diff --git a/React/Executors/RCTJSCExecutor.h b/React/Executors/RCTJSCExecutor.h
index 474db76e2..11932c1d8 100644
--- a/React/Executors/RCTJSCExecutor.h
+++ b/React/Executors/RCTJSCExecutor.h
@@ -54,11 +54,6 @@ RCT_EXTERN NSString *const RCTJavaScriptContextCreatedNotification;
  */
 - (instancetype)initWithUseCustomJSCLibrary:(BOOL)useCustomJSCLibrary;
 
-/**
- * Pass a RCTJSContextProvider object to use an NSThread/JSContext pair that have already been created.
- */
-- (instancetype)initWithJSContextProvider:(RCTJSContextProvider *)JSContextProvider;
-
 /**
  * Create a NSError from a JSError object.
  *
@@ -68,8 +63,16 @@ RCT_EXTERN NSString *const RCTJavaScriptContextCreatedNotification;
 - (NSError *)convertJSErrorToNSError:(JSValueRef)jsError context:(JSContextRef)context;
 
 /**
- * Returns the underlying JSContext.
+ * @experimental
+ * Pass a RCTJSContextProvider object to use an NSThread/JSContext pair that have already been created.
+ * The returned executor has already executed the supplied application script synchronously.
+ * The underlying JSContext will be returned in the JSContext pointer if it is non-NULL and there was no error.
+ * If an error occurs, this method will return nil and specify the error in the error pointer if it is non-NULL.
  */
-- (JSContext *)underlyingJSContext;
++ (instancetype)initializedExecutorWithContextProvider:(RCTJSContextProvider *)JSContextProvider
+                                     applicationScript:(NSData *)applicationScript
+                                             sourceURL:(NSURL *)sourceURL
+                                             JSContext:(JSContext **)JSContext
+                                                 error:(NSError **)error;
 
 @end
diff --git a/React/Executors/RCTJSCExecutor.mm b/React/Executors/RCTJSCExecutor.mm
index 1e920a367..7359c0368 100644
--- a/React/Executors/RCTJSCExecutor.mm
+++ b/React/Executors/RCTJSCExecutor.mm
@@ -320,10 +320,26 @@ static NSThread *newJavaScriptThread(void)
   return self;
 }
 
-- (instancetype)initWithJSContextProvider:(RCTJSContextProvider *)JSContextProvider
++ (instancetype)initializedExecutorWithContextProvider:(RCTJSContextProvider *)JSContextProvider
+                                     applicationScript:(NSData *)applicationScript
+                                             sourceURL:(NSURL *)sourceURL
+                                             JSContext:(JSContext **)JSContext
+                                                 error:(NSError **)error
+{
+  const RCTJSContextData data = JSContextProvider.data;
+  if (JSContext) {
+    *JSContext = data.context;
+  }
+  RCTJSCExecutor *executor = [[RCTJSCExecutor alloc] initWithJSContextData:data];
+  if (![executor _synchronouslyExecuteApplicationScript:applicationScript sourceURL:sourceURL JSContext:data.context error:error]) {
+    return nil; // error has been set by _synchronouslyExecuteApplicationScript:
+  }
+  return executor;
+}
+
+- (instancetype)initWithJSContextData:(const RCTJSContextData &)data
 {
   if (self = [super init]) {
-    const RCTJSContextData data = JSContextProvider.data;
     _useCustomJSCLibrary = data.useCustomJSCLibrary;
     _valid = YES;
     _javaScriptThread = data.javaScriptThread;
@@ -333,6 +349,30 @@ static NSThread *newJavaScriptThread(void)
   return self;
 }
 
+- (BOOL)_synchronouslyExecuteApplicationScript:(NSData *)script
+                                     sourceURL:(NSURL *)sourceURL
+                                     JSContext:(JSContext *)context
+                                         error:(NSError **)error
+{
+  BOOL isRAMBundle = NO;
+  script = loadPossiblyBundledApplicationScript(script, sourceURL, _performanceLogger, isRAMBundle, _randomAccessBundle, error);
+  if (!script) {
+    return NO;
+  }
+  if (isRAMBundle) {
+    registerNativeRequire(context, self);
+  }
+  NSError *returnedError = executeApplicationScript(script, sourceURL, _jscWrapper, _performanceLogger, _context.context.JSGlobalContextRef);
+  if (returnedError) {
+    if (error) {
+      *error = returnedError;
+    }
+    return NO;
+  } else {
+    return YES;
+  }
+}
+
 - (RCTJavaScriptContext *)context
 {
   RCTAssertThread(_javaScriptThread, @"Must be called on JS thread.");
@@ -343,11 +383,6 @@ static NSThread *newJavaScriptThread(void)
   return _context;
 }
 
-- (JSContext *)underlyingJSContext
-{
-  return self.context.context;
-}
-
 - (void)setUp
 {
 #if RCT_PROFILE
@@ -662,36 +697,16 @@ static void installBasicSynchronousHooksOnContext(JSContext *context)
   RCTAssertParam(script);
   RCTAssertParam(sourceURL);
 
-  // The RAM bundle has a magic number in the 4 first bytes `(0xFB0BD1E5)`.
-  uint32_t magicNumber = NSSwapLittleIntToHost(*((uint32_t *)script.bytes));
-  BOOL isRAMBundle = magicNumber == RCTRAMBundleMagicNumber;
-  if (isRAMBundle) {
-    [_performanceLogger markStartForTag:RCTPLRAMBundleLoad];
+  BOOL isRAMBundle = NO;
+  {
     NSError *error;
-    script = loadRAMBundle(sourceURL, &error, _randomAccessBundle);
-    [_performanceLogger markStopForTag:RCTPLRAMBundleLoad];
-    [_performanceLogger setValue:script.length forTag:RCTPLRAMStartupCodeSize];
-
-    // Reset the counters that the native require implementation uses
-    [_performanceLogger setValue:0 forTag:RCTPLRAMNativeRequires];
-    [_performanceLogger setValue:0 forTag:RCTPLRAMNativeRequiresCount];
-    [_performanceLogger setValue:0 forTag:RCTPLRAMNativeRequiresSize];
-
-    if (error) {
+    script = loadPossiblyBundledApplicationScript(script, sourceURL, _performanceLogger, isRAMBundle, _randomAccessBundle, &error);
+    if (script == nil) {
       if (onComplete) {
         onComplete(error);
       }
       return;
     }
-  } else {
-    // JSStringCreateWithUTF8CString expects a null terminated C string.
-    // RAM Bundling already provides a null terminated one.
-    NSMutableData *nullTerminatedScript = [NSMutableData dataWithCapacity:script.length + 1];
-
-    [nullTerminatedScript appendData:script];
-    [nullTerminatedScript appendBytes:"" length:1];
-
-    script = nullTerminatedScript;
   }
 
   [self executeBlockOnJavaScriptQueue:RCTProfileBlock((^{
@@ -699,26 +714,63 @@ static void installBasicSynchronousHooksOnContext(JSContext *context)
       return;
     }
     if (isRAMBundle) {
-      __weak RCTJSCExecutor *weakSelf = self;
-      self.context.context[@"nativeRequire"] = ^(NSNumber *moduleID) { [weakSelf _nativeRequire:moduleID]; };
+      registerNativeRequire(self.context.context, self);
     }
-    [self->_performanceLogger markStartForTag:RCTPLScriptExecution];
-    NSError *error = executeApplicationScript(self->_jscWrapper, script, sourceURL, self->_context.context.JSGlobalContextRef);
-    [self->_performanceLogger markStopForTag:RCTPLScriptExecution];
+    NSError *error = executeApplicationScript(script, sourceURL, self->_jscWrapper, self->_performanceLogger,
+                                              self->_context.context.JSGlobalContextRef);
     if (onComplete) {
       onComplete(error);
     }
   }), 0, @"js_call", (@{ @"url": sourceURL.absoluteString }))];
 }
 
-static NSError *executeApplicationScript(RCTJSCWrapper *jscWrapper, NSData *script, NSURL *sourceURL, JSGlobalContextRef ctx)
+static NSData *loadPossiblyBundledApplicationScript(NSData *script, NSURL *sourceURL,
+                                                    RCTPerformanceLogger *performanceLogger,
+                                                    BOOL &isRAMBundle, RandomAccessBundleData &randomAccessBundle,
+                                                    NSError **error)
 {
+  // The RAM bundle has a magic number in the 4 first bytes `(0xFB0BD1E5)`.
+  uint32_t magicNumber = NSSwapLittleIntToHost(*((uint32_t *)script.bytes));
+  isRAMBundle = magicNumber == RCTRAMBundleMagicNumber;
+  if (isRAMBundle) {
+    [performanceLogger markStartForTag:RCTPLRAMBundleLoad];
+    script = loadRAMBundle(sourceURL, error, randomAccessBundle);
+    [performanceLogger markStopForTag:RCTPLRAMBundleLoad];
+    [performanceLogger setValue:script.length forTag:RCTPLRAMStartupCodeSize];
+
+    // Reset the counters that the native require implementation uses
+    [performanceLogger setValue:0 forTag:RCTPLRAMNativeRequires];
+    [performanceLogger setValue:0 forTag:RCTPLRAMNativeRequiresCount];
+    [performanceLogger setValue:0 forTag:RCTPLRAMNativeRequiresSize];
+
+    return script;
+  } else {
+    // JSStringCreateWithUTF8CString expects a null terminated C string.
+    // RAM Bundling already provides a null terminated one.
+    NSMutableData *nullTerminatedScript = [NSMutableData dataWithCapacity:script.length + 1];
+    [nullTerminatedScript appendData:script];
+    [nullTerminatedScript appendBytes:"" length:1];
+    return nullTerminatedScript;
+  }
+}
+
+static void registerNativeRequire(JSContext *context, RCTJSCExecutor *executor)
+{
+  __weak RCTJSCExecutor *weakExecutor = executor;
+  context[@"nativeRequire"] = ^(NSNumber *moduleID) { [weakExecutor _nativeRequire:moduleID]; };
+}
+
+static NSError *executeApplicationScript(NSData *script, NSURL *sourceURL, RCTJSCWrapper *jscWrapper,
+                                         RCTPerformanceLogger *performanceLogger, JSGlobalContextRef ctx)
+{
+  [performanceLogger markStartForTag:RCTPLScriptExecution];
   JSValueRef jsError = NULL;
   JSStringRef execJSString = jscWrapper->JSStringCreateWithUTF8CString((const char *)script.bytes);
   JSStringRef bundleURL = jscWrapper->JSStringCreateWithUTF8CString(sourceURL.absoluteString.UTF8String);
   JSValueRef result = jscWrapper->JSEvaluateScript(ctx, execJSString, NULL, bundleURL, 0, &jsError);
   jscWrapper->JSStringRelease(bundleURL);
   jscWrapper->JSStringRelease(execJSString);
+  [performanceLogger markStopForTag:RCTPLScriptExecution];
   return result ? nil : RCTNSErrorFromJSError(jscWrapper, ctx, jsError);
 }