`QueryDepthLimiter`#

This extension adds a validator to limit the query depth of GraphQL operations.

Usage example:#

import strawberry
from strawberry.extensions import QueryDepthLimiter

schema = strawberry.Schema(
    Query,
    extensions=[
        QueryDepthLimiter(max_depth=10),
    ],
)

API reference:#

class QueryDepthLimiter(max_depth, ignore=None, callback=None):
    ...

`max_depth: int`#

The maximum allowed depth for any operation in a GraphQL document.

`ignore: Optional[List[IgnoreType]]`#

Stops recursive depth checking based on a field name. Either a string or regexp to match the name, or a function that returns a boolean.

`callback: Optional[Callable[[Dict[str, int]], None]`#

Called each time validation runs. Receives a dictionary which is a map of the depths for each operation.

More examples:#

Ignoring fields

import strawberry
from strawberry.extensions import QueryDepthLimiter

schema = strawberry.Schema(
    Query,
    extensions=[
        QueryDepthLimiter(max_depth=2, ignore=["user"]),
    ],
)

# This query fails
schema.execute(
    """
  query TooDeep {
    book {
      author {
        publishedBooks {
          title
        }
      }
    }
  }
"""
)

# This query succeeds because the `user` field is ignored
schema.execute(
    """
  query NotTooDeep {
    user {
      favouriteBooks {
        author {
          publishedBooks {
            title
          }
        }
      }
    }
  }
"""
)

Ignoring fields with regex

import re
import strawberry
from strawberry.extensions import QueryDepthLimiter

schema = strawberry.Schema(
    Query,
    extensions=[
        QueryDepthLimiter(max_depth=2, ignore=[re.compile(r".*favourite.*")]),
    ],
)

# This query succeeds because an field that contains `favourite` is ignored
schema.execute(
    """
  query NotTooDeep {
    user {
      favouriteBooks {
        author {
          publishedBooks {
            title
          }
        }
      }
    }
  }
"""
)

Ignoring fields with a function

import strawberry
from strawberry.extensions import QueryDepthLimiter

schema = strawberry.Schema(
    Query,
    extensions=[
        QueryDepthLimiter(
            max_depth=2, ignore=[lambda field_name: field_name == "user"]
        ),
    ],
)

schema.execute(
    """
  query NotTooDeep {
    user {
      favouriteBooks {
        author {
          publishedBooks {
            title
          }
        }
      }
    }
  }
"""
)

QueryDepthLimiter#