Pydantic Type of validation context (Fix)

The Fix

pip install pydantic==2.7.2

Based on closed pydantic/pydantic issue #9411 · PR/commit linked

Production note: Most teams hit this during upgrades or environment changes. Roll out with a canary and smoke critical endpoints (health, OpenAPI/docs) before 100%.

Jump to Verify Open PR/Commit

@@ -327,7 +327,7 @@ def model_dump(
         include: IncEx = None,
         exclude: IncEx = None,
-        context: dict[str, Any] | None = None,
+        context: Any | None = None,
         by_alias: bool = False,

repro.py

from typing import Any

from pydantic import BaseModel, model_validator
from pydantic_core.core_schema import ValidationInfo


class Model(BaseModel):
    @model_validator(mode="after")
    def validator(self, info: ValidationInfo) -> Any:
        info.context  # this returns a object of type "Any | None"


Model.model_validate_json("{}", context={})  # type of context has to be "dict[str, Any] | None"

verify

Re-run the minimal reproduction on your broken version, then apply the fix and re-run.

fix.md

Option A — Upgrade to fixed release\npip install pydantic==2.7.2\nWhen NOT to use: Do not use this fix if your code relies on the previous dict type for context.\n\n

Why This Fix Works in Production

Trigger: Type of validation context
Mechanism: The type hint for the validation context was incorrectly set to dict[str, Any] instead of Any
Why the fix works: Fixed the type hint of the validation context to be Any | None instead of dict[str, Any] | None. (first fixed release: 2.7.2).

Production impact:

If left unfixed, the same config can fail only in production (env differences), causing startup failures or partial feature outages.

Why This Breaks in Prod

The type hint for the validation context was incorrectly set to dict[str, Any] instead of Any
Production symptom (often without a traceback): Type of validation context

Proof / Evidence

GitHub issue: #9411
Fix PR: https://github.com/pydantic/pydantic/pull/9508
First fixed release: 2.7.2
Reproduced locally: No (not executed)
Last verified: 2026-02-09
Confidence: 0.85
Did this fix it?: Yes (upstream fix exists)
Own content ratio: 0.58

Discussion

High-signal excerpts from the issue thread (symptoms, repros, edge-cases).

Jump to Sources Open on GitHub

“@sydney-runkle I have fixed the type hints in 9508 I agree with @mjog that Any is the correct type.”

@OhioDschungel6 · 2024-05-27 · source

“@OhioDschungel6, Indeed, looks like our type hints could be improved. Would you be interested in opening a PR to fix this issue? Thanks for bringing…”

@sydney-runkle · 2024-05-16 · source

“Can we keep ValidationInfo's type annotations for context instead of Model.model_validate[_json] please? I.e”

@mjog · 2024-05-26 · source

Failure Signature (Search String)

Type of validation context
This context is made available to validators via the ValidationInfo object.

Copy-friendly signature

signature.txt

Failure Signature
-----------------
Type of validation context
This context is made available to validators via the ValidationInfo object.

Error Message

Signature-only (no traceback captured)

error.txt

Error Message
-------------
Type of validation context
This context is made available to validators via the ValidationInfo object.

Minimal Reproduction

repro.py

from typing import Any

from pydantic import BaseModel, model_validator
from pydantic_core.core_schema import ValidationInfo


class Model(BaseModel):
    @model_validator(mode="after")
    def validator(self, info: ValidationInfo) -> Any:
        info.context  # this returns a object of type "Any | None"


Model.model_validate_json("{}", context={})  # type of context has to be "dict[str, Any] | None"

Environment

Pydantic: 2

What Broke

Type errors occurred when passing non-dict objects to validation functions.

Why It Broke

The type hint for the validation context was incorrectly set to dict[str, Any] instead of Any

Fix Options (Details)

Option A — Upgrade to fixed release Safe default (recommended)

pip install pydantic==2.7.2

When NOT to use: Do not use this fix if your code relies on the previous dict type for context.

Use when you can deploy the upstream fix. It is usually lower-risk than long-lived workarounds.

Fix reference: https://github.com/pydantic/pydantic/pull/9508

First fixed release: 2.7.2

Last verified: 2026-02-09. Validate in your environment.

When NOT to Use This Fix

Do not use this fix if your code relies on the previous dict type for context.

Verify Fix

verify

Re-run the minimal reproduction on your broken version, then apply the fix and re-run.

Did This Fix Work in Your Case?

Quick signal helps us prioritize which fixes to verify and improve.

Prevention

Add a CI check that diffs key outputs after upgrades (OpenAPI schema snapshots, JSON payload shapes, CLI output).
Upgrade behind a canary and run integration tests against the canary before 100% rollout.

Version Compatibility Table

Version	Status
2.7.2	Fixed

Related Issues

No related fixes found.

Cluster: pydantic:configuration-error Pydantic hub Pydantic best practices All hubs All clusters

Related clusters: Data consistency OpenAPI schema Serialization

Sources

We don’t republish the full GitHub discussion text. Use the links above for context.