diff --git a/open-sse/config/freeModelCatalog.data.ts b/open-sse/config/freeModelCatalog.data.ts
index 38c17abf2d..7b3ad6946f 100644
--- a/open-sse/config/freeModelCatalog.data.ts
+++ b/open-sse/config/freeModelCatalog.data.ts
@@ -16,7 +16,7 @@ import type { FreeModelBudget } from "./freeModelCatalog.ts";
  * rewrites file timestamps on every deploy, which would report a months-old
  * catalog as "updated today". Bump this whenever the entries below change.
  */
-export const FREE_CATALOG_CURATED_AT = "2026-08-18";
+export const FREE_CATALOG_CURATED_AT = "2026-08-20";
 
 export const FREE_MODEL_BUDGETS: FreeModelBudget[] = [
   { provider: "chatgpt-web", modelId: "gpt-5.6-luna-free", displayName: "GPT-5.6 Luna (Free)", monthlyTokens: 0, creditTokens: 0, freeType: "recurring-uncapped", poolKey: "chatgpt-web-free", tos: "caution" },
@@ -318,6 +318,7 @@ export const FREE_MODEL_BUDGETS: FreeModelBudget[] = [
   { provider: "opencode-zen", modelId: "opencode/north-mini-code-free", displayName: "North Mini Code (free)", monthlyTokens: 0, creditTokens: 0, freeType: "recurring-uncapped", poolKey: "opencode-zen-free", tos: "caution" },
   { provider: "opencode-zen", modelId: "opencode/nemotron-3-ultra-free", displayName: "Nemotron 3 Ultra (free)", monthlyTokens: 0, creditTokens: 0, freeType: "recurring-uncapped", poolKey: "opencode-zen-free", tos: "caution" },
   { provider: "openrouter", modelId: "auto", displayName: "Auto (Best Available)", monthlyTokens: 1200000, creditTokens: 0, freeType: "recurring-daily", poolKey: "openrouter-free", tos: "caution" },
+  { provider: "openrouter", modelId: "stealth/ox-alpha", displayName: "Stealth Ox Alpha (free)", monthlyTokens: 0, creditTokens: 0, freeType: "recurring-daily", poolKey: "openrouter-free", tos: "caution" },
   { provider: "pollinations", modelId: "openai", displayName: "OpenAI (Pollinations)", monthlyTokens: 0, creditTokens: 0, freeType: "keyless", poolKey: "pollinations", tos: "caution" },
   { provider: "pollinations", modelId: "openai-fast", displayName: "OpenAI Fast (Pollinations)", monthlyTokens: 0, creditTokens: 0, freeType: "keyless", poolKey: "pollinations", tos: "caution" },
   { provider: "pollinations", modelId: "openai-large", displayName: "OpenAI Large (Pollinations)", monthlyTokens: 0, creditTokens: 0, freeType: "keyless", poolKey: "pollinations", tos: "caution" },
diff --git a/tests/unit/free-model-catalog-ox-alpha.test.ts b/tests/unit/free-model-catalog-ox-alpha.test.ts
new file mode 100644
index 0000000000..00a551ab0f
--- /dev/null
+++ b/tests/unit/free-model-catalog-ox-alpha.test.ts
@@ -0,0 +1,16 @@
+// Regression: stealth/ox-alpha (Stealth Ox Alpha, free 0/0 pricing, 1M context) must
+// stay in the openrouter free roster — the /v1/models synced-row filter drops
+// pricing metadata, so roster presence is what keeps this model visible under
+// hidePaidModels (see #6328).
+import { test } from "node:test";
+import assert from "node:assert/strict";
+import { FREE_MODEL_BUDGETS } from "../../open-sse/config/freeModelCatalog.data.ts";
+
+test("openrouter free roster includes stealth/ox-alpha", () => {
+  const entry = FREE_MODEL_BUDGETS.find(
+    (m) => m.provider === "openrouter" && m.modelId === "stealth/ox-alpha"
+  );
+  assert.ok(entry, "stealth/ox-alpha must be in the openrouter free roster");
+  assert.equal(entry!.poolKey, "openrouter-free");
+  assert.equal(entry!.monthlyTokens, 0, "must not inflate the shared free-pool budget");
+});