diff --git a/godot.nimble b/godot.nimble
index 72b93a8..fc2f0b3 100644
--- a/godot.nimble
+++ b/godot.nimble
@@ -1,4 +1,4 @@
-version = "0.6.5"
+version = "0.6.6"
 author = "Xored Software, Inc."
 description = "Godot Engine bindings"
 license = "MIT"
diff --git a/godot/gdnativeapi.nim b/godot/gdnativeapi.nim
index 64ea7eb..7283ed7 100644
--- a/godot/gdnativeapi.nim
+++ b/godot/gdnativeapi.nim
@@ -9,10 +9,6 @@ type
     GDNativeExtPluginScript,
     GDNativeExtNativeARVR
 
-  GDNativeAPIVersion = object
-    major: cuint
-    minor: cuint
-
   GDNativeAPIHeader = object
     typ: cuint
     version: GDNativeAPIVersion
@@ -1271,8 +1267,6 @@ type
     stringGetData: proc (self: GodotString, dest: cstring, size: var cint)
                         {.noconv, raises: [], gcsafe, tags: [], locks: 0.}
     stringOperatorIndex: pointer
-    stringCStr: proc (self: GodotString): cstring
-                      {.noconv, raises: [], gcsafe, tags: [], locks: 0.}
     stringOperatorIndexConst: pointer
     stringUTF16Str: pointer
     stringOperatorEqual: proc (self, other: GodotString): bool
@@ -1450,7 +1444,10 @@ type
                           {.noconv, raises: [], gcsafe, tags: [], locks: 0.}
     getClassConstructor: proc (className: cstring): GodotClassConstructor
                               {.noconv, raises: [], gcsafe, tags: [], locks: 0.}
-
+    registerNativeCallType: proc (callType: cstring,
+                                  cb: proc (procHandle: pointer,
+                                            args: ptr GodotArray): GodotVariant
+                                           {.noconv.}) {.noconv.}
     alloc: proc (bytes: cint): pointer
                 {.noconv, raises: [], gcsafe, tags: [], locks: 0.}
     realloc: proc (p: pointer, bytes: cint): pointer
@@ -2535,8 +2532,6 @@ type
                          {.noconv, raises: [], gcsafe, tags: [], locks: 0.}
     stringGetData*: proc (self: GodotString, dest: cstring, size: var cint)
                          {.noconv, raises: [], gcsafe, tags: [], locks: 0.}
-    stringCStr*: proc (self: GodotString): cstring
-                      {.noconv, raises: [], gcsafe, tags: [], locks: 0.}
     stringOperatorEqual*: proc (self, other: GodotString): bool
                                {.noconv, raises: [], gcsafe, tags: [], locks: 0.}
     stringOperatorLess*: proc (self, other: GodotString): bool
@@ -2627,7 +2622,7 @@ var gdNativeAPI: GDNativeAPI
 proc getGDNativeAPI*(): ptr GDNativeAPI {.inline.} =
   addr gdNativeAPI
 
-proc setGDNativeAPI*(apiStruct: pointer) {.inline.} =
+proc setGDNativeAPI*(apiStruct: pointer, initOptions: ptr GDNativeInitOptions) =
   let header = cast[ptr GDNativeAPIHeader](apiStruct)
 
   if header.typ >= ord(low(GDNativeAPIType)).cuint and header.typ <= ord(high(GDNativeAPIType)).cuint:
@@ -3110,7 +3105,6 @@ proc setGDNativeAPI*(apiStruct: pointer) {.inline.} =
           stringNewCopy
           stringNewData
           stringGetData
-          stringCStr
           stringOperatorEqual
           stringOperatorLess
           stringOperatorPlus
@@ -3134,7 +3128,11 @@ proc setGDNativeAPI*(apiStruct: pointer) {.inline.} =
           print
 
         for i in 0.cuint..<coreApi.numExtensions:
-          setGDNativeAPI(coreApi.extensions[][i.int])
+          setGDNativeAPI(coreApi.extensions[][i.int], initOptions)
+      else:
+        let want = GDNativeAPIVersion(major: 1, minor: 0)
+        initOptions[].reportVersionMismatch(
+          initOptions[].gdNativeLibrary, cstring"Core", want, coreApi[].version)
     of GDNativeExtNativeScript:
       let nativeScriptApi = cast[ptr GDNativeNativeScriptAPI1](apiStruct)
       if nativeScriptApi[].version.major == 1:
@@ -3145,10 +3143,15 @@ proc setGDNativeAPI*(apiStruct: pointer) {.inline.} =
           nativeScriptRegisterProperty
           nativeScriptRegisterSignal
           nativeScriptGetUserdata
+      else:
+        let want = GDNativeAPIVersion(major: 1, minor: 0)
+        initOptions[].reportVersionMismatch(
+          initOptions[].gdNativeLibrary, cstring"NativeScript",
+          want, nativeScriptApi[].version)
 
     of GDNativeExtPluginScript, GDNativeExtNativeARVR:
       # Not used
       discard
 
   if not header.next.isNil:
-    setGDNativeAPI(header.next)
+    setGDNativeAPI(header.next, initOptions)
diff --git a/godot/godotinternal.nim b/godot/godotinternal.nim
index c89ea6c..90903a7 100644
--- a/godot/godotinternal.nim
+++ b/godot/godotinternal.nim
@@ -29,8 +29,7 @@ proc nativeScriptRegisterClass*(libHandle: pointer; name, base: cstring;
                                 createFunc: GodotInstanceCreateFunc;
                                 destroyFunc: GodotInstanceDestroyFunc)
                                {.inline.} =
-  let api = getGDNativeAPI()
-  api.nativeScriptRegisterClass(
+  getGDNativeAPI().nativeScriptRegisterClass(
     libHandle, name, base, createFunc, destroyFunc)
 
 proc nativeScriptRegisterToolClass*(libHandle: pointer; name, base: cstring;
@@ -73,8 +72,7 @@ proc deinit*(o: ptr GodotObject) {.inline.} =
 
 proc godotPrintError*(description, function, file: cstring;
                       line: cint) {.inline.} =
-  let api = getGDNativeAPI()
-  api.printError(description, function, file, line)
+  getGDNativeAPI().printError(description, function, file, line)
 
 proc godotPrintWarning*(description, function, file: cstring;
                         line: cint) {.inline.} =
diff --git a/godot/internal/godotinternaltypes.nim b/godot/internal/godotinternaltypes.nim
index ba661ad..508c39e 100644
--- a/godot/internal/godotinternaltypes.nim
+++ b/godot/internal/godotinternaltypes.nim
@@ -82,16 +82,23 @@ type
 type GodotMethodBind* = object
 
 type
-  GodotNativeInitOptions* = object
+  GDNativeAPIVersion* = object
+    major*: cuint
+    minor*: cuint
+
+  GDNativeInitOptions* = object
     inEditor*: bool
     coreApiHash*: uint64
     editorApiHash*: uint64
     noApiHash*: uint64
+    reportVersionMismatch*: proc (library: ptr GodotObject, extension: cstring,
+                                  want: GDNativeAPIVersion, have: GDNativeAPIVersion) {.noconv.}
+    reportLoadingError*: proc (library: ptr GodotObject, what: cstring) {.noconv.}
     gdNativeLibrary*: ptr GodotObject
     gdNativeAPIStruct*: pointer
     activeLibraryPath*: ptr GodotString
 
-  GodotNativeTerminateOptions* = object
+  GDNativeTerminateOptions* = object
     inEditor*: bool
 
   GodotMethodRPCMode* {.size: sizeof(cint), pure.} = enum
diff --git a/godot/internal/godotstrings.nim b/godot/internal/godotstrings.nim
index e5529e5..58e4a24 100644
--- a/godot/internal/godotstrings.nim
+++ b/godot/internal/godotstrings.nim
@@ -19,9 +19,6 @@ proc len*(self: GodotString): cint {.inline.} =
   ## Returns the length of string in bytes if it is represented as UTF-8.
   getData(self, nil, result)
 
-proc cstring*(self: GodotString): cstring {.inline.} =
-  getGDNativeAPI().stringCStr(self)
-
 proc `==`*(self, b: GodotString): bool {.inline.} =
   getGDNativeAPI().stringOperatorEqual(self, b)
 
diff --git a/godot/nim/godotnim.nim b/godot/nim/godotnim.nim
index b1c4be5..0eccb6b 100644
--- a/godot/nim/godotnim.nim
+++ b/godot/nim/godotnim.nim
@@ -801,12 +801,12 @@ proc godot_nativescript_init(handle: pointer) {.
   GC_fullCollect()
   GC_disable()
 
-proc godot_gdnative_init(options: ptr GodotNativeInitOptions) {.
+proc godot_gdnative_init(options: ptr GDNativeInitOptions) {.
     cdecl, exportc, dynlib.} =
   gdNativeLibraryObj = options.gdNativeLibrary
-  setGDNativeAPI(options.gdNativeAPIStruct)
+  setGDNativeAPI(options.gdNativeAPIStruct, options)
 
-proc godot_gdnative_terminate(options: ptr GodotNativeTerminateOptions) {.
+proc godot_gdnative_terminate(options: ptr GDNativeTerminateOptions) {.
     cdecl, exportc, dynlib.} =
   deallocHeap(runFinalizers = not options[].inEditor, allowGcAfterwards = false)