diff --git a/open-sse/config/constants.ts b/open-sse/config/constants.ts
index 29a5d3393d..f310f8ab2c 100644
--- a/open-sse/config/constants.ts
+++ b/open-sse/config/constants.ts
@@ -4,7 +4,9 @@ import { loadProviderCredentials } from "./credentialLoader.ts";
 export const FETCH_TIMEOUT_MS = parseInt(process.env.FETCH_TIMEOUT_MS || "120000", 10);
 
 // Idle timeout for SSE streams (ms). Closes stream if no data for this duration.
-export const STREAM_IDLE_TIMEOUT_MS = parseInt(process.env.STREAM_IDLE_TIMEOUT_MS || "60000", 10);
+// Default: 300s to support extended-thinking models (claude-opus-4-6, o3, etc.)
+// that may pause for >60s during deep reasoning phases. Override with STREAM_IDLE_TIMEOUT_MS env var.
+export const STREAM_IDLE_TIMEOUT_MS = parseInt(process.env.STREAM_IDLE_TIMEOUT_MS || "300000", 10);
 
 // Provider configurations
 // OAuth credentials read from env vars with hardcoded fallbacks for backward compatibility.
diff --git a/open-sse/handlers/chatCore.ts b/open-sse/handlers/chatCore.ts
index afcc2bbc0e..5661765ebd 100644
--- a/open-sse/handlers/chatCore.ts
+++ b/open-sse/handlers/chatCore.ts
@@ -192,6 +192,16 @@ export async function handleChatCore({
         return item;
       });
     }
+    // ── #346: Strip tools with empty function.name ──
+    // Claude Code sometimes forwards tool definitions with empty names, causing
+    // OpenAI-compatible upstream providers to reject with:
+    // "Invalid 'input[N].name': empty string. Expected minimum length 1."
+    if (Array.isArray(body.tools)) {
+      body.tools = body.tools.filter((tool: Record<string, unknown>) => {
+        const fn = tool.function as Record<string, unknown> | undefined;
+        return fn?.name && String(fn.name).trim().length > 0;
+      });
+    }
 
     translatedBody = translateRequest(
       sourceFormat,
diff --git a/src/app/api/combos/test/route.ts b/src/app/api/combos/test/route.ts
index a21aaad98e..3506acb47d 100644
--- a/src/app/api/combos/test/route.ts
+++ b/src/app/api/combos/test/route.ts
@@ -49,6 +49,7 @@ export async function POST(request) {
       const startTime = Date.now();
       try {
         // Send a minimal chat request to the internal SSE handler
+        // Use OpenAI-compatible format — universally accepted by all providers via the translator
         const testBody = {
           model: modelStr,
           messages: [{ role: "user", content: "Hi" }],
@@ -58,11 +59,15 @@ export async function POST(request) {
 
         const internalUrl = `${getBaseUrl(request)}/v1/chat/completions`;
         const controller = new AbortController();
-        const timeout = setTimeout(() => controller.abort(), 15000); // 15s timeout
+        const timeout = setTimeout(() => controller.abort(), 20000); // 20s timeout (was 15s, slow providers need more)
 
         const res = await fetch(internalUrl, {
           method: "POST",
-          headers: { "Content-Type": "application/json" },
+          headers: {
+            "Content-Type": "application/json",
+            // Fix #350: bypass REQUIRE_API_KEY for internal admin combo tests
+            "X-Internal-Test": "combo-health-check",
+          },
           body: JSON.stringify(testBody),
           signal: controller.signal,
         });
diff --git a/src/sse/handlers/chat.ts b/src/sse/handlers/chat.ts
index 742bf107de..f9e5767255 100644
--- a/src/sse/handlers/chat.ts
+++ b/src/sse/handlers/chat.ts
@@ -133,7 +133,9 @@ export async function handleChat(request: any, clientRawRequest: any = null) {
 
   // Optional strict API key mode for /v1 endpoints.
   // Keep disabled by default to preserve local-mode compatibility.
-  if (process.env.REQUIRE_API_KEY === "true") {
+  // Exception: X-Internal-Test header bypasses auth for admin-side combo health checks (#350)
+  const isInternalTest = request.headers?.get?.("x-internal-test") === "combo-health-check";
+  if (process.env.REQUIRE_API_KEY === "true" && !isInternalTest) {
     if (!apiKey) {
       log.warn("AUTH", "Missing API key while REQUIRE_API_KEY=true");
       return errorResponse(HTTP_STATUS.UNAUTHORIZED, "Missing API key");