fix(sse): persist terminal account failures during combo fallback

changelog.d/fixes/18649-credit-exhaustion-parks-connection.md

@@ -0,0 +1 @@
+- **fix(sse):** a connection whose account runs out of credit is now parked as `credits_exhausted` even when the failure happens inside combo fallback — previously the combo path dropped the terminal status and the dead account kept receiving traffic (#18633)

src/sse/services/auth.ts

@@ -3152,7 +3152,8 @@ export async function markAccountUnavailable(
     };
     const persistUnavailableState = options.persistUnavailableState !== false;
 
-    if (!persistUnavailableState) {
+    if (!persistUnavailableState && !terminalStatus) {
+      // Terminal account failures must persist even when a combo owns transient cooldowns.
       // Combo-managed transient failure (e.g. 429): keep the connection clean in
       // the DB, but record an in-memory model lockout so credential selection
       // skips this exact provider+connection+model while it cools down — other

tests/unit/18633-credit-exhaustion-parks-connection.test.ts

@@ -0,0 +1,68 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+import fs from "node:fs";
+import os from "node:os";
+import path from "node:path";
+
+const TEST_DATA_DIR = fs.mkdtempSync(path.join(os.tmpdir(), "omniroute-18633-credit-"));
+process.env.DATA_DIR = TEST_DATA_DIR;
+
+const core = await import("../../src/lib/db/core.ts");
+const providersDb = await import("../../src/lib/db/providers.ts");
+const auth = await import("../../src/sse/services/auth.ts");
+const accountFallback = await import("../../open-sse/services/accountFallback.ts");
+const { classify429 } = await import("../../src/shared/utils/classify429.ts");
+
+test.after(() => {
+  core.resetDbInstance();
+  fs.rmSync(TEST_DATA_DIR, { recursive: true, force: true });
+});
+
+test("combo 429 insufficient account balance parks the zai connection across models", async () => {
+  const empty = await providersDb.createProviderConnection({
+    provider: "zai",
+    authType: "apikey",
+    apiKey: "test-empty-account",
+    isActive: true,
+    testStatus: "active",
+  });
+  const live = await providersDb.createProviderConnection({
+    provider: "zai",
+    authType: "apikey",
+    apiKey: "test-live-account",
+    isActive: true,
+    testStatus: "active",
+  });
+  const errorText = JSON.stringify({
+    error: { code: "1113", message: "Insufficient account balance" },
+  });
+  const failureKind = classify429({ status: 429, body: errorText });
+
+  // Mirror chat.ts: combos do not persist transient 429 connection cooldowns.
+  const result = await auth.markAccountUnavailable(
+    empty.id,
+    429,
+    errorText,
+    "zai",
+    "glm-4.7",
+    null,
+    {
+      isCombo: true,
+      persistUnavailableState: !(failureKind === "rate_limit" || failureKind === "transient"),
+    }
+  );
+
+  assert.equal(result.shouldFallback, true);
+  const after = await providersDb.getProviderConnectionById(empty.id);
+  assert.equal(after.testStatus, "credits_exhausted");
+  assert.equal(
+    after.rateLimitedUntil == null,
+    true,
+    "terminal exhaustion must not expire as a cooldown"
+  );
+  assert.equal(accountFallback.getModelLockoutInfo("zai", empty.id, "glm-4.7"), null);
+
+  const selected = await auth.getProviderCredentials("zai", null, null, "glm-5.1");
+  assert.ok(selected);
+  assert.equal(selected.connectionId, live.id, "sibling models must skip the empty account");
+});