fix: improve Claude message conversion

main.js

@@ -16,7 +16,9 @@ const ProxyServerSystem = require("./src/core/ProxyServerSystem");
  * Initialize and start the server
  */
 const initializeServer = async () => {
- const initialAuthIndex = parseInt(process.env.INITIAL_AUTH_INDEX, 10) || null;
+ const parsedInitialAuthIndex = parseInt(process.env.INITIAL_AUTH_INDEX, 10);
+ const initialAuthIndex =
+ Number.isInteger(parsedInitialAuthIndex) && parsedInitialAuthIndex >= 0 ? parsedInitialAuthIndex : null;
 
  try {
  const serverSystem = new ProxyServerSystem();

src/core/FormatConverter.js

@@ -2117,15 +2117,46 @@ class FormatConverter {
  }
  }
 
- // Extract system message (Claude uses a separate 'system' field)
+ const appendSystemContent = content => {
+ let text = "";
+ if (typeof content === "string") {
+ text = content;
+ } else if (Array.isArray(content)) {
+ text = content
+ .map(block => {
+ if (typeof block === "string") return block;
+ if (block && block.type === "text") return block.text || "";
+ return block?.text || "";
+ })
+ .filter(Boolean)
+ .join("\n");
+ } else if (content && typeof content === "object") {
+ text = content.text || "";
+ }
+
+ if (!text) return;
+
+ if (systemInstruction) {
+ systemInstruction.parts[0].text = `${systemInstruction.parts[0].text}\n${text}`;
+ } else {
+ systemInstruction = {
+ parts: [{ text }],
+ role: "system",
+ };
+ }
+ };
+
+ // Extract system messages into Gemini systemInstruction.
  if (claudeBody.system) {
- const systemContent = Array.isArray(claudeBody.system)
- ? claudeBody.system.map(block => (typeof block === "string" ? block : block.text || "")).join("\n")
- : claudeBody.system;
- systemInstruction = {
- parts: [{ text: systemContent }],
- role: "system",
- };
+ appendSystemContent(claudeBody.system);
+ }
+
+ if (Array.isArray(claudeBody.messages)) {
+ for (const message of claudeBody.messages) {
+ if (message.role === "system") {
+ appendSystemContent(message.content);
+ }
+ }
  }
 
  // Buffer for accumulating consecutive tool result parts
@@ -2141,37 +2172,54 @@ class FormatConverter {
  }
  };
 
+ const ensureGeminiFunctionResponseObject = value => {
+ if (typeof value === "object" && value !== null && !Array.isArray(value)) {
+ return value;
+ }
+ return { result: value };
+ };
+
+ const normalizeClaudeToolResultContent = content => {
+ if (typeof content === "string") {
+ try {
+ return ensureGeminiFunctionResponseObject(JSON.parse(content));
+ } catch {
+ return { result: content };
+ }
+ }
+
+ if (Array.isArray(content)) {
+ const textParts = content
+ .filter(c => c && c.type === "text")
+ .map(c => c.text || "")
+ .join("\n");
+
+ if (textParts.length > 0) {
+ try {
+ return ensureGeminiFunctionResponseObject(JSON.parse(textParts));
+ } catch {
+ return { result: textParts };
+ }
+ }
+
+ return { result: content };
+ }
+
+ return ensureGeminiFunctionResponseObject(content ?? { result: "" });
+ };
+
  // Convert Claude messages to Google format
  for (const message of claudeBody.messages) {
+ if (message.role === "system") continue;
+
  const googleParts = [];
 
  // Handle tool_result role (Claude's function response)
  if (message.role === "user" && Array.isArray(message.content)) {
  const toolResults = message.content.filter(block => block.type === "tool_result");
  if (toolResults.length > 0) {
  for (const toolResult of toolResults) {
- let responseContent;
- if (typeof toolResult.content === "string") {
- try {
- responseContent = JSON.parse(toolResult.content);
- } catch (e) {
- /* eslint-disable-line no-unused-vars */
- responseContent = { result: toolResult.content };
- }
- } else if (Array.isArray(toolResult.content)) {
- // Handle array content (text blocks, etc.)
- const textParts = toolResult.content
- .filter(c => c.type === "text")
- .map(c => c.text)
- .join("\n");
- try {
- responseContent = JSON.parse(textParts);
- } catch {
- responseContent = { result: textParts };
- }
- } else {
- responseContent = toolResult.content || { result: "" };
- }
+ const responseContent = normalizeClaudeToolResultContent(toolResult.content);
 
  // Resolve function name using the map
  const toolUseId = toolResult.tool_use_id;
@@ -2195,12 +2243,11 @@ class FormatConverter {
  // Process non-tool_result content in the same message
  const otherContent = message.content.filter(block => block.type !== "tool_result");
  if (otherContent.length > 0) {
- flushToolParts();
  for (const block of otherContent) {
  if (block.type === "text") {
-googleParts.push({ text: block.text });
+pendingToolParts.push({ text: block.text });
  } else if (block.type === "image") {
-googleParts.push({
+pendingToolParts.push({
  inlineData: {
  data: block.source.data,
  mimeType: block.source.media_type,