6e03217c83Handlers and client/server methods take a single request argument combining the session and params. This slightly simplifies the signature for handlers, since there is no longer an often-ignored session argument. But more importantly, it opens the door to adding more information in requests, such as auth info and HTTP request headers. For #243.
90 lines
2.5 KiB
Go
90 lines
2.5 KiB
Go
// Copyright 2025 The Go MCP SDK Authors. All rights reserved.
|
|
// Use of this source code is governed by an MIT-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
package main
|
|
|
|
import (
|
|
"context"
|
|
"flag"
|
|
"fmt"
|
|
"log"
|
|
"net/http"
|
|
"net/url"
|
|
"os"
|
|
|
|
"github.com/modelcontextprotocol/go-sdk/mcp"
|
|
)
|
|
|
|
var httpAddr = flag.String("http", "", "if set, use streamable HTTP at this address, instead of stdin/stdout")
|
|
|
|
type HiArgs struct {
|
|
Name string `json:"name" jsonschema:"the name to say hi to"`
|
|
}
|
|
|
|
func SayHi(ctx context.Context, req *mcp.ServerRequest[*mcp.CallToolParamsFor[HiArgs]]) (*mcp.CallToolResultFor[struct{}], error) {
|
|
return &mcp.CallToolResultFor[struct{}]{
|
|
Content: []mcp.Content{
|
|
&mcp.TextContent{Text: "Hi " + req.Params.Arguments.Name},
|
|
},
|
|
}, nil
|
|
}
|
|
|
|
func PromptHi(ctx context.Context, ss *mcp.ServerSession, params *mcp.GetPromptParams) (*mcp.GetPromptResult, error) {
|
|
return &mcp.GetPromptResult{
|
|
Description: "Code review prompt",
|
|
Messages: []*mcp.PromptMessage{
|
|
{Role: "user", Content: &mcp.TextContent{Text: "Say hi to " + params.Arguments["name"]}},
|
|
},
|
|
}, nil
|
|
}
|
|
|
|
func main() {
|
|
flag.Parse()
|
|
|
|
server := mcp.NewServer(&mcp.Implementation{Name: "greeter"}, nil)
|
|
mcp.AddTool(server, &mcp.Tool{Name: "greet", Description: "say hi"}, SayHi)
|
|
server.AddPrompt(&mcp.Prompt{Name: "greet"}, PromptHi)
|
|
server.AddResource(&mcp.Resource{
|
|
Name: "info",
|
|
MIMEType: "text/plain",
|
|
URI: "embedded:info",
|
|
}, handleEmbeddedResource)
|
|
|
|
if *httpAddr != "" {
|
|
handler := mcp.NewStreamableHTTPHandler(func(*http.Request) *mcp.Server {
|
|
return server
|
|
}, nil)
|
|
log.Printf("MCP handler listening at %s", *httpAddr)
|
|
http.ListenAndServe(*httpAddr, handler)
|
|
} else {
|
|
t := &mcp.LoggingTransport{Transport: &mcp.StdioTransport{}, Writer: os.Stderr}
|
|
if err := server.Run(context.Background(), t); err != nil {
|
|
log.Printf("Server failed: %v", err)
|
|
}
|
|
}
|
|
}
|
|
|
|
var embeddedResources = map[string]string{
|
|
"info": "This is the hello example server.",
|
|
}
|
|
|
|
func handleEmbeddedResource(_ context.Context, req *mcp.ServerRequest[*mcp.ReadResourceParams]) (*mcp.ReadResourceResult, error) {
|
|
u, err := url.Parse(req.Params.URI)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
if u.Scheme != "embedded" {
|
|
return nil, fmt.Errorf("wrong scheme: %q", u.Scheme)
|
|
}
|
|
key := u.Opaque
|
|
text, ok := embeddedResources[key]
|
|
if !ok {
|
|
return nil, fmt.Errorf("no embedded resource named %q", key)
|
|
}
|
|
return &mcp.ReadResourceResult{
|
|
Contents: []*mcp.ResourceContents{
|
|
{URI: req.Params.URI, MIMEType: "text/plain", Text: text},
|
|
},
|
|
}, nil
|
|
}
|