The IR called them react-message and django-message, so a FastAPI channel had to declare a DjangoMessage. They are client-message and server-message now, and the direction words hold wherever a channel is declared: Params / ClientMessage / ServerMessage, with mizan-core deriving <Pascal>Params and friends so no backend names a type itself. Django's ReactChannel and FastAPI's ReactChannel are both Channel. mizan-fastapi never registered a channels extension, so build_ir() emitted no channel at all and every payload type was invisible to codegen. It registers one now. RegistryExtension is an ABC requiring all(), which is what the IR reads — an extension that cannot enumerate its registrations no longer exists. The gate that should have caught the rename could not: tests/afi registered no channel because mizan-rust had no channel registry to register one in, so a five-package rename of the wire contract passed byte-parity without a channel byte crossing it. mizan-rust grows ChannelSlotKind, a CHANNELS slice, a #[mizan::channel] macro, and KDL emission whose wire_to_pascal matches Python's split; the AFI fixture now carries a channel with every slot and one with a single slot, so all three backends prove the contract byte for byte. MizanChannel held three Option<String> beside three has_*() predicates and unwrapped them with defaults; it holds an ordered slot vector, so an absent slot is absent rather than defaulted. The channels target emitted a React hooks file that a stage1-only consumer could not compile — react emits that now. The codegen's parity tests byte-compared emitted source against baselines without ever compiling it: they compile the generated crate and run its tests, import the generated Python package and call every method, and typecheck each TypeScript target against a consumer. Also fixed at source: app_visitor printed its import diagnostic to stdout, the stream export_mizan_ir writes KDL to, so a failed import silently corrupted the IR; the apps root was hardcoded to "apps"; _default_literal crashed build_ir on any non-JSON-serializable field default; Django and mizan-core derived Pascal names two different ways, disagreeing on every dotted channel name. ir.py builds a document and renders templates/ir/document.kdl.j2 rather than appending KDL strings with hand-tracked indentation, and named types resolve to a fixed point — a model reachable only through a union branch was referenced by a ref that no type block ever defined. The rest is the write-gate's own classifiers run over the standing tree: relative imports, silent swallows, Protocol contracts that should be ABCs, emitters hand-rendering target source, catch-all arms over closed enums, and comments narrating the project rather than the code. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
mizan-django
Django backend adapter for the Mizan protocol. One decorator on a server function. Typed React client generated. Invalidation automatic.
Install
uv add "mizan[channels]"
Setup
# settings.py
INSTALLED_APPS = ["mizan", "myapp", ...]
MIZAN_CACHE_SECRET = "..." # 32-byte HMAC signing key
MIZAN_CACHE_REDIS_URL = "redis://localhost:6379/0"
MIZAN_MWT_SECRET = "..." # MWT signing key (separate from cache + JWT)
# urls.py
from django.urls import include, path
urlpatterns = [
path("api/mizan/", include("mizan.urls")),
]
# asgi.py — for WebSocket / Channels support
from django.core.asgi import get_asgi_application
from mizan import wrap_asgi
application = wrap_asgi(get_asgi_application())
Define server functions
# myapp/clients.py
from mizan.client import client
from mizan.setup import register
from pydantic import BaseModel
class EchoOutput(BaseModel):
message: str
@client
def echo(request, text: str) -> EchoOutput:
return EchoOutput(message=text)
register(echo, "echo")
Auto-discover clients.py modules from each Django app:
# myapp/apps.py
from django.apps import AppConfig
class MyAppConfig(AppConfig):
name = "myapp"
def ready(self) -> None:
from mizan.setup import mizan_clients
mizan_clients("myapp") # imports myapp/clients.py — triggers @client side effects
@client parameters
@client # plain RPC function
@client(context="global") # singleton context — fetched once, SSR-hydrated
@client(context="user") # named context — fetched per provider mount
@client(affects="user") # mutation — invalidates the user context
@client(affects=user_profile) # mutation — invalidates a specific function
@client(websocket=True) # WebSocket transport (requires channels)
@client(auth=True) # requires authentication
@client(auth="staff") # requires is_staff
@client(auth="superuser") # requires is_superuser
@client(auth=lambda req: ...) # custom predicate
@client(route="/profile/<id>/") # view-path function (returns HttpResponse)
@client(rev=2) # cache revision (busts on bump)
Forms
Django Forms become server functions + typed React hooks with Zod validation:
from django import forms
from mizan.forms import mizanFormMixin, mizanFormMeta
class ContactForm(mizanFormMixin, forms.Form):
mizan = mizanFormMeta(name="contact", title="Contact Us", submit_label="Send")
name = forms.CharField()
email = forms.EmailField()
message = forms.CharField(widget=forms.Textarea)
def on_submit_success(self, request):
send_email(self.cleaned_data)
return {"sent": True}
Auto-registers contact.schema, contact.validate, contact.submit. Frontend
gets useContactForm().
Auth-provider forms (django-allauth login, signup, MFA, WebAuthn) live in the
dedicated mizan-allauth repository, built on this mixin.
Channels
WebSocket-native RPC via a flag flip:
from pydantic import BaseModel
from mizan.channels import ReactChannel
class ChatChannel(ReactChannel):
class Params(BaseModel):
room: str
class DjangoMessage(BaseModel):
text: str
user: str
def authorize(self, params):
return self.user.is_authenticated
def group(self, params):
return f"chat_{params.room}"
Frontend gets useChatChannel({ room }).
Generate the frontend
The codegen is the mizan-generate Rust binary (source at
protocol/mizan-codegen/; protocol/mizan-generate/ is a thin npm
launcher that dispatches to the platform binary). From your frontend
project, point a mizan.toml at the Django backend and run the CLI:
# frontend/mizan.toml
output = "src/api"
targets = ["react"]
[source.django]
manage_path = "../backend/manage.py"
command = ["uv", "run", "python"] # optional — defaults to ["python"]
[source.django.env]
PYTHONPATH = "../backend"
DJANGO_SETTINGS_MODULE = "myproject.settings"
mizan-generate --config mizan.toml
The codegen drives Django's management command (export_mizan_ir) under
the hood, parses the emitted KDL IR, then emits Stage 1 (typed
callXxx/fetchXxx over the runtime kernel) + Stage 2 (<MizanContext>
provider, per-context providers, use{Hook}() hooks) into src/api/.
// app.tsx
import { MizanContext } from "./api"
export default function App({ children }) {
return <MizanContext baseUrl="/api/mizan">{children}</MizanContext>
}
// any component
import { useEcho, useCurrentUser } from "./api"
const echo = useEcho()
echo.mutate({ text: "hi" }).then(r => console.log(r.message))
const user = useCurrentUser() // global context — auto-fetched, auto-refreshed on mutation
Running tests
uv sync --extra dev --extra channels
uv run pytest
Architecture
mizan-django is one of two reference backend adapters (the other is
backends/mizan-fastapi). Both implement the same Mizan protocol on top of
the shared cores/mizan-python core (@client, registry, MWT, HMAC cache
keys). See docs/AFI_ARCHITECTURE.md.