Request

See API docs: sanic.request

The sanic.request.Request instance contains a lot of helpful information available on its parameters. Refer to the API documentation for full details.

As we saw in the section on handlers, the first argument in a route handler is usually the sanic.request.Request object. Because Sanic is an async framework, the handler will run inside of a asyncio.Task and will be scheduled by the event loop. This means that the handler will be executed in an isolated context and the request object will be unique to that handler's task.

@app.get("/foo")
async def typical_use_case(request):
    return text("I said foo!")

@app.get("/foo")
async def atypical_use_case(req):
    return text("I said foo!")

from sanic.request import Request
from sanic.response import text

@app.get("/typed")
async def typed_handler(request: Request):
    return text("Done.")

Body#

The Request object allows you to access the content of the request body in a few different ways.

JSON#

$ curl localhost:8000 -d '{"foo": "bar"}'

>>> print(request.json)
{'foo': 'bar'}

Raw#

$ curl localhost:8000 -d '{"foo": "bar"}'

>>> print(request.body)
b'{"foo": "bar"}'

Form#

$ curl localhost:8000 -d 'foo=bar'

>>> print(request.body)
b'foo=bar'

>>> print(request.form)
{'foo': ['bar']}

>>> print(request.form.get("foo"))
bar

>>> print(request.form.getlist("foo"))
['bar']

Uploaded#

$ curl -F 'my_file=@/path/to/TEST' http://localhost:8000

>>> print(request.body)
b'--------------------------cb566ad845ad02d3\r\nContent-Disposition: form-data; name="my_file"; filename="TEST"\r\nContent-Type: application/octet-stream\r\n\r\nhello\n\r\n--------------------------cb566ad845ad02d3--\r\n'

>>> print(request.files)
{'my_file': [File(type='application/octet-stream', body=b'hello\n', name='TEST')]}

>>> print(request.files.get("my_file"))
File(type='application/octet-stream', body=b'hello\n', name='TEST')

>>> print(request.files.getlist("my_file"))
[File(type='application/octet-stream', body=b'hello\n', name='TEST')]

Context#

Request context#

The request.ctx object is your playground to store whatever information you need to about the request. This lives only for the duration of the request and is unique to the request.

This can be constrasted with the app.ctx object which is shared across all requests. Be careful not to confuse them!

The request.ctx object by default is a SimpleNamespace object allowing you to set arbitrary attributes on it. Sanic will not use this object for anything, so you are free to use it however you want without worrying about name clashes.

Typical use case#

This is often used to store items like authenticated user details. We will get more into middleware later, but here is a simple example.

@app.on_request
async def run_before_handler(request):
    request.ctx.user = await fetch_user_by_token(request.token)

@app.route('/hi')
async def hi_my_name_is(request):
    if not request.ctx.user:
        return text("Hmm... I don't know you)
    return text(f"Hi, my name is {request.ctx.user.name}")

As you can see, the request.ctx object is a great place to store information that you need to access in multiple handlers making your code more DRY and easier to maintain. But, as we will learn in the middleware section, you can also use it to store information from one middleware that will be used in another.

Connection context#

@app.on_request
async def increment_foo(request):
    if not hasattr(request.conn_info.ctx, "foo"):
        request.conn_info.ctx.foo = 0
    request.conn_info.ctx.foo += 1

@app.get("/")
async def count_foo(request):
    return text(f"request.conn_info.ctx.foo={request.conn_info.ctx.foo}")

$ curl localhost:8000 localhost:8000 localhost:8000
request.conn_info.ctx.foo=1
request.conn_info.ctx.foo=2
request.conn_info.ctx.foo=3

Custom Request Objects#

As dicussed in application customization, you can create a subclass of sanic.request.Request to add additional functionality to the request object. This is useful for adding additional attributes or methods that are specific to your application.

from sanic import Sanic, Request

class CustomRequest(Request):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.user_id = self.headers.get("X-User-ID")

app = Sanic("Example", request_class=CustomRequest)

@app.route("/")
async def handler(request: CustomRequest):
    return text(f"User ID: {request.user_id}")

Custom Request Context#

By default, the request context (request.ctx) is a Simplenamespace object allowing you to set arbitrary attributes on it. While this is super helpful to reuse logic across your application, it can be difficult in the development experience since the IDE will not know what attributes are available.

To help with this, you can create a custom request context object that will be used instead of the default SimpleNamespace. This allows you to add type hints to the context object and have them be available in your IDE.

from sanic import Sanic, Request
from types import SimpleNamespace

class CustomRequest(Request):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.ctx.user_id = self.headers.get("X-User-ID")

    @staticmethod
    def make_context() -> CustomContext:
        return CustomContext()

@dataclass
class CustomContext:
    user_id: str = None

Added in v23.6

Parameters#

@app.route('/tag/<tag>')
async def tag_handler(request, tag):
    return text("Tag - {}".format(tag))

# or, explicitly as keyword arguments
@app.route('/tag/<tag>')
async def tag_handler(request, *, tag):
    return text("Tag - {}".format(tag))

Arguments#

There are two attributes on the request instance to get query parameters:

• request.args
• request.query_args

These allow you to access the query parameters from the request path (the part after the ? in the URL).

Typical use case#

In most use cases, you will want to use the request.args object to access the query parameters. This will be the parsed query string as a dictionary.

This is by far the most common pattern.

@app.get("/search")
async def search(request):
   query = request.args.get("q")
    if not query:
        return text("No query string provided")
    return text(f"Searching for: {query}")

Parsing the query string#

Sometimes, however, you may want to access the query string as a raw string or as a list of tuples. For this, you can use the request.query_string and request.query_args attributes.

It also should be noted that HTTP allows multiple values for a single key. Although request.args may seem like a regular dictionary, it is actually a special type that allows for multiple values for a single key. You can access this by using the request.args.getlist() method.

• request.query_string - The raw query string
• request.query_args - The parsed query string as a list of tuples
• request.args - The parsed query string as a special dictionary
  • request.args.get() - Get the first value for a key (behaves like a regular dictionary)
  • request.args.getlist() - Get all values for a key

curl "http://localhost:8000?key1=val1&key2=val2&key1=val3"

>>> print(request.args)
{'key1': ['val1', 'val3'], 'key2': ['val2']}

>>> print(request.args.get("key1"))
val1

>>> print(request.args.getlist("key1"))
['val1', 'val3']

>>> print(request.query_args)
[('key1', 'val1'), ('key2', 'val2'), ('key1', 'val3')]

>>> print(request.query_string)
key1=val1&key2=val2&key1=val3

Current request getter#

Sometimes you may find that you need access to the current request in your application in a location where it is not accessible. A typical example might be in a logging format. You can use Request.get_current() to fetch the current request (if any).

Remember, the request object is confined to the single asyncio.Task that is running the handler. If you are not in that task, there is no request object.

import logging

from sanic import Request, Sanic, json
from sanic.exceptions import SanicException
from sanic.log import LOGGING_CONFIG_DEFAULTS

LOGGING_FORMAT = (
    "%(asctime)s - (%(name)s)[%(levelname)s][%(host)s]: "
    "%(request_id)s %(request)s %(message)s %(status)d %(byte)d"
)

old_factory = logging.getLogRecordFactory()

def record_factory(*args, **kwargs):
    record = old_factory(*args, **kwargs)
    record.request_id = ""

    try:
        request = Request.get_current()
    except SanicException:
        ...
    else:
        record.request_id = str(request.id)

    return record

logging.setLogRecordFactory(record_factory)


LOGGING_CONFIG_DEFAULTS["formatters"]["access"]["format"] = LOGGING_FORMAT
app = Sanic("Example", log_config=LOGGING_CONFIG_DEFAULTS)

In this example, we are adding the request.id to every access log message.

Added in v22.6