Add limited use token to functions

[AustinBenoit]

Description

Provide details of the change, and generalize the change in the PR title above.

Add limited use token to functions. Developers can now set http options to include limited use tokens

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Testing

Describe how you've tested these changes.

Added new integration test.

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Type of Change

Place an x the applicable box:

• Bug fix. Add the issue # below if applicable.
• New feature. A non-breaking change which adds functionality.
• Other, such as a build process or documentation change.

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[gemini-code-assist]

Code Review

This pull request introduces support for Limited Use App Check tokens in Firebase Functions by updating the reflection-based interop layer and adding a new HttpsCallableOptions class. The changes also include updates to the test application and CI scripts to verify the new functionality. Feedback was provided concerning a potential breaking change in the reflection initialization logic that could disable App Check for older SDKs, along with a suggestion to improve an incomplete error message.

[github-actions]

❌  Integration test FAILED

Requested by @firebase-workflow-trigger[bot] on commit be211d1
Last updated: Fri May 8 14:31 PDT 2026
View integration test log & download artifacts

Failures	Configs
/Users/runner/work/firebase-unity-sdk/firebase-unity-sdk/testapps/firebaseai/MacOSTestapp/testapp.app/Contents/MacOS/Firebase AI Unity Testapp	[TEST] [FAILURE] [2021] [1/2 Build OS(s): windows] [1/5 Platform(s): macOS] [1/2 Test Device(s): github_runner]
/home/runner/work/firebase-unity-sdk/firebase-unity-sdk/testapps/firebaseai/LinuxTestapp/testapp	[TEST] [FAILURE] [2021] [1/2 Build OS(s): windows] [1/5 Platform(s): Linux] [1/2 Test Device(s): github_runner]
/home/runner/work/firebase-unity-sdk/firebase-unity-sdk/testapps/iOS/firebaseai/FirebaseAIUnityTestapp.ipa	[TEST] [FAILURE] [2021] [1/2 Build OS(s): macos] [1/5 Platform(s): 14] [1/2 Test Device(s): iOS]
D:\a\firebase-unity-sdk\firebase-unity-sdk\testapps\Unity2021.3.43f1-NET4.6\FirebaseAI\testapp	[TEST] [FAILURE] [2021] [1/2 Build OS(s): windows] [1/5 Platform(s): Playmode] [1/2 Test Device(s): github_runner]
D:\a\firebase-unity-sdk\firebase-unity-sdk\testapps\firebaseai\WindowsTestapp\testapp.exe	[TEST] [FAILURE] [2021] [1/2 Build OS(s): windows] [1/5 Platform(s): Windows] [1/2 Test Device(s): github_runner]