reflex-dev/reflex v0.11.0a1 on GitHub

Breaking Changes

Browser storage vars (rx.Cookie, rx.LocalStorage, rx.SessionStorage) must be declared with a storage value as the default or with a storage type annotation. A default_factory on a storage var, or one returning a storage value, now fails at compile time instead of being silently ignored or treated as an ordinary var. (#7582)
In prod mode, when deploy_url is unset (now the default), the backend no longer sends CORS headers, so browsers cannot read cross-origin responses, and Socket.IO accepts same-origin connections only. With deploy_url set, only that origin is allowed. Previously any origin was allowed. Set cors_allowed_origins explicitly for other setups (["*"] restores the old behavior). (#7641)
A set or frozenset state var is now a SetVar rather than an ArrayVar, so it no longer type-checks as a sequence in frontend code: indexing, slicing, map, filter, join, reverse, +, *, the comparisons <, <=, > and >=, and contains with a field on it are deprecated. They still compile for now with a deprecation warning and will be removed in 1.0. Call .to_array() first:
```
State.tags[0]  # deprecated
State.tags.to_array()[0]
``` ([#7642](https://github.com/reflex-dev/reflex/issues/7642))
```
@rx.event now returns an EventHandler instead of the decorated function. A decorator stacked above @rx.event is deprecated: the method still runs and registers under its own name, with a deprecation warning, until 1.0; apply other decorators below @rx.event. @rx.event on a method of a class that is not a state keeps working when called through an instance, and on a staticmethod or classmethod leaves it unchanged; both warn and should be removed, and calling such a method through the class (Helper.compute(obj, 3)) is not supported. A module-level function decorated with @rx.event whose first parameter is not a state stays a plain function and warns; drop the decorator from plain helper functions. (#7673)
Remove the built-in starlette-admin dashboard. rx.AdminDash(...) now raises an error linking to the admin dashboard guide, which shows how to mount starlette-admin yourself with api_transformer. (#7739)

Deprecations

reflex.model.alembic_autogenerate, reflex.model.get_migration_history and reflex.model.format_revision, and the rx.Model.alembic_autogenerate and rx.Model.get_migration_history class methods, are deprecated and will be removed in 1.0.0. alembic_autogenerate now runs through the generated alembic/env.py and ignores its connection argument. Use alembic revision --autogenerate, alembic check and alembic history --indicate-current, or the matching reflex db commands, instead. (#7742)

Features

Add rx.client_state for client-only state. A named var (rx.client_state("", name="query")) is global: any component can read and write it, and the backend can push and retrieve it. An unnamed var is owned by the outermost page or @rx.memo that uses it, so each @rx.memo instance gets its own value and a page's values reset when it unmounts. Setting a var re-renders only the components that read it. .set takes a value, a FunctionVar, or a lambda (count.set(lambda v: v + 1)) and replaces .set_value, which is deprecated and will be removed in 1.0. rx._x.client_state remains available with a deprecation warning. (#6936)
Add rx.vars.SetVar for set[T] and frozenset[T] state vars and literals, with set operations (contains, union, intersection, issubset, ...) and to_array() for list operations and rx.foreach. Array operations used directly on a set var are deprecated. (#7642)
Add development-time detection for event handlers that block the asyncio event loop. (#7672)
Event handlers are awaitable: await State.handler(args) inside another event handler runs it right away on the same locked state and returns its result, so a handler may return a value to the backend code awaiting it (returned events still chain, a returned coroutine still raises, and return values are not sent to the frontend yet). @rx.event returns the EventHandler itself, and self.handler() keeps calling the plain method as before.
```
@rx.event
def add(self, amount: int) -> int:
    self.total += amount
    return self.total


@rx.event
async def add_twice(self, amount: int):
    first = await type(self).add(amount)
    yield rx.toast(f"total is now {await type(self).add(amount)}")
``` ([#7673](https://github.com/reflex-dev/reflex/issues/7673))
```
The db extra now installs aiosqlite, the async SQLite driver, so reflex[db] works with SQLAlchemy's async engine and sessions on the default SQLite database without a separate install. (#7679)
Add the experimental auto_memoize option (REFLEX_AUTO_MEMOIZE). Set auto_memoize=False together with react_compiler=True to let React Compiler memoize whole pages instead of Reflex's generated memo wrappers, which also shortens compilation. Disabling both options logs a warning. Components with lifecycle events or hooks of their own keep a wrapper, so on_mount and on_unmount still follow their rx.cond branch. (#7694)
reflex db init now runs alembic init and installs an alembic/env.py that loads the app and reads db_url from rxconfig.py, and reflex db migrate, makemigrations and status are thin wrappers over alembic upgrade head, alembic revision --autogenerate and alembic history --indicate-current. The alembic command line works on the same environment, so alembic downgrade -1 needs no extra setup, and alembic revision --autogenerate and alembic check evaluate the pages as reflex db makemigrations does, so a model that only a page imports is compared too. In apps initialized by an earlier release, the next reflex db command or migrate() call replaces the stock env.py with the current template, keeping the previous file as env.old and the existing revisions; migrate() logs a warning when it does so. (#7742)
reflex db init writes alembic/env.py from the template when the file is missing, so an env.py edited by hand can be replaced by moving it aside, and it no longer prints alembic's list of generated template files. (#7742)
Allow redis-py 8. Reflex's redis clients disable redis-py 8's new default socket timeout, as redis-py 7 had none; on Python 3.11 that timeout loses task cancellations and can hang shutdown. (#7757)

Bug Fixes

Preserve state changes made by foreground event handlers that raise or are cancelled when using Redis, including updates already yielded to the client before a superseding event, matching the other state managers. (#7412)
Fixed the redis state manager stalling a token's events until its lock expired after an event was cancelled (for example by supersedes) or failed, or after a lock release notification was lost. With REFLEX_OPLOCK_ENABLED, events queued on a lease no longer lose their updates when together they outlast the lock expiration, and events waiting on other instances are no longer passed over by the next lease. (#7534)
Make production frontend builds reproducible: exporting the same app twice now gives identical files, so a deploy no longer renames scripts that did not change. (#7564)
Backend workers now load rxconfig.py before they import the app, so state_auto_setters=True generates set_<var> setters in workers started with spawn (Windows, macOS, REFLEX_STRICT_HOT_RELOAD, REFLEX_BACKEND_START_METHOD=spawn). (#7590)
Match page routes case-insensitively on the backend, as React Router does on the frontend, so on_load events and router.page.path resolve for a URL like /About instead of falling back to the 404 page. (#7599)
After a hot reload in dev mode, cached vars restored by the disk or Redis state manager are recomputed with the new code instead of showing values from before the reload. State fields keep their values. (#7616)
Fixed a polling-transport stall where an event larger than REFLEX_SOCKET_MAX_HTTP_BUFFER_SIZE left the page unable to reconnect: the backend now reads the oversized request body before it rejects it, so the browser can reconnect. (#7621)
Apps passed to api_transformer now get ASGI lifespan events, so the lifespan (and on_startup/on_shutdown handlers) of a FastAPI or Starlette transformer run, and state the lifespan yields is available on request.state. Events are forwarded through callable transformers as the ASGI spec describes; apps you mount on a transformer yourself still get none. If you worked around this by also registering the transformer's lifespan with register_lifespan_task, or by finding the transformer through the starlette_app lifespan task argument, remove the workaround: the first now runs the lifespan twice, and starlette_app is now the Starlette app serving Reflex's own routes. (#7624)
Synced LocalStorage vars that share one storage name now update in the tab that writes, not only in other tabs. (#7637)
reflex run now stops the whole frontend process tree on SIGINT or SIGTERM, including a dev server left behind by npm run, a repeat right after the first signal no longer interrupts that cleanup, and a later Ctrl-C forces the exit when the cleanup is stuck. An exit the CLI asked for is no longer reported as a frontend failure. (#7650)
app.add_page(...) now raises BackendVarFormatError when title, description or image is a backend var such as State._title, instead of failing later at compile time with an unrelated error. (#7651)
reflex run --frontend-only and reflex run --backend-only no longer exit with "Cannot specify --backend-port/--frontend-port" when rxconfig.py sets frontend_port or backend_port. Only a port flag given on the command line for the side that does not run is an error. (#7693)
A background task whose async with on a state reached through get_state was cancelled, or failed while loading that state, no longer leaves the client's state locked, which hung every later event for that client and the server's shutdown. (#7738)
reflex db migrate, reflex db makemigrations and reflex db status now report that db_url is not configured in rxconfig.py instead of failing inside alembic, and exit with status 1 when there is no database to migrate or it is not initialized. (#7742)
The schema check that runs after reflex db migrate and at app startup now evaluates the pages first, so a model that only a page imports no longer triggers the "Detected database schema changes" warning. (#7742)
reflex db init and reflex db makemigrations now evaluate every page before comparing the models, so a model that a page imports lazily is no longer missed or dropped from the generated revision after a previous reflex run has written the stateful-pages marker. (#7742)
The Redis state manager now starts its lock subscriber on the event loop that serves the app, not the one running when the app is built. This fixes RuntimeError: ... attached to a different loop at backend shutdown, and the occasional Redis error deleting token failure, in AppHarness tests that use Playwright's sync API with Redis. (#7751)
Fix hooks of a component inside rx.foreach, such as on_mount, on_unmount, and hooks from add_hooks. A hook that used the loop variable crashed the page, and other hooks ran once for the whole list. Each item now runs its own hooks. A loop inside an @rx.memo function is not covered yet. (#7793)

Performance

Lazy bundled libraries now load only the modules required by each dynamic component instead of loading every registered optional library at once. (#7276)
The backend no longer wraps the app in an extra Starlette application to run lifespan tasks, which removes a routing layer from every request. As a result, calling the rx.App instance returns a plain ASGI app rather than a Starlette instance. (#7624)