ASGI Ref

3.11.1 · active · verified Sat Apr 11

ASGI specification and utilities, version 3.11.1, released on a regular cadence. Provides ASGI specs, helper code, and adapters for Python applications.

Common errors

```
ERROR: Invalid requirement: 'asgiref 3.5.2'
```
cause The requirements.txt file contains an invalid format with extra spaces between the package name and version number.

fix Ensure there are no extra spaces in the requirements.txt file; use 'asgiref==3.5.2' instead of 'asgiref 3.5.2'.
```
ModuleNotFoundError: No module named 'asgiref.base_layer'
```
cause The 'asgi_redis' package depends on an outdated version of 'asgiref' that no longer includes 'base_layer'.

fix Replace 'asgi_redis' with 'channels_redis', which is compatible with newer versions of 'asgiref'.
```
ImportError: cannot import name 'ThreadSensitiveContext' from 'asgiref.sync'
```
cause The 'ThreadSensitiveContext' class has been removed in newer versions of 'asgiref'.

fix Update the code to remove references to 'ThreadSensitiveContext' and use alternative approaches for thread-sensitive operations.
```
ModuleNotFoundError: No module named 'asgiref.sync'
```
cause The 'asgiref' package is either not installed or not properly included in the project.

fix Install 'asgiref' using 'pip install asgiref' and ensure it's included in your project's dependencies.
```
ERROR: Cannot install -r requirements.txt (line 8) and asgiref==3.2.5 because these package versions have conflicting dependencies.
```
cause The specified version of 'asgiref' conflicts with the version required by Django.

fix Remove the specific version constraint for 'asgiref' in 'requirements.txt' to allow compatibility with Django's required version.

Warnings

breaking Import paths have changed in asgiref 3.11.1; ensure correct imports to avoid ImportError.
Fix: Update import statements to reflect the new module structure.
gotcha Using AsyncToSync without proper context can lead to deadlocks; ensure it's used within an appropriate event loop.
Fix: Use AsyncToSync within an event loop or ensure it's called from an asynchronous context.
breaking The 'channels' package is not found. Ensure it is installed in the environment.
Fix: Install the 'channels' package using pip: `pip install channels`.
breaking The 'channels' module is not found. Ensure it is installed in your environment.
Fix: Install the 'channels' package using pip: `pip install channels`.

Install

pip install asgiref Install asgiref

Imports

ASGIApp
```
from asgiref.typing import ASGIApp
```
Importing ASGIApp from asgiref.typing is the correct approach.
AsyncToSync
```
from asgiref.sync import AsyncToSync
```
AsyncToSync is used to call asynchronous code from synchronous code.

Quickstart

A basic ASGI application setup using asgiref and Channels, including routing and middleware.

import os
from asgiref.sync import AsyncToSync
from channels.routing import ProtocolTypeRouter, URLRouter
from channels.auth import AuthMiddlewareStack
from django.urls import path

os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'your_project.settings')

application = ProtocolTypeRouter({
    'http': get_asgi_application(),
    'websocket': AuthMiddlewareStack(
        URLRouter([
            path('ws/some_path/', your_consumer.as_asgi()),
        ])
    ),
})

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