puttsk/go-mcp
If you are the rightful owner of go-mcp and would like to certify it and/or have it hosted online, please leave a comment on the right or send an email to henry@mcphub.com.
Go module for running MCP server on AWS Lambda.
add
Tool for adding two integers
go-mcp
Go module for running MCP server on AWS Lambda.
Install
go get -u github.com/puttsk/go-mcp
Usage
AWS Lambda function
This example demonstrates how to create an MCP server on AWS Lambda with a simple tool named add
, which adds two integers. The server uses an in-memory session manager along with a Lambda transport handler.
Note: The in-memory session manager used in this example is intended for testing purposes only. Since AWS Lambda instances are stateless and can be terminated at any time, session data cannot be shared across instances and will be reset when the function ends.
// main.go
import (
"context"
"fmt"
"log"
"net/http"
"github.com/aws/aws-lambda-go/events"
"github.com/aws/aws-lambda-go/lambda"
"github.com/puttsk/go-mcp"
"github.com/puttsk/go-mcp/session/memory"
"github.com/puttsk/go-mcp/transport/awslambda"
)
var server *mcp.McpServer
func handler(ctx context.Context, request events.APIGatewayProxyRequest) (events.APIGatewayProxyResponse, error) {
// Processing request from AWS Lambda
resp, err := server.ProcessRequest(ctx, request)
if err != nil {
return events.APIGatewayProxyResponse{
Body: "Error processing request",
Headers: headers,
StatusCode: http.StatusInternalServerError,
}, nil
}
if response, ok := resp.(events.APIGatewayProxyResponse); ok {
return response, nil
} else {
return events.APIGatewayProxyResponse{
Body: "Invalid response type",
Headers: headers,
StatusCode: http.StatusInternalServerError,
}, nil
}
}
func init() {
// Initialize the MCP server with in-memory session manager and AWS Lambda transport handler
server, _ = mcp.NewMcpServer("mcptest", "1.0.0", mcp.McpProtocol2025_30_26)
server.LogLevel = mcp.LogLevelDebug
server.TransportHandler = &awslambda.TransportHandler{} // Setup transport handler
server.SessionManager = memory.NewSessionManager() // Setup in-memory session manager
// Register tool "add" with the server
server.RegisterTool("add",
func(a, b int) int { return a + b },
mcp.McpToolParameter{Name: "a", Description: "First number"},
mcp.McpToolParameter{Name: "b", Description: "Second number"},
)
server.SetToolDescription("add", "Tool for adding two integers")
}
func main() {
lambda.Start(handler)
}
Tool Functions
Tool functions can accept a Go context as their first parameter. You can retrieve the current session and MCP request ID using the following helper functions:
GetSessionFromContext(ctx)
GetRequestIDFromContext(ctx)
These functions allow you to access session-specific and request-specific information within your tool logic.
Known Limitations
- Only support streamable HTTP transport; Server-Sent Event (SSE) and stdin are not support
- Only support following MCP methods
initailize
notifications/initialized
tools/list
tools/call
- Tool inputs are limited to scalar types:
number
,string
,boolean
, andimage
. - Tool outputs are limited to text and image.