diff --git a/airbyte_cdk/sources/declarative/interpolation/jinja.py b/airbyte_cdk/sources/declarative/interpolation/jinja.py
index ec5e861c..3bb9b0c2 100644
--- a/airbyte_cdk/sources/declarative/interpolation/jinja.py
+++ b/airbyte_cdk/sources/declarative/interpolation/jinja.py
@@ -4,7 +4,7 @@
 
 import ast
 from functools import cache
-from typing import Any, Mapping, Optional, Tuple, Type
+from typing import Any, Mapping, Optional, Set, Tuple, Type
 
 from jinja2 import meta
 from jinja2.environment import Template
@@ -27,7 +27,35 @@ class StreamPartitionAccessEnvironment(SandboxedEnvironment):
     def is_safe_attribute(self, obj: Any, attr: str, value: Any) -> bool:
         if attr in ["_partition"]:
             return True
-        return super().is_safe_attribute(obj, attr, value)
+        return super().is_safe_attribute(obj, attr, value)  # type: ignore  # for some reason, mypy says 'Returning Any from function declared to return "bool"'
+
+
+# These aliases are used to deprecate existing keywords without breaking all existing connectors.
+_ALIASES = {
+    "stream_interval": "stream_slice",  # Use stream_interval to access incremental_sync values
+    "stream_partition": "stream_slice",  # Use stream_partition to access partition router's values
+}
+
+# These extensions are not installed so they're not currently a problem,
+# but we're still explicitly removing them from the jinja context.
+# At worst, this is documentation that we do NOT want to include these extensions because of the potential security risks
+_RESTRICTED_EXTENSIONS = ["jinja2.ext.loopcontrols"]  # Adds support for break continue in loops
+
+# By default, these Python builtin functions are available in the Jinja context.
+# We explicitly remove them because of the potential security risk.
+# Please add a unit test to test_jinja.py when adding a restriction.
+_RESTRICTED_BUILTIN_FUNCTIONS = [
+    "range"
+]  # The range function can cause very expensive computations
+
+_ENVIRONMENT = StreamPartitionAccessEnvironment()
+_ENVIRONMENT.filters.update(**filters)
+_ENVIRONMENT.globals.update(**macros)
+
+for extension in _RESTRICTED_EXTENSIONS:
+    _ENVIRONMENT.extensions.pop(extension, None)
+for builtin in _RESTRICTED_BUILTIN_FUNCTIONS:
+    _ENVIRONMENT.globals.pop(builtin, None)
 
 
 class JinjaInterpolation(Interpolation):
@@ -48,34 +76,6 @@ class JinjaInterpolation(Interpolation):
     Additional information on jinja templating can be found at https://jinja.palletsprojects.com/en/3.1.x/templates/#
     """
 
-    # These aliases are used to deprecate existing keywords without breaking all existing connectors.
-    ALIASES = {
-        "stream_interval": "stream_slice",  # Use stream_interval to access incremental_sync values
-        "stream_partition": "stream_slice",  # Use stream_partition to access partition router's values
-    }
-
-    # These extensions are not installed so they're not currently a problem,
-    # but we're still explicitely removing them from the jinja context.
-    # At worst, this is documentation that we do NOT want to include these extensions because of the potential security risks
-    RESTRICTED_EXTENSIONS = ["jinja2.ext.loopcontrols"]  # Adds support for break continue in loops
-
-    # By default, these Python builtin functions are available in the Jinja context.
-    # We explicitely remove them because of the potential security risk.
-    # Please add a unit test to test_jinja.py when adding a restriction.
-    RESTRICTED_BUILTIN_FUNCTIONS = [
-        "range"
-    ]  # The range function can cause very expensive computations
-
-    def __init__(self) -> None:
-        self._environment = StreamPartitionAccessEnvironment()
-        self._environment.filters.update(**filters)
-        self._environment.globals.update(**macros)
-
-        for extension in self.RESTRICTED_EXTENSIONS:
-            self._environment.extensions.pop(extension, None)
-        for builtin in self.RESTRICTED_BUILTIN_FUNCTIONS:
-            self._environment.globals.pop(builtin, None)
-
     def eval(
         self,
         input_str: str,
@@ -86,7 +86,7 @@ def eval(
     ) -> Any:
         context = {"config": config, **additional_parameters}
 
-        for alias, equivalent in self.ALIASES.items():
+        for alias, equivalent in _ALIASES.items():
             if alias in context:
                 # This is unexpected. We could ignore or log a warning, but failing loudly should result in fewer surprises
                 raise ValueError(
@@ -105,6 +105,7 @@ def eval(
                 raise Exception(f"Expected a string, got {input_str}")
         except UndefinedError:
             pass
+
         # If result is empty or resulted in an undefined error, evaluate and return the default string
         return self._literal_eval(self._eval(default, context), valid_types)
 
@@ -132,16 +133,16 @@ def _eval(self, s: Optional[str], context: Mapping[str, Any]) -> Optional[str]:
             return s
 
     @cache
-    def _find_undeclared_variables(self, s: Optional[str]) -> set[str]:
+    def _find_undeclared_variables(self, s: Optional[str]) -> Set[str]:
         """
         Find undeclared variables and cache them
         """
-        ast = self._environment.parse(s)  # type: ignore # parse is able to handle None
+        ast = _ENVIRONMENT.parse(s)  # type: ignore # parse is able to handle None
         return meta.find_undeclared_variables(ast)
 
     @cache
-    def _compile(self, s: Optional[str]) -> Template:
+    def _compile(self, s: str) -> Template:
         """
         We must cache the Jinja Template ourselves because we're using `from_string` instead of a template loader
         """
-        return self._environment.from_string(s)  # type: ignore [arg-type]  # Expected `str | Template` but passed `str | None`
+        return _ENVIRONMENT.from_string(s)