Fix MITM

open-sse/translator/request/openai-to-cursor.js

@@ -1,6 +1,7 @@
 /**
  * OpenAI to Cursor Request Translator
  * - assistant tool_calls → kept as-is (Cursor generates tool calls)
+ * - Claude tool_use blocks → converted to OpenAI tool_calls format
  * - tool results → converted to user message string
  */
 import { register } from "../index.js";
@@ -14,6 +15,16 @@ function extractContent(content) {
   return "";
 }
 
+// Build a map of tool_use_id → tool_name from the previous assistant message
+function getToolNameMap(prevMsg) {
+  const map = {};
+  if (!prevMsg?.tool_calls) return map;
+  for (const tc of prevMsg.tool_calls) {
+    if (tc.id && tc.function?.name) map[tc.id] = tc.function.name;
+  }
+  return map;
+}
+
 function convertMessages(messages) {
   const result = [];
 
@@ -26,7 +37,25 @@ function convertMessages(messages) {
     }
 
     if (msg.role === "user") {
-      result.push({ role: "user", content: extractContent(msg.content) || "" });
+      if (Array.isArray(msg.content)) {
+        const parts = [];
+        const prevMsg = result[result.length - 1];
+        const nameMap = getToolNameMap(prevMsg);
+        for (const block of msg.content) {
+          if (block.type === "text") {
+            parts.push(block.text);
+          } else if (block.type === "tool_result") {
+            // Claude format: user message with tool_result blocks
+            const toolResultText = extractContent(block.content) || "";
+            const toolCallId = block.tool_use_id || "";
+            const toolName = nameMap[toolCallId] || "";
+            parts.push(`<tool_result>\n<tool_name>${toolName}</tool_name>\n<tool_call_id>${toolCallId}</tool_call_id>\n<result>${toolResultText}</result>\n</tool_result>`);
+          }
+        }
+        result.push({ role: "user", content: parts.join("\n") || "" });
+      } else {
+        result.push({ role: "user", content: extractContent(msg.content) || "" });
+      }
       continue;
     }
 
@@ -34,10 +63,10 @@ function convertMessages(messages) {
       // Strip system-reminder tags injected by Claude Code
       const raw = extractContent(msg.content) || "";
       const toolContent = raw.replace(/<system-reminder>[\s\S]*?<\/system-reminder>/g, "").trim();
-      // Find matching tool name from previous assistant message
       const prevMsg = result[result.length - 1];
-      const toolName = prevMsg?.tool_calls?.[0]?.function?.name || "";
+      const nameMap = getToolNameMap(prevMsg);
       const toolCallId = msg.tool_call_id || "";
+      const toolName = nameMap[toolCallId] || "";
       result.push({
         role: "user",
         content: `<tool_result>\n<tool_name>${toolName}</tool_name>\n<tool_call_id>${toolCallId}</tool_call_id>\n<result>${toolContent}</result>\n</tool_result>`
@@ -46,10 +75,28 @@ function convertMessages(messages) {
     }
 
     if (msg.role === "assistant") {
-      const content = extractContent(msg.content) || "";
+      let content = extractContent(msg.content) || "";
+      let tool_calls = null;
+
       if (msg.tool_calls && msg.tool_calls.length > 0) {
-        // Strip `index` field — not needed in history, may confuse Cursor
-        const tool_calls = msg.tool_calls.map(({ index, ...tc }) => tc);
+        // OpenAI format: strip `index` field
+        tool_calls = msg.tool_calls.map(({ index, ...tc }) => tc);
+      } else if (Array.isArray(msg.content)) {
+        // Claude format: extract tool_use blocks from content array
+        const extracted = msg.content
+          .filter(b => b.type === "tool_use")
+          .map(b => ({
+            id: b.id,
+            type: "function",
+            function: {
+              name: b.name,
+              arguments: JSON.stringify(b.input || {})
+            }
+          }));
+        if (extracted.length > 0) tool_calls = extracted;
+      }
+
+      if (tool_calls) {
         result.push({ role: "assistant", content, tool_calls });
       } else if (content) {
         result.push({ role: "assistant", content });