diff --git a/dev/managedservicesplatform/internal/stack/cloudrun/cloudrun.go b/dev/managedservicesplatform/internal/stack/cloudrun/cloudrun.go
index 11eb8f4af06..04502166543 100644
--- a/dev/managedservicesplatform/internal/stack/cloudrun/cloudrun.go
+++ b/dev/managedservicesplatform/internal/stack/cloudrun/cloudrun.go
@@ -129,11 +129,16 @@ func NewStack(stacks *stack.Set, vars Variables) (crossStackOutput *CrossStackOu
 	// convention across MSP services.
 	cloudRunBuilder.AddEnv("DIAGNOSTICS_SECRET", diagnosticsSecret.HexValue)
 
+	// Add the domain as an environment variable.
+	dnsName := pointers.DerefZero(vars.Environment.EnvironmentServiceSpec).Domain.GetDNSName()
+	if dnsName != "" {
+		cloudRunBuilder.AddEnv("EXTERNAL_DNS_NAME", dnsName)
+	}
+
 	// Add user-configured env vars
 	if err := addContainerEnvVars(cloudRunBuilder, vars.Environment.Env, vars.Environment.SecretEnv, envVariablesData{
-		ProjectID: vars.ProjectID,
-		ServiceDnsName: pointers.DerefZero(vars.Environment.EnvironmentServiceSpec).
-			Domain.GetDNSName(),
+		ProjectID:      vars.ProjectID,
+		ServiceDnsName: dnsName,
 	}); err != nil {
 		return nil, errors.Wrap(err, "add user env vars")
 	}
diff --git a/lib/managedservicesplatform/service/config.go b/lib/managedservicesplatform/service/config.go
index a95b5f77a70..d95626f3f08 100644
--- a/lib/managedservicesplatform/service/config.go
+++ b/lib/managedservicesplatform/service/config.go
@@ -9,14 +9,18 @@ import (
 	"github.com/sourcegraph/sourcegraph/lib/errors"
 )
 
+// Contract loads standardized MSP-provisioned configuration.
 type Contract struct {
 	// Port is the port the service must listen on.
 	Port int
+	// ExternalDNSName is the DNS name the service uses, if one is configured.
+	ExternalDNSName *string
 }
 
 func newContract(env *Env) Contract {
 	return Contract{
-		Port: env.GetInt("PORT", "", "service port"),
+		Port:            env.GetInt("PORT", "", "service port"),
+		ExternalDNSName: env.GetOptional("EXTERNAL_DNS_NAME", "external DNS name provisioned for the service"),
 	}
 }
 
@@ -86,8 +90,12 @@ func (e *Env) Get(name, defaultValue, description string) string {
 }
 
 // GetOptional returns the value with the given name.
-func (e *Env) GetOptional(name, description string) string {
-	return e.get(name, "", description)
+func (e *Env) GetOptional(name, description string) *string {
+	v, ok := e.env[name]
+	if !ok {
+		return nil
+	}
+	return &v
 }
 
 // GetInt returns the value with the given name interpreted as an integer. If no