reflex-dev/reflex v0.9.11a1

on GitHub

Features

• Propagate a frontend traceparent into event spans, count websocket connections and message sizes, and wrap the ASGI app when the reflex-otel instrumentor is active. (#6227)

Bug Fixes

• A backend var whose name is annotated on a state now takes the default declared by a field() on a base class instead of silently becoming None, and an error raised by that field's default_factory surfaces instead of being swallowed. (#6812)
• State classes no longer resolve descriptors while being constructed, so a hybrid property's frontend var is no longer built against a half-built class. (#6812)
• Assigning to a state attribute backed by a property (including a hybrid_property) now runs its setter instead of raising SetUndefinedStateVarError. (#6812)
• Telemetry events are now collected under the submitting thread's registration context, so the background worker reuses the config the app already loaded instead of re-importing rxconfig.py (and mutating sys.path) off-thread. (#6960)
• Make reflex.testing importable without test-only dependencies and provide a testing extra for AppHarness. (#6974)
• Mutable proxies over dataclass state values now carry the wrapped type's __dataclass_params__ and __match_args__ on their class alongside __dataclass_fields__, so code that inspects a dataclass through the class — reading the frozen/eq flags or the positional field names after dataclasses.is_dataclass — no longer raises AttributeError on a proxied value. (#7014)
• AdminDash now works with starlette-admin 1.0, which renamed the SQLAlchemy Admin(engine=...) argument to session_provider. Both starlette-admin 0.x and 1.x are supported. (#7019)
• Compiling an app from several processes against one working directory — pytest-xdist workers, parallel builds, or containers sharing a bind mount — no longer aborts with FileNotFoundError or FileExistsError while linking a rx.asset(shared=True) file into assets/external/. A shared asset whose link already points at a different file is repointed at the asset rather than left alone. (#7039)
• reflex run --env prod and reflex export no longer fail with FileNotFoundError when frontend_path is set and route prerendering is disabled (REFLEX_SSR=false), and no longer fail on Windows with cannot instantiate 'PosixPath' whenever frontend_path is set. (#7044)
• Generate the frontend context module as utils/context.jsx so reflex run hot updates keep the state providers mounted; a stale utils/context.js is removed on the next compile. (#7071)

Performance

• Clear auto-memoization naming caches after compiling app. (#6947)
• New opt-in dev-server knobs: REFLEX_DEV_PROD_REACT=1 serves React's production build under the Vite dev server (navigation CPU on a large app 54 → 36 ms, prod build 24 ms; edits become a full reload since Fast Refresh needs dev React), and REFLEX_VITE_WARMUP_ROUTES=1 pre-transforms route modules at startup so the first visit to a page no longer waits on Vite (105–131 → 43–69 ms, or 20–32 ms with both). (#7021)
• Trimmed the framework overhead around every event handler: the state fast-paths its own bookkeeping attributes, foreground handler tasks start eagerly on Python 3.12+, the computed-var expiry check only looks at interval vars, route matching is memoized per path, and socket.io handlers run inline. About 28% less CPU per trivial event and 20% more events per second per worker under concurrent load. (#7025)
• Reduce CLI startup time by loading component and cloud command implementations only when invoked, and avoid frontend package reinstalls after backend-only config changes. (#7050)
• Avoid repeated PyPI requests by caching successful latest-version checks for 24 hours and throttling failed checks for one hour. (#7050)

Miscellaneous

• Allow wrapt 2.2 and 2.3. (#7019)