fix(codex): translate messages to input for Cursor 5.5 compact endpoint passthrough (#1832)

CHANGELOG.md

@@ -15,6 +15,8 @@
 
 ### 🐛 Bug Fixes
 
+- **Combo Routing:** Fixed an issue where Gemini `-preview` models were incorrectly normalized to their canonical names, causing 404 errors during combo routing (#1834)
+- **Codex Native Passthrough:** Added support for Cursor 5.5 sending `messages` arrays to the `responses/compact` endpoint, preventing upstream rejections with empty requests (#1832)
 - **Rate-limit Watchdog:** Implemented a new rate-limit watchdog with environment override capabilities and Stage Tracing to prevent and diagnose silent wedges (#1828)
 - **Encryption Resiliency:** Prevent sending encrypted tokens to providers by returning null on decryption failure (#763d353)
 - **i18n & Locales:** Fixed OpenCode baseUrl locale placeholders and added compression keys across 32 languages

open-sse/executors/codex.ts

@@ -1251,6 +1251,23 @@ export class CodexExecutor extends BaseExecutor {
     // so any references to previous response items would cause 404 errors.
     stripStoredItemReferences(body);
 
+    // Issue #1832: Map messages to input for clients like Cursor 5.5 that use responses/compact but send messages instead of input
+    if (!body.input && Array.isArray(body.messages)) {
+      body.input = body.messages.map((msg: any) => ({
+        type: "message",
+        role: typeof msg.role === "string" ? msg.role : "user",
+        content:
+          typeof msg.content === "string"
+            ? [{ type: "input_text", text: msg.content }]
+            : Array.isArray(msg.content)
+              ? msg.content.map((c: any) => {
+                  if (c && c.type === "text") return { type: "input_text", text: c.text };
+                  return c;
+                })
+              : [],
+      }));
+    }
+
     // Issue #806: Even for native passthrough, some clients (purist completions) might indiscriminately inject
     // a `messages` or `prompt` array which the strict Codex Responses schema rejects.
     delete body.messages;