weft-django 0.9.21

Django integration layer for Weft

weft-django

weft-django is the first-party Django integration for Weft.

The package is typed (py.typed) and depends on Weft through the public weft.client API.

It provides:

• @weft_task for Django-owned synchronous background functions
• transaction-safe submission helpers such as enqueue_on_commit()
• native TaskSpec, stored spec, and pipeline submission helpers
• read-only Django URLs for task inspection
• SSE by default, with optional Channels/WebSocket transport
• Django management commands for task status and control

Install:

uv add weft-django

Or from the main package convenience extra:

uv add "weft[django]"

Install the optional Channels transport with:

uv add "weft-django[channels]"

Equivalent install surfaces:

uv add "weft-django[realtime]"
uv add "weft[django-channels]"

Basic usage:

from weft_django import weft_task


@weft_task(name="billing.send_invoice", timeout=60)
def send_invoice(invoice_id: int) -> dict[str, int]:
    return {"invoice_id": invoice_id}


submission = send_invoice.enqueue(123)
result = submission.result(timeout=30)
assert result.status == "completed"

Submission Handle

enqueue(...) and the native submission helpers return WeftSubmission.

The handle exposes:

• tid
• name
• status()
• wait(timeout=None)
• result(timeout=None)
• stop()
• kill()
• events(follow=False)

status() returns the current public status string or None if no snapshot is available yet. wait() and result() both return the structured Weft TaskResult.

enqueue_on_commit(...) and the native *_on_commit(...) helpers return WeftDeferredSubmission. The deferred handle has a stable name immediately and gains tid plus task methods after the outer transaction commits. Calling result-like methods before commit raises a local RuntimeError.

Deferred helpers validate and snapshot before registering Django's transaction.on_commit() callback. Missing spec references, invalid overrides, and unserializable payloads fail before the app transaction commits. Mutating args, kwargs, or payload objects after helper call time does not change the work submitted at commit.

Native Helpers

Use these helpers when Django code wants to launch native Weft work instead of a decorated Django function:

from pathlib import Path

from weft_django import (
    submit_pipeline_reference,
    submit_spec_reference,
    submit_taskspec,
)


task = submit_taskspec(taskspec, payload={"job": 1})
task = submit_spec_reference(Path(".weft/tasks/report.json"), payload={"job": 1})
task = submit_pipeline_reference("nightly-report", payload={"job": 1})

Keyword rules:

• native helpers use payload=...
• work_payload=... and input=... are intentionally not supported
• deferred helpers reject wait=True

Testing

weft-django does not ship an eager or inline execution mode.

Use the direct Python callable for narrow unit tests:

assert send_invoice(123)["invoice_id"] == 123

Use broker-backed tests for enqueue behavior, transaction hooks, process boundaries, streaming, native TaskSpecs, bundles, agents, and pipelines.

Realtime And URLs

Include the read-only URLs explicitly:

from django.urls import include, path

urlpatterns = [
    path("weft/", include("weft_django.urls")),
]

You must configure an authz callable:

WEFT_DJANGO = {
    "AUTHZ": "myapp.weft_authz:authorize",
}

Supported realtime settings:

WEFT_DJANGO = {
    "REALTIME": {
        "TRANSPORT": "sse",  # "none" | "sse" | "channels"
    },
}

Notes:

• GET /weft/tasks/<tid>/ returns the current task snapshot
• GET /weft/tasks/<tid>/events/ is the SSE endpoint when TRANSPORT="sse"
• TRANSPORT="none" disables the SSE endpoint
• TRANSPORT="channels" switches browser realtime delivery to the optional WebSocket consumer in weft_django.channels
• the Channels consumer starts a cancellable background stream after socket accept rather than blocking the connect lifecycle
• the HTTP and realtime surfaces are diagnostics only; they do not create a second task-truth store

Celery Migration Guide

Celery habit	weft-django
@shared_task	@weft_task
task.delay(...)	task.enqueue(...)
transaction.on_commit(lambda: task.delay(...))	task.enqueue_on_commit(...)
AsyncResult	WeftSubmission

delay and shared_task are intentionally not shipped. They are close enough to invite mechanical porting and far enough from Weft semantics to create delayed failures.