during loading only affect the tools loaded in that call.
Binding Dynamic Values
Instead of a static value, you can bind a parameter to a synchronous or asynchronous function. This function will be called each time the tool is invoked to dynamically determine the parameter’s value at runtime. Functions with the return type (data_type, error) can be provided.
getDynamicValue := func() (string, error) { return "req-123", nil }
dynamicBoundTool, err := tool.ToolFrom(core.WithBindParamStringFunc("param", getDynamicValue))
Info
You don’t need to modify tool configurations to bind parameter values.
Using with Orchestration Frameworks
To see how the MCP Toolbox Go SDK works with orchestration frameworks, check out the end-to-end examples in the /samples/ folder.
Use the tbgenkit package to convert Toolbox Tools into Genkit compatible tools.
Contributing
Contributions are welcome! Please refer to the DEVELOPER.md file for guidelines on how to set up a development environment and run tests.
License
This project is licensed under the Apache License 2.0. See the LICENSE file for details.
Support
If you encounter issues or have questions, check the existing GitHub Issues for the main Toolbox project.
Samples for Reference
These samples demonstrate how to integrate the MCP Toolbox Go Core SDK with popular orchestration frameworks.
Google GenAI
// This sample demonstrates integration with the standard Google GenAI framework.
package main
import (
"context"
"encoding/json"
"fmt"
"log"
"os"
"github.com/googleapis/mcp-toolbox-sdk-go/core"
"google.golang.org/genai"
)
// ConvertToGenaiTool translates a ToolboxTool into the genai.FunctionDeclaration format.
func ConvertToGenaiTool(toolboxTool *core.ToolboxTool) *genai.Tool {
inputschema, err := toolboxTool.InputSchema()
if err != nil {
return &genai.Tool{}
}
var schema *genai.Schema
_ = json.Unmarshal(inputschema, &schema)
// First, create the function declaration.
funcDeclaration := &genai.FunctionDeclaration{
Name: toolboxTool.Name(),
Description: toolboxTool.Description(),
Parameters: schema,
}
// Then, wrap the function declaration in a genai.Tool struct.
return &genai.Tool{
FunctionDeclarations: []*genai.FunctionDeclaration{funcDeclaration},
}
}
// printResponse extracts and prints the relevant parts of the model's response.
func printResponse(resp *genai.GenerateContentResponse) {
for _, cand := range resp.Candidates {
if cand.Content != nil {
for _, part := range cand.Content.Parts {
fmt.Println(part.Text)
}
}
}
}
func main() {
// Setup
ctx := context.Background()
apiKey := os.Getenv("GOOGLE_API_KEY")
toolboxURL := "http://localhost:5000"
// Initialize the Google GenAI client using the explicit ClientConfig.
client, err := genai.NewClient(ctx, &genai.ClientConfig{
APIKey: apiKey,
})
if err != nil {
log.Fatalf("Failed to create Google GenAI client: %v", err)
}
// Initialize the MCP Toolbox client.
toolboxClient, err := core.NewToolboxClient(toolboxURL)
if err != nil {
log.Fatalf("Failed to create Toolbox client: %v", err)
}
// Load the tools using the MCP Toolbox SDK.
tools, err := toolboxClient.LoadToolset("my-toolset", ctx)
if err != nil {
log.Fatalf("Failed to load tools: %v\nMake sure your Toolbox server is running and the tool is configured.", err)
}
genAITools := make([]*genai.Tool, len(tools))
toolsMap := make(map[string]*core.ToolboxTool, len(tools))
for i, tool := range tools {
// Convert the tools into usable format
genAITools[i] = ConvertToGenaiTool(tool)
// Add tool to a map for lookup later
toolsMap[tool.Name()] = tool
}
// Set up the generative model with the available tool.
modelName := "gemini-2.0-flash"
query := "Find hotels in Basel with Basel in it's name and share the names with me"
// Create the initial content prompt for the model.
contents := []*genai.Content{
genai.NewContentFromText(query, genai.RoleUser),
}
config := &genai.GenerateContentConfig{
Tools: genAITools,
ToolConfig: &genai.ToolConfig{
FunctionCallingConfig: &genai.FunctionCallingConfig{
Mode: genai.FunctionCallingConfigModeAny,
},
},
}
genContentResp, _ := client.Models.GenerateContent(ctx, modelName, contents, config)
printResponse(genContentResp)
functionCalls := genContentResp.FunctionCalls()
if len(functionCalls) == 0 {
log.Println("No function call returned by the AI. The model likely answered directly.")
return
}
// Process the first function call (the example assumes one for simplicity).
fc := functionCalls[0]
log.Printf("--- Gemini requested function call: %s ---\n", fc.Name)
log.Printf("--- Arguments: %+v ---\n", fc.Args)
var toolResultString string
if fc.Name == "search-hotels-by-name" {
tool := toolsMap["search-hotels-by-name"]
toolResult, err := tool.Invoke(ctx, fc.Args)
toolResultString = fmt.Sprintf("%v", toolResult)
if err != nil {
log.Fatalf("Failed to execute tool '%s': %v", fc.Name, err)
}
} else {
log.Println("LLM did not request our tool")
}
resultContents := []*genai.Content{
genai.NewContentFromText("The tool returned this result, share it with the user based of their previous querys"+toolResultString, genai.RoleUser),
}
finalResponse, err := client.Models.GenerateContent(ctx, modelName, resultContents, &genai.GenerateContentConfig{})
if err != nil {
log.Fatalf("Error calling GenerateContent (with function result): %v", err)
}
log.Println("=== Final Response from Model (after processing function result) ===")
printResponse(finalResponse)
}
LangChain
// This sample demonstrates how to use Toolbox tools as function definitions in LangChain Go.
package main
import (
"context"
"encoding/json"
"fmt"
"log"
"os"
"github.com/googleapis/mcp-toolbox-sdk-go/core"
"github.com/tmc/langchaingo/llms"
"github.com/tmc/langchaingo/llms/googleai"
)
// ConvertToLangchainTool converts a generic core.ToolboxTool into a LangChainGo llms.Tool.
func ConvertToLangchainTool(toolboxTool *core.ToolboxTool) llms.Tool {
// Fetch the tool's input schema
inputschema, err := toolboxTool.InputSchema()
if err != nil {
return llms.Tool{}
}
var paramsSchema map[string]any
_ = json.Unmarshal(inputschema, ¶msSchema)
// Convert into LangChain's llms.Tool
return llms.Tool{
Type: "function",
Function: &llms.FunctionDefinition{
Name: toolboxTool.Name(),
Description: toolboxTool.Description(),
Parameters: paramsSchema,
},
}
}
func main() {
genaiKey := os.Getenv("GOOGLE_API_KEY")
toolboxURL := "http://localhost:5000"
ctx := context.Background()
// Initialize the Google AI client (LLM).
llm, err := googleai.New(ctx, googleai.WithAPIKey(genaiKey), googleai.WithDefaultModel("gemini-1.5-flash"))
if err != nil {
log.Fatalf("Failed to create Google AI client: %v", err)
}
// Initialize the MCP Toolbox client.
toolboxClient, err := core.NewToolboxClient(toolboxURL)
if err != nil {
log.Fatalf("Failed to create Toolbox client: %v", err)
}
// Load the tools using the MCP Toolbox SDK.
tools, err := toolboxClient.LoadToolset("my-toolset", ctx)
if err != nil {
log.Fatalf("Failed to load tools: %v\nMake sure your Toolbox server is running and the tool is configured.", err)
}
toolsMap := make(map[string]*core.ToolboxTool, len(tools))
langchainTools := make([]llms.Tool, len(tools))
for i, tool := range tools {
// Convert the loaded ToolboxTools into the format LangChainGo requires.
langchainTools[i] = ConvertToLangchainTool(tool)
// Add tool to a map for lookup later
toolsMap[tool.Name()] = tool
}
// Start the conversation history.
messageHistory := []llms.MessageContent{
llms.TextParts(llms.ChatMessageTypeHuman, "Find hotels in Basel with Basel in it's name."),
}
// Make the first call to the LLM, making it aware of the tool.
resp, err := llm.GenerateContent(ctx, messageHistory, llms.WithTools(langchainTools))
if err != nil {
log.Fatalf("LLM call failed: %v", err)
}
// Add the model's response (which should be a tool call) to the history.
respChoice := resp.Choices[0]
assistantResponse := llms.TextParts(llms.ChatMessageTypeAI, respChoice.Content)
for _, tc := range respChoice.ToolCalls {
assistantResponse.Parts = append(assistantResponse.Parts, tc)
}
messageHistory = append(messageHistory, assistantResponse)
// Process each tool call requested by the model.
for _, tc := range respChoice.ToolCalls {
toolName := tc.FunctionCall.Name
switch tc.FunctionCall.Name {
case "search-hotels-by-name":
var args map[string]any
if err := json.Unmarshal([]byte(tc.FunctionCall.Arguments), &args); err != nil {
log.Fatalf("Failed to unmarshal arguments for tool '%s': %v", toolName, err)
}
tool := toolsMap["search-hotels-by-name"]
toolResult, err := tool.Invoke(ctx, args)
if err != nil {
log.Fatalf("Failed to execute tool '%s': %v", toolName, err)
}
// Create the tool call response message and add it to the history.
toolResponse := llms.MessageContent{
Role: llms.ChatMessageTypeTool,
Parts: []llms.ContentPart{
llms.ToolCallResponse{
Name: toolName,
Content: fmt.Sprintf("%v", toolResult),
},
},
}
messageHistory = append(messageHistory, toolResponse)
default:
log.Fatalf("got unexpected function call: %v", tc.FunctionCall.Name)
}
}
// Final LLM Call for Natural Language Response
log.Println("Sending tool response back to LLM for a final answer...")
// Call the LLM again with the updated history, which now includes the tool's result.
finalResp, err := llm.GenerateContent(ctx, messageHistory)
if err != nil {
log.Fatalf("Final LLM call failed: %v", err)
}
// Display the Result
fmt.Println("\n======================================")
fmt.Println("Final Response from LLM:")
fmt.Println(finalResp.Choices[0].Content)
fmt.Println("======================================")
}
OpenAI
// This sample demonstrates integration with the OpenAI Go client.
package main
import (
"context"
"encoding/json"
"fmt"
"log"
"github.com/googleapis/mcp-toolbox-sdk-go/core"
openai "github.com/openai/openai-go"
)
// ConvertToOpenAITool converts a ToolboxTool into the go-openai library's Tool format.
func ConvertToOpenAITool(toolboxTool *core.ToolboxTool) openai.ChatCompletionToolParam {
// Get the input schema
jsonSchemaBytes, err := toolboxTool.InputSchema()
if err != nil {
return openai.ChatCompletionToolParam{}
}
// Unmarshal the JSON bytes into FunctionParameters
var paramsSchema openai.FunctionParameters
if err := json.Unmarshal(jsonSchemaBytes, ¶msSchema); err != nil {
return openai.ChatCompletionToolParam{}
}
// Create and return the final tool parameter struct.
return openai.ChatCompletionToolParam{
Function: openai.FunctionDefinitionParam{
Name: toolboxTool.Name(),
Description: openai.String(toolboxTool.Description()),
Parameters: paramsSchema,
},
}
}
func main() {
// Setup
ctx := context.Background()
toolboxURL := "http://localhost:5000"
openAIClient := openai.NewClient()
// Initialize the MCP Toolbox client.
toolboxClient, err := core.NewToolboxClient(toolboxURL)
if err != nil {
log.Fatalf("Failed to create Toolbox client: %v", err)
}
// Load the tools using the MCP Toolbox SDK.
tools, err := toolboxClient.LoadToolset("my-toolset", ctx)
if err != nil {
log.Fatalf("Failed to load tool : %v\nMake sure your Toolbox server is running and the tool is configured.", err)
}
openAITools := make([]openai.ChatCompletionToolParam, len(tools))
toolsMap := make(map[string]*core.ToolboxTool, len(tools))
for i, tool := range tools {
// Convert the Toolbox tool into the openAI FunctionDeclaration format.
openAITools[i] = ConvertToOpenAITool(tool)
// Add tool to a map for lookup later
toolsMap[tool.Name()] = tool
}
question := "Find hotels in Basel with Basel in it's name "
params := openai.ChatCompletionNewParams{
Messages: []openai.ChatCompletionMessageParamUnion{
openai.UserMessage(question),
},
Tools: openAITools,
Seed: openai.Int(0),
Model: openai.ChatModelGPT4o,
}
// Make initial chat completion request
completion, err := openAIClient.Chat.Completions.New(ctx, params)
if err != nil {
panic(err)
}
toolCalls := completion.Choices[0].Message.ToolCalls
// Return early if there are no tool calls
if len(toolCalls) == 0 {
fmt.Printf("No function call")
return
}
// If there was a function call, continue the conversation
params.Messages = append(params.Messages, completion.Choices[0].Message.ToParam())
for _, toolCall := range toolCalls {
if toolCall.Function.Name == "search-hotels-by-name" {
// Extract the location from the function call arguments
var args map[string]interface{}
tool := toolsMap["search-hotels-by-name"]
err := json.Unmarshal([]byte(toolCall.Function.Arguments), &args)
if err != nil {
panic(err)
}
result, err := tool.Invoke(ctx, args)
if err != nil {
log.Fatal("Could not invoke tool", err)
}
params.Messages = append(params.Messages, openai.ToolMessage(result.(string), toolCall.ID))
}
}
completion, err = openAIClient.Chat.Completions.New(ctx, params)
if err != nil {
panic(err)
}
fmt.Println(completion.Choices[0].Message.Content)
}