Adapter axes

z4j adapters are organized along three independent axes. They compose freely: any framework × any engine × any scheduler is supported.

Axis 1: Framework

A framework adapter knows how your process boots and how to read its settings.

Package	Covers
z4j-django	Django 4.2 - 5.x. Reads settings.Z4J. Uses app-config for agent lifecycle.
z4j-flask	Flask 2.x / 3.x. Z4J(app, config) factory-style init.
z4j-fastapi	FastAPI 0.10x+. Z4JAgent context manager in the lifespan.
z4j-bare	Any Python 3.11+ process. Direct Agent(...) usage. Foundation of all others.

All framework adapters delegate the actual agent runtime to z4j-bare.

Axis 2: Engine

An engine adapter knows how your queue enqueues, executes, and fails tasks.

Package	Engine	Native retry	Native cancel	Bulk retry	Schedule support
z4j-celery	Celery 5+	✓	partial	polyfill	celery-beat
z4j-rq	RQ 1.15+	✓	✓	polyfill	rq-scheduler
z4j-dramatiq	Dramatiq 1.15+	✓	no	polyfill	APScheduler
z4j-huey	Huey 2.5+	partial	partial	polyfill	huey-periodic
z4j-arq	arq 0.25+	polyfill	✓	polyfill	arq cron
z4j-taskiq	taskiq 0.11+	✓	✓	polyfill	taskiqscheduler

“polyfill” means: z4j implements the capability by re-enqueueing with the original payload and cancelling the original. The user sees one uniform button.

Axis 3: Scheduler

A scheduler adapter knows how to discover, create, update, and delete periodic tasks.

Package	Scheduler	Read	Write	Notes
z4j-celerybeat	celery-beat	✓	✓ (if django-celery-beat)	Filesystem beat is read-only
z4j-rqscheduler	rq-scheduler	✓	read-only	Writable UI not yet shipped
z4j-apscheduler	APScheduler 3	✓	✓	Works standalone or with Dramatiq
z4j-hueyperiodic	Huey periodic tasks	✓	read-only	Decorators are code; UI can’t add new ones
z4j-arqcron	arq cron jobs	✓	read-only	Same limitation, decorators in source
z4j-taskiqscheduler	taskiq-scheduler	✓	✓	Depends on backend (Redis / file)

Composing adapters

You install one framework + one or more engines + zero or more schedulers:

# Django + Celery + beat
pip install z4j-django z4j-celery z4j-celerybeat

# Flask + RQ + scheduler + Dramatiq + APScheduler (unusual but supported)
pip install z4j-flask z4j-rq z4j-rqscheduler z4j-dramatiq z4j-apscheduler

The framework adapter discovers the installed engines and schedulers via entry points; no wiring code.

Custom adapters

The adapter interface is internal and not currently documented for third-party authors. If you need a custom engine adapter, the existing packages (z4j-celery, z4j-rq, etc.) are the working reference implementations.

See the per-engine pages for the exact adapter surface of each.