diff --git a/cmd/ndt7-client/main.go b/cmd/ndt7-client/main.go
index 7e083c5..3aa7856 100644
--- a/cmd/ndt7-client/main.go
+++ b/cmd/ndt7-client/main.go
@@ -86,7 +86,8 @@ import (
 )
 
 const (
-	userAgent      = "ndt7-client-go/0.1.0"
+	clientName     = "ndt7-client-go-cmd"
+	clientVersion  = "0.1.0"
 	defaultTimeout = 55 * time.Second
 )
 
@@ -163,7 +164,7 @@ func main() {
 	ctx, cancel := context.WithTimeout(context.Background(), *flagTimeout)
 	defer cancel()
 	var r runner
-	r.client = ndt7.NewClient(userAgent)
+	r.client = ndt7.NewClient(clientName, clientVersion)
 	r.client.Dialer.TLSClientConfig = &tls.Config{
 		InsecureSkipVerify: *flagNoVerify,
 	}
diff --git a/cmd/ndt7-client/main_test.go b/cmd/ndt7-client/main_test.go
index fea739e..fd532ad 100644
--- a/cmd/ndt7-client/main_test.go
+++ b/cmd/ndt7-client/main_test.go
@@ -103,7 +103,7 @@ func (me mockedEmitter) OnComplete(subtest string) error {
 // the emitter.OnStarting function fails.
 func TestRunSubtestOnStartingError(t *testing.T) {
 	runner := runner{
-		client: ndt7.NewClient(userAgent),
+		client: ndt7.NewClient(clientName, clientVersion),
 		emitter: mockedEmitter{
 			StartingError: errors.New("mocked error"),
 		},
@@ -129,7 +129,7 @@ func TestRunSubtestOnStartingError(t *testing.T) {
 // the emitter.OnConnected function fails.
 func TestRunSubtestOnConnectedError(t *testing.T) {
 	runner := runner{
-		client: ndt7.NewClient(userAgent),
+		client: ndt7.NewClient(clientName, clientVersion),
 		emitter: mockedEmitter{
 			ConnectedError: errors.New("mocked error"),
 		},
@@ -155,7 +155,7 @@ func TestRunSubtestOnConnectedError(t *testing.T) {
 // the emitter.OnComplete function fails.
 func TestRunSubtestOnCompleteError(t *testing.T) {
 	runner := runner{
-		client: ndt7.NewClient(userAgent),
+		client: ndt7.NewClient(clientName, clientVersion),
 		emitter: mockedEmitter{
 			CompleteError: errors.New("mocked error"),
 		},
@@ -181,7 +181,7 @@ func TestRunSubtestOnCompleteError(t *testing.T) {
 // the emitEvent function fails.
 func TestRunSubtestEmitEventError(t *testing.T) {
 	runner := runner{
-		client:  ndt7.NewClient(userAgent),
+		client:  ndt7.NewClient(clientName, clientVersion),
 		emitter: mockedEmitter{},
 	}
 	code := runner.runSubtest(
@@ -213,7 +213,7 @@ func TestBatchEmitterEventsOrderNormal(t *testing.T) {
 	}
 	writer := &mocks.SavingWriter{}
 	runner := runner{
-		client:  ndt7.NewClient(userAgent),
+		client:  ndt7.NewClient(clientName, clientVersion),
 		emitter: emitter.Batch{Writer: writer},
 	}
 	code := runner.runSubtest(
@@ -269,7 +269,7 @@ func TestBatchEmitterEventsOrderFailure(t *testing.T) {
 	}
 	writer := &mocks.SavingWriter{}
 	runner := runner{
-		client:  ndt7.NewClient(userAgent),
+		client:  ndt7.NewClient(clientName, clientVersion),
 		emitter: emitter.Batch{Writer: writer},
 	}
 	runner.client.MLabNSClient.BaseURL = "\t" // URL parser error
diff --git a/example_test.go b/example_test.go
index dfc5ff8..f7de1cd 100644
--- a/example_test.go
+++ b/example_test.go
@@ -12,7 +12,7 @@ import (
 func Example() {
 	ctx, cancel := context.WithTimeout(context.Background(), 60*time.Second)
 	defer cancel()
-	client := ndt7.NewClient("example/v0.1.0")
+	client := ndt7.NewClient("ndt7-client-go-example", "0.1.0")
 	ch, err := client.StartDownload(ctx)
 	if err != nil {
 		log.Fatal(err)
diff --git a/ndt7.go b/ndt7.go
index d6a07af..f9f0b50 100644
--- a/ndt7.go
+++ b/ndt7.go
@@ -13,6 +13,7 @@ import (
 	"context"
 	"net/http"
 	"net/url"
+	"runtime"
 	"time"
 
 	"github.com/gorilla/websocket"
@@ -24,6 +25,14 @@ import (
 	"github.com/m-lab/ndt7-client-go/spec"
 )
 
+const (
+	// libraryName is the name of this library
+	libraryName = "ndt7-client-go"
+
+	// libraryVersion is the version of this library
+	libraryVersion = "0.1.0"
+)
+
 // locateFn is the type of function used to locate a server.
 type locateFn = func(ctx context.Context, client *mlabns.Client) (string, error)
 
@@ -58,9 +67,13 @@ type Client struct {
 	// defaults in NewClient and you may override it.
 	MLabNSClient *mlabns.Client
 
-	// UserAgent is the user-agent that will be used. It's set by
+	// ClientName is the name of the software running ndt7 tests. It's set by
 	// NewClient; you may want to change this value.
-	UserAgent string
+	ClientName string
+
+	// ClientVersion is the version of the software running ndt7 tests. It's
+	// set by NewClient; you may want to change this value.
+	ClientVersion string
 
 	// connect is the function for connecting a specific
 	// websocket cnnection. It's set to its default value by
@@ -80,11 +93,18 @@ type Client struct {
 	upload subtestFn
 }
 
-// NewClient creates a new client instance identified by the
-// specified user agent. M-Lab services may reject requests coming
-// from clients with empty user agents in the future.
-func NewClient(userAgent string) *Client {
+// makeUserAgent creates the user agent string
+func makeUserAgent(clientName, clientVersion string) string {
+	return clientName + "/" + clientVersion + " " + libraryName + "/" + libraryVersion
+}
+
+// NewClient creates a new client instance identified by the specified
+// clientName and clientVersion. M-Lab services may reject requests coming
+// from clients that do not identify themselves properly.
+func NewClient(clientName, clientVersion string) *Client {
 	return &Client{
+		ClientName:    clientName,
+		ClientVersion: clientVersion,
 		connect: func(
 			dialer websocket.Dialer, ctx context.Context, urlStr string,
 			requestHeader http.Header) (*websocket.Conn, *http.Response, error,
@@ -98,9 +118,10 @@ func NewClient(userAgent string) *Client {
 		locate: func(ctx context.Context, c *mlabns.Client) (string, error) {
 			return c.Query(ctx)
 		},
-		MLabNSClient: mlabns.NewClient("ndt7", userAgent),
-		upload:       upload.Run,
-		UserAgent:    userAgent,
+		MLabNSClient: mlabns.NewClient(
+			"ndt7", makeUserAgent(clientName, clientVersion),
+		),
+		upload: upload.Run,
 	}
 }
 
@@ -115,9 +136,17 @@ func (c *Client) doConnect(ctx context.Context, URLPath string) (*websocket.Conn
 	URL.Scheme = "wss"
 	URL.Host = c.FQDN
 	URL.Path = URLPath
+	q := URL.Query()
+	q.Set("client_arch", runtime.GOARCH)
+	q.Set("client_library_name", libraryName)
+	q.Set("client_library_version", libraryVersion)
+	q.Set("client_name", c.ClientName)
+	q.Set("client_os", runtime.GOOS)
+	q.Set("client_version", c.ClientVersion)
+	URL.RawQuery = q.Encode()
 	headers := http.Header{}
 	headers.Add("Sec-WebSocket-Protocol", params.SecWebSocketProtocol)
-	headers.Add("User-Agent", c.UserAgent)
+	headers.Add("User-Agent", makeUserAgent(c.ClientName, c.ClientVersion))
 	conn, _, err := c.connect(c.Dialer, ctx, URL.String(), headers)
 	return conn, err
 }
diff --git a/ndt7_test.go b/ndt7_test.go
index f07b75c..fd0fc6d 100644
--- a/ndt7_test.go
+++ b/ndt7_test.go
@@ -11,13 +11,15 @@ import (
 	"github.com/m-lab/ndt7-client-go/spec"
 )
 
-// userAgent is the user agent used throughout this file
-const userAgent = "ndt7-client-go/0.1.0"
+const (
+	clientName    = "ndt7-client-go-tests"
+	clientVersion = "0.1.0"
+)
 
 // newMockedClient returns a mocked client that does nothing
 // except pretending it is doing something.
 func newMockedClient(ctx context.Context) *Client {
-	client := NewClient(userAgent)
+	client := NewClient(clientName, clientVersion)
 	// Override locate to return a fake IP address
 	client.locate = func(ctx context.Context, c *mlabns.Client) (string, error) {
 		return "127.0.0.1", nil
@@ -72,7 +74,7 @@ func TestUploadCase(t *testing.T) {
 // with an error when discovering a server.
 func TestStartDiscoverServerError(t *testing.T) {
 	ctx := context.Background()
-	client := NewClient(userAgent)
+	client := NewClient(clientName, clientVersion)
 	client.MLabNSClient.BaseURL = "\t" // cause URL parse to fail
 	_, err := client.start(ctx, nil, "")
 	if err == nil {
@@ -84,7 +86,7 @@ func TestStartDiscoverServerError(t *testing.T) {
 // with an error when connecting.
 func TestStartConnectError(t *testing.T) {
 	ctx := context.Background()
-	client := NewClient(userAgent)
+	client := NewClient(clientName, clientVersion)
 	client.FQDN = "\t" // cause URL parse to fail
 	_, err := client.start(ctx, nil, "")
 	if err == nil {
@@ -97,7 +99,7 @@ func TestIntegrationDownload(t *testing.T) {
 	if testing.Short() {
 		t.Skip("Skipping test in short mode")
 	}
-	client := NewClient(userAgent)
+	client := NewClient(clientName, clientVersion)
 	ch, err := client.StartDownload(context.Background())
 	if err != nil {
 		t.Fatal(err)
@@ -139,7 +141,7 @@ func TestIntegrationUpload(t *testing.T) {
 	if testing.Short() {
 		t.Skip("Skipping test in short mode")
 	}
-	client := NewClient(userAgent)
+	client := NewClient(clientName, clientVersion)
 	ch, err := client.StartUpload(context.Background())
 	if err != nil {
 		t.Fatal(err)