diff --git a/cchat.go b/cchat.go
index 103c23a..5a28dd5 100644
--- a/cchat.go
+++ b/cchat.go
@@ -318,12 +318,10 @@ type Completer interface {
 }
 
 // Configurator is an interface which the backend can implement for a primitive
-// configuration API. Since these methods do return an error, they are allowed
-// to do IO. The frontend should handle this appropriately, including running
-// them asynchronously.
+// configuration API.
 type Configurator interface {
-	SetConfiguration(context.Context, map[string]string) error // Blocking
-	Configuration(context.Context) (map[string]string, error)  // Blocking
+	SetConfiguration(map[string]string) error
+	Configuration() map[string]string
 }
 
 // Editor adds message editing to the messenger. Only EditMessage can do IO.
diff --git a/cmd/internal/cchat-generator/generate_interface.go b/cmd/internal/cchat-generator/generate_interface.go
index f47e4f4..e0ebf00 100644
--- a/cmd/internal/cchat-generator/generate_interface.go
+++ b/cmd/internal/cchat-generator/generate_interface.go
@@ -66,6 +66,7 @@ func generateInterfaces(ifaces []repository.Interface) jen.Code {
 					stmt.Params(generateFuncParams(method.Returns, method.ErrorType)...)
 				case repository.SetterMethod:
 					stmt.Params(generateFuncParams(method.Parameters, "")...)
+					stmt.Params(generateFuncParamsErr(repository.NamedType{}, method.ErrorType)...)
 				case repository.IOMethod:
 					stmt.Params(generateFuncParamsCtx(method.Parameters, "")...)
 					stmt.Params(generateFuncParamsErr(method.ReturnValue, method.ErrorType)...)
diff --git a/repository/gob/repository.gob b/repository/gob/repository.gob
index 2257f30..b608ccb 100644
Binary files a/repository/gob/repository.gob and b/repository/gob/repository.gob differ
diff --git a/repository/interface.go b/repository/interface.go
index a3345e0..97e350b 100644
--- a/repository/interface.go
+++ b/repository/interface.go
@@ -78,6 +78,10 @@ type SetterMethod struct {
 	// Parameters is the list of parameters in the function. These parameters
 	// should be the parameters to set.
 	Parameters []NamedType
+	// ErrorType is non-empty if the function returns an error at the end of
+	// returns. An error may be returned from the backend if the input is
+	// invalid, but it must not do IO. Frontend setters must never error.
+	ErrorType string
 }
 
 // IOMethod is a regular method that can do IO and thus is blocking. These
diff --git a/repository/main.go b/repository/main.go
index 17525d2..347c3fd 100644
--- a/repository/main.go
+++ b/repository/main.go
@@ -817,18 +817,15 @@ var Main = Packages{
 		}, {
 			Comment: Comment{`
 				Configurator is an interface which the backend can implement for a
-				primitive configuration API. Since these methods do return an error,
-				they are allowed to do IO. The frontend should handle this
-				appropriately, including running them asynchronously.
+				primitive configuration API.
 			`},
 			Name: "Configurator",
 			Methods: []Method{
-				IOMethod{
-					method:      method{Name: "Configuration"},
-					ReturnValue: NamedType{Type: "map[string]string"},
-					ErrorType:   "error",
+				GetterMethod{
+					method:  method{Name: "Configuration"},
+					Returns: []NamedType{{Type: "map[string]string"}},
 				},
-				IOMethod{
+				SetterMethod{
 					method:     method{Name: "SetConfiguration"},
 					Parameters: []NamedType{{Type: "map[string]string"}},
 					ErrorType:  "error",