Add Tool Call ID (#12956)

* routes/types: add tool call id

---------

Co-authored-by: ParthSareen <parth.sareen@ollama.com>

server/routes.go

@@ -13,6 +13,7 @@ import (
 	"io/fs"
 	"log/slog"
 	"math"
+	"math/rand"
 	"net"
 	"net/http"
 	"net/netip"
@@ -1812,6 +1813,15 @@ func (s *Server) PsHandler(c *gin.Context) {
 	c.JSON(http.StatusOK, api.ProcessResponse{Models: models})
 }
 
+func toolCallId() string {
+	const letterBytes = "abcdefghijklmnopqrstuvwxyz0123456789"
+	b := make([]byte, 8)
+	for i := range b {
+		b[i] = letterBytes[rand.Intn(len(letterBytes))]
+	}
+	return "call_" + strings.ToLower(string(b))
+}
+
 func (s *Server) ChatHandler(c *gin.Context) {
 	checkpointStart := time.Now()
 
@@ -2130,6 +2140,9 @@ func (s *Server) ChatHandler(c *gin.Context) {
 
 					res.Message.Content = content
 					res.Message.Thinking = thinking
+					for i := range toolCalls {
+						toolCalls[i].ID = toolCallId()
+					}
 					res.Message.ToolCalls = toolCalls
 
 					tb.WriteString(thinking)
@@ -2174,6 +2187,9 @@ func (s *Server) ChatHandler(c *gin.Context) {
 					if len(content) > 0 {
 						res.Message.Content = content
 					} else if len(toolCalls) > 0 {
+						for i := range toolCalls {
+							toolCalls[i].ID = toolCallId()
+						}
 						res.Message.ToolCalls = toolCalls
 						res.Message.Content = ""
 					} else if res.Message.Thinking != "" {

server/routes_generate_test.go

@@ -554,6 +554,14 @@ func TestGenerateChat(t *testing.T) {
 			t.Error("expected tool calls, got nil")
 		}
 
+		gotToolCall := resp.Message.ToolCalls[0]
+		if gotToolCall.ID == "" {
+			t.Error("expected tool call ID to be populated")
+		}
+		if !strings.HasPrefix(gotToolCall.ID, "call_") {
+			t.Errorf("expected tool call ID to have call_ prefix, got %q", gotToolCall.ID)
+		}
+
 		expectedToolCall := api.ToolCall{
 			Function: api.ToolCallFunction{
 				Name: "get_weather",
@@ -564,7 +572,8 @@ func TestGenerateChat(t *testing.T) {
 			},
 		}
 
-		if diff := cmp.Diff(resp.Message.ToolCalls[0], expectedToolCall); diff != "" {
+		expectedToolCall.ID = gotToolCall.ID
+		if diff := cmp.Diff(gotToolCall, expectedToolCall); diff != "" {
 			t.Errorf("tool call mismatch (-got +want):\n%s", diff)
 		}
 	})
@@ -669,6 +678,17 @@ func TestGenerateChat(t *testing.T) {
 				t.Fatal(err)
 			}
 
+			if len(resp.Message.ToolCalls) > 0 {
+				for _, call := range resp.Message.ToolCalls {
+					if call.ID == "" {
+						t.Fatal("expected streaming tool call to have an ID")
+					}
+					if !strings.HasPrefix(call.ID, "call_") {
+						t.Fatalf("expected streaming tool call ID to have call_ prefix, got %q", call.ID)
+					}
+				}
+			}
+
 			if resp.Done {
 				if len(resp.Message.ToolCalls) != 1 {
 					t.Errorf("expected 1 tool call in final response, got %d", len(resp.Message.ToolCalls))
@@ -687,6 +707,14 @@ func TestGenerateChat(t *testing.T) {
 			},
 		}
 
+		if finalToolCall.ID == "" {
+			t.Fatal("expected final tool call to have an ID")
+		}
+		if !strings.HasPrefix(finalToolCall.ID, "call_") {
+			t.Fatalf("expected final tool call ID to have call_ prefix, got %q", finalToolCall.ID)
+		}
+
+		expectedToolCall.ID = finalToolCall.ID
 		if diff := cmp.Diff(finalToolCall, expectedToolCall); diff != "" {
 			t.Errorf("final tool call mismatch (-got +want):\n%s", diff)
 		}