feat: API `/models` & `/models/:model` implemented (close #68)

controller/model.go

+package controller
+
+import (
+	"fmt"
+	"github.com/gin-gonic/gin"
+)
+
+// https://platform.openai.com/docs/api-reference/models/list
+
+type OpenAIModelPermission struct {
+	Id                 string  `json:"id"`
+	Object             string  `json:"object"`
+	Created            int     `json:"created"`
+	AllowCreateEngine  bool    `json:"allow_create_engine"`
+	AllowSampling      bool    `json:"allow_sampling"`
+	AllowLogprobs      bool    `json:"allow_logprobs"`
+	AllowSearchIndices bool    `json:"allow_search_indices"`
+	AllowView          bool    `json:"allow_view"`
+	AllowFineTuning    bool    `json:"allow_fine_tuning"`
+	Organization       string  `json:"organization"`
+	Group              *string `json:"group"`
+	IsBlocking         bool    `json:"is_blocking"`
+}
+
+type OpenAIModels struct {
+	Id         string                `json:"id"`
+	Object     string                `json:"object"`
+	Created    int                   `json:"created"`
+	OwnedBy    string                `json:"owned_by"`
+	Permission OpenAIModelPermission `json:"permission"`
+	Root       string                `json:"root"`
+	Parent     *string               `json:"parent"`
+}
+
+var openAIModels []OpenAIModels
+var openAIModelsMap map[string]OpenAIModels
+
+func init() {
+	permission := OpenAIModelPermission{
+		Id:                 "modelperm-LwHkVFn8AcMItP432fKKDIKJ",
+		Object:             "model_permission",
+		Created:            1626777600,
+		AllowCreateEngine:  true,
+		AllowSampling:      true,
+		AllowLogprobs:      true,
+		AllowSearchIndices: false,
+		AllowView:          true,
+		AllowFineTuning:    false,
+		Organization:       "*",
+		Group:              nil,
+		IsBlocking:         false,
+	}
+	// https://platform.openai.com/docs/models/model-endpoint-compatibility
+	openAIModels = []OpenAIModels{
+		{
+			Id:         "gpt-3.5-turbo",
+			Object:     "model",
+			Created:    1677649963,
+			OwnedBy:    "openai",
+			Permission: permission,
+			Root:       "gpt-3.5-turbo",
+			Parent:     nil,
+		},
+		{
+			Id:         "gpt-3.5-turbo-0301",
+			Object:     "model",
+			Created:    1677649963,
+			OwnedBy:    "openai",
+			Permission: permission,
+			Root:       "gpt-3.5-turbo-0301",
+			Parent:     nil,
+		},
+		{
+			Id:         "gpt-4",
+			Object:     "model",
+			Created:    1677649963,
+			OwnedBy:    "openai",
+			Permission: permission,
+			Root:       "gpt-4",
+			Parent:     nil,
+		},
+		{
+			Id:         "gpt-4-0314",
+			Object:     "model",
+			Created:    1677649963,
+			OwnedBy:    "openai",
+			Permission: permission,
+			Root:       "gpt-4-0314",
+			Parent:     nil,
+		},
+		{
+			Id:         "gpt-4-32k",
+			Object:     "model",
+			Created:    1677649963,
+			OwnedBy:    "openai",
+			Permission: permission,
+			Root:       "gpt-4-32k",
+			Parent:     nil,
+		},
+		{
+			Id:         "gpt-4-32k-0314",
+			Object:     "model",
+			Created:    1677649963,
+			OwnedBy:    "openai",
+			Permission: permission,
+			Root:       "gpt-4-32k-0314",
+			Parent:     nil,
+		},
+		{
+			Id:         "gpt-3.5-turbo",
+			Object:     "model",
+			Created:    1677649963,
+			OwnedBy:    "openai",
+			Permission: permission,
+			Root:       "gpt-3.5-turbo",
+			Parent:     nil,
+		},
+		{
+			Id:         "text-embedding-ada-002",
+			Object:     "model",
+			Created:    1677649963,
+			OwnedBy:    "openai",
+			Permission: permission,
+			Root:       "text-embedding-ada-002",
+			Parent:     nil,
+		},
+	}
+	openAIModelsMap = make(map[string]OpenAIModels)
+	for _, model := range openAIModels {
+		openAIModelsMap[model.Id] = model
+	}
+}
+
+func ListModels(c *gin.Context) {
+	c.JSON(200, openAIModels)
+}
+
+func RetrieveModel(c *gin.Context) {
+	modelId := c.Param("model")
+	if model, ok := openAIModelsMap[modelId]; ok {
+		c.JSON(200, model)
+	} else {
+		openAIError := OpenAIError{
+			Message: fmt.Sprintf("The model '%s' does not exist", modelId),
+			Type:    "invalid_request_error",
+			Param:   "model",
+			Code:    "model_not_found",
+		}
+		c.JSON(200, gin.H{
+			"error": openAIError,
+		})
+	}
+}

router/relay-router.go

@@ -11,8 +11,8 @@ func SetRelayRouter(router *gin.Engine) {
 	relayV1Router := router.Group("/v1")
 	relayV1Router.Use(middleware.TokenAuth(), middleware.Distribute())
 	{
-		relayV1Router.GET("/models", controller.Relay)
-		relayV1Router.GET("/models/:model", controller.Relay)
+		relayV1Router.GET("/models", controller.ListModels)
+		relayV1Router.GET("/models/:model", controller.RetrieveModel)
 		relayV1Router.POST("/completions", controller.RelayNotImplemented)
 		relayV1Router.POST("/chat/completions", controller.Relay)
 		relayV1Router.POST("/edits", controller.RelayNotImplemented)