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>
The @client(merge=[context, ...]) decorator lets a mutation patch its
return value directly into the cached context bundle by matching the
mutation's Output type against each context-function's Output type
to identify the slot, then splicing server-side. Kernel runs
splice_slot on the response to apply locally — no refetch, no
invalidate-cascade.
Lands H14, H15, H16, M19, M20 from ISSUES.md.
Backends (Django + FastAPI):
_resolve_merges() in both executors walks @client(merge=...) targets,
resolves the per-context slot via types_match_for_merge, and emits
{context, slot, value, params?} entries on the response. Param
auto-scoping mirrors _resolve_invalidation's tier-1 logic.
Frontend kernel (mizan-base):
Response handler reads the merge[] array and applies splice_slot
for each entry — locates the cached context bundle by name+params,
overwrites the named slot with the new value, notifies subscribers.
Core (mizan-python):
@client decorator extended with merge= parameter. Schema export
threads merge metadata onto the OpenAPI x-mizan-functions entries.
Examples / fixtures:
fastapi-react-site harness exercises merge + Playwright spec covers
the end-to-end happy path (mutation → instant UI update without
network refetch). AFI fixture's rename_user function is the
canonical merge target.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Demonstration milestone. The substrate work earlier in the session
established that mizan-fastapi can dispatch RPC, bundle context
fetches, and emit invalidation envelopes via TestClient (in-process
ASGI). This commit closes the demonstration gap: a real FastAPI server
on port 8001 + a real React harness on port 5175 + Playwright in real
Chromium, exercising generated hooks.
What ships:
backends/mizan-fastapi/src/mizan_fastapi/cli.py — schema-export CLI:
- `python -m mizan_fastapi.cli <module>` imports the named module
(triggering @client decorations + register() side effects), then
prints the OpenAPI schema to stdout. Mirrors mizan-django's
`manage.py export_mizan_schema` so the codegen consumes either
backend the same subprocess way.
backends/mizan-django/generate/generator/lib/fetch.mjs — codegen now
dispatches on source.django vs source.fastapi. Refactored the
subprocess plumbing into a shared runSubprocess helper. The codegen
package is still named "mizan-django" by historical accident — it's
the framework-agnostic CLI now (a rename for later).
backends/mizan-fastapi/src/mizan_fastapi/executor.py — bug fix:
mizan_core's @client decorator normalizes auth=True to
meta['auth']='required'. The executor's match was only handling True,
not 'required', so any auth-required endpoint failed with
INTERNAL_ERROR. Now matches both. Caught when wiring up the FastAPI
example backend's whoami fixture; would have surfaced first time any
real FastAPI app used auth=True.
backends/mizan-fastapi/tests/test_dispatch.py — added AuthTests
covering the auth=True path so the bug fix has unit coverage. Suite
now 12/12.
examples/fastapi-react-site/ — parallel to examples/django-react-site/:
- backend/main.py: FastAPI app with 11 @client fixtures matching the
harness surface (echo, add, multiply, whoami, staff/superuser/
verified-only, notImplementedFn, buggyFn, permissionCheckFn,
current_user context). Drops Django-only stuff (forms, channels,
ws-whoami, session-bound JWT).
- harness/: vite proxy → FastAPI on 8001; generated api/ produced by
the codegen against fastapi.config.mjs.
- mizan.spec.ts: Playwright suite, 14 tests covering the same axes
as Django minus channel-chat.
- ContextCurrentUser fixture renders 'loading' until data arrives
rather than emitting <pre>null</pre> — fixes a race the Django
harness has too (just doesn't trip in practice).
Verified:
- mizan-fastapi unit: 12/12 (incl. new auth=True coverage)
- mizan-fastapi e2e: 14/14 (Playwright via real Chromium)
- mizan-core unit: 15/15
- mizan-django unit: 348 pass, 21 skip
- AFI conformance: 3/3
- mizan-django e2e: 14/15 (1 skip — channels, deferred)
What remains for FastAPI side:
- Dockerfile.test + docker-compose.test.yml so CI can run the e2e
in the same containerized way as the Django example.
- Makefile test-integration target for symmetry.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
