diff --git a/router/router.go b/router/router.go
index 13077b3..9484583 100644
--- a/router/router.go
+++ b/router/router.go
@@ -2,7 +2,9 @@ package router
 
 import (
 	"bufio"
+	"bytes"
 	"crypto/tls"
+	"encoding/json"
 	"errors"
 	"fmt"
 	"io"
@@ -18,6 +20,7 @@ import (
 	"github.com/gin-gonic/gin"
 	"github.com/google/uuid"
 	"gorm.io/gorm"
+	// "github.com/pkoukk/tiktoken-go"
 )
 
 var (
@@ -292,6 +295,12 @@ func GenerateToken() string {
 	return token.String()
 }
 
+type _ struct {
+	model           string
+	promptCount     int
+	completionCount int
+}
+
 func HandleProy(c *gin.Context) {
 	var localuser bool
 	var isStream bool
@@ -376,6 +385,7 @@ func HandleProy(c *gin.Context) {
 	// 	return
 	// }
 	reader := bufio.NewReader(resp.Body)
+	// var resbuf = bytes.NewBuffer(nil)
 
 	if resp.StatusCode == 200 && isStream {
 		//todo
@@ -437,6 +447,18 @@ func HandleReverseProxy(c *gin.Context) {
 	proxy.ServeHTTP(c.Writer, req)
 
 }
+func Cost(model string, promptCount, completionCount int) float64 {
+	var cost float64
+	switch model {
+	case "gpt-3.5":
+		cost = 0.002 * float64((promptCount+completionCount)/1000)
+	case "gpt-4-32k":
+		cost = 0.06*float64(promptCount/1000) + 0.12*float64(completionCount/1000)
+	case "gpt-4":
+		cost = 0.03*float64(promptCount/1000) + 0.06*float64(completionCount/1000)
+	}
+	return cost
+}
 
 func HandleUsage(c *gin.Context) {
 	fromStr := c.Query("from")
@@ -463,39 +485,46 @@ func HandleUsage(c *gin.Context) {
 	c.JSON(200, usage)
 }
 
-// todo
-func streamEvent(reader *bufio.Reader) error {
-
-	lineChan := make(chan string, 1)
-
-	timeout := time.AfterFunc(60*time.Second, func() {
-		lineChan <- ""
-	})
-
+func fetchResponseContent(buf *bytes.Buffer, responseBody *bufio.Reader) <-chan string {
+	contentCh := make(chan string)
 	go func() {
-		line, err := reader.ReadString('\n')
-		if err == nil {
-			lineChan <- line
+		defer close(contentCh)
+		for {
+			line, err := responseBody.ReadString('\n')
+			if err == nil {
+				buf.WriteString(line)
+				if line == "\n" {
+					continue
+				}
+				if strings.HasPrefix(line, "data:") {
+					line = strings.TrimSpace(strings.TrimPrefix(line, "data:"))
+					if strings.HasSuffix(line, "[DONE]") {
+						break
+					}
+					line = strings.TrimSpace(line)
+				}
+
+				dec := json.NewDecoder(strings.NewReader(line))
+				var data map[string]interface{}
+				if err := dec.Decode(&data); err == io.EOF {
+					log.Println("EOF:", err)
+					break
+				} else if err != nil {
+					fmt.Println("Error decoding response:", err)
+					return
+				}
+				if choices, ok := data["choices"].([]interface{}); ok {
+					for _, choice := range choices {
+						choiceMap := choice.(map[string]interface{})
+						if content, ok := choiceMap["delta"].(map[string]interface{})["content"]; ok {
+							contentCh <- content.(string)
+						}
+					}
+				}
+			} else {
+				break
+			}
 		}
 	}()
-
-	line := <-lineChan
-
-	timeout.Stop()
-	if line == "" {
-
-	}
-
-	if strings.HasPrefix(line, "data:") {
-		line = strings.TrimSpace(strings.TrimPrefix(line, "data:"))
-		//log.Println("Received data:", line)
-
-		if line == "[DONE]" {
-
-		}
-
-		line = strings.TrimSpace(line)
-
-	}
-	return nil
+	return contentCh
 }