diff --git a/aggen.py b/aggen.py
index 49c8160..c6aa791 100644
--- a/aggen.py
+++ b/aggen.py
@@ -4,7 +4,6 @@ import re
 import copy
 import json
 from collections import defaultdict
-from re import Pattern
 
 from agast import *
 
@@ -113,13 +112,13 @@ def gen(program: List[Decl]) -> GenResult:
     print("what_ifaces:", what_ifaces)
     print("what_fields:", what_fields)
 
-    # a high-level dictionary of productions; this has sub-productions
-    # that should be further expanded at a later step before converting
-    # into lark code
+    # a high-level dictionary of productions; this has sub-productions that
+    # should be further expanded at a later step before converting into lark
+    # code
     productions_hi: Dict[str, Union[str, List[str]]] = dict()
 
-    # TODO: this should probably not be inlined here, but i'll move it
-    # out once i get more info into the 'env'
+    # TODO: this should probably not be inlined here, but i'll move it out once
+    # i get more info into the 'env'
     def collect_required_thunks(
         env: List[Tuple[str, NodeRef]], expr: Expr
     ) -> Dict[str, str]:
@@ -210,17 +209,16 @@ def gen(program: List[Decl]) -> GenResult:
                 ParseEquation(prod_name, seq, v_class_name)
             )
 
-            # create an environment for checking the equations based on
-            # the production
+            # create an environment for checking the equations based on the
+            # production
             env: List[Tuple[str, NodeRef]] = list()
             for sym in variant.prod:
                 if isinstance(sym, SymRename):
                     env.append((sym.name, sym.ty))
             print(env)
 
-            # for each of the equations, find out what the equation is
-            # trying to compute, and generate a thunk corresponding to
-            # that value.
+            # for each of the equations, find out what the equation is trying
+            # to compute, and generate a thunk corresponding to that value.
             for eq in variant.equations:
                 eq_name = gensym(f"eq_{node_desc.name}")
                 thunk_name = gensym(f"thunk_{node_desc.name}")
diff --git a/agmain.py b/agmain.py
index cd49b2e..3d0a453 100644
--- a/agmain.py
+++ b/agmain.py
@@ -25,46 +25,7 @@ if __name__ == "__main__":
     if not os.path.exists("gen"):
         os.makedirs("gen")
     with open("gen/arith.py", "w") as f:
-        fmt_str = textwrap.dedent(
-            """
-            # This document is generated by agtest.
-
-            __all__ = ["parse"]
-            from typing import Generic, TypeVar, Optional, Callable, Dict, Any
-            from lark import Lark, Transformer
-            T = TypeVar('T')
-            builtins: Dict[str, Any] = {{
-                "parseInt": lambda s: int(s)
-            }}
-
-            class Thunk(Generic[T]):
-                ''' A thunk represents a value that may be computed lazily. '''
-                value: Optional[T]
-                def __init__(self, func: Callable[[], T]):
-                    self.func = func
-                    self.value = None
-                def get(self) -> T:
-                    if self.value is None:
-                        self.value = self.func()
-                    return self.value
-
-            parser = Lark('''
-            {pd}
-            ''', parser='lalr', start={starts}, debug=True)
-
-            {ex}
-
-            class Trans(Transformer[None]): {transdef}
-
-            __agNonterminals = {ntmap}
-            def parse(input: str, start: Optional[str] = None) -> Any:
-                if start is not None: start = __agNonterminals[start]
-                tree = parser.parse(input, start)
-                trans = Trans()
-                res = trans.transform(tree)
-                return res
-        """
-        )
+        fmt_str = open("agruntime.tmpl.py", "r").read()
         f.write(
             fmt_str.format(
                 pd=res.parser_data,
diff --git a/agruntime.tmpl.py b/agruntime.tmpl.py
new file mode 100644
index 0000000..f2c72f2
--- /dev/null
+++ b/agruntime.tmpl.py
@@ -0,0 +1,39 @@
+# This document is generated by agtest.
+# type: ignore
+
+__all__ = ["parse"]
+import re
+from typing import Generic, TypeVar, Optional, Callable, Dict, Any
+from lark import Lark, Transformer
+
+T = TypeVar('T')
+builtins: Dict[str, Any] = {{
+    "parseInt": lambda s: int(s)
+}}
+
+class Thunk(Generic[T]):
+    ''' A thunk represents a value that may be computed lazily. '''
+    value: Optional[T]
+    def __init__(self, func: Callable[[], T]):
+        self.func = func
+        self.value = None
+    def get(self) -> T:
+        if self.value is None:
+            self.value = self.func()
+        return self.value
+
+parser = Lark('''
+{pd}
+''', parser='lalr', start={starts}, debug=True)
+
+{ex}
+
+class Trans(Transformer[None]): {transdef}
+
+__agNonterminals = {ntmap}
+def parse(input: str, start: Optional[str] = None) -> Any:
+    if start is not None: start = __agNonterminals[start]
+    tree = parser.parse(input, start)
+    trans = Trans()
+    res = trans.transform(tree)
+    return res