diff --git a/build_capabilities_test.go b/build_capabilities_test.go
new file mode 100644
index 0000000..db8da51
--- /dev/null
+++ b/build_capabilities_test.go
@@ -0,0 +1,21 @@
+package main
+
+import (
+	"context"
+	"testing"
+
+	builderv0 "github.com/codefly-dev/core/generated/go/codefly/services/builder/v0"
+)
+
+// The CLI verifies every agent before dispatching a build to a selected Buildx
+// builder (an environment that mirrors a registry builds on one of its own);
+// an agent that cannot answer fails the whole render.
+func TestBuildCapabilitiesHonourASelectedBuilder(t *testing.T) {
+	capabilities, err := NewBuilder().BuildCapabilities(context.Background(), &builderv0.BuildCapabilitiesRequest{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !capabilities.GetBuildxSelection() {
+		t.Fatal("a selected Buildx builder must be honoured")
+	}
+}
diff --git a/builder.go b/builder.go
index c1a23df..f9f6c34 100644
--- a/builder.go
+++ b/builder.go
@@ -53,6 +53,17 @@ type deploymentTemplateParameters struct {
 	External    bool
 }
 
+// BuildCapabilities answers the CLI's check before a build that names a Buildx
+// builder: this agent executes no docker build of its own — its Build hands
+// the CLI a recipe or no image at all — so a selected builder is always
+// honoured, by the CLI, which runs every recipe on the builder it selected.
+// Without this answer core refuses the whole render of any environment that
+// mirrors a registry, because such an environment builds on a dedicated
+// builder and core verifies every agent before dispatching to it.
+func (s *Builder) BuildCapabilities(context.Context, *builderv0.BuildCapabilitiesRequest) (*builderv0.BuildCapabilitiesResponse, error) {
+	return &builderv0.BuildCapabilitiesResponse{BuildxSelection: true}, nil
+}
+
 func NewBuilder() *Builder {
 	return &Builder{
 		Service: NewService(),