'ImmutableMutableProxy' object cannot be converted to 'PyDict' with Pydantic v2

[clemlesne]

Describe the bug

Manipulating any Pydantic model type from a state raise a library error pydantic_core._pydantic_core.PydanticSerializationError: ... 'ImmutableMutableProxy' object cannot be converted to 'PyDict'.

To reproduce

• Define two Pydantic v2 models, A and B, B a child if the first
• Assign B to the app state as b: B = B()
• Execute TypeAdapter(A).dump_json(self.b)
• See the error

Expected behavior

Any manipulation of a Pydantic model inside the state work like it should out of the state.

Context

• Python version: v3.13
• Reflex version: v0.7.0
• Pydantic version: v2.10.6
• OS: Debian Bookworm
• Browser (Optional): n/a

[linear]

ENG-5452 'ImmutableMutableProxy' object cannot be converted to 'PyDict' with Pydantic v2

[adhami3310]

Reflex wraps the state arguments in proxies, you can get the inner value with __wrapped__.

TypeAdapter(A).dump_json(self.b.__wrapped__)

I'm not sure if we can provide a way to hook into pydantic serialization?

[clemlesne]

Maybe test in ImmutableMutableProxy.__dict__ method override the caller package and return the original response with super().__dict__ instead of the wrapper? Hacky and not a good practice, but it should work out of the box and kept simple.