fix: spec compliant instantiation and termination of streams (#341)

api/openai.go

@@ -259,10 +259,17 @@ func embeddingsEndpoint(cm *ConfigMerger, o *Option) func(c *fiber.Ctx) error {
 func chatEndpoint(cm *ConfigMerger, o *Option) func(c *fiber.Ctx) error {
 
 	process := func(s string, req *OpenAIRequest, config *Config, loader *model.ModelLoader, responses chan OpenAIResponse) {
+		initialMessage := OpenAIResponse{
+			Model:   req.Model, // we have to return what the user sent here, due to OpenAI spec.
+			Choices: []Choice{{Delta: &Message{Role: "assistant"}}},
+			Object:  "chat.completion.chunk",
+		}
+		responses <- initialMessage
+
 		ComputeChoices(s, req, config, loader, func(s string, c *[]Choice) {}, func(s string) bool {
 			resp := OpenAIResponse{
 				Model:   req.Model, // we have to return what the user sent here, due to OpenAI spec.
-				Choices: []Choice{{Delta: &Message{Role: "assistant", Content: s}}},
+				Choices: []Choice{{Delta: &Message{Content: s}}},
 				Object:  "chat.completion.chunk",
 			}
 			log.Debug().Msgf("Sending goroutine: %s", s)
@@ -339,13 +346,11 @@ func chatEndpoint(cm *ConfigMerger, o *Option) func(c *fiber.Ctx) error {
 					enc := json.NewEncoder(&buf)
 					enc.Encode(ev)
 
-					fmt.Fprintf(w, "event: data\n\n")
-					fmt.Fprintf(w, "data: %v\n\n", buf.String())
 					log.Debug().Msgf("Sending chunk: %s", buf.String())
+					fmt.Fprintf(w, "data: %v\n", buf.String())
 					w.Flush()
 				}
 
-				w.WriteString("event: data\n\n")
 				resp := &OpenAIResponse{
 					Model:   input.Model, // we have to return what the user sent here, due to OpenAI spec.
 					Choices: []Choice{{FinishReason: "stop"}},
@@ -353,6 +358,7 @@ func chatEndpoint(cm *ConfigMerger, o *Option) func(c *fiber.Ctx) error {
 				respData, _ := json.Marshal(resp)
 
 				w.WriteString(fmt.Sprintf("data: %s\n\n", respData))
+				w.WriteString("data: [DONE]\n\n")
 				w.Flush()
 			}))
 			return nil