From 1ec455a9c31021d96903e821a4c9fc96fa9b87dc Mon Sep 17 00:00:00 2001
From: Aditya Vikram Singh <247195684+avs-io@users.noreply.github.com>
Date: Wed, 12 Aug 2026 19:50:00 +0530
Subject: [PATCH] fix(models): correct Sonnet 4 thinking alias

---
 src/models.ts        |  2 +-
 tests/models.test.ts | 10 +++++++++-
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/src/models.ts b/src/models.ts
index f1d9ad0b..ff400df4 100644
--- a/src/models.ts
+++ b/src/models.ts
@@ -311,7 +311,7 @@ const BUILTIN_ALIASES: Record<string, string> = {
   // reports that quote literal slugs (e.g. forum.cursor.com/t/154933).
   'claude-4-sonnet':                'claude-sonnet-4',
   'claude-4-sonnet-1m':             'claude-sonnet-4',
-  'claude-4-sonnet-thinking':       'claude-sonnet-4-5',
+  'claude-4-sonnet-thinking':       'claude-sonnet-4',
   'claude-4.5-sonnet':              'claude-sonnet-4-5',
   'claude-4.5-sonnet-thinking':     'claude-sonnet-4-5',
   'claude-4.6-sonnet':              'claude-sonnet-4-6',
diff --git a/tests/models.test.ts b/tests/models.test.ts
index e8910e37..3e2b1655 100644
--- a/tests/models.test.ts
+++ b/tests/models.test.ts
@@ -505,7 +505,7 @@ describe('Cursor model variants resolve to pricing', () => {
     // Sonnet family
     ['claude-4-sonnet', 'claude-sonnet-4'],
     ['claude-4-sonnet-1m', 'claude-sonnet-4'],
-    ['claude-4-sonnet-thinking', 'claude-sonnet-4-5'],
+    ['claude-4-sonnet-thinking', 'claude-sonnet-4'],
     ['claude-4.5-sonnet', 'claude-sonnet-4-5'],
     ['claude-4.5-sonnet-thinking', 'claude-sonnet-4-5'],
     ['claude-4.6-sonnet', 'claude-sonnet-4-6'],
@@ -558,6 +558,14 @@ describe('Cursor model variants resolve to pricing', () => {
       expect(costs!.outputCostPerToken).toBe(expected!.outputCostPerToken)
     })
   }
+
+  // Regression for #912: Cursor's unversioned `claude-4-sonnet-thinking`
+  // slug is the thinking variant of Sonnet 4, not Sonnet 4.5. The two models
+  // currently share a price, so the display name pins the canonical identity
+  // independently of today's pricing coincidence.
+  it('keeps claude-4-sonnet-thinking in the Sonnet 4 model family', () => {
+    expect(getShortModelName('claude-4-sonnet-thinking')).toBe('Sonnet 4')
+  })
 })
 
 describe('Cursor house model pricing', () => {