Is the json override in airflow_local_settings.py still relevant?

[kyungjunleeme]

Hello. I’m wondering if this approach
https://airflow.apache.org/docs/apache-airflow/stable/administration-and-deployment/dag-serialization.html#using-a-different-json-library

is still relevant or useful in real-world Airflow deployments.

Why it might have limited value

1. Limited scope – This override only affects Airflow components that import json from airflow_local_settings. Many operators, hooks, and provider packages import Python’s built-in json module directly, so they wouldn’t be impacted.

2. Minimal performance gains – In most Airflow environments, performance bottlenecks are related to I/O (e.g., DB queries, network calls, XCom storage) rather than JSON parsing speed. Switching to something like ujson may not yield noticeable improvements.

3. Compatibility risks – Alternative libraries can behave differently (e.g., handling of datetime, Decimal, NaN), which might cause subtle bugs or inconsistencies, especially in XCom serialization.

Questions for the community

• Is this override mechanism still actively used or tested in Airflow core?
• Should we consider clarifying in the docs that it only affects a limited part of the codebase?
• Would it make sense to deprecate this recommendation in favor of patching JSON handling directly in custom hooks/operators if needed?

I’d love to hear thoughts from the community and maintainers.
If the consensus is that this is no longer valuable, perhaps we could update the docs to reflect that.

[potiuk]

I don't even know why it's there. IMHO we should remove it - maybe you could track the history of it by git history and you will find more explanations and you can ask the right person who did it and why - because I doubt there is even a general knowledge that this paragraph is there.

[kyungjunleeme]

I’ve looked into this and confirmed that this part is valid. Rather, I think it would be better to add an explanation in the documentation about where it can be used, so that users can understand it more easily.

• [AIRFLOW-5947] Make the json backend pluggable for DAG Serialization #6630
• https://github.com/penguinolog/sqlalchemy_jsonfield

[potiuk]

I’ve looked into this and confirmed that this part is valid. Rather, I think it would be better to add an explanation in the documentation about where it can be used, so that users can understand it more easily.

• [AIRFLOW-5947] Make the json backend pluggable for DAG Serialization #6630
• https://github.com/penguinolog/sqlalchemy_jsonfield

Sounds good :)