Author a backend

"""A minimal fictional worker backend.

A backend is where tools run when they leave the request path — background,
scheduled, and distributed execution. It is a single strategy object with one
job: launch the task runtime that pulls work from the broker. The app core
depends only on the ``Backend`` ABC and stays backend-agnostic; a concrete
backend (celery, rq, arq) implements it and registers through the handle.

Propagating a config change across the fleet is NOT a backend concern — it is
the app's own internal worker bus. A backend-runtime process receives fleet ops
through that bus exactly like a serving HTTP worker, so a backend that registers
here requires the bus: set ``TAI_BUS_REDIS_URL`` (a placeholder host below), or
the boot rules refuse to start.

    # TAI_BUS_REDIS_URL=redis://redis.internal:6379/0
"""

from collections.abc import Sequence

from tai42_contract.app import tai42_app
from tai42_contract.backend import Backend


@tai42_app.backends.register_backend
class InlineBackend(Backend):
    async def launch(self, args: Sequence[str]) -> None:
        # Start the worker runtime that consumes the broker. An inline backend
        # has no separate runtime, so this returns immediately.
        return None

backend_module: your_package.backend