fix: resolve batch inference crash by handling non-serializable objects in GCS cache

[SalimMessaad1]

Problem: The batch inference process was crashing when trying to compute a cache hash for requests containing non-serializable objects, such as Enum (used in SafetySettings) or Dataclasses. This triggered a TypeError: Object of type ... is not JSON serializable during json.dumps.

Solution:

1. Added a private helper function _json_serializer to handle dataclasses and Enum types during JSON serialization.

2. Updated GCSBatchCache._compute_hash to use this serializer, ensuring stable and reliable hashing even with complex request configurations.

Impact: Prevents runtime crashes during batch processing and ensures caching works correctly with all Gemini model configurations.

Resolves #353

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[SalimMessaad1]

I've enabled maintainer edits. Please feel free to adjust the indentation or formatting to match the project's standards if needed. I'm also waiting for community support on issue #353 as per the guidelines

[Muitamax]

Solution: Use a default serializer
You can pass a default function to json.dumps that converts non-serializable objects to strings or dicts.
import json
from dataclasses import asdict, is_dataclass
from enum import Enum
def custom_serializer(obj):
if isinstance(obj, Enum):
return obj.value # Or str(obj)
if is_dataclass(obj):
return asdict(obj)
raise TypeError(f"Object of type {type(obj).name} is not JSON serializable")

hash_string = json.dumps(key_data, sort_keys=True, default=custom_serializer)
print(hash_string)

✅ Notes:
Enum → convert to .value or str(obj)
dataclass → convert to dictionary using asdict
sort_keys=True ensures stable hashing order
This way, GCSBatchCache._compute_hash will no longer crash.

[SalimMessaad1]

Hi @Muitamax, thank you so much for the review and for confirming the solution, I really appreciate the feedback and the approval.

Hi @aksg87, as mentioned above, the logic has been verified and approved by the community. This PR fixes a deterministic TypeError crash in the Batch API hashing process, which is critical for users with complex SafetySettings.

I would appreciate your final review as a maintainer to help move this towards a merge. I've enabled maintainer edits to facilitate any minor formatting adjustments needed for the CI. Thanks for your time and support

[Muitamax]

I am honoured to be of help.

…

On Wed, Feb 11, 2026 at 2:17 PM Salim Messaad ***@***.***> wrote: *SalimMessaad1* left a comment (google/langextract#352) <#352 (comment)> Hi @Muitamax <https://github.com/Muitamax>, thank you so much for the review and for confirming the solution, I really appreciate the feedback and the approval. Hi @aksg87 <https://github.com/aksg87>, as mentioned above, the logic has been verified and approved by the community. This PR fixes a deterministic TypeError crash in the Batch API hashing process, which is critical for users with complex SafetySettings. I would appreciate your final review as a maintainer to help move this towards a merge. I've enabled maintainer edits to facilitate any minor formatting adjustments needed for the CI. Thanks for your time and support — Reply to this email directly, view it on GitHub <#352 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/BP7B6IJ4CGVU42CKNQBLQYL4LMFWJAVCNFSM6AAAAACUVEVQYSVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTQOBTG44DMMRVGU> . You are receiving this because you were mentioned.Message ID: ***@***.***>

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