DOC: Max Tokens Vs. Max Completions Tokens Not Clear In ChatOpenAI
Issue with Current Documentation
The way that Max Tokens and Max Completion Tokens are documented within the ChatOpenAI class has been causing confusion among developers. In the dropdown over the class header, max_tokens is shown as the example way to instantiate the ChatOpenAI class. However, in the parameters for that class, there is only max_completion_tokens. Furthermore, anytime you use max_tokens, it gets popped and the value is written to max_completion_tokens. This has led to issues in understanding the correct usage of these parameters.
Understanding the Issue
The issue lies in the fact that OpenAI is trying to phase out the use of max_tokens in favor of max_completion_tokens. However, max_tokens is still accepted as a parameter for non-reasoning models. This has caused confusion among developers, as both parameters are used in different parts of the documentation. At my work, we were only handling max_tokens as an acceptable parameter for GPT-4 calls and discovered that max_tokens was getting overwritten and not passed through. This was due to the fact that we were not supporting the new parameter, max_completion_tokens.
The Problem with the Current Documentation
The current documentation suggests that both max_tokens and max_completion_tokens are used as separate parameters. However, this is not the case. The ChatOpenAI class is not handling them as two separate parameters, but instead as one, only max_completion_tokens. This has led to confusion among developers, as they are not aware that max_tokens is being overwritten and not passed through.
Proposed Solution
To resolve this issue, more documentation could be made to explain that:
- max_tokens is deprecated via OpenAI and is being overwritten in favor of max_completion_tokens
- Langchain's implementation is not handling them as two separate parameters but instead as one (only max_completion_tokens)
- Changes to the recommended example instantiation process to use max_completion_tokens instead of max_tokens to avoid further confusion
Alternatively, changes could be made to still allow max_tokens as a parameter to support legacy systems. This would ensure that developers who are using the older version of the API can continue to use max_tokens without any issues.
Conclusion
The issue with the current documentation of max_tokens and max_completion_tokens in the ChatOpenAI class has been causing confusion among developers. To resolve this issue, more documentation is needed to explain the correct usage of these parameters. This would ensure that developers can use the API correctly and avoid any issues that may arise from the use of max_tokens.
Recommendations
- Update the documentation to reflect the correct usage of max_tokens and max_completion_tokens
- Change the recommended example instantiation process to use max_completion_tokens instead of max_tokens
- Consider allowing max_tokens as a parameter to support legacy systems
Future Development
In the future, it would be beneficial to update the ChatOpenAI class to handle max_tokens and max_completion_tokens as two separate parameters. This would ensure that developers can use the API correctly and avoid any issues that may arise from the use of max_tokens.
Additional Resources
Conclusion
Frequently Asked Questions
Q: What is the difference between max_tokens and max_completion_tokens?
A: max_tokens and max_completion_tokens are two parameters used in the ChatOpenAI class to limit the number of tokens in a response. However, max_tokens is deprecated via OpenAI and is being overwritten in favor of max_completion_tokens.
Q: Why is max_tokens being overwritten?
A: max_tokens is being overwritten because OpenAI is trying to phase out its use in favor of max_completion_tokens. However, max_tokens is still accepted as a parameter for non-reasoning models.
Q: What is the recommended way to instantiate the ChatOpenAI class?
A: The recommended way to instantiate the ChatOpenAI class is to use max_completion_tokens instead of max_tokens. This is because max_completion_tokens is the parameter that is actually used by the API.
Q: Can I still use max_tokens as a parameter?
A: Yes, you can still use max_tokens as a parameter, but it will be overwritten by max_completion_tokens. This is because max_tokens is deprecated and is being phased out in favor of max_completion_tokens.
Q: Why is this causing confusion among developers?
A: This is causing confusion among developers because the documentation suggests that both max_tokens and max_completion_tokens are used as separate parameters. However, this is not the case, and max_tokens is being overwritten by max_completion_tokens.
Q: What can I do to avoid this issue?
A: To avoid this issue, you can update your code to use max_completion_tokens instead of max_tokens. This will ensure that you are using the correct parameter and avoid any issues that may arise from the use of max_tokens.
Q: What is the future of max_tokens?
A: The future of max_tokens is that it will be phased out in favor of max_completion_tokens. This means that max_tokens will no longer be accepted as a parameter, and max_completion_tokens will be the only parameter used by the API.
Q: What is the recommended way to handle legacy systems?
A: The recommended way to handle legacy systems is to continue to support max_tokens as a parameter. This will ensure that developers who are using the older version of the API can continue to use max_tokens without any issues.
Conclusion
The issue with the current documentation of max_tokens and max_completion_tokens in the ChatOpenAI class has been causing confusion among developers. To resolve this issue, more documentation is needed to explain the correct usage of these parameters. This would ensure that developers can use the API correctly and avoid any issues that may arise from the use of max_tokens.
Additional Resources
Conclusion
The issue with the current documentation of max_tokens and max_completion_tokens in the ChatOpenAI class has been causing confusion among developers. To resolve this issue, more documentation is needed to explain the correct usage of these parameters. This would ensure that developers can use the API correctly and avoid any issues that may arise from the use of max_tokens.