docs: explanation about LogitBias. (129) (#426)

Author: vvatanabe

chat.go

@@ -52,10 +52,13 @@ type ChatCompletionRequest struct {
 	Stop             []string                `json:"stop,omitempty"`
 	PresencePenalty  float32                 `json:"presence_penalty,omitempty"`
 	FrequencyPenalty float32                 `json:"frequency_penalty,omitempty"`
-	LogitBias        map[string]int          `json:"logit_bias,omitempty"`
-	User             string                  `json:"user,omitempty"`
-	Functions        []FunctionDefinition    `json:"functions,omitempty"`
-	FunctionCall     any                     `json:"function_call,omitempty"`
+	// LogitBias is must be a token id string (specified by their token ID in the tokenizer), not a word string.
+	// incorrect: `"logit_bias":{"You": 6}`, correct: `"logit_bias":{"1639": 6}`
+	// refs: https://platform.openai.com/docs/api-reference/chat/create#chat/create-logit_bias
+	LogitBias    map[string]int       `json:"logit_bias,omitempty"`
+	User         string               `json:"user,omitempty"`
+	Functions    []FunctionDefinition `json:"functions,omitempty"`
+	FunctionCall any                  `json:"function_call,omitempty"`
 }
 
 type FunctionDefinition struct {

completion.go

@@ -109,22 +109,25 @@ func checkPromptType(prompt any) bool {
 
 // CompletionRequest represents a request structure for completion API.
 type CompletionRequest struct {
-	Model            string         `json:"model"`
-	Prompt           any            `json:"prompt,omitempty"`
-	Suffix           string         `json:"suffix,omitempty"`
-	MaxTokens        int            `json:"max_tokens,omitempty"`
-	Temperature      float32        `json:"temperature,omitempty"`
-	TopP             float32        `json:"top_p,omitempty"`
-	N                int            `json:"n,omitempty"`
-	Stream           bool           `json:"stream,omitempty"`
-	LogProbs         int            `json:"logprobs,omitempty"`
-	Echo             bool           `json:"echo,omitempty"`
-	Stop             []string       `json:"stop,omitempty"`
-	PresencePenalty  float32        `json:"presence_penalty,omitempty"`
-	FrequencyPenalty float32        `json:"frequency_penalty,omitempty"`
-	BestOf           int            `json:"best_of,omitempty"`
-	LogitBias        map[string]int `json:"logit_bias,omitempty"`
-	User             string         `json:"user,omitempty"`
+	Model            string   `json:"model"`
+	Prompt           any      `json:"prompt,omitempty"`
+	Suffix           string   `json:"suffix,omitempty"`
+	MaxTokens        int      `json:"max_tokens,omitempty"`
+	Temperature      float32  `json:"temperature,omitempty"`
+	TopP             float32  `json:"top_p,omitempty"`
+	N                int      `json:"n,omitempty"`
+	Stream           bool     `json:"stream,omitempty"`
+	LogProbs         int      `json:"logprobs,omitempty"`
+	Echo             bool     `json:"echo,omitempty"`
+	Stop             []string `json:"stop,omitempty"`
+	PresencePenalty  float32  `json:"presence_penalty,omitempty"`
+	FrequencyPenalty float32  `json:"frequency_penalty,omitempty"`
+	BestOf           int      `json:"best_of,omitempty"`
+	// LogitBias is must be a token id string (specified by their token ID in the tokenizer), not a word string.
+	// incorrect: `"logit_bias":{"You": 6}`, correct: `"logit_bias":{"1639": 6}`
+	// refs: https://platform.openai.com/docs/api-reference/completions/create#completions/create-logit_bias
+	LogitBias map[string]int `json:"logit_bias,omitempty"`
+	User      string         `json:"user,omitempty"`
 }
 
 // CompletionChoice represents one of possible completions.