diff --git a/apps/server/src/provider/CodexProvider.ts b/apps/server/src/provider/CodexProvider.ts
index 7d4bbfdf5d0fa..4393230eeae4b 100644
--- a/apps/server/src/provider/CodexProvider.ts
+++ b/apps/server/src/provider/CodexProvider.ts
@@ -740,6 +740,8 @@ export const checkCodexProviderStatus = Effect.fn("checkCodexProviderStatus")(fu
     ? { status: "ready" as const, auth: managedAuth, message: undefined }
     : accountProbeStatus(snapshot);
   const usageLimits =
+    // Only a ChatGPT login has quotas; a custom model provider runs with no account.
+    (!snapshot.account.account && !snapshot.account.requiresOpenaiAuth) ||
     snapshot.account.account?.type === "apiKey"
       ? makeUnavailableUsageLimits({ checkedAt, reason: "unsupported" })
       : snapshot.rateLimits === undefined || "failure" in snapshot.rateLimits
diff --git a/apps/server/src/provider/ProviderRegistry.test.ts b/apps/server/src/provider/ProviderRegistry.test.ts
index d0c1f348a7366..2e4d7662551d0 100644
--- a/apps/server/src/provider/ProviderRegistry.test.ts
+++ b/apps/server/src/provider/ProviderRegistry.test.ts
@@ -506,6 +506,7 @@ it.layer(
           status.message,
           "Codex CLI is not authenticated. Run `codex login` and try again.",
         );
+        assert.strictEqual(status.usageLimits?.unavailable?.reason, "probeFailed");
       }),
     );
 
@@ -547,6 +548,22 @@ it.layer(
       }),
     );
 
+    it.effect("marks usage unsupported when a custom provider runs without an account", () =>
+      Effect.gen(function* () {
+        const status = yield* checkCodexProviderStatus(defaultCodexSettings, () =>
+          Effect.succeed(
+            makeCodexProbeSnapshot({
+              account: { account: null, requiresOpenaiAuth: false },
+              rateLimits: { failure: "Codex could not read usage (JSON-RPC -32600)." },
+            }),
+          ),
+        );
+
+        assert.strictEqual(status.status, "ready");
+        assert.deepStrictEqual(status.usageLimits?.unavailable, { reason: "unsupported" });
+      }),
+    );
+
     it.effect("returns an Amazon Bedrock label for codex Bedrock auth", () =>
       Effect.gen(function* () {
         const status = yield* checkCodexProviderStatus(defaultCodexSettings, () =>