LiteLLM Responses API Bug: Extra Body Field Not Sent

Hey guys! It looks like we've got a bug in the LiteLLM Responses API that's preventing the extra_body field from being sent correctly. Let's dive into the details and see what's going on.

What's the Deal?

So, the main issue here is that when you try to pass in the extra_body parameter in your LiteLLM responses call, it's not actually being sent to the API. This can be a real pain, especially when you need to customize your requests with additional configurations like caching or disabling certain features. In the following sections, we'll be diving deeper into the specifics, showcasing the trigger, root cause, and potential solutions to get you back on track.

Bug Trigger

Let's take a look at the code snippet that triggers this bug. This is where you can see how the extra_body parameter is being used, but isn't working as expected.

response = litellm.responses(
    api_base="xxxxxxxxx",
    api_key="xxxx",
    model="openai/xxxxxxxx",
    input=["xxxxxxxxx" ],
    extra_body={
        "caching": {"type": "enabled"},
        "thinking":{"type":"disabled"}
    }
)

In this example, the user is trying to pass in extra_body to configure caching and disable the "thinking" feature. The expectation is that these configurations should be applied when the request is sent to the LiteLLM API. However, due to the bug, these configurations are not being recognized, which can lead to unexpected behavior or performance issues. Understanding the trigger is the first step in diagnosing and fixing the problem, ensuring that your API calls behave as you intend.

Root Cause Analysis

After digging into the code, it turns out the bug lies within the async_response_api_handler function. Specifically, this function is responsible for handling asynchronous requests to the API, and it seems like it's not correctly processing the extra_body parameter. Let's take a closer look at the problematic code snippet:

https://github.com/BerriAI/litellm/blob/main/litellm/llms/custom_httpx/llm_http_handler.py#L2090

By examining the code around this line, we can see that the extra_body parameter is not being properly included in the request payload. This could be due to a variety of reasons, such as an incorrect assignment, a missing argument, or a logical error in the function's execution flow. Identifying the root cause is crucial for implementing an effective fix and preventing similar issues from occurring in the future. Once the exact cause is pinpointed, a targeted solution can be developed to ensure the extra_body parameter is correctly processed and sent with the API request.

Diving Deeper into the Bug

Understanding the Impact

Okay, so why is this bug such a big deal? Well, the extra_body parameter is your way of adding custom configurations to your API requests. Think of it as the secret sauce that lets you tweak things like caching, request timeouts, and other cool features. When this parameter isn't working, you lose a ton of flexibility and control over how your requests are handled. You might end up with inefficient caching, unexpected delays, or even features that you wanted disabled still running. In short, it's like trying to drive a car without being able to adjust the mirrors or the seat – you can still get from point A to point B, but it's not going to be a smooth ride. Let's get this fixed so you can get back to smooth sailing!

Reproducing the Issue

Alright, let's get our hands dirty and try to reproduce this bug ourselves. This is super important because it helps us confirm the issue and make sure our fix actually works. Grab the code snippet from the bug trigger section and plug it into your environment. Make sure you're on LiteLLM version v1.79.1, since that's where this bug is hanging out. Run the code and check if the extra_body configurations are being applied. If they're not, congrats, you've reproduced the bug! Now we can start thinking about how to squash it. Reproducing the bug gives us a solid foundation to test our solutions and ensure we're not just slapping a band-aid on the problem. It's all about being thorough and making sure we've got a fix that sticks.

Debugging the Code

Time to put on our detective hats and dive into the code! Grab your favorite debugger and let's step through the async_response_api_handler function. Pay close attention to how the extra_body parameter is being handled. Is it being passed correctly? Is it getting lost somewhere along the way? Use print statements or breakpoints to inspect the values of variables and see what's happening at each step. This can be a bit like untangling a messy ball of yarn, but stick with it. The more you poke around, the better you'll understand the code and the easier it'll be to spot the bug. Remember, every bug has a story, and debugging is how we uncover it. Let's get to the bottom of this!

Potential Solutions and Workarounds

Hotfix Time!

Okay, so we've found the bug, we understand why it's happening, and now it's time to brainstorm some solutions. One immediate workaround might be to try setting the caching and thinking configurations directly in the main body of the request, rather than using extra_body. This might not be ideal, but it could get you unblocked in the short term. For a more permanent fix, we'll need to dive into the async_response_api_handler function and figure out where the extra_body parameter is getting dropped. It could be a simple typo, a missing assignment, or a more complex logical error. The key is to trace the flow of the parameter and see where it goes astray. Once we've identified the exact spot, we can implement a targeted fix and get this bug squashed for good.

Community Contributions

This is where you guys come in! If you've got some ideas or even a potential fix, don't be shy – jump in and share your thoughts. Open-source projects like LiteLLM thrive on community contributions, and your insights can be super valuable. Maybe you've spotted something we missed, or maybe you've got a clever workaround that we haven't thought of. Whatever it is, let's hear it! You can contribute by submitting a pull request with your fix, or simply by sharing your ideas in the discussion forums. Together, we can make LiteLLM even better. So, what are you waiting for? Let's get those brains buzzing and solve this bug together!

Wrapping Up

Alright, we've taken a good look at this bug in the LiteLLM Responses API. We've seen how the extra_body field isn't being sent, we've explored the potential causes, and we've brainstormed some solutions. This is a classic example of how software development can be a bit of a rollercoaster, but with a little teamwork and some solid debugging skills, we can tackle any challenge. Remember, every bug we fix makes the software stronger and more reliable. So, let's keep up the great work, keep contributing, and keep making LiteLLM awesome! Thanks for joining me on this bug-hunting adventure, and I'll see you in the next one!