diff --git a/src/agents/pi-embedded-helpers/failover-matches.test.ts b/src/agents/pi-embedded-helpers/failover-matches.test.ts
index 0e1a022ca93..6fe520965cb 100644
--- a/src/agents/pi-embedded-helpers/failover-matches.test.ts
+++ b/src/agents/pi-embedded-helpers/failover-matches.test.ts
@@ -99,6 +99,10 @@ describe("server error status classification", () => {
     expect(isServerErrorMessage("status: internal server error")).toBe(true);
   });
 
+  it("classifies provider HTTP 5xx wrapper errors as server errors", () => {
+    expect(isServerErrorMessage("provider failed (HTTP 500): upstream apiKey is empty")).toBe(true);
+  });
+
   it("does not classify prefixed plain internal server error status prose", () => {
     expect(isServerErrorMessage("Proxy notice: Status: Internal Server Error")).toBe(false);
   });
diff --git a/src/agents/pi-embedded-helpers/failover-matches.ts b/src/agents/pi-embedded-helpers/failover-matches.ts
index 3a023d5ac55..e36b9f74684 100644
--- a/src/agents/pi-embedded-helpers/failover-matches.ts
+++ b/src/agents/pi-embedded-helpers/failover-matches.ts
@@ -53,6 +53,7 @@ const ZAI_AUTH_CODE_1113_RE = /"code"\s*:\s*1113\b/;
 const STATUS_INTERNAL_SERVER_ERROR_RE = /\bstatus:\s*internal server error\b/i;
 const STATUS_INTERNAL_SERVER_ERROR_WITH_500_RE =
   /^(?=[\s\S]*\bstatus:\s*internal server error\b)(?=[\s\S]*\bcode["']?\s*[:=]\s*500\b)/i;
+const HTTP_5XX_STATUS_RE = /\bHTTP\s+5\d\d\b/i;
 
 const ZAI_AUTH_ERROR_PATTERNS = [
   // Z.ai: error 1113 = wrong endpoint or invalid credentials (#48988)
@@ -305,7 +306,7 @@ export function isServerErrorMessage(raw: string): boolean {
   if (!value) {
     return false;
   }
-  if (STATUS_INTERNAL_SERVER_ERROR_WITH_500_RE.test(value)) {
+  if (STATUS_INTERNAL_SERVER_ERROR_WITH_500_RE.test(value) || HTTP_5XX_STATUS_RE.test(value)) {
     return true;
   }
   const scrubbed = value.replace(STATUS_INTERNAL_SERVER_ERROR_RE, "").trim();