diff --git a/.changes/dev-fn.md b/.changes/dev-fn.md
new file mode 100644
index 000000000..7b0b12901
--- /dev/null
+++ b/.changes/dev-fn.md
@@ -0,0 +1,5 @@
+---
+"tauri": patch:enhance
+---
+
+Added `tauri::dev()` to determine whether we are running in development mode or not.
diff --git a/core/tauri/src/lib.rs b/core/tauri/src/lib.rs
index 873d7b212..7c78fcf8d 100644
--- a/core/tauri/src/lib.rs
+++ b/core/tauri/src/lib.rs
@@ -333,6 +333,11 @@ macro_rules! tauri_build_context {
 
 pub use pattern::Pattern;
 
+/// Whether we are running in development mode or not.
+pub fn dev() -> bool {
+  !cfg!(feature = "custom-protocol")
+}
+
 /// User supplied data required inside of a Tauri application.
 ///
 /// # Stability
diff --git a/core/tauri/src/manager/mod.rs b/core/tauri/src/manager/mod.rs
index a1b49d09e..fa70ccd06 100644
--- a/core/tauri/src/manager/mod.rs
+++ b/core/tauri/src/manager/mod.rs
@@ -320,7 +320,7 @@ impl<R: Runtime> AppManager<R> {
   }
 
   fn csp(&self) -> Option<Csp> {
-    if cfg!(feature = "custom-protocol") {
+    if !crate::dev() {
       self.config.app.security.csp.clone()
     } else {
       self