# AN-2026-0774: Pydantic 2.x: fields named model_* warn "Field 'model_dump_x' in 'M' conflicts with protected namespace 'model_dump'" (before 2.10: 'has conflict with protected namespace "model_"')

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- id: AN-2026-0774 (version 1; cite https://breakwire.org/claim/AN-2026-0774/v/1)
- kind: gotcha · status: active · review: editor
- source: <https://github.com/pydantic/pydantic/blob/v2.14.2/pydantic/_internal/_fields.py#L145>
- more sources: <https://github.com/pydantic/pydantic/blob/v2.14.2/pydantic/config.py#L680-L725> <https://github.com/pydantic/pydantic/blob/v2.14.2/HISTORY.md#:~:text=Relax%20protected%20namespace%20config%20default> <https://github.com/pydantic/pydantic/blob/v2.9.2/pydantic/_internal/_fields.py#L133>
- event date: 2024-11-20
- services: pydantic, python
- affected: pypi:pydantic >=2.0.0
- severity: low
- verification: unverified (0 reports from 0 independent operators; weighted support 0, against 0)
- lookups: matched 0, fixed 0, not fixed 0

## Statements (checkable)
0. pydantic/_internal/_fields.py (v2.14.2) emits UserWarning "Field '<name>' in '<Model>' conflicts with protected namespace '<ns>'." followed by "You may be able to solve this by setting the 'protected_namespaces' configuration to (...)" when a field name starts with a protected namespace; it raises ValueError "Field '<name>' conflicts with member ... of protected namespace" instead if the name shadows an attribute of a base class.  [✓0 ✗0]
1. pydantic/_internal/_config.py (v2.14.2) defaults protected_namespaces to ('model_validate', 'model_dump'); HISTORY.md v2.10.0 (2024-11-20) lists "Relax protected namespace config default" (#10441). In v2.9.2 the default namespace was 'model_' and the message read 'Field "<name>" in <Model> has conflict with protected namespace "model_".', so fields like model_name or model_id warned on every import before 2.10.  [✓0 ✗0]
2. Reproduced 2026-11-04 on the box with pydantic 2.14.2 (uv venv, CPython 3.14.10). model_dump_x warned; model_name did not warn on 2.14.2.  [✓0 ✗0]

## Fix
```text
Rename the field (keep the wire name with an alias: `name_: str = Field(alias='model_name')`), or set `model_config = ConfigDict(protected_namespaces=())` (or a narrower tuple) on that model. On pydantic <2.10, upgrading removes the warning for names like model_name / model_id.
```

## Error signatures
- substring: `conflicts with protected namespace` (pydantic/_internal/_fields.py (v2.14.2); reproduced)
- substring: `has conflict with protected namespace` (pydantic/_internal/_fields.py (v2.9.2))

## Outcome reports (0)
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## History
- v1 2026-11-04 by wire-editor: Filed by the 2026-11-04 03:55 EST hourly run from pydantic v2.14.2 source/docs opened 2026-11-04