fix(kiro): Handle tool results correctly in OpenAI format translation

internal/translator/kiro/common/message_merge.go

@@ -10,6 +10,7 @@ import (
 // MergeAdjacentMessages merges adjacent messages with the same role.
 // This reduces API call complexity and improves compatibility.
 // Based on AIClient-2-API implementation.
+// NOTE: Tool messages are NOT merged because each has a unique tool_call_id that must be preserved.
 func MergeAdjacentMessages(messages []gjson.Result) []gjson.Result {
 	if len(messages) <= 1 {
 		return messages
@@ -26,6 +27,12 @@ func MergeAdjacentMessages(messages []gjson.Result) []gjson.Result {
 		currentRole := msg.Get("role").String()
 		lastRole := lastMsg.Get("role").String()
 
+		// Don't merge tool messages - each has a unique tool_call_id
+		if currentRole == "tool" || lastRole == "tool" {
+			merged = append(merged, msg)
+			continue
+		}
+
 		if currentRole == lastRole {
 			// Merge content from current message into last message
 			mergedContent := mergeMessageContent(lastMsg, msg)

internal/translator/kiro/openai/kiro_openai_request.go

@@ -450,24 +450,10 @@ func processOpenAIMessages(messages gjson.Result, modelID, origin string) ([]Kir
 	// Merge adjacent messages with the same role
 	messagesArray := kirocommon.MergeAdjacentMessages(messages.Array())
 
-	// Build tool_call_id to name mapping from assistant messages
-	toolCallIDToName := make(map[string]string)
-	for _, msg := range messagesArray {
-		if msg.Get("role").String() == "assistant" {
-			toolCalls := msg.Get("tool_calls")
-			if toolCalls.IsArray() {
-				for _, tc := range toolCalls.Array() {
-					if tc.Get("type").String() == "function" {
-						id := tc.Get("id").String()
-						name := tc.Get("function.name").String()
-						if id != "" && name != "" {
-							toolCallIDToName[id] = name
-						}
-					}
-				}
-			}
-		}
-	}
+	// Track pending tool results that should be attached to the next user message
+	// This is critical for LiteLLM-translated requests where tool results appear
+	// as separate "tool" role messages between assistant and user messages
+	var pendingToolResults []KiroToolResult
 
 	for i, msg := range messagesArray {
 		role := msg.Get("role").String()
@@ -480,6 +466,10 @@ func processOpenAIMessages(messages gjson.Result, modelID, origin string) ([]Kir
 
 		case "user":
 			userMsg, toolResults := buildUserMessageFromOpenAI(msg, modelID, origin)
+			// Merge any pending tool results from preceding "tool" role messages
+			toolResults = append(pendingToolResults, toolResults...)
+			pendingToolResults = nil // Reset pending tool results
+
 			if isLastMessage {
 				currentUserMsg = &userMsg
 				currentToolResults = toolResults
@@ -505,6 +495,24 @@ func processOpenAIMessages(messages gjson.Result, modelID, origin string) ([]Kir
 
 		case "assistant":
 			assistantMsg := buildAssistantMessageFromOpenAI(msg)
+
+			// If there are pending tool results, we need to insert a synthetic user message
+			// before this assistant message to maintain proper conversation structure
+			if len(pendingToolResults) > 0 {
+				syntheticUserMsg := KiroUserInputMessage{
+					Content: "Tool results provided.",
+					ModelID: modelID,
+					Origin:  origin,
+					UserInputMessageContext: &KiroUserInputMessageContext{
+						ToolResults: pendingToolResults,
+					},
+				}
+				history = append(history, KiroHistoryMessage{
+					UserInputMessage: &syntheticUserMsg,
+				})
+				pendingToolResults = nil
+			}
+
 			if isLastMessage {
 				history = append(history, KiroHistoryMessage{
 					AssistantResponseMessage: &assistantMsg,
@@ -524,7 +532,7 @@ func processOpenAIMessages(messages gjson.Result, modelID, origin string) ([]Kir
 		case "tool":
 			// Tool messages in OpenAI format provide results for tool_calls
 			// These are typically followed by user or assistant messages
-			// Process them and merge into the next user message's tool results
+			// Collect them as pending and attach to the next user message
 			toolCallID := msg.Get("tool_call_id").String()
 			content := msg.Get("content").String()
 
@@ -534,9 +542,21 @@ func processOpenAIMessages(messages gjson.Result, modelID, origin string) ([]Kir
 					Content:   []KiroTextContent{{Text: content}},
 					Status:    "success",
 				}
-				// Tool results should be included in the next user message
-				// For now, collect them and they'll be handled when we build the current message
-				currentToolResults = append(currentToolResults, toolResult)
+				// Collect pending tool results to attach to the next user message
+				pendingToolResults = append(pendingToolResults, toolResult)
+			}
+		}
+	}
+
+	// Handle case where tool results are at the end with no following user message
+	if len(pendingToolResults) > 0 {
+		currentToolResults = append(currentToolResults, pendingToolResults...)
+		// If there's no current user message, create a synthetic one for the tool results
+		if currentUserMsg == nil {
+			currentUserMsg = &KiroUserInputMessage{
+				Content: "Tool results provided.",
+				ModelID: modelID,
+				Origin:  origin,
 			}
 		}
 	}
@@ -551,9 +571,6 @@ func buildUserMessageFromOpenAI(msg gjson.Result, modelID, origin string) (KiroU
 	var toolResults []KiroToolResult
 	var images []KiroImage
 
-	// Track seen toolCallIds to deduplicate
-	seenToolCallIDs := make(map[string]bool)
-
 	if content.IsArray() {
 		for _, part := range content.Array() {
 			partType := part.Get("type").String()
@@ -589,9 +606,6 @@ func buildUserMessageFromOpenAI(msg gjson.Result, modelID, origin string) (KiroU
 		contentBuilder.WriteString(content.String())
 	}
 
-	// Check for tool_calls in the message (shouldn't be in user messages, but handle edge cases)
-	_ = seenToolCallIDs // Used for deduplication if needed
-
 	userMsg := KiroUserInputMessage{
 		Content: contentBuilder.String(),
 		ModelID: modelID,