diff --git a/python_aternos/__init__.py b/python_aternos/__init__.py
index b7590bc..362159e 100644
--- a/python_aternos/__init__.py
+++ b/python_aternos/__init__.py
@@ -28,7 +28,8 @@ from .aterrors import ServerError
 from .aterrors import ServerStartError
 from .aterrors import FileError
 from .aterrors import AternosPermissionError
-from .atjsparse import exec_js
+from .atjsparse import Js2PyInterpreter
+from .atjsparse import NodeInterpreter
 
 __all__ = [
 
@@ -42,7 +43,8 @@ __all__ = [
     'FileManager', 'AternosFile', 'AternosError',
     'CloudflareError', 'CredentialsError', 'TokenError',
     'ServerError', 'ServerStartError', 'FileError',
-    'AternosPermissionError', 'exec_js',
+    'AternosPermissionError',
+    'Js2PyInterpreter', 'NodeInterpreter',
 
     'Edition', 'Status', 'Lists',
     'ServerOpts', 'WorldOpts', 'WorldRules',
diff --git a/python_aternos/atjsparse.py b/python_aternos/atjsparse.py
index 206dff1..929fe9f 100644
--- a/python_aternos/atjsparse.py
+++ b/python_aternos/atjsparse.py
@@ -1,36 +1,134 @@
 """Parsing and executing JavaScript code"""
 
+import abc
 import base64
+import subprocess
+
+from pathlib import Path
+from typing import Optional, Union, Any
+from typing import Type
+
 import regex
 import js2py
 
-# Thanks to http://regex.inginf.units.it/
-arrowexp = regex.compile(r'\w[^\}]*+')
+js: Optional['Interpreter'] = None
 
 
-def to_ecma5_function(f: str) -> str:
-    """Converts a ECMA6 function
-    to ECMA5 format (without arrow expressions)
+class Interpreter(abc.ABC):
+    """Base JS interpreter class"""
 
-    Args:
-        f (str): ECMA6 function
+    def __init__(self) -> None:
+        pass
 
-    Returns:
-        ECMA5 function
-    """
+    def __getitem__(self, name: str) -> Any:
+        return self.get_var(name)
 
-    f = regex.sub(r'/\*.+?\*/', '', f)
-    match = arrowexp.search(f)
-    conv = '(function(){' + match.group(0) + '})()'
-    return regex.sub(
-        r'(?:s|\(s\)) => s.split\([\'"]{2}\).reverse\(\).join\([\'"]{2}\)',
-        'function(s){return s.split(\'\').reverse().join(\'\')}',
-        conv
-    )
+    @abc.abstractmethod
+    def exec_js(self, func: str) -> None:
+        """Executes JavaScript code
+
+        Args:
+            func (str): JS function
+        """
+        pass
+
+    @abc.abstractmethod
+    def get_var(self, name: str) -> Any:
+        """Returns JS variable value
+        from the interpreter
+
+        Args:
+            name (str): Variable name
+
+        Returns:
+            Variable value
+        """
+        pass
+
+
+class NodeInterpreter(Interpreter):
+
+    def __init__(self, node: Union[str, Path]) -> None:
+        super().__init__()
+        self.proc = subprocess.Popen(
+            node,
+            stdout=subprocess.PIPE,
+        )
+    
+    def exec_js(self, func: str) -> None:
+        self.proc.communicate(func.encode('utf-8'))
+    
+    def get_var(self, name: str) -> Any:
+        assert self.proc.stdout is not None
+        self.proc.stdout.read()
+        self.proc.communicate(name.encode('utf-8'))
+        return self.proc.stdout.read().decode('utf-8')
+    
+    def __del__(self) -> None:
+        self.proc.terminate()
+
+
+class Js2PyInterpreter(Interpreter):
+
+    # Thanks to http://regex.inginf.units.it
+    arrowexp = regex.compile(r'\w[^\}]*+')
+
+    def __init__(self) -> None:
+
+        super().__init__()
+
+        ctx = js2py.EvalJs({'atob': atob})
+        ctx.execute('window.document = { };')
+        ctx.execute('window.Map = function(_i){ };')
+        ctx.execute('window.setTimeout = function(_f,_t){ };')
+        ctx.execute('window.setInterval = function(_f,_t){ };')
+        ctx.execute('window.encodeURIComponent = function(_s){ };')
+
+        self.ctx = ctx
+    
+    def exec_js(self, func: str) -> None:
+        self.ctx.execute(self.to_ecma5(func))
+    
+    def get_var(self, name: str) -> Any:
+        return self.ctx[name]
+    
+    def to_ecma5(self, func: str) -> str:
+        """Converts from ECMA6 format to ECMA5
+        (replacing arrow expressions)
+        and removes comment blocks
+
+        Args:
+            func (str): ECMA6 function
+
+        Returns:
+            ECMA5 function
+        """
+
+        # Delete anything between /* and */
+        func = regex.sub(r'/\*.+?\*/', '', func)
+
+        # Search for arrow expressions
+        match = self.arrowexp.search(func)
+        if match is None:
+            return func
+        
+        # Convert the function
+        conv = '(function(){' + match[0] + '})()'
+
+        # Convert 1 more expression.
+        # It doesn't change,
+        # so it was hardcoded
+        # as a regexp
+        return regex.sub(
+            r'(?:s|\(s\)) => s.split\([\'"]{2}\).reverse\(\).join\([\'"]{2}\)',
+            'function(s){return s.split(\'\').reverse().join(\'\')}',
+            conv
+        )
 
 
 def atob(s: str) -> str:
-    """Decodes base64 string
+    """Wrapper for the built-in library function.
+    Decodes base64 string
 
     Args:
         s (str): Encoded data
@@ -42,21 +140,8 @@ def atob(s: str) -> str:
     return base64.standard_b64decode(str(s)).decode('utf-8')
 
 
-def exec_js(f: str) -> js2py.EvalJs:
-    """Executes a JavaScript function
-
-    Args:
-        f (str): ECMA6 function
-
-    Returns:
-        JavaScript interpreter context
-    """
-
-    ctx = js2py.EvalJs({'atob': atob})
-    ctx.execute('window.document = { };')
-    ctx.execute('window.Map = function(_i){ };')
-    ctx.execute('window.setTimeout = function(_f,_t){ };')
-    ctx.execute('window.setInterval = function(_f,_t){ };')
-    ctx.execute('window.encodeURIComponent = function(_s){ };')
-    ctx.execute(to_ecma5_function(f))
-    return ctx
+def get_interpreter(create: Type[Interpreter] = Js2PyInterpreter) -> 'Interpreter':
+    global js
+    if js is None:
+        js = create()
+    return js
diff --git a/tests/test_js.py b/tests/test_js.py
index e33027f..f077739 100644
--- a/tests/test_js.py
+++ b/tests/test_js.py
@@ -13,6 +13,7 @@ class TestJs2Py(unittest.TestCase):
 
         self.tests = files.read_sample('token_input.txt')
         self.results = files.read_sample('token_output.txt')
+        self.js = atjsparse.Js2PyInterpreter()
 
     def test_base64(self) -> None:
 
@@ -23,7 +24,7 @@ class TestJs2Py(unittest.TestCase):
     def test_conv(self) -> None:
 
         token = CONV_TOKEN_ARROW
-        f = atjsparse.to_ecma5_function(token)
+        f = self.js.to_ecma5(token)
         self.assertEqual(f, CONV_TOKEN_FUNC)
 
     def test_ecma6parse(self) -> None:
@@ -38,21 +39,21 @@ class TestJs2Py(unittest.TestCase):
         part2 = '''window.t2 = Boolean(!window[["p","Ma"].reverse().join('')]);'''
         part3 = '''window.t3 = Boolean(!window[["ut","meo","i","etT","s"].reverse().join('')]);'''
 
-        ctx0 = atjsparse.exec_js(code)
-        ctx1 = atjsparse.exec_js(part1)
-        ctx2 = atjsparse.exec_js(part2)
-        ctx3 = atjsparse.exec_js(part3)
+        self.js.exec_js(code)
+        self.js.exec_js(part1)
+        self.js.exec_js(part2)
+        self.js.exec_js(part3)
 
-        self.assertEqual(ctx0.window['t0'], False)
-        self.assertEqual(ctx1.window['t1'], True)
-        self.assertEqual(ctx2.window['t2'], False)
-        self.assertEqual(ctx3.window['t3'], False)
+        self.assertEqual(self.js['t0'], False)
+        self.assertEqual(self.js['t1'], True)
+        self.assertEqual(self.js['t2'], False)
+        self.assertEqual(self.js['t3'], False)
 
     def test_exec(self) -> None:
 
         for i, f in enumerate(self.tests):
-            ctx = atjsparse.exec_js(f)
-            res = ctx.window['AJAX_TOKEN']
+            self.js.exec_js(f)
+            res = self.js['AJAX_TOKEN']
             self.assertEqual(res, self.results[i])