diff --git a/chat.go b/chat.go
index ef2ab79..5d8b77b 100644
--- a/chat.go
+++ b/chat.go
@@ -276,6 +276,8 @@ func HandleChat(w http.ResponseWriter, r *http.Request) {
 	for iteration := range raw.Iterations {
 		debug("iteration %d of %d", iteration+1, raw.Iterations)
 
+		response.Send(StartChunk())
+
 		if len(request.Tools) > 0 && iteration == raw.Iterations-1 {
 			debug("no more tool calls")
 
@@ -341,6 +343,8 @@ func HandleChat(w http.ResponseWriter, r *http.Request) {
 			tool.AsAssistantToolCall(message),
 			tool.AsToolMessage(),
 		)
+
+		response.Send(EndChunk())
 	}
 }
 
diff --git a/stream.go b/stream.go
index 8338fc5..493fe0c 100644
--- a/stream.go
+++ b/stream.go
@@ -13,7 +13,7 @@ import (
 
 type Chunk struct {
 	Type string `json:"type"`
-	Text any    `json:"text"`
+	Text any    `json:"text,omitempty"`
 }
 
 type Stream struct {
@@ -72,6 +72,18 @@ func IDChunk(id string) Chunk {
 	}
 }
 
+func EndChunk() Chunk {
+	return Chunk{
+		Type: "end",
+	}
+}
+
+func StartChunk() Chunk {
+	return Chunk{
+		Type: "start",
+	}
+}
+
 func ErrorChunk(err error) Chunk {
 	return Chunk{
 		Type: "error",