refactor: replace json.Marshal and json.Unmarshal with sjson and gjson

Optimized the handling of JSON serialization and deserialization by replacing redundant `json.Marshal` and `json.Unmarshal` calls with `sjson` and `gjson`. Introduced a `marshalJSONValue` utility for compact JSON encoding, improving performance and code simplicity. Removed unused `encoding/json` imports.
2026-02-02 20:40:52 +08:00 · 2025-12-22 11:27:55 +08:00
parent dbcbe48ead
commit a86d501dc2
27 changed files with 862 additions and 1613 deletions
--- a/internal/translator/openai/claude/openai_claude_response.go
+++ b/internal/translator/openai/claude/openai_claude_response.go
@@ -8,7 +8,6 @@ package claude
 import (
 	"bytes"
 	"context"
-	"encoding/json"
 	"fmt"
 	"strings"

@@ -133,24 +132,10 @@ func convertOpenAIStreamingChunkToAnthropic(rawJSON []byte, param *ConvertOpenAI
 	if delta := root.Get("choices.0.delta"); delta.Exists() {
 		if !param.MessageStarted {
 			// Send message_start event
-			messageStart := map[string]interface{}{
-				"type": "message_start",
-				"message": map[string]interface{}{
-					"id":            param.MessageID,
-					"type":          "message",
-					"role":          "assistant",
-					"model":         param.Model,
-					"content":       []interface{}{},
-					"stop_reason":   nil,
-					"stop_sequence": nil,
-					"usage": map[string]interface{}{
-						"input_tokens":  0,
-						"output_tokens": 0,
-					},
-				},
-			}
-			messageStartJSON, _ := json.Marshal(messageStart)
-			results = append(results, "event: message_start\ndata: "+string(messageStartJSON)+"\n\n")
+			messageStartJSON := `{"type":"message_start","message":{"id":"","type":"message","role":"assistant","model":"","content":[],"stop_reason":null,"stop_sequence":null,"usage":{"input_tokens":0,"output_tokens":0}}}`
+			messageStartJSON, _ = sjson.Set(messageStartJSON, "message.id", param.MessageID)
+			messageStartJSON, _ = sjson.Set(messageStartJSON, "message.model", param.Model)
+			results = append(results, "event: message_start\ndata: "+messageStartJSON+"\n\n")
 			param.MessageStarted = true

 			// Don't send content_block_start for text here - wait for actual content
@@ -168,29 +153,16 @@ func convertOpenAIStreamingChunkToAnthropic(rawJSON []byte, param *ConvertOpenAI
 						param.ThinkingContentBlockIndex = param.NextContentBlockIndex
 						param.NextContentBlockIndex++
 					}
-					contentBlockStart := map[string]interface{}{
-						"type":  "content_block_start",
-						"index": param.ThinkingContentBlockIndex,
-						"content_block": map[string]interface{}{
-							"type":     "thinking",
-							"thinking": "",
-						},
-					}
-					contentBlockStartJSON, _ := json.Marshal(contentBlockStart)
-					results = append(results, "event: content_block_start\ndata: "+string(contentBlockStartJSON)+"\n\n")
+					contentBlockStartJSON := `{"type":"content_block_start","index":0,"content_block":{"type":"thinking","thinking":""}}`
+					contentBlockStartJSON, _ = sjson.Set(contentBlockStartJSON, "index", param.ThinkingContentBlockIndex)
+					results = append(results, "event: content_block_start\ndata: "+contentBlockStartJSON+"\n\n")
 					param.ThinkingContentBlockStarted = true
 				}

-				thinkingDelta := map[string]interface{}{
-					"type":  "content_block_delta",
-					"index": param.ThinkingContentBlockIndex,
-					"delta": map[string]interface{}{
-						"type":     "thinking_delta",
-						"thinking": reasoningText,
-					},
-				}
-				thinkingDeltaJSON, _ := json.Marshal(thinkingDelta)
-				results = append(results, "event: content_block_delta\ndata: "+string(thinkingDeltaJSON)+"\n\n")
+				thinkingDeltaJSON := `{"type":"content_block_delta","index":0,"delta":{"type":"thinking_delta","thinking":""}}`
+				thinkingDeltaJSON, _ = sjson.Set(thinkingDeltaJSON, "index", param.ThinkingContentBlockIndex)
+				thinkingDeltaJSON, _ = sjson.Set(thinkingDeltaJSON, "delta.thinking", reasoningText)
+				results = append(results, "event: content_block_delta\ndata: "+thinkingDeltaJSON+"\n\n")
 			}
 		}

@@ -203,29 +175,16 @@ func convertOpenAIStreamingChunkToAnthropic(rawJSON []byte, param *ConvertOpenAI
 					param.TextContentBlockIndex = param.NextContentBlockIndex
 					param.NextContentBlockIndex++
 				}
-				contentBlockStart := map[string]interface{}{
-					"type":  "content_block_start",
-					"index": param.TextContentBlockIndex,
-					"content_block": map[string]interface{}{
-						"type": "text",
-						"text": "",
-					},
-				}
-				contentBlockStartJSON, _ := json.Marshal(contentBlockStart)
-				results = append(results, "event: content_block_start\ndata: "+string(contentBlockStartJSON)+"\n\n")
+				contentBlockStartJSON := `{"type":"content_block_start","index":0,"content_block":{"type":"text","text":""}}`
+				contentBlockStartJSON, _ = sjson.Set(contentBlockStartJSON, "index", param.TextContentBlockIndex)
+				results = append(results, "event: content_block_start\ndata: "+contentBlockStartJSON+"\n\n")
 				param.TextContentBlockStarted = true
 			}

-			contentDelta := map[string]interface{}{
-				"type":  "content_block_delta",
-				"index": param.TextContentBlockIndex,
-				"delta": map[string]interface{}{
-					"type": "text_delta",
-					"text": content.String(),
-				},
-			}
-			contentDeltaJSON, _ := json.Marshal(contentDelta)
-			results = append(results, "event: content_block_delta\ndata: "+string(contentDeltaJSON)+"\n\n")
+			contentDeltaJSON := `{"type":"content_block_delta","index":0,"delta":{"type":"text_delta","text":""}}`
+			contentDeltaJSON, _ = sjson.Set(contentDeltaJSON, "index", param.TextContentBlockIndex)
+			contentDeltaJSON, _ = sjson.Set(contentDeltaJSON, "delta.text", content.String())
+			results = append(results, "event: content_block_delta\ndata: "+contentDeltaJSON+"\n\n")

 			// Accumulate content
 			param.ContentAccumulator.WriteString(content.String())
@@ -263,18 +222,11 @@ func convertOpenAIStreamingChunkToAnthropic(rawJSON []byte, param *ConvertOpenAI
 						stopTextContentBlock(param, &results)

 						// Send content_block_start for tool_use
-						contentBlockStart := map[string]interface{}{
-							"type":  "content_block_start",
-							"index": blockIndex,
-							"content_block": map[string]interface{}{
-								"type":  "tool_use",
-								"id":    accumulator.ID,
-								"name":  accumulator.Name,
-								"input": map[string]interface{}{},
-							},
-						}
-						contentBlockStartJSON, _ := json.Marshal(contentBlockStart)
-						results = append(results, "event: content_block_start\ndata: "+string(contentBlockStartJSON)+"\n\n")
+						contentBlockStartJSON := `{"type":"content_block_start","index":0,"content_block":{"type":"tool_use","id":"","name":"","input":{}}}`
+						contentBlockStartJSON, _ = sjson.Set(contentBlockStartJSON, "index", blockIndex)
+						contentBlockStartJSON, _ = sjson.Set(contentBlockStartJSON, "content_block.id", accumulator.ID)
+						contentBlockStartJSON, _ = sjson.Set(contentBlockStartJSON, "content_block.name", accumulator.Name)
+						results = append(results, "event: content_block_start\ndata: "+contentBlockStartJSON+"\n\n")
 					}

 					// Handle function arguments
@@ -298,12 +250,9 @@ func convertOpenAIStreamingChunkToAnthropic(rawJSON []byte, param *ConvertOpenAI

 		// Send content_block_stop for thinking content if needed
 		if param.ThinkingContentBlockStarted {
-			contentBlockStop := map[string]interface{}{
-				"type":  "content_block_stop",
-				"index": param.ThinkingContentBlockIndex,
-			}
-			contentBlockStopJSON, _ := json.Marshal(contentBlockStop)
-			results = append(results, "event: content_block_stop\ndata: "+string(contentBlockStopJSON)+"\n\n")
+			contentBlockStopJSON := `{"type":"content_block_stop","index":0}`
+			contentBlockStopJSON, _ = sjson.Set(contentBlockStopJSON, "index", param.ThinkingContentBlockIndex)
+			results = append(results, "event: content_block_stop\ndata: "+contentBlockStopJSON+"\n\n")
 			param.ThinkingContentBlockStarted = false
 			param.ThinkingContentBlockIndex = -1
 		}
@@ -319,24 +268,15 @@ func convertOpenAIStreamingChunkToAnthropic(rawJSON []byte, param *ConvertOpenAI

 				// Send complete input_json_delta with all accumulated arguments
 				if accumulator.Arguments.Len() > 0 {
-					inputDelta := map[string]interface{}{
-						"type":  "content_block_delta",
-						"index": blockIndex,
-						"delta": map[string]interface{}{
-							"type":         "input_json_delta",
-							"partial_json": util.FixJSON(accumulator.Arguments.String()),
-						},
-					}
-					inputDeltaJSON, _ := json.Marshal(inputDelta)
-					results = append(results, "event: content_block_delta\ndata: "+string(inputDeltaJSON)+"\n\n")
+					inputDeltaJSON := `{"type":"content_block_delta","index":0,"delta":{"type":"input_json_delta","partial_json":""}}`
+					inputDeltaJSON, _ = sjson.Set(inputDeltaJSON, "index", blockIndex)
+					inputDeltaJSON, _ = sjson.Set(inputDeltaJSON, "delta.partial_json", util.FixJSON(accumulator.Arguments.String()))
+					results = append(results, "event: content_block_delta\ndata: "+inputDeltaJSON+"\n\n")
 				}

-				contentBlockStop := map[string]interface{}{
-					"type":  "content_block_stop",
-					"index": blockIndex,
-				}
-				contentBlockStopJSON, _ := json.Marshal(contentBlockStop)
-				results = append(results, "event: content_block_stop\ndata: "+string(contentBlockStopJSON)+"\n\n")
+				contentBlockStopJSON := `{"type":"content_block_stop","index":0}`
+				contentBlockStopJSON, _ = sjson.Set(contentBlockStopJSON, "index", blockIndex)
+				results = append(results, "event: content_block_stop\ndata: "+contentBlockStopJSON+"\n\n")
 				delete(param.ToolCallBlockIndexes, index)
 			}
 			param.ContentBlocksStopped = true
@@ -361,20 +301,11 @@ func convertOpenAIStreamingChunkToAnthropic(rawJSON []byte, param *ConvertOpenAI
 			}
 		}
 		// Send message_delta with usage
-		messageDelta := map[string]interface{}{
-			"type": "message_delta",
-			"delta": map[string]interface{}{
-				"stop_reason":   mapOpenAIFinishReasonToAnthropic(param.FinishReason),
-				"stop_sequence": nil,
-			},
-			"usage": map[string]interface{}{
-				"input_tokens":  inputTokens,
-				"output_tokens": outputTokens,
-			},
-		}
-
-		messageDeltaJSON, _ := json.Marshal(messageDelta)
-		results = append(results, "event: message_delta\ndata: "+string(messageDeltaJSON)+"\n\n")
+		messageDeltaJSON := `{"type":"message_delta","delta":{"stop_reason":"","stop_sequence":null},"usage":{"input_tokens":0,"output_tokens":0}}`
+		messageDeltaJSON, _ = sjson.Set(messageDeltaJSON, "delta.stop_reason", mapOpenAIFinishReasonToAnthropic(param.FinishReason))
+		messageDeltaJSON, _ = sjson.Set(messageDeltaJSON, "usage.input_tokens", inputTokens)
+		messageDeltaJSON, _ = sjson.Set(messageDeltaJSON, "usage.output_tokens", outputTokens)
+		results = append(results, "event: message_delta\ndata: "+messageDeltaJSON+"\n\n")
 		param.MessageDeltaSent = true

 		emitMessageStopIfNeeded(param, &results)
@@ -390,12 +321,9 @@ func convertOpenAIDoneToAnthropic(param *ConvertOpenAIResponseToAnthropicParams)

 	// Ensure all content blocks are stopped before final events
 	if param.ThinkingContentBlockStarted {
-		contentBlockStop := map[string]interface{}{
-			"type":  "content_block_stop",
-			"index": param.ThinkingContentBlockIndex,
-		}
-		contentBlockStopJSON, _ := json.Marshal(contentBlockStop)
-		results = append(results, "event: content_block_stop\ndata: "+string(contentBlockStopJSON)+"\n\n")
+		contentBlockStopJSON := `{"type":"content_block_stop","index":0}`
+		contentBlockStopJSON, _ = sjson.Set(contentBlockStopJSON, "index", param.ThinkingContentBlockIndex)
+		results = append(results, "event: content_block_stop\ndata: "+contentBlockStopJSON+"\n\n")
 		param.ThinkingContentBlockStarted = false
 		param.ThinkingContentBlockIndex = -1
 	}
@@ -408,24 +336,15 @@ func convertOpenAIDoneToAnthropic(param *ConvertOpenAIResponseToAnthropicParams)
 			blockIndex := param.toolContentBlockIndex(index)

 			if accumulator.Arguments.Len() > 0 {
-				inputDelta := map[string]interface{}{
-					"type":  "content_block_delta",
-					"index": blockIndex,
-					"delta": map[string]interface{}{
-						"type":         "input_json_delta",
-						"partial_json": util.FixJSON(accumulator.Arguments.String()),
-					},
-				}
-				inputDeltaJSON, _ := json.Marshal(inputDelta)
-				results = append(results, "event: content_block_delta\ndata: "+string(inputDeltaJSON)+"\n\n")
+				inputDeltaJSON := `{"type":"content_block_delta","index":0,"delta":{"type":"input_json_delta","partial_json":""}}`
+				inputDeltaJSON, _ = sjson.Set(inputDeltaJSON, "index", blockIndex)
+				inputDeltaJSON, _ = sjson.Set(inputDeltaJSON, "delta.partial_json", util.FixJSON(accumulator.Arguments.String()))
+				results = append(results, "event: content_block_delta\ndata: "+inputDeltaJSON+"\n\n")
 			}

-			contentBlockStop := map[string]interface{}{
-				"type":  "content_block_stop",
-				"index": blockIndex,
-			}
-			contentBlockStopJSON, _ := json.Marshal(contentBlockStop)
-			results = append(results, "event: content_block_stop\ndata: "+string(contentBlockStopJSON)+"\n\n")
+			contentBlockStopJSON := `{"type":"content_block_stop","index":0}`
+			contentBlockStopJSON, _ = sjson.Set(contentBlockStopJSON, "index", blockIndex)
+			results = append(results, "event: content_block_stop\ndata: "+contentBlockStopJSON+"\n\n")
 			delete(param.ToolCallBlockIndexes, index)
 		}
 		param.ContentBlocksStopped = true
@@ -433,16 +352,9 @@ func convertOpenAIDoneToAnthropic(param *ConvertOpenAIResponseToAnthropicParams)

 	// If we haven't sent message_delta yet (no usage info was received), send it now
 	if param.FinishReason != "" && !param.MessageDeltaSent {
-		messageDelta := map[string]interface{}{
-			"type": "message_delta",
-			"delta": map[string]interface{}{
-				"stop_reason":   mapOpenAIFinishReasonToAnthropic(param.FinishReason),
-				"stop_sequence": nil,
-			},
-		}
-
-		messageDeltaJSON, _ := json.Marshal(messageDelta)
-		results = append(results, "event: message_delta\ndata: "+string(messageDeltaJSON)+"\n\n")
+		messageDeltaJSON := `{"type":"message_delta","delta":{"stop_reason":"","stop_sequence":null}}`
+		messageDeltaJSON, _ = sjson.Set(messageDeltaJSON, "delta.stop_reason", mapOpenAIFinishReasonToAnthropic(param.FinishReason))
+		results = append(results, "event: message_delta\ndata: "+messageDeltaJSON+"\n\n")
 		param.MessageDeltaSent = true
 	}

@@ -455,105 +367,73 @@ func convertOpenAIDoneToAnthropic(param *ConvertOpenAIResponseToAnthropicParams)
 func convertOpenAINonStreamingToAnthropic(rawJSON []byte) []string {
 	root := gjson.ParseBytes(rawJSON)

-	// Build Anthropic response
-	response := map[string]interface{}{
-		"id":            root.Get("id").String(),
-		"type":          "message",
-		"role":          "assistant",
-		"model":         root.Get("model").String(),
-		"content":       []interface{}{},
-		"stop_reason":   nil,
-		"stop_sequence": nil,
-		"usage": map[string]interface{}{
-			"input_tokens":  0,
-			"output_tokens": 0,
-		},
-	}
+	out := `{"id":"","type":"message","role":"assistant","model":"","content":[],"stop_reason":null,"stop_sequence":null,"usage":{"input_tokens":0,"output_tokens":0}}`
+	out, _ = sjson.Set(out, "id", root.Get("id").String())
+	out, _ = sjson.Set(out, "model", root.Get("model").String())

 	// Process message content and tool calls
-	var contentBlocks []interface{}
-
-	if choices := root.Get("choices"); choices.Exists() && choices.IsArray() {
+	if choices := root.Get("choices"); choices.Exists() && choices.IsArray() && len(choices.Array()) > 0 {
 		choice := choices.Array()[0] // Take first choice
-		reasoningNode := choice.Get("message.reasoning_content")
-		allReasoning := collectOpenAIReasoningTexts(reasoningNode)

-		for _, reasoningText := range allReasoning {
+		reasoningNode := choice.Get("message.reasoning_content")
+		for _, reasoningText := range collectOpenAIReasoningTexts(reasoningNode) {
 			if reasoningText == "" {
 				continue
 			}
-			contentBlocks = append(contentBlocks, map[string]interface{}{
-				"type":     "thinking",
-				"thinking": reasoningText,
-			})
+			block := `{"type":"thinking","thinking":""}`
+			block, _ = sjson.Set(block, "thinking", reasoningText)
+			out, _ = sjson.SetRaw(out, "content.-1", block)
 		}

 		// Handle text content
 		if content := choice.Get("message.content"); content.Exists() && content.String() != "" {
-			textBlock := map[string]interface{}{
-				"type": "text",
-				"text": content.String(),
-			}
-			contentBlocks = append(contentBlocks, textBlock)
+			block := `{"type":"text","text":""}`
+			block, _ = sjson.Set(block, "text", content.String())
+			out, _ = sjson.SetRaw(out, "content.-1", block)
 		}

 		// Handle tool calls
 		if toolCalls := choice.Get("message.tool_calls"); toolCalls.Exists() && toolCalls.IsArray() {
 			toolCalls.ForEach(func(_, toolCall gjson.Result) bool {
-				toolUseBlock := map[string]interface{}{
-					"type": "tool_use",
-					"id":   toolCall.Get("id").String(),
-					"name": toolCall.Get("function.name").String(),
-				}
+				toolUseBlock := `{"type":"tool_use","id":"","name":"","input":{}}`
+				toolUseBlock, _ = sjson.Set(toolUseBlock, "id", toolCall.Get("id").String())
+				toolUseBlock, _ = sjson.Set(toolUseBlock, "name", toolCall.Get("function.name").String())

-				// Parse arguments
-				argsStr := toolCall.Get("function.arguments").String()
-				argsStr = util.FixJSON(argsStr)
-				if argsStr != "" {
-					var args interface{}
-					if err := json.Unmarshal([]byte(argsStr), &args); err == nil {
-						toolUseBlock["input"] = args
+				argsStr := util.FixJSON(toolCall.Get("function.arguments").String())
+				if argsStr != "" && gjson.Valid(argsStr) {
+					argsJSON := gjson.Parse(argsStr)
+					if argsJSON.IsObject() {
+						toolUseBlock, _ = sjson.SetRaw(toolUseBlock, "input", argsJSON.Raw)
 					} else {
-						toolUseBlock["input"] = map[string]interface{}{}
+						toolUseBlock, _ = sjson.SetRaw(toolUseBlock, "input", "{}")
 					}
 				} else {
-					toolUseBlock["input"] = map[string]interface{}{}
+					toolUseBlock, _ = sjson.SetRaw(toolUseBlock, "input", "{}")
 				}

-				contentBlocks = append(contentBlocks, toolUseBlock)
+				out, _ = sjson.SetRaw(out, "content.-1", toolUseBlock)
 				return true
 			})
 		}

 		// Set stop reason
 		if finishReason := choice.Get("finish_reason"); finishReason.Exists() {
-			response["stop_reason"] = mapOpenAIFinishReasonToAnthropic(finishReason.String())
+			out, _ = sjson.Set(out, "stop_reason", mapOpenAIFinishReasonToAnthropic(finishReason.String()))
 		}
 	}

-	response["content"] = contentBlocks
-
 	// Set usage information
 	if usage := root.Get("usage"); usage.Exists() {
-		response["usage"] = map[string]interface{}{
-			"input_tokens":  usage.Get("prompt_tokens").Int(),
-			"output_tokens": usage.Get("completion_tokens").Int(),
-			"reasoning_tokens": func() int64 {
-				if v := usage.Get("completion_tokens_details.reasoning_tokens"); v.Exists() {
-					return v.Int()
-				}
-				return 0
-			}(),
-		}
-	} else {
-		response["usage"] = map[string]interface{}{
-			"input_tokens":  0,
-			"output_tokens": 0,
+		out, _ = sjson.Set(out, "usage.input_tokens", usage.Get("prompt_tokens").Int())
+		out, _ = sjson.Set(out, "usage.output_tokens", usage.Get("completion_tokens").Int())
+		reasoningTokens := int64(0)
+		if v := usage.Get("completion_tokens_details.reasoning_tokens"); v.Exists() {
+			reasoningTokens = v.Int()
 		}
+		out, _ = sjson.Set(out, "usage.reasoning_tokens", reasoningTokens)
 	}

-	responseJSON, _ := json.Marshal(response)
-	return []string{string(responseJSON)}
+	return []string{out}
 }

 // mapOpenAIFinishReasonToAnthropic maps OpenAI finish reasons to Anthropic equivalents
@@ -620,12 +500,9 @@ func stopThinkingContentBlock(param *ConvertOpenAIResponseToAnthropicParams, res
 	if !param.ThinkingContentBlockStarted {
 		return
 	}
-	contentBlockStop := map[string]interface{}{
-		"type":  "content_block_stop",
-		"index": param.ThinkingContentBlockIndex,
-	}
-	contentBlockStopJSON, _ := json.Marshal(contentBlockStop)
-	*results = append(*results, "event: content_block_stop\ndata: "+string(contentBlockStopJSON)+"\n\n")
+	contentBlockStopJSON := `{"type":"content_block_stop","index":0}`
+	contentBlockStopJSON, _ = sjson.Set(contentBlockStopJSON, "index", param.ThinkingContentBlockIndex)
+	*results = append(*results, "event: content_block_stop\ndata: "+contentBlockStopJSON+"\n\n")
 	param.ThinkingContentBlockStarted = false
 	param.ThinkingContentBlockIndex = -1
 }
@@ -642,12 +519,9 @@ func stopTextContentBlock(param *ConvertOpenAIResponseToAnthropicParams, results
 	if !param.TextContentBlockStarted {
 		return
 	}
-	contentBlockStop := map[string]interface{}{
-		"type":  "content_block_stop",
-		"index": param.TextContentBlockIndex,
-	}
-	contentBlockStopJSON, _ := json.Marshal(contentBlockStop)
-	*results = append(*results, "event: content_block_stop\ndata: "+string(contentBlockStopJSON)+"\n\n")
+	contentBlockStopJSON := `{"type":"content_block_stop","index":0}`
+	contentBlockStopJSON, _ = sjson.Set(contentBlockStopJSON, "index", param.TextContentBlockIndex)
+	*results = append(*results, "event: content_block_stop\ndata: "+contentBlockStopJSON+"\n\n")
 	param.TextContentBlockStarted = false
 	param.TextContentBlockIndex = -1
 }
@@ -667,29 +541,19 @@ func ConvertOpenAIResponseToClaudeNonStream(_ context.Context, _ string, origina
 	_ = requestRawJSON

 	root := gjson.ParseBytes(rawJSON)
+	out := `{"id":"","type":"message","role":"assistant","model":"","content":[],"stop_reason":null,"stop_sequence":null,"usage":{"input_tokens":0,"output_tokens":0}}`
+	out, _ = sjson.Set(out, "id", root.Get("id").String())
+	out, _ = sjson.Set(out, "model", root.Get("model").String())

-	response := map[string]interface{}{
-		"id":            root.Get("id").String(),
-		"type":          "message",
-		"role":          "assistant",
-		"model":         root.Get("model").String(),
-		"content":       []interface{}{},
-		"stop_reason":   nil,
-		"stop_sequence": nil,
-		"usage": map[string]interface{}{
-			"input_tokens":  0,
-			"output_tokens": 0,
-		},
-	}
-
-	contentBlocks := make([]interface{}, 0)
 	hasToolCall := false
+	stopReasonSet := false

 	if choices := root.Get("choices"); choices.Exists() && choices.IsArray() && len(choices.Array()) > 0 {
 		choice := choices.Array()[0]

 		if finishReason := choice.Get("finish_reason"); finishReason.Exists() {
-			response["stop_reason"] = mapOpenAIFinishReasonToAnthropic(finishReason.String())
+			out, _ = sjson.Set(out, "stop_reason", mapOpenAIFinishReasonToAnthropic(finishReason.String()))
+			stopReasonSet = true
 		}

 		if message := choice.Get("message"); message.Exists() {
@@ -702,10 +566,9 @@ func ConvertOpenAIResponseToClaudeNonStream(_ context.Context, _ string, origina
 						if textBuilder.Len() == 0 {
 							return
 						}
-						contentBlocks = append(contentBlocks, map[string]interface{}{
-							"type": "text",
-							"text": textBuilder.String(),
-						})
+						block := `{"type":"text","text":""}`
+						block, _ = sjson.Set(block, "text", textBuilder.String())
+						out, _ = sjson.SetRaw(out, "content.-1", block)
 						textBuilder.Reset()
 					}

@@ -713,16 +576,14 @@ func ConvertOpenAIResponseToClaudeNonStream(_ context.Context, _ string, origina
 						if thinkingBuilder.Len() == 0 {
 							return
 						}
-						contentBlocks = append(contentBlocks, map[string]interface{}{
-							"type":     "thinking",
-							"thinking": thinkingBuilder.String(),
-						})
+						block := `{"type":"thinking","thinking":""}`
+						block, _ = sjson.Set(block, "thinking", thinkingBuilder.String())
+						out, _ = sjson.SetRaw(out, "content.-1", block)
 						thinkingBuilder.Reset()
 					}

 					for _, item := range contentResult.Array() {
-						typeStr := item.Get("type").String()
-						switch typeStr {
+						switch item.Get("type").String() {
 						case "text":
 							flushThinking()
 							textBuilder.WriteString(item.Get("text").String())
@@ -733,25 +594,23 @@ func ConvertOpenAIResponseToClaudeNonStream(_ context.Context, _ string, origina
 							if toolCalls.IsArray() {
 								toolCalls.ForEach(func(_, tc gjson.Result) bool {
 									hasToolCall = true
-									toolUse := map[string]interface{}{
-										"type": "tool_use",
-										"id":   tc.Get("id").String(),
-										"name": tc.Get("function.name").String(),
-									}
+									toolUse := `{"type":"tool_use","id":"","name":"","input":{}}`
+									toolUse, _ = sjson.Set(toolUse, "id", tc.Get("id").String())
+									toolUse, _ = sjson.Set(toolUse, "name", tc.Get("function.name").String())

 									argsStr := util.FixJSON(tc.Get("function.arguments").String())
-									if argsStr != "" {
-										var parsed interface{}
-										if err := json.Unmarshal([]byte(argsStr), &parsed); err == nil {
-											toolUse["input"] = parsed
+									if argsStr != "" && gjson.Valid(argsStr) {
+										argsJSON := gjson.Parse(argsStr)
+										if argsJSON.IsObject() {
+											toolUse, _ = sjson.SetRaw(toolUse, "input", argsJSON.Raw)
 										} else {
-											toolUse["input"] = map[string]interface{}{}
+											toolUse, _ = sjson.SetRaw(toolUse, "input", "{}")
 										}
 									} else {
-										toolUse["input"] = map[string]interface{}{}
+										toolUse, _ = sjson.SetRaw(toolUse, "input", "{}")
 									}

-									contentBlocks = append(contentBlocks, toolUse)
+									out, _ = sjson.SetRaw(out, "content.-1", toolUse)
 									return true
 								})
 							}
@@ -771,10 +630,9 @@ func ConvertOpenAIResponseToClaudeNonStream(_ context.Context, _ string, origina
 				} else if contentResult.Type == gjson.String {
 					textContent := contentResult.String()
 					if textContent != "" {
-						contentBlocks = append(contentBlocks, map[string]interface{}{
-							"type": "text",
-							"text": textContent,
-						})
+						block := `{"type":"text","text":""}`
+						block, _ = sjson.Set(block, "text", textContent)
+						out, _ = sjson.SetRaw(out, "content.-1", block)
 					}
 				}
 			}
@@ -784,81 +642,52 @@ func ConvertOpenAIResponseToClaudeNonStream(_ context.Context, _ string, origina
 					if reasoningText == "" {
 						continue
 					}
-					contentBlocks = append(contentBlocks, map[string]interface{}{
-						"type":     "thinking",
-						"thinking": reasoningText,
-					})
+					block := `{"type":"thinking","thinking":""}`
+					block, _ = sjson.Set(block, "thinking", reasoningText)
+					out, _ = sjson.SetRaw(out, "content.-1", block)
 				}
 			}

 			if toolCalls := message.Get("tool_calls"); toolCalls.Exists() && toolCalls.IsArray() {
 				toolCalls.ForEach(func(_, toolCall gjson.Result) bool {
 					hasToolCall = true
-					toolUseBlock := map[string]interface{}{
-						"type": "tool_use",
-						"id":   toolCall.Get("id").String(),
-						"name": toolCall.Get("function.name").String(),
-					}
+					toolUseBlock := `{"type":"tool_use","id":"","name":"","input":{}}`
+					toolUseBlock, _ = sjson.Set(toolUseBlock, "id", toolCall.Get("id").String())
+					toolUseBlock, _ = sjson.Set(toolUseBlock, "name", toolCall.Get("function.name").String())

-					argsStr := toolCall.Get("function.arguments").String()
-					argsStr = util.FixJSON(argsStr)
-					if argsStr != "" {
-						var args interface{}
-						if err := json.Unmarshal([]byte(argsStr), &args); err == nil {
-							toolUseBlock["input"] = args
+					argsStr := util.FixJSON(toolCall.Get("function.arguments").String())
+					if argsStr != "" && gjson.Valid(argsStr) {
+						argsJSON := gjson.Parse(argsStr)
+						if argsJSON.IsObject() {
+							toolUseBlock, _ = sjson.SetRaw(toolUseBlock, "input", argsJSON.Raw)
 						} else {
-							toolUseBlock["input"] = map[string]interface{}{}
+							toolUseBlock, _ = sjson.SetRaw(toolUseBlock, "input", "{}")
 						}
 					} else {
-						toolUseBlock["input"] = map[string]interface{}{}
+						toolUseBlock, _ = sjson.SetRaw(toolUseBlock, "input", "{}")
 					}

-					contentBlocks = append(contentBlocks, toolUseBlock)
+					out, _ = sjson.SetRaw(out, "content.-1", toolUseBlock)
 					return true
 				})
 			}
 		}
 	}

-	response["content"] = contentBlocks
-
 	if respUsage := root.Get("usage"); respUsage.Exists() {
-		usageJSON := `{}`
-		usageJSON, _ = sjson.Set(usageJSON, "input_tokens", respUsage.Get("prompt_tokens").Int())
-		usageJSON, _ = sjson.Set(usageJSON, "output_tokens", respUsage.Get("completion_tokens").Int())
-		parsedUsage := gjson.Parse(usageJSON).Value().(map[string]interface{})
-		response["usage"] = parsedUsage
-	} else {
-		response["usage"] = `{"input_tokens":0,"output_tokens":0}`
+		out, _ = sjson.Set(out, "usage.input_tokens", respUsage.Get("prompt_tokens").Int())
+		out, _ = sjson.Set(out, "usage.output_tokens", respUsage.Get("completion_tokens").Int())
 	}

-	if response["stop_reason"] == nil {
+	if !stopReasonSet {
 		if hasToolCall {
-			response["stop_reason"] = "tool_use"
+			out, _ = sjson.Set(out, "stop_reason", "tool_use")
 		} else {
-			response["stop_reason"] = "end_turn"
+			out, _ = sjson.Set(out, "stop_reason", "end_turn")
 		}
 	}

-	if !hasToolCall {
-		if toolBlocks := response["content"].([]interface{}); len(toolBlocks) > 0 {
-			for _, block := range toolBlocks {
-				if m, ok := block.(map[string]interface{}); ok && m["type"] == "tool_use" {
-					hasToolCall = true
-					break
-				}
-			}
-		}
-		if hasToolCall {
-			response["stop_reason"] = "tool_use"
-		}
-	}
-
-	responseJSON, err := json.Marshal(response)
-	if err != nil {
-		return ""
-	}
-	return string(responseJSON)
+	return out
 }

 func ClaudeTokenCount(ctx context.Context, count int64) string {