diff --git a/lib/flags/doc.go b/lib/flags/doc.go
index 8681ac4..ff98c9d 100644
--- a/lib/flags/doc.go
+++ b/lib/flags/doc.go
@@ -1,3 +1,36 @@
-// Package flags provides implementations of the flag.Value interface
-// that are commonly used.
+// Package flags provides flag definitions for commonly used flags and
+// and, where appropriate, implementations of the flag.Value interface
+// for those flags to ensure that only valid values of those flags
+// are supplied.
+// In general, this package will be used by veyron profiles and the
+// runtime implementations, but can also be used by any application
+// that wants access to the flags and environment variables it supports.
+//
+// TODO(cnicolaou): move reading of environment variables to here also,
+// flags will override the environment variable settings.
 package flags
+
+import "flag"
+
+type Flags struct {
+	ListenProtocolFlag TCPProtocolFlag
+	ListenAddressFlag  IPHostPortFlag
+	ListenProxyFlag    string
+	NamespaceRootsFlag string // TODO(cnicolaou): provide flag.Value impl
+	CredentialsFlag    string // TODO(cnicolaou): provide flag.Value impl
+}
+
+// New returns a new instance of flags.Flags. Calling Parse on the supplied
+// flagSet will populate the fields of the return flags.Flags with the appropriate
+// values.
+func New(fs *flag.FlagSet) *Flags {
+	t := &Flags{}
+	t.ListenProtocolFlag = TCPProtocolFlag{"tcp"}
+	t.ListenAddressFlag = IPHostPortFlag{Port: "0"}
+	fs.Var(&t.ListenProtocolFlag, "veyron.tcp.protocol", "protocol to listen with")
+	fs.Var(&t.ListenAddressFlag, "veyron.tcp.address", "address to listen on")
+	fs.StringVar(&t.ListenProxyFlag, "veyron.proxy", "", "object name of proxy service to use to export services across network boundaries")
+	fs.StringVar(&t.NamespaceRootsFlag, "veyron.namespace.roots", "", ": separated list of roots for the local namespace")
+	fs.StringVar(&t.CredentialsFlag, "veyron.credentials", "", "directory to use for storing security credentials")
+	return t
+}
diff --git a/lib/flags/flags_test.go b/lib/flags/flags_test.go
new file mode 100644
index 0000000..4030af6
--- /dev/null
+++ b/lib/flags/flags_test.go
@@ -0,0 +1,24 @@
+package flags_test
+
+import (
+	"flag"
+	"testing"
+
+	"veyron.io/veyron/veyron/lib/flags"
+)
+
+func TestFlags(t *testing.T) {
+	fs := flag.NewFlagSet("test", flag.ContinueOnError)
+	fl := flags.New(fs)
+
+	addr := "192.168.10.1:0"
+	roots := "ab:cd:ef"
+	args := []string{"--veyron.tcp.address=" + addr, "--veyron.namespace.roots=" + roots}
+	fs.Parse(args)
+	if got, want := fl.NamespaceRootsFlag, roots; got != want {
+		t.Errorf("got %q, want %q", got, want)
+	}
+	if got, want := fl.ListenAddressFlag.String(), addr; got != want {
+		t.Errorf("got %q, want %q", got, want)
+	}
+}
diff --git a/profiles/roaming/roaming.go b/profiles/roaming/roaming.go
index d9314bb..2f9381f 100644
--- a/profiles/roaming/roaming.go
+++ b/profiles/roaming/roaming.go
@@ -30,19 +30,14 @@
 )
 
 var (
-	listenProtocolFlag = flags.TCPProtocolFlag{"tcp"}
-	listenAddressFlag  = flags.IPHostPortFlag{Port: "0"}
-	listenProxyFlag    string
-
+	commonFlags *flags.Flags
 	// ListenSpec is an initialized instance of ipc.ListenSpec that can
 	// be used with ipc.Listen.
 	ListenSpec ipc.ListenSpec
 )
 
 func init() {
-	flag.Var(&listenProtocolFlag, "veyron.tcp.protocol", "protocol to listen with")
-	flag.Var(&listenAddressFlag, "veyron.tcp.address", "address to listen on")
-	flag.StringVar(&listenProxyFlag, "veyron.proxy", "", "object name of proxy service to use to export services across network boundaries")
+	commonFlags = flags.New(flag.CommandLine)
 	rt.RegisterProfile(New())
 }
 
@@ -75,9 +70,9 @@
 	log := rt.Logger()
 
 	ListenSpec = ipc.ListenSpec{
-		Protocol: listenProtocolFlag.Protocol,
-		Address:  listenAddressFlag.String(),
-		Proxy:    listenProxyFlag,
+		Protocol: commonFlags.ListenProtocolFlag.Protocol,
+		Address:  commonFlags.ListenAddressFlag.String(),
+		Proxy:    commonFlags.ListenProxyFlag,
 	}
 
 	// Our address is private, so we test for running on GCE and for its
diff --git a/profiles/static/static.go b/profiles/static/static.go
index 960f347..4997720 100644
--- a/profiles/static/static.go
+++ b/profiles/static/static.go
@@ -18,19 +18,14 @@
 )
 
 var (
-	listenProtocolFlag = flags.TCPProtocolFlag{"tcp"}
-	listenAddressFlag  = flags.IPHostPortFlag{Port: "0"}
-	listenProxyFlag    string
-
+	commonFlags *flags.Flags
 	// ListenSpec is an initialized instance of ipc.ListenSpec that can
 	// be used with ipc.Listen.
 	ListenSpec ipc.ListenSpec
 )
 
 func init() {
-	flag.Var(&listenProtocolFlag, "veyron.tcp.protocol", "protocol to listen with")
-	flag.Var(&listenAddressFlag, "veyron.tcp.address", "address to listen on")
-	flag.StringVar(&listenProxyFlag, "veyron.proxy", "", "object name of proxy service to use to export services across network boundaries")
+	commonFlags = flags.New(flag.CommandLine)
 	rt.RegisterProfile(New())
 }
 
@@ -61,9 +56,9 @@
 	log := rt.Logger()
 
 	ListenSpec = ipc.ListenSpec{
-		Protocol: listenProtocolFlag.Protocol,
-		Address:  listenAddressFlag.String(),
-		Proxy:    listenProxyFlag,
+		Protocol: commonFlags.ListenProtocolFlag.Protocol,
+		Address:  commonFlags.ListenAddressFlag.String(),
+		Proxy:    commonFlags.ListenProxyFlag,
 	}
 
 	// Our address is private, so we test for running on GCE and for its