[Fix] Callback Environment Variables Casing

[yuneng-jiang]

[Fix] Callback Environment Variables Casing

Relevant issues

Callback environment variables are stored as lower case in the DB, which is an issue because the server expects uppercase.
This leads to the following problematic workflow: User adds callback in the UI > env stored in DB as lowercase and saved to memory as lowercase > Testing the callback fails because the logger is trying to find the uppercase version of the env varaible.

Pre-Submission checklist

Please complete all items before asking a LiteLLM maintainer to review your PR

• I have Added testing in the tests/litellm/ directory, Adding at least 1 test is a hard requirement - see details
• I have added a screenshot of my new test passing locally
• My PR passes all unit tests on make test-unit
• My PR's scope is as isolated as possible, it only solves 1 specific problem

Type

🐛 Bug Fix
✅ Test

Changes

After Clicking Test Connection on the UI:

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Project	Deployment	Review	Updated (UTC)
litellm	Ready	Preview, Comment	Dec 13, 2025 2:07am