Python - topic.subscribe()

Subscribes to a topic.

from nitric.resources import topic
from nitric.application import Nitric
from nitric.context import EventContext

updates = topic("updates")

@updates.subscribe
async def updates_sub(ctx: EventContext):
  print(ctx.req.payload)

Nitric.run()

Parameters

Name
middleware
Required
Required
Type
Middleware
Description
The middleware (code) to be triggered by the topic.

Examples

from nitric.resources import topic
from nitric.application import Nitric
from nitric.context import EventContext

updates = topic("updates")

@updates.subscribe
async def updates_sub(ctx: EventContext):
  print(ctx.req.payload)

Nitric.run()

Notes

A function may only subscribe to a topic once, if multiple subscribers are required, create them in different services.
A function may subscribe to OR publish to a topic but not both. This is in place to stop services calling themselves infinitely.

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Last updated on May 9, 2025