diff --git a/implementations/Crafter.Build-Clang.cpp b/implementations/Crafter.Build-Clang.cpp
index c17f6db..fe106bc 100644
--- a/implementations/Crafter.Build-Clang.cpp
+++ b/implementations/Crafter.Build-Clang.cpp
@@ -865,6 +865,18 @@ std::string Crafter::HostTarget() {
     return cached;
 }
 
+bool Crafter::ArgQuery::Has(std::string_view flag) const {
+    for (std::string_view a : args) if (a == flag) return true;
+    return false;
+}
+
+std::optional<std::string> Crafter::ArgQuery::Get(std::string_view prefix) const {
+    for (std::string_view a : args) {
+        if (a.starts_with(prefix)) return std::string(a.substr(prefix.size()));
+    }
+    return std::nullopt;
+}
+
 ArgQuery Crafter::ApplyStandardArgs(Configuration& cfg, std::span<const std::string_view> args) {
     if (const char* envMarch = std::getenv("CRAFTER_BUILD_MARCH"); envMarch && *envMarch) {
         cfg.march = envMarch;
diff --git a/interfaces/Crafter.Build-Clang.cppm b/interfaces/Crafter.Build-Clang.cppm
index 7d22d72..f988623 100644
--- a/interfaces/Crafter.Build-Clang.cppm
+++ b/interfaces/Crafter.Build-Clang.cppm
@@ -168,22 +168,15 @@ export namespace Crafter {
     // outputName so renaming the binary later requires another call.
     CRAFTER_API void EnableWasiBrowserRuntime(Configuration& cfg);
 
-    // View over the project's args with simple query helpers — kept inline
-    // so it works across the DLL boundary without an extra ABI hop. Use
-    // Has(flag) for boolean switches and Get(prefix) for valued options
-    // (e.g. Get("--prefix=") returns the substring after the equals).
+    // View over the project's args with simple query helpers. Has(flag) for
+    // boolean switches; Get(prefix) for valued options (e.g. Get("--prefix=")
+    // returns the substring after the equals). Definitions are out-of-line
+    // and CRAFTER_API so they cross the Windows DLL boundary cleanly — clang
+    // does not emit module-attached in-class inline bodies into consumers.
     struct ArgQuery {
         std::span<const std::string_view> args;
-        bool Has(std::string_view flag) const {
-            for (std::string_view a : args) if (a == flag) return true;
-            return false;
-        }
-        std::optional<std::string> Get(std::string_view prefix) const {
-            for (std::string_view a : args) {
-                if (a.starts_with(prefix)) return std::string(a.substr(prefix.size()));
-            }
-            return std::nullopt;
-        }
+        CRAFTER_API bool Has(std::string_view flag) const;
+        CRAFTER_API std::optional<std::string> Get(std::string_view prefix) const;
     };
 
     // Apply the framework's standard CLI args + env vars onto cfg: