`omitempty` option of request struct will generate incorrect request when parameter is 0.

[ArthurAmes]

The 'omitempty' option of the request structs should be removed. This is because it generates an incorrect request when a parameter is 0. For example, a request with the temperate field set to '0' will actually return a response as if the field had been set to one. This is because the go JSON parser does not differentiate between a 0 value and no value for float32, so Openai will receive a request without a temperate field which then defaults to a temperature value of 1.

[sashabaranov]

Thank you for the issue! So, with omitempty we have:

• "Empty" (zero-valued) arguments are removed
• OpenAI's backend uses its default for omitted arguments
• Zeroing floats requires something like 1e-45 ≈ math.SmallestNonzeroFloat32

Without omitempty:

• Non-specified arguments are zero-valued and present in request json
• OpenAPI's backend does not apply its defaults (which may or may not be equal to zero-values)
• In case OpenAPI defaults ≠ zero-values, we may have a default request value which can be tuned

I would check whether OpenAPI defaults match Go's zero-values. In case they do I think it is best to remove omitempty.

[sashabaranov]

Looking at CompletionRequest in completion.go it seems that OpenAPI's default parameter values do not match Go's zero-values:

type CompletionRequest struct {
	Prompt    string `json:"prompt,omitempty"`
	MaxTokens int    `json:"max_tokens,omitempty"` // OpenAPI defaults to 16

	Temperature float32 `json:"temperature,omitempty"` // OpenAPI defaults to 1
	TopP        float32 `json:"top_p,omitempty"` // OpenAPI defaults to 1

	N int `json:"n,omitempty"` // OpenAPI defaults to 1

	LogProbs int `json:"logprobs,omitempty"`

	Model *string `json:"model,omitempty"`

	Echo bool     `json:"echo,omitempty"`
	Stop []string `json:"stop,omitempty"`

	PresencePenalty  float32 `json:"presence_penalty,omitempty"` // OpenAPI defaults to 0
	FrequencyPenalty float32 `json:"frequency_penalty,omitempty"` // OpenAPI defaults to 0
	BestOf           int     `json:"best_of,omitempty"` // OpenAPI defaults to 1
}

[ArthurAmes]

Perhaps it would be best to make a constructor function for the struct then? Or at least documenting the quirk. As of right now, calling the API with parameters generated from the playground will have (sometimes significantly) different results as calling the exact same parameters from a similar API in another language.

[sashabaranov]

It seems that playground's default parameters match API ones, except for max_tokens. Which parameters did you tune in order to get proper result?

[neilmadsen]

Hello,
Wanted to mention that I've just run into this problem as well.

If we don't want to get rid of the omitempty (because of different defaults), could we make the types for fields like Temperature a pointer (e.g. *float32)? That way, it will be omitted if you don't set it but it will be marshaled as 0 if you specifically set it to 0.

From reading about other people's usage of Temperature and TopP, it seems like the most common values for them are 1, 0.5, and 0. So 0 isn't an edge case. For now, I'm setting Temperature to a tiny amount to mimic 0, but that seems a little hacky.

[SentientRamen12]

Hi, just another idea to resolve this: when marshalling and unmarshalling, we can set default values other than 0 by building a custom 'UnmarshalJSON' for an Options struct type.

reference: https://eli.thegreenplace.net/2020/optional-json-fields-in-go/

[fussraider]

How do you like an option similar to how it is done in the SQL package from the GO standard library for nullable fields in the database? They just added a separate structure for such properties - NullString, NullFloat64 and etc. (example: https://cs.opensource.google/go/go/+/master:src/database/sql/sql.go;l=319).

If valid is false, then send the default value for the API - that is, 1, otherwise explicitly send the value from the corresponding property.

[SentientRamen12]

@fussraider that can also be done, we just need to make sure the marshalling and unmarshalling handles it cleanly.