diff --git a/config/staging.yml b/config/staging.yml
--- a/config/staging.yml
+++ b/config/staging.yml
@@ -6,6 +6,6 @@
   cls: remote
   url: http://webapp.internal.staging.swh.network:5010
 
-debug: yes
+debug: no
 
 server-type: wsgi
diff --git a/swh/graphql/errors/__init__.py b/swh/graphql/errors/__init__.py
--- a/swh/graphql/errors/__init__.py
+++ b/swh/graphql/errors/__init__.py
@@ -3,7 +3,12 @@
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
-from .errors import ObjectNotFoundError, PaginationError
+from .errors import InvalidInputError, ObjectNotFoundError, PaginationError
 from .handlers import format_error
 
-__all__ = ["ObjectNotFoundError", "PaginationError", "format_error"]
+__all__ = [
+    "ObjectNotFoundError",
+    "PaginationError",
+    "InvalidInputError",
+    "format_error",
+]
diff --git a/swh/graphql/errors/errors.py b/swh/graphql/errors/errors.py
--- a/swh/graphql/errors/errors.py
+++ b/swh/graphql/errors/errors.py
@@ -7,6 +7,11 @@
 class ObjectNotFoundError(Exception):
     """ """
 
+    msg: str = "Object error"
+
+    def __init__(self, message, errors=None):
+        super().__init__(f"{self.msg}: {message}")
+
 
 class PaginationError(Exception):
     """ """
@@ -14,5 +19,13 @@
     msg: str = "Pagination error"
 
     def __init__(self, message, errors=None):
-        # FIXME, log this error
+        super().__init__(f"{self.msg}: {message}")
+
+
+class InvalidInputError(Exception):
+    """ """
+
+    msg: str = "Input error"
+
+    def __init__(self, message, errors=None):
         super().__init__(f"{self.msg}: {message}")
diff --git a/swh/graphql/errors/handlers.py b/swh/graphql/errors/handlers.py
--- a/swh/graphql/errors/handlers.py
+++ b/swh/graphql/errors/handlers.py
@@ -3,11 +3,27 @@
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
+from ariadne import format_error as original_format_error
+from graphql import GraphQLError
+import sentry_sdk
 
-def format_error(error) -> dict:
+from .errors import InvalidInputError, ObjectNotFoundError, PaginationError
+
+
+def format_error(error: GraphQLError, debug: bool = False):
     """
     Response error formatting
     """
+    original_format = original_format_error(error, debug)
+    if debug:
+        # If debug is enabled, reuse Ariadne's formatting logic with stack trace
+        return original_format
+
+    expected_errors = [ObjectNotFoundError, PaginationError, InvalidInputError]
     formatted = error.formatted
-    formatted["message"] = "Unknown error"
+    formatted["message"] = error.message
+    if error.original_error.__class__ not in expected_errors:
+        # a crash, send to sentry
+        sentry_sdk.capture_exception(error)
+    # FIXME log the original_format to kibana (with stack trace)
     return formatted
diff --git a/swh/graphql/resolvers/scalars.py b/swh/graphql/resolvers/scalars.py
--- a/swh/graphql/resolvers/scalars.py
+++ b/swh/graphql/resolvers/scalars.py
@@ -7,6 +7,7 @@
 
 from ariadne import ScalarType
 
+from swh.graphql.errors import InvalidInputError
 from swh.graphql.utils import utils
 from swh.model import hashutil
 from swh.model.model import TimestampWithTimezone
@@ -51,10 +52,8 @@
         hash_type, hash_string = value.split(":")
         hash_value = hashutil.hash_to_bytes(hash_string)
     except ValueError as e:
-        # FIXME, log this error
-        raise AttributeError("Invalid content checksum", e)
+        raise InvalidInputError("Invalid content checksum", e)
     except Exception as e:
-        # FIXME, log this error
-        raise AttributeError("Invalid content checksum", e)
+        raise InvalidInputError("Invalid content checksum", e)
     # FIXME, add validation for the hash_type
     return hash_type, hash_value
diff --git a/swh/graphql/server.py b/swh/graphql/server.py
--- a/swh/graphql/server.py
+++ b/swh/graphql/server.py
@@ -63,6 +63,7 @@
     configuration path to load.
     """
     from .app import schema
+    from .errors.handlers import format_error
 
     global graphql_cfg
 
@@ -77,12 +78,14 @@
 
         # Enable cors in the asgi version
         application = CORSMiddleware(
-            GraphQL(schema),
+            GraphQL(schema, debug=graphql_cfg["debug"], error_formatter=format_error),
             allow_origins=["*"],
             allow_methods=("GET", "POST", "OPTIONS"),
         )
     else:
         from ariadne.wsgi import GraphQL
 
-        application = GraphQL(schema)
+        application = GraphQL(
+            schema, debug=graphql_cfg["debug"], error_formatter=format_error
+        )
     return application
diff --git a/swh/graphql/tests/functional/test_content.py b/swh/graphql/tests/functional/test_content.py
--- a/swh/graphql/tests/functional/test_content.py
+++ b/swh/graphql/tests/functional/test_content.py
@@ -117,7 +117,7 @@
     )
     # API will throw an error in case of an invalid content hash
     assert len(errors) == 1
-    assert "Invalid content checksum" in errors[0]["message"]
+    assert "Input error: Invalid content checksum" in errors[0]["message"]
 
 
 def test_get_content_as_target(client):
diff --git a/swh/graphql/tests/functional/utils.py b/swh/graphql/tests/functional/utils.py
--- a/swh/graphql/tests/functional/utils.py
+++ b/swh/graphql/tests/functional/utils.py
@@ -22,7 +22,7 @@
     data, errors = get_query_response(client, query_str)
     assert data[obj_type] is None
     assert len(errors) == 1
-    assert errors[0]["message"] == "Requested object is not available"
+    assert errors[0]["message"] == "Object error: Requested object is not available"
 
 
 def get_error_response(client, query_str: str, error_code: int = 400) -> Dict: