diff --git a/design/design.md b/design/design.md
index df86171..7d069f1 100644
--- a/design/design.md
+++ b/design/design.md
@@ -283,6 +283,14 @@ func NewStreamableClientTransport(url string) *StreamableClientTransport {
 func (*StreamableClientTransport) Connect(context.Context) (Stream, error)
 ```
 
+Finally, we also provide an in-memory transport, for scenarios such as testing,
+where the MCP client and server are in the same process.
+
+```go
+type InMemoryTransport struct { /* ... */ }
+func NewInMemoryTransport() (*InMemoryTransport, *InMemoryTransport)
+```
+
 **Differences from mcp-go**: The Go team has a battle-tested JSON-RPC
 implementation that we use for gopls, our Go LSP server. We are using the new
 version of this library as part of our MCP SDK. It handles all JSON-RPC 2.0
diff --git a/mcp/mcp_test.go b/mcp/mcp_test.go
index 1165633..0a87f93 100644
--- a/mcp/mcp_test.go
+++ b/mcp/mcp_test.go
@@ -33,7 +33,7 @@ func sayHi(ctx context.Context, cc *ServerSession, v hiParams) ([]*Content, erro
 
 func TestEndToEnd(t *testing.T) {
 	ctx := context.Background()
-	ct, st := NewLocalTransport()
+	ct, st := NewInMemoryTransport()
 
 	s := NewServer("testServer", "v1.0.0", nil)
 
@@ -286,7 +286,7 @@ func basicConnection(t *testing.T, tools ...*ServerTool) (*ServerSession, *Clien
 	t.Helper()
 
 	ctx := context.Background()
-	ct, st := NewLocalTransport()
+	ct, st := NewInMemoryTransport()
 
 	s := NewServer("testServer", "v1.0.0", nil)
 
@@ -329,7 +329,7 @@ func TestServerClosing(t *testing.T) {
 
 func TestBatching(t *testing.T) {
 	ctx := context.Background()
-	ct, st := NewLocalTransport()
+	ct, st := NewInMemoryTransport()
 
 	s := NewServer("testServer", "v1.0.0", nil)
 	_, err := s.Connect(ctx, st, nil)
diff --git a/mcp/server_example_test.go b/mcp/server_example_test.go
index 14a3248..85fccd1 100644
--- a/mcp/server_example_test.go
+++ b/mcp/server_example_test.go
@@ -24,7 +24,7 @@ func SayHi(ctx context.Context, cc *mcp.ServerSession, params *SayHiParams) ([]*
 
 func ExampleServer() {
 	ctx := context.Background()
-	clientTransport, serverTransport := mcp.NewLocalTransport()
+	clientTransport, serverTransport := mcp.NewInMemoryTransport()
 
 	server := mcp.NewServer("greeter", "v0.0.1", nil)
 	server.AddTools(mcp.NewTool("greet", "say hi", SayHi))
diff --git a/mcp/transport.go b/mcp/transport.go
index 29a29c3..1cbc1d2 100644
--- a/mcp/transport.go
+++ b/mcp/transport.go
@@ -48,27 +48,39 @@ type ConnectionOptions struct {
 	Logger    io.Writer // if set, write RPC logs
 }
 
-// An IOTransport is a [Transport] that communicates using newline-delimited
+// A StdIOTransport is a [Transport] that communicates over stdin/stdout using
+// newline-delimited JSON.
+type StdIOTransport struct {
+	ioTransport
+}
+
+// An ioTransport is a [Transport] that communicates using newline-delimited
 // JSON over an io.ReadWriteCloser.
-type IOTransport struct {
+type ioTransport struct {
 	rwc io.ReadWriteCloser
 }
 
-func (t *IOTransport) Connect(context.Context) (Stream, error) {
+func (t *ioTransport) Connect(context.Context) (Stream, error) {
 	return newIOStream(t.rwc), nil
 }
 
 // NewStdIOTransport constructs a transport that communicates over
 // stdin/stdout.
-func NewStdIOTransport() *IOTransport {
-	return &IOTransport{rwc{os.Stdin, os.Stdout}}
+func NewStdIOTransport() *StdIOTransport {
+	return &StdIOTransport{ioTransport{rwc{os.Stdin, os.Stdout}}}
 }
 
-// NewLocalTransport returns two in-memory transports that connect to
-// each other, for testing purposes.
-func NewLocalTransport() (*IOTransport, *IOTransport) {
+// An InMemoryTransport is a [Transport] that communicates over an in-memory
+// network connection, using newline-delimited JSON.
+type InMemoryTransport struct {
+	ioTransport
+}
+
+// NewInMemoryTransport returns two InMemoryTransports that connect to each
+// other.
+func NewInMemoryTransport() (*InMemoryTransport, *InMemoryTransport) {
 	c1, c2 := net.Pipe()
-	return &IOTransport{c1}, &IOTransport{c2}
+	return &InMemoryTransport{ioTransport{c1}}, &InMemoryTransport{ioTransport{c2}}
 }
 
 // handler is an unexported version of jsonrpc2.Handler.