modelcontextprotocol/go-sdk

This repository contains an implementation of the official Go software
development kit (SDK) for the Model Context Protocol (MCP).
## Package / Feature documentation
The SDK consists of several importable packages:
The
github.com/modelcontextprotocol/go-sdk/mcp
package defines the primary APIs for constructing and using MCP clients and
servers.
The
github.com/modelcontextprotocol/go-sdk/jsonrpc package is for users implementing
their own transports.
The
github.com/modelcontextprotocol/go-sdk/auth
package provides some primitives for supporting OAuth.
The
github.com/modelcontextprotocol/go-sdk/oauthex
package provides extensions to the OAuth protocol, such as ProtectedResourceMetadata.
The SDK endeavors to implement the full MCP spec. The docs/ directory
contains feature documentation, mapping the MCP spec to the packages above.
## Version Compatibility
The following table shows which versions of the Go SDK support which versions of the MCP specification:
| SDK Version | Latest MCP Spec | All Supported MCP Specs |
| v1.7.0+ | 2026-07-28 | 2026-07-28, 2025-11-25\, 2025-06-18, 2025-03-26, 2024-11-05 |
| v1.4.0 - v1.6.1 | 2025-11-25\ | 2025-11-25\, 2025-06-18, 2025-03-26, 2024-11-05 |
| v1.2.0 - v1.3.1 | 2025-11-25\\ | 2025-11-25\\, 2025-06-18, 2025-03-26, 2024-11-05 |
| v1.0.0 - v1.1.0 | 2025-06-18 | 2025-06-18, 2025-03-26, 2024-11-05 |
\ Client side OAuth has experimental support.
\\ Partial support for 2025-11-25 (client side OAuth and Sampling with tools not available).
The roots, sampling, and logging features are deprecated as of protocol version
2026-07-28 by
SEP-2577.
The SDK continues to support them for compatibility during the deprecation
window (at least twelve months). See the individual feature documentation for
migration guidance.
New releases of the SDK target only supported versions of Go. See
https://go.dev/doc/devel/release#policy for more information.
## Getting started
To get started creating an MCP server, create an mcp.Server instance, add
features to it, and then run it over an mcp.Transport. For example, this
server adds a single simple tool, and then connects it to clients over
stdin/stdout:
go
package main
import (
"context"
"log"
"github.com/modelcontextprotocol/go-sdk/mcp"
type Input struct {
Name string json:"name" jsonschema:"the name of the person to greet"
type Output struct {
Greeting string json:"greeting" jsonschema:"the greeting to tell to the user"
func SayHi(ctx context.Context, req mcp.CallToolRequest, input Input) (
mcp.CallToolResult,
Output,
error,
) {
return nil, Output{Greeting: "Hi " + input.Name}, nil
func main() {
// Create a server with a single tool.
server := mcp.NewServer(&mcp.Implementation{Name: "greeter", Version: "v1.0.0"}, nil)
mcp.AddTool(server, &mcp.Tool{Name: "greet", Description: "say hi"}, SayHi)
// Run the server over stdin/stdout, until the client disconnects.
if err := server.Run(context.Background(), &mcp.StdioTransport{}); err != nil {
log.Fatal(err)
To communicate with that server, create an mcp.Client and connect it to the