diff --git a/aws_lambda_powertools/event_handler/api_gateway.py b/aws_lambda_powertools/event_handler/api_gateway.py
index 391b1e4a2c2..b6e9cd4698b 100644
--- a/aws_lambda_powertools/event_handler/api_gateway.py
+++ b/aws_lambda_powertools/event_handler/api_gateway.py
@@ -1,7 +1,9 @@
 import base64
 import json
 import logging
+import os
 import re
+import traceback
 import zlib
 from enum import Enum
 from http import HTTPStatus
@@ -9,6 +11,8 @@
 
 from aws_lambda_powertools.event_handler import content_types
 from aws_lambda_powertools.event_handler.exceptions import ServiceError
+from aws_lambda_powertools.shared import constants
+from aws_lambda_powertools.shared.functions import resolve_truthy_env_var_choice
 from aws_lambda_powertools.shared.json_encoder import Encoder
 from aws_lambda_powertools.utilities.data_classes import ALBEvent, APIGatewayProxyEvent, APIGatewayProxyEventV2
 from aws_lambda_powertools.utilities.data_classes.common import BaseProxyEvent
@@ -28,43 +32,46 @@ class ProxyEventType(Enum):
 class CORSConfig(object):
     """CORS Config
 
-
     Examples
     --------
 
     Simple cors example using the default permissive cors, not this should only be used during early prototyping
 
-        from aws_lambda_powertools.event_handler.api_gateway import ApiGatewayResolver
+    ```python
+    from aws_lambda_powertools.event_handler.api_gateway import ApiGatewayResolver
 
-        app = ApiGatewayResolver()
+    app = ApiGatewayResolver()
 
-        @app.get("/my/path", cors=True)
-        def with_cors():
-            return {"message": "Foo"}
+    @app.get("/my/path", cors=True)
+    def with_cors():
+        return {"message": "Foo"}
+    ```
 
     Using a custom CORSConfig where `with_cors` used the custom provided CORSConfig and `without_cors`
     do not include any cors headers.
 
-        from aws_lambda_powertools.event_handler.api_gateway import (
-            ApiGatewayResolver, CORSConfig
-        )
-
-        cors_config = CORSConfig(
-            allow_origin="https://wwww.example.com/",
-            expose_headers=["x-exposed-response-header"],
-            allow_headers=["x-custom-request-header"],
-            max_age=100,
-            allow_credentials=True,
-        )
-        app = ApiGatewayResolver(cors=cors_config)
-
-        @app.get("/my/path")
-        def with_cors():
-            return {"message": "Foo"}
+    ```python
+    from aws_lambda_powertools.event_handler.api_gateway import (
+        ApiGatewayResolver, CORSConfig
+    )
+
+    cors_config = CORSConfig(
+        allow_origin="https://wwww.example.com/",
+        expose_headers=["x-exposed-response-header"],
+        allow_headers=["x-custom-request-header"],
+        max_age=100,
+        allow_credentials=True,
+    )
+    app = ApiGatewayResolver(cors=cors_config)
+
+    @app.get("/my/path")
+    def with_cors():
+        return {"message": "Foo"}
 
-        @app.get("/another-one", cors=False)
-        def without_cors():
-            return {"message": "Foo"}
+    @app.get("/another-one", cors=False)
+    def without_cors():
+        return {"message": "Foo"}
+    ```
     """
 
     _REQUIRED_HEADERS = ["Authorization", "Content-Type", "X-Amz-Date", "X-Api-Key", "X-Amz-Security-Token"]
@@ -240,7 +247,12 @@ def lambda_handler(event, context):
     current_event: BaseProxyEvent
     lambda_context: LambdaContext
 
-    def __init__(self, proxy_type: Enum = ProxyEventType.APIGatewayProxyEvent, cors: CORSConfig = None):
+    def __init__(
+        self,
+        proxy_type: Enum = ProxyEventType.APIGatewayProxyEvent,
+        cors: CORSConfig = None,
+        debug: Optional[bool] = None,
+    ):
         """
         Parameters
         ----------
@@ -248,12 +260,18 @@ def __init__(self, proxy_type: Enum = ProxyEventType.APIGatewayProxyEvent, cors:
             Proxy request type, defaults to API Gateway V1
         cors: CORSConfig
             Optionally configure and enabled CORS. Not each route will need to have to cors=True
+        debug: Optional[bool]
+            Enables debug mode, by default False. Can be also be enabled by "POWERTOOLS_EVENT_HANDLER_DEBUG"
+            environment variable
         """
         self._proxy_type = proxy_type
         self._routes: List[Route] = []
         self._cors = cors
         self._cors_enabled: bool = cors is not None
         self._cors_methods: Set[str] = {"OPTIONS"}
+        self._debug = resolve_truthy_env_var_choice(
+            choice=debug, env=os.getenv(constants.EVENT_HANDLER_DEBUG_ENV, "false")
+        )
 
     def get(self, rule: str, cors: bool = None, compress: bool = False, cache_control: str = None):
         """Get route decorator with GET `method`
@@ -416,6 +434,8 @@ def resolve(self, event, context) -> Dict[str, Any]:
         dict
             Returns the dict response
         """
+        if self._debug:
+            print(self._json_dump(event))
         self.current_event = self._to_proxy_event(event)
         self.lambda_context = context
         return self._resolve().build(self.current_event, self._cors)
@@ -489,6 +509,19 @@ def _call_route(self, route: Route, args: Dict[str, str]) -> ResponseBuilder:
                 ),
                 route,
             )
+        except Exception:
+            if self._debug:
+                # If the user has turned on debug mode,
+                # we'll let the original exception propagate so
+                # they get more information about what went wrong.
+                return ResponseBuilder(
+                    Response(
+                        status_code=500,
+                        content_type=content_types.TEXT_PLAIN,
+                        body="".join(traceback.format_exc()),
+                    )
+                )
+            raise
 
     def _to_response(self, result: Union[Dict, Response]) -> Response:
         """Convert the route's result to a Response
@@ -509,7 +542,9 @@ def _to_response(self, result: Union[Dict, Response]) -> Response:
             body=self._json_dump(result),
         )
 
-    @staticmethod
-    def _json_dump(obj: Any) -> str:
-        """Does a concise json serialization"""
-        return json.dumps(obj, separators=(",", ":"), cls=Encoder)
+    def _json_dump(self, obj: Any) -> str:
+        """Does a concise json serialization or pretty print when in debug mode"""
+        if self._debug:
+            return json.dumps(obj, indent=4, cls=Encoder)
+        else:
+            return json.dumps(obj, separators=(",", ":"), cls=Encoder)
diff --git a/aws_lambda_powertools/event_handler/content_types.py b/aws_lambda_powertools/event_handler/content_types.py
index 00ec3db168e..0f55b1088ad 100644
--- a/aws_lambda_powertools/event_handler/content_types.py
+++ b/aws_lambda_powertools/event_handler/content_types.py
@@ -1,4 +1,5 @@
 # use mimetypes library to be certain, e.g., mimetypes.types_map[".json"]
 
 APPLICATION_JSON = "application/json"
-PLAIN_TEXT = "text/plain"
+TEXT_PLAIN = "text/plain"
+TEXT_HTML = "text/html"
diff --git a/aws_lambda_powertools/shared/constants.py b/aws_lambda_powertools/shared/constants.py
index eaad5640dfd..8388eded654 100644
--- a/aws_lambda_powertools/shared/constants.py
+++ b/aws_lambda_powertools/shared/constants.py
@@ -10,11 +10,12 @@
 
 METRICS_NAMESPACE_ENV: str = "POWERTOOLS_METRICS_NAMESPACE"
 
+EVENT_HANDLER_DEBUG_ENV: str = "POWERTOOLS_EVENT_HANDLER_DEBUG"
+
 SAM_LOCAL_ENV: str = "AWS_SAM_LOCAL"
 CHALICE_LOCAL_ENV: str = "AWS_CHALICE_CLI_MODE"
 SERVICE_NAME_ENV: str = "POWERTOOLS_SERVICE_NAME"
 XRAY_TRACE_ID_ENV: str = "_X_AMZN_TRACE_ID"
 
-
-XRAY_SDK_MODULE = "aws_xray_sdk"
-XRAY_SDK_CORE_MODULE = "aws_xray_sdk.core"
+XRAY_SDK_MODULE: str = "aws_xray_sdk"
+XRAY_SDK_CORE_MODULE: str = "aws_xray_sdk.core"
diff --git a/tests/functional/event_handler/test_api_gateway.py b/tests/functional/event_handler/test_api_gateway.py
index e542483d73e..b39dccc6084 100644
--- a/tests/functional/event_handler/test_api_gateway.py
+++ b/tests/functional/event_handler/test_api_gateway.py
@@ -5,6 +5,8 @@
 from pathlib import Path
 from typing import Dict
 
+import pytest
+
 from aws_lambda_powertools.event_handler import content_types
 from aws_lambda_powertools.event_handler.api_gateway import (
     ApiGatewayResolver,
@@ -20,6 +22,7 @@
     ServiceError,
     UnauthorizedError,
 )
+from aws_lambda_powertools.shared import constants
 from aws_lambda_powertools.shared.json_encoder import Encoder
 from aws_lambda_powertools.utilities.data_classes import ALBEvent, APIGatewayProxyEvent, APIGatewayProxyEventV2
 from tests.functional.utils import load_event
@@ -31,7 +34,6 @@ def read_media(file_name: str) -> bytes:
 
 
 LOAD_GW_EVENT = load_event("apiGatewayProxyEvent.json")
-TEXT_HTML = "text/html"
 
 
 def test_alb_event():
@@ -42,7 +44,7 @@ def test_alb_event():
     def foo():
         assert isinstance(app.current_event, ALBEvent)
         assert app.lambda_context == {}
-        return Response(200, TEXT_HTML, "foo")
+        return Response(200, content_types.TEXT_HTML, "foo")
 
     # WHEN calling the event handler
     result = app(load_event("albEvent.json"), {})
@@ -50,7 +52,7 @@ def foo():
     # THEN process event correctly
     # AND set the current_event type as ALBEvent
     assert result["statusCode"] == 200
-    assert result["headers"]["Content-Type"] == TEXT_HTML
+    assert result["headers"]["Content-Type"] == content_types.TEXT_HTML
     assert result["body"] == "foo"
 
 
@@ -80,7 +82,7 @@ def test_api_gateway():
     @app.get("/my/path")
     def get_lambda() -> Response:
         assert isinstance(app.current_event, APIGatewayProxyEvent)
-        return Response(200, TEXT_HTML, "foo")
+        return Response(200, content_types.TEXT_HTML, "foo")
 
     # WHEN calling the event handler
     result = app(LOAD_GW_EVENT, {})
@@ -88,7 +90,7 @@ def get_lambda() -> Response:
     # THEN process event correctly
     # AND set the current_event type as APIGatewayProxyEvent
     assert result["statusCode"] == 200
-    assert result["headers"]["Content-Type"] == TEXT_HTML
+    assert result["headers"]["Content-Type"] == content_types.TEXT_HTML
     assert result["body"] == "foo"
 
 
@@ -100,7 +102,7 @@ def test_api_gateway_v2():
     def my_path() -> Response:
         assert isinstance(app.current_event, APIGatewayProxyEventV2)
         post_data = app.current_event.json_body
-        return Response(200, content_types.PLAIN_TEXT, post_data["username"])
+        return Response(200, content_types.TEXT_PLAIN, post_data["username"])
 
     # WHEN calling the event handler
     result = app(load_event("apiGatewayProxyV2Event.json"), {})
@@ -108,7 +110,7 @@ def my_path() -> Response:
     # THEN process event correctly
     # AND set the current_event type as APIGatewayProxyEventV2
     assert result["statusCode"] == 200
-    assert result["headers"]["Content-Type"] == content_types.PLAIN_TEXT
+    assert result["headers"]["Content-Type"] == content_types.TEXT_PLAIN
     assert result["body"] == "tom"
 
 
@@ -119,14 +121,14 @@ def test_include_rule_matching():
     @app.get("/<name>/<my_id>")
     def get_lambda(my_id: str, name: str) -> Response:
         assert name == "my"
-        return Response(200, TEXT_HTML, my_id)
+        return Response(200, content_types.TEXT_HTML, my_id)
 
     # WHEN calling the event handler
     result = app(LOAD_GW_EVENT, {})
 
     # THEN
     assert result["statusCode"] == 200
-    assert result["headers"]["Content-Type"] == TEXT_HTML
+    assert result["headers"]["Content-Type"] == content_types.TEXT_HTML
     assert result["body"] == "path"
 
 
@@ -187,11 +189,11 @@ def test_cors():
 
     @app.get("/my/path", cors=True)
     def with_cors() -> Response:
-        return Response(200, TEXT_HTML, "test")
+        return Response(200, content_types.TEXT_HTML, "test")
 
     @app.get("/without-cors")
     def without_cors() -> Response:
-        return Response(200, TEXT_HTML, "test")
+        return Response(200, content_types.TEXT_HTML, "test")
 
     def handler(event, context):
         return app.resolve(event, context)
@@ -202,7 +204,7 @@ def handler(event, context):
     # THEN the headers should include cors headers
     assert "headers" in result
     headers = result["headers"]
-    assert headers["Content-Type"] == TEXT_HTML
+    assert headers["Content-Type"] == content_types.TEXT_HTML
     assert headers["Access-Control-Allow-Origin"] == "*"
     assert "Access-Control-Allow-Credentials" not in headers
     assert headers["Access-Control-Allow-Headers"] == ",".join(sorted(CORSConfig._REQUIRED_HEADERS))
@@ -268,7 +270,7 @@ def test_compress_no_accept_encoding():
 
     @app.get("/my/path", compress=True)
     def return_text() -> Response:
-        return Response(200, content_types.PLAIN_TEXT, expected_value)
+        return Response(200, content_types.TEXT_PLAIN, expected_value)
 
     # WHEN calling the event handler
     result = app({"path": "/my/path", "httpMethod": "GET", "headers": {}}, None)
@@ -284,7 +286,7 @@ def test_cache_control_200():
 
     @app.get("/success", cache_control="max-age=600")
     def with_cache_control() -> Response:
-        return Response(200, TEXT_HTML, "has 200 response")
+        return Response(200, content_types.TEXT_HTML, "has 200 response")
 
     def handler(event, context):
         return app.resolve(event, context)
@@ -295,7 +297,7 @@ def handler(event, context):
 
     # THEN return the set Cache-Control
     headers = result["headers"]
-    assert headers["Content-Type"] == TEXT_HTML
+    assert headers["Content-Type"] == content_types.TEXT_HTML
     assert headers["Cache-Control"] == "max-age=600"
 
 
@@ -305,7 +307,7 @@ def test_cache_control_non_200():
 
     @app.delete("/fails", cache_control="max-age=600")
     def with_cache_control_has_500() -> Response:
-        return Response(503, TEXT_HTML, "has 503 response")
+        return Response(503, content_types.TEXT_HTML, "has 503 response")
 
     def handler(event, context):
         return app.resolve(event, context)
@@ -316,7 +318,7 @@ def handler(event, context):
 
     # THEN return a Cache-Control of "no-cache"
     headers = result["headers"]
-    assert headers["Content-Type"] == TEXT_HTML
+    assert headers["Content-Type"] == content_types.TEXT_HTML
     assert headers["Cache-Control"] == "no-cache"
 
 
@@ -479,7 +481,7 @@ def test_custom_preflight_response():
     def custom_preflight():
         return Response(
             status_code=200,
-            content_type=TEXT_HTML,
+            content_type=content_types.TEXT_HTML,
             body="Foo",
             headers={"Access-Control-Allow-Methods": "CUSTOM"},
         )
@@ -495,7 +497,7 @@ def custom_method():
     assert result["statusCode"] == 200
     assert result["body"] == "Foo"
     headers = result["headers"]
-    assert headers["Content-Type"] == TEXT_HTML
+    assert headers["Content-Type"] == content_types.TEXT_HTML
     assert "Access-Control-Allow-Origin" in result["headers"]
     assert headers["Access-Control-Allow-Methods"] == "CUSTOM"
 
@@ -582,3 +584,83 @@ def service_error():
     assert "Access-Control-Allow-Origin" in result["headers"]
     expected = {"statusCode": 502, "message": "Something went wrong!"}
     assert result["body"] == json_dump(expected)
+
+
+def test_debug_unhandled_exceptions_debug_on():
+    # GIVEN debug is enabled
+    # AND an unhandled exception is raised
+    app = ApiGatewayResolver(debug=True)
+    assert app._debug
+
+    @app.get("/raises-error")
+    def raises_error():
+        raise RuntimeError("Foo")
+
+    # WHEN calling the handler
+    result = app({"path": "/raises-error", "httpMethod": "GET"}, None)
+
+    # THEN return a 500
+    # AND Content-Type is set to text/plain
+    # AND include the exception traceback in the response
+    assert result["statusCode"] == 500
+    assert "Traceback (most recent call last)" in result["body"]
+    headers = result["headers"]
+    assert headers["Content-Type"] == content_types.TEXT_PLAIN
+
+
+def test_debug_unhandled_exceptions_debug_off():
+    # GIVEN debug is disabled
+    # AND an unhandled exception is raised
+    app = ApiGatewayResolver(debug=False)
+    assert not app._debug
+
+    @app.get("/raises-error")
+    def raises_error():
+        raise RuntimeError("Foo")
+
+    # WHEN calling the handler
+    # THEN raise the original exception
+    with pytest.raises(RuntimeError) as e:
+        app({"path": "/raises-error", "httpMethod": "GET"}, None)
+
+    # AND include the original error
+    assert e.value.args == ("Foo",)
+
+
+def test_debug_mode_environment_variable(monkeypatch):
+    # GIVEN a debug mode environment variable is set
+    monkeypatch.setenv(constants.EVENT_HANDLER_DEBUG_ENV, "true")
+    app = ApiGatewayResolver()
+
+    # WHEN calling app._debug
+    # THEN the debug mode is enabled
+    assert app._debug
+
+
+def test_debug_json_formatting():
+    # GIVEN debug is True
+    app = ApiGatewayResolver(debug=True)
+    response = {"message": "Foo"}
+
+    @app.get("/foo")
+    def foo():
+        return response
+
+    # WHEN calling the handler
+    result = app({"path": "/foo", "httpMethod": "GET"}, None)
+
+    # THEN return a pretty print json in the body
+    assert result["body"] == json.dumps(response, indent=4)
+
+
+def test_debug_print_event(capsys):
+    # GIVE debug is True
+    app = ApiGatewayResolver(debug=True)
+
+    # WHEN calling resolve
+    event = {"path": "/foo", "httpMethod": "GET"}
+    app(event, None)
+
+    # THEN print the event
+    out, err = capsys.readouterr()
+    assert json.loads(out) == event
diff --git a/tests/functional/py.typed b/tests/functional/py.typed
new file mode 100644
index 00000000000..e69de29bb2d