diff --git a/MODULE.bazel b/MODULE.bazel
index 4c256e3..26bf6d0 100644
--- a/MODULE.bazel
+++ b/MODULE.bazel
@@ -12,6 +12,11 @@ go_deps = use_extension("@gazelle//:extensions.bzl", "go_deps")
 go_deps.from_file(go_mod = "//:go.mod")
 use_repo(go_deps, "com_github_engoengine_ecs", "com_github_threedotslabs_watermill")
 
+go_sdk = use_extension("@rules_go//go:extensions.bzl", "go_sdk")
+
+# Download an SDK for the host OS & architecture.
+go_sdk.download(version = "1.21.0")
+
 oci = use_extension("@rules_oci//oci:extensions.bzl", "oci")
 oci.pull(
     name = "distroless_base",
diff --git a/cmd/echo/BUILD.bazel b/cmd/echo/BUILD.bazel
index 3ce5677..1345e6b 100644
--- a/cmd/echo/BUILD.bazel
+++ b/cmd/echo/BUILD.bazel
@@ -1,4 +1,4 @@
-load("@rules_go//go:def.bzl", "go_binary", "go_library")
+load("@rules_go//go:def.bzl", "go_binary", "go_library", "go_cross_binary")
 
 go_library(
     name = "echo_lib",
@@ -6,11 +6,9 @@ go_library(
     importpath = "code.ndumas.com/ndumas/gomud/cmd/echo",
     visibility = ["//visibility:private"],
     deps = [
-        "//:gomud",
-        "//engine",
         "//logger",
         "//telnet",
-        "@com_github_engoengine_ecs//:ecs",
+        "@com_github_threedotslabs_watermill//:watermill",
         "@com_github_threedotslabs_watermill//message",
         "@com_github_threedotslabs_watermill//message/router/middleware",
         "@com_github_threedotslabs_watermill//message/router/plugin",
@@ -23,11 +21,19 @@ go_binary(
     embed = [":echo_lib"],
     visibility = ["//visibility:public"],
     x_defs = {
-        "code.ndumas.com/ndumas/gomud.Version": "STABLE_GIT_VERSION",
-        "code.ndumas.com/ndumas/gomud.Build": "STABLE_GIT_COMMIT",
+        "code.ndumas.com/ndumas/gomud.Version":"STABLE_GIT_VERSION",
+        "code.ndumas.com/ndumas/gomud.Build":"STABLE_GIT_COMMIT",
     },
 )
 
+
+
+go_cross_binary(
+    name  = "cross_binary",
+    target = ":echo",
+    sdk_version = "1.21.0",
+)
+
 load("@rules_pkg//:pkg.bzl", "pkg_tar")
 
 pkg_tar(