From f737a7925fa673ca9628628fc220224491e44536 Mon Sep 17 00:00:00 2001
From: "gemini-cli[bot]" <gemini-cli[bot]@users.noreply.github.com>
Date: Wed, 13 May 2026 23:24:54 +0000
Subject: [PATCH] fix(core): add gemini-2.5-flash-lite to default fallback
 chain

This PR updates the default model policy chain to include `gemini-2.5-flash-lite` as the final resort.

Currently, the chain only includes `gemini-2.5-pro` and `gemini-2.5-flash`. Free-tier users have significantly more quota (1,000 RPD) for Flash-Lite compared to Pro (100 RPD) and Flash (250 RPD). When both Pro and Flash quotas are exhausted, the CLI fails hard despite available Flash-Lite capacity.

Changes:
- Updated `getModelPolicyChain` in `packages/core/src/availability/policyCatalog.ts` to include `DEFAULT_GEMINI_FLASH_LITE_MODEL`.
- Updated tests in `packages/core/src/availability/policyCatalog.test.ts` to reflect the new chain length.

Fixes #26841

cc @adamfweidman @davidapierce
---
 packages/core/src/availability/policyCatalog.test.ts | 2 +-
 packages/core/src/availability/policyCatalog.ts      | 4 ++++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/packages/core/src/availability/policyCatalog.test.ts b/packages/core/src/availability/policyCatalog.test.ts
index 04e35018d5..d57d9c139f 100644
--- a/packages/core/src/availability/policyCatalog.test.ts
+++ b/packages/core/src/availability/policyCatalog.test.ts
@@ -50,7 +50,7 @@ describe('policyCatalog', () => {
   it('returns default chain when preview disabled', () => {
     const chain = getModelPolicyChain({ previewEnabled: false });
     expect(chain[0]?.model).toBe(DEFAULT_GEMINI_MODEL);
-    expect(chain).toHaveLength(2);
+    expect(chain).toHaveLength(3);
   });
 
   it('marks preview transients as sticky retries when auto-selected', () => {
diff --git a/packages/core/src/availability/policyCatalog.ts b/packages/core/src/availability/policyCatalog.ts
index a5694e94b8..811c81fa87 100644
--- a/packages/core/src/availability/policyCatalog.ts
+++ b/packages/core/src/availability/policyCatalog.ts
@@ -122,6 +122,10 @@ export function getModelPolicyChain(
     }),
     definePolicy({
       model: DEFAULT_GEMINI_FLASH_MODEL,
+      maxAttempts: 10,
+    }),
+    definePolicy({
+      model: DEFAULT_GEMINI_FLASH_LITE_MODEL,
       isLastResort: true,
       maxAttempts: 10,
     }),