[fixfon]

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Type of change

• Bug fix (non-breaking change which fixes an issue)

Changes To Core Features:

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Description

_transform_event_arg drops non-field keys from a dict payload hinted as an rx.Model. It checked each key against hinted_args.__fields__, which Pydantic v2 deprecates, so every key of every event emitted a PydanticDeprecatedSince20 warning. It now reads hinted_args.model_fields once before filtering. The filtering behaviour is unchanged.

This touches a different call site than #7592, which covers reflex_base/utils/types.py. The two PRs don't overlap.

closes #7634

Verification

• New unit test test_transform_event_arg_model_drops_non_fields_without_deprecation. It asserts that no PydanticDeprecatedSince20 is emitted, that the field values are kept, and that the extra keys are dropped (model_extra is empty; rx.Model uses extra="allow", so the test fails if the filter is removed). The test fails on main and passes with this change.
• tests/units/reflex_base/event/processor/test_base_state_processor.py: 156 passed.
• ruff format --check, ruff check and codespell pass on the changed files.
• Not run: pyright, ty, biome, the integration tests and the full unit suite.

A towncrier news fragment is included (packages/reflex-base/news/+model-event-arg-fields.bugfix.md).

[greptile-apps]

Confidence Score: 5/5

[Low impact] The PR appears safe to merge.

Summary

Reads model_fields once when converting event arguments hinted as rx.Model, replacing deprecated __fields__ access.

• Model event arguments stop warning while extra keys are dropped.

No actionable issues found. Tests were not run during this review.

_{Reviews (1) · Last reviewed commit: "fix: read model_fields once when filteri..." · Reviewed by Greptile}

[cubic-dev-ai]

No issues found across 3 files

_{View guided diff | Re-trigger cubic}

[codspeed]

Merging this PR will degrade performance by 5.78%

1 warning

⚠️ 21 benchmarks are dominated by system calls

System calls cannot be simulated consistently and are left out of the measure. The reported value understates the real cost. Switch to the Walltime instrument to measure them.

Learn more about system calls

See affected benchmarks

❌ 1 regressed benchmark
✅ 147 untouched benchmarks

Warning

Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Benchmark	BASE	HEAD	Efficiency
❌	test_state_access[get_handler]	72.9 ms	77.4 ms	-5.78%

Tip

Investigate this regression by commenting @codspeedbot fix this regression on this PR, or directly use the CodSpeed MCP with your agent.

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_{Comparing fixfon:fix/7634-model-fields-event-arg (96e102c) with main (74bcd8b)}