# Custom extensions

It is possible to create your own custom extensions.

Version 22.9 added the Extend.register method. This makes it extremely easy to add custom expensions to an application.

# Anatomy of an extension

All extensions must subclass Extension.

# Required

  • name: By convention, the name is an all-lowercase string
  • startup: A method that runs when the extension is added

# Optional

  • label: A method that returns additional information about the extension in the MOTD
  • included: A method that returns a boolean whether the extension should be enabled or not (could be used for example to check config state)

# Example

from sanic import Request, Sanic, json
from sanic_ext import Extend, Extension
app = Sanic(__name__)
app.config.MONITOR = True
class AutoMonitor(Extension):
    name = "automonitor"
    def startup(self, bootstrap) -> None:
        if self.included():
    async def monitor(request: Request):
        if request.route and request.route.ctx.monitor:
    async def ensure_monitor_set(app: Sanic):
        for route in app.router.routes:
            if not hasattr(route.ctx, "monitor"):
                route.ctx.monitor = False
    def label(self):
        has_monitor = [
            for route in self.app.router.routes
            if getattr(route.ctx, "monitor", None)
        return f"{len(has_monitor)} endpoint(s)"
    def included(self):
        return self.app.config.MONITOR
@app.get("/", ctx_monitor=True)
async def handler(request: Request):
    return json({"foo": "bar"})

# Extension preregistration

Extend.register simplifies the addition of custom extensions.

from sanic_ext import Extend, Extension
class MyCustomExtension(Extension):

Added in v22.9

MIT Licensed
Copyright © 2018-present Sanic Community Organization

~ Made with ❤️ and ☕️ ~