Litestar
Strawberry comes with an integration for Litestar by
providing a make_graphql_controller
function that can be used to create a
GraphQL controller.
See the example below for integrating Litestar with Strawberry:
import strawberry
from litestar import Litestar
from strawberry.litestar import make_graphql_controller
@strawberry.type
class Query:
@strawberry.field
def hello(self) -> str:
return "Hello World"
schema = strawberry.Schema(Query)
GraphQLController = make_graphql_controller(
schema,
path="/graphql",
)
app = Litestar(route_handlers=[GraphQLController])
Options
The make_graphql_controller
function accepts the following options:
-
schema
: mandatory, the schema created bystrawberry.Schema
. -
path
: optional, defaults to “, the path where the GraphQL endpoint will be mounted. -
graphql_ide
: optional, defaults to"graphiql"
, allows to choose the GraphQL IDE interface (one ofgraphiql
,apollo-sandbox
orpathfinder
) or to disable it by passingNone
. -
allow_queries_via_get
: optional, defaults toTrue
, whether to enable queries viaGET
requests -
context_getter
: optional Litestar dependency for providing custom context value. -
root_value_getter
: optional Litestar dependency for providing custom root value. -
debug
: optional, defaults toFalse
, whether to enable debug mode. -
keep_alive
: optional, defaults toFalse
, whether to enable keep alive mode for websockets. -
keep_alive_interval
: optional, defaults to1
, the interval in seconds for keep alive messages. -
subscription_protocols
optional, defaults to(GRAPHQL_TRANSPORT_WS_PROTOCOL, GRAPHQL_WS_PROTOCOL)
, the allowed subscription protocols -
connection_init_wait_timeout
optional, default totimedelta(minutes=1)
, the maximum time to wait for the connection initialization message when usinggraphql-transport-ws
protocol -
multipart_uploads_enabled
: optional, defaults toFalse
, controls whether to enable multipart uploads. Please make sure to consider the security implications mentioned in the GraphQL Multipart Request Specification when enabling this feature.
context_getter
The context_getter
option allows you to provide a Litestar dependency that
return a custom context object that can be used in your resolver.
import strawberry
from litestar import Request, Litestar
from strawberry.litestar import make_graphql_controller
from strawberry.types.info import Info
async def custom_context_getter():
return {"custom": "context"}
@strawberry.type
class Query:
@strawberry.field
def hello(self, info: strawberry.Info[dict, None]) -> str:
return info.context["custom"]
schema = strawberry.Schema(Query)
GraphQLController = make_graphql_controller(
schema,
path="/graphql",
context_getter=custom_context_getter,
)
app = Litestar(route_handlers=[GraphQLController])
The context_getter
is a standard Litestar dependency and can receive any
existing dependency:
import strawberry
from litestar import Request, Litestar
from strawberry.litestar import make_graphql_controller
from strawberry.types.info import Info
from sqlalchemy.ext.asyncio import AsyncSession
from app.models import User
from sqlalchemy import select
async def custom_context_getter(request: Request, db_session: AsyncSession):
return {"user": request.user, "session": db_session}
@strawberry.type
class Query:
@strawberry.field
async def hello(self, info: strawberry.Info[dict, None]) -> str:
session: AsyncSession = info.context["session"]
user: User = info.context["user"]
query = select(User).where(User.id == user.id)
user = (await session.execute((query))).scalar_one()
return f"Hello {user.first_name}"
schema = strawberry.Schema(Query)
GraphQLController = make_graphql_controller(
schema,
path="/graphql",
context_getter=custom_context_getter,
)
app = Litestar(route_handlers=[GraphQLController])
You can also use a class-based custom context. To do this, you must inherit from
BaseContext
msgspec Struct or
an InvalidCustomContext
exception will be raised.
import strawberry
from litestar import Request, Litestar
from strawberry.litestar import make_graphql_controller, BaseContext
from strawberry.types.info import Info
from sqlalchemy.ext.asyncio import AsyncSession
from app.models import User
from sqlalchemy import select
class CustomContext(BaseContext):
user: User
session: AsyncSession
async def custom_context_getter(
request: Request, db_session: AsyncSession
) -> CustomContext:
return CustomContext(user=request.user, session=db_session)
@strawberry.type
class Query:
@strawberry.field
async def hello(self, info: strawberry.Info[CustomContext, None]) -> str:
session: AsyncSession = info.context.session
user: User = info.context.user
query = select(User).where(User.id == user.id)
user = (await session.execute((query))).scalar_one()
return f"Hello {user.first_name}"
schema = strawberry.Schema(Query)
GraphQLController = make_graphql_controller(
schema,
path="/graphql",
context_getter=custom_context_getter,
)
app = Litestar(route_handlers=[GraphQLController])
Context typing
In our previous example using class based context, the actual runtime context a
CustomContext
type. Because it inherits from BaseContext
, the request
,
socket
and response
attributes are typed as optional.
When inside a query/mutation resolver, request
and response
are always set
and socket
is only set in subscriptions.
To distinguish theses cases typing wise, the integration provides two classes that will help you to enforce strong typing:
from strawberry.litestar import HTTPContextType, WebSocketContextType
These classes does not actually exists at runtime, they are intended to be used
to define a custom Info
type with proper context typing. Taking over our
previous example with class based custom context, here it how we can define two
Info
types for both queries/mutations and subscriptions:
import strawberry
from typing import Any
from litestar import Request, Litestar
from litestar.datastructures import State
from strawberry.litestar import (
make_graphql_controller,
BaseContext,
HTTPContextType,
WebSocketContextType,
)
from strawberry.types.info import Info
from sqlalchemy.ext.asyncio import AsyncSession
from app.models import User
from sqlalchemy import select
class CustomContext(BaseContext, kw_only=True):
user: User
session: AsyncSession
class CustomHTTPContextType(HTTPContextType, CustomContext):
request: Request[User, Any, State]
class CustomWSContextType(WebSocketContextType, CustomContext):
socket: WebSocket[User, Token, State]
async def custom_context_getter(
request: Request, db_session: AsyncSession
) -> CustomContext:
return CustomContext(user=request.user, session=db_session)
@strawberry.type
class Query:
@strawberry.field
async def hello(self, info: strawberry.Info[CustomHTTPContextType, None]) -> str:
session: AsyncSession = info.context.session
user: User = info.context.user
query = select(User).where(User.id == user.id)
user = (await session.execute((query))).scalar_one()
return f"Hello {user.first_name}"
@strawberry.type
class Subscription:
@strawberry.subscription
async def count(
self, info: strawberry.Info[CustomWSContextType, None], target: int = 100
) -> AsyncGenerator[int, None]:
import devtools
devtools.debug(info.context)
devtools.debug(info.context.socket)
for i in range(target):
yield i
await asyncio.sleep(0.5)
schema = strawberry.Schema(Query, subscription=Subscription)
GraphQLController = make_graphql_controller(
schema,
path="/graphql",
context_getter=custom_context_getter,
)
app = Litestar(route_handlers=[GraphQLController])
root_value_getter
The root_value_getter
option allows you to provide a custom root value that
can be used in your resolver
import strawberry
from litestar import Request, Litestar
from strawberry.litestar import make_graphql_controller
@strawberry.type
class Query:
example: str = "Hello World"
@strawberry.field
def hello(self) -> str:
return self.example
def custom_get_root_value():
return Query()
schema = strawberry.Schema(Query)
GraphQLController = make_graphql_controller(
schema,
path="/graphql",
root_value_getter=custom_get_root_value,
)
app = Litestar(route_handlers=[GraphQLController])
Extending the controller
The base GraphQLController
class returned by make_graphql_controller
can be
extended by overriding any of the following methods:
-
async def process_result(self, request: Request, result: ExecutionResult) -> GraphQLHTTPResponse
-
def decode_json(self, data: Union[str, bytes]) -> object
-
def encode_json(self, data: object) -> str
-
async def render_graphql_ide(self, request: Request) -> Response
-
async def on_ws_connect(self, context: Context) -> Union[UnsetType, None, Dict[str, object]]
process_result
The process_result
option allows you to customize and/or process results
before they are sent to the clients. This can be useful for logging errors or
hiding them (for example to hide internal exceptions).
It needs to return a GraphQLHTTPResponse
object and accepts the request and
execution results.
import strawberry
from strawberry.http import GraphQLHTTPResponse
from strawberry.types import ExecutionResult
from strawberry.litestar import make_graphql_controller
from litestar import Request
@strawberry.type
class Query:
@strawberry.field
def hello(self) -> str:
return "world"
schema = strawberry.Schema(Query)
GraphQLController = make_graphql_controller(
schema,
path="/graphql",
)
class MyGraphQLController(GraphQLController):
async def process_result(
self, request: Request, result: ExecutionResult
) -> GraphQLHTTPResponse:
data: GraphQLHTTPResponse = {"data": result.data}
if result.errors:
data["errors"] = [err.formatted for err in result.errors]
return data
In this case we are doing the default processing of the result, but it can be tweaked based on your needs.
decode_json
decode_json
allows to customize the decoding of HTTP and WebSocket JSON
requests. By default we use json.loads
but you can override this method to use
a different decoder.
import strawberry
import orjson
from strawberry.litestar import make_graphql_controller
from typing import Union
@strawberry.type
class Query:
@strawberry.field
def hello(self) -> str:
return "world"
schema = strawberry.Schema(Query)
GraphQLController = make_graphql_controller(
schema,
path="/graphql",
)
class MyGraphQLController(GraphQLController):
def decode_json(self, data: Union[str, bytes]) -> object:
return orjson.loads(data)
Make sure your code raises json.JSONDecodeError
or a subclass of it if the
JSON cannot be decoded. The library shown in the example above, orjson
, does
this by default.
encode_json
encode_json
allows to customize the encoding of HTTP and WebSocket JSON
responses. By default we use json.dumps
but you can override this method to
use a different encoder.
import json
import strawberry
from strawberry.litestar import make_graphql_controller
@strawberry.type
class Query:
@strawberry.field
def hello(self) -> str:
return "world"
schema = strawberry.Schema(Query)
GraphQLController = make_graphql_controller(
schema,
path="/graphql",
)
class MyGraphQLController(GraphQLController):
def encode_json(self, data: object) -> bytes:
return json.dumps(data, indent=2)
render_graphql_ide
In case you need more control over the rendering of the GraphQL IDE than the
graphql_ide
option provides, you can override the render_graphql_ide
method.
import strawberry
from strawberry.litestar import make_graphql_controller
from litestar import MediaType, Request, Response
@strawberry.type
class Query:
@strawberry.field
def hello(self) -> str:
return "world"
schema = strawberry.Schema(Query)
GraphQLController = make_graphql_controller(
schema,
path="/graphql",
)
class MyGraphQLController(GraphQLController):
async def render_graphql_ide(self, request: Request) -> Response:
custom_html = """<html><body><h1>Custom GraphQL IDE</h1></body></html>"""
return Response(custom_html, media_type=MediaType.HTML)
on_ws_connect
By overriding on_ws_connect
you can customize the behavior when a graphql-ws
or graphql-transport-ws
connection is established. This is particularly useful
for authentication and authorization. By default, all connections are accepted.
To manually accept a connection, return strawberry.UNSET
or a connection
acknowledgment payload. The acknowledgment payload will be sent to the client.
Note that the legacy protocol does not support None
/null
acknowledgment
payloads, while the new protocol does. Our implementation will treat
None
/null
payloads the same as strawberry.UNSET
in the context of the
legacy protocol.
To reject a connection, raise a ConnectionRejectionError
. You can optionally
provide a custom error payload that will be sent to the client when the legacy
GraphQL over WebSocket protocol is used.
import strawberry
from typing import Dict
from strawberry.exceptions import ConnectionRejectionError
from strawberry.litestar import make_graphql_controller
@strawberry.type
class Query:
@strawberry.field
def hello(self) -> str:
return "world"
schema = strawberry.Schema(Query)
GraphQLController = make_graphql_controller(
schema,
path="/graphql",
)
class MyGraphQLController(GraphQLController):
async def on_ws_connect(self, context: Dict[str, object]):
connection_params = context["connection_params"]
if not isinstance(connection_params, dict):
# Reject without a custom graphql-ws error payload
raise ConnectionRejectionError()
if connection_params.get("password") != "secret":
# Reject with a custom graphql-ws error payload
raise ConnectionRejectionError({"reason": "Invalid password"})
if username := connection_params.get("username"):
# Accept with a custom acknowledgment payload
return {"message": f"Hello, {username}!"}
# Accept without a acknowledgment payload
return await super().on_ws_connect(context)