fix(iflow): add signed headers for chat requests

[redzrush101]

Summary

• Add iFlow signed headers (session-id, x-iflow-timestamp, x-iflow-signature) to match CLIProxyAPI request protocol.
• Build iFlow request headers via one helper and keep better context for empty upstream error bodies.
• Verified locally: the same iFlow credential now works and streams successfully in LLM-API-Key-Proxy curl tests.

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Important

Add iFlow signed headers for chat requests and improve error handling in iflow_provider.py.

• Headers:
  • Add iFlow signed headers (session-id, x-iflow-timestamp, x-iflow-signature) in iflow_provider.py to match CLIProxyAPI protocol.
  • Implement _create_iflow_signature() and _build_iflow_headers() to generate and include these headers.
• Error Handling:
  • Improve handling of empty upstream error bodies in stream_handler() in iflow_provider.py by logging content-type.
• Misc:
  • Change result.get("data", {}) to result.get("data") or {} in iflow_auth_base.py to handle None values.

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[mirrobot-agent]

I'm starting my review of the iFlow signed headers implementation. I'll be checking the signature logic and the new header construction to ensure it aligns with the protocol requirements.

[mirrobot-agent]

Overall Assessment

This PR successfully implements the signed header protocol for iFlow requests, bringing it in line with the CLIProxyAPI requirements. The addition of session tracking and HMAC signatures improves the robustness of the authentication layer. The code is well-structured, with header construction centralized and error handling improved for edge cases like empty response bodies.

Architectural Feedback

The centralization of header logic into _build_iflow_headers is a good architectural choice, making the chat_completion logic cleaner and easier to maintain.

Key Suggestions

• Signature Robustness: Consider adding explicit validation for the api_key before generating signatures to provide clearer error messages if authentication details are missing.
• Session ID Format: Verify if the session- prefix is strictly required by the upstream iFlow API.

Questions for the Author

• Can you confirm if the session- prefix in the session-id header is standard for all iFlow integrations or specific to this one?

This review was generated by an AI assistant.

[mirrobot-agent]

The _create_iflow_signature method returns an empty string if api_key is missing. While this prevents a crash, sending an empty signature to the upstream API will likely result in a 401/403 anyway. Consider adding a check or logging a warning if this occurs during a request.

[mirrobot-agent]

Is the session- prefix in f"session-{uuid.uuid4()}" a requirement of the iFlow protocol? Just want to ensure the upstream expects this specific format rather than a raw UUID.

[redzrush101]

I dont know I basically just copied what https://github.com/router-for-me/CLIProxyAPI does which is written in go which worked and this fixed the issue

[mirrobot-agent]

Using .get("data") or {} is a solid improvement over .get("data", {}). This pattern correctly handles cases where the API returns an explicit null (None in Python), which would otherwise cause downstream errors when trying to access keys on a None object.