Fix double reply callback on tool calls

pkg/lmcli/provider/anthropic/anthropic.go

@@ -197,6 +197,8 @@ func (c *AnthropicClient) CreateChatCompletionStream(
 	scanner := bufio.NewScanner(resp.Body)
 	sb := strings.Builder{}
 
+	isToolCall := false
+
 	for scanner.Scan() {
 		line := scanner.Text()
 		line = strings.TrimSpace(line)
@@ -271,6 +273,8 @@ func (c *AnthropicClient) CreateChatCompletionStream(
 							return content, fmt.Errorf("reached </function_calls> stop sequence but no opening tag found")
 						}
 
+						isToolCall = true
+
 						funcCallXml := content[start:]
 						funcCallXml += FUNCTION_STOP_SEQUENCE
 
@@ -316,10 +320,12 @@ func (c *AnthropicClient) CreateChatCompletionStream(
 			case "message_stop":
 				// return the completed message
 				if callback != nil {
-					callback(model.Message{
-						Role:    model.MessageRoleAssistant,
-						Content: sb.String(),
-					})
+					if !isToolCall {
+						callback(model.Message{
+							Role:    model.MessageRoleAssistant,
+							Content: sb.String(),
+						})
+					}
 				}
 				return sb.String(), nil
 			case "error":

pkg/lmcli/provider/openai/openai.go

@@ -204,7 +204,7 @@ func (c *OpenAIClient) CreateChatCompletionStream(
 	ctx context.Context,
 	params model.RequestParameters,
 	messages []model.Message,
-	callbback provider.ReplyCallback,
+	callback provider.ReplyCallback,
 	output chan<- string,
 ) (string, error) {
 	client := openai.NewClient(c.APIKey)
@@ -256,22 +256,22 @@ func (c *OpenAIClient) CreateChatCompletionStream(
 			return content.String(), err
 		}
 
-		if callbback != nil {
+		if callback != nil {
 			for _, result := range results {
-				callbback(result)
+				callback(result)
 			}
 		}
 
 		// Recurse into CreateChatCompletionStream with the tool call replies
 		messages = append(messages, results...)
-		return c.CreateChatCompletionStream(ctx, params, messages, callbback, output)
-	}
-
-	if callbback != nil {
-		callbback(model.Message{
-			Role:    model.MessageRoleAssistant,
-			Content: content.String(),
-		})
+		return c.CreateChatCompletionStream(ctx, params, messages, callback, output)
+	} else {
+		if callback != nil {
+			callback(model.Message{
+				Role:    model.MessageRoleAssistant,
+				Content: content.String(),
+			})
+		}
 	}
 
 	return content.String(), err