From 23f4fd3181de7ffddf0dd2a5c5bc6df059b6d16f Mon Sep 17 00:00:00 2001
From: Brennan Benson <79079362+brennanb2025@users.noreply.github.com>
Date: Mon, 9 Nov 2026 15:28:28 -0800
Subject: [PATCH] fix(usage): price Claude Fable 5.2 and Mythos 5.2 (#40506)

---
 src/main/claude-usage/claude-model-pricing.test.ts | 2 +-
 src/main/claude-usage/claude-model-pricing.ts      | 9 +++++++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/src/main/claude-usage/claude-model-pricing.test.ts b/src/main/claude-usage/claude-model-pricing.test.ts
index 7d616f471c5..5eea907a6cd 100644
--- a/src/main/claude-usage/claude-model-pricing.test.ts
+++ b/src/main/claude-usage/claude-model-pricing.test.ts
@@ -48,7 +48,7 @@ describe('model pricing name matching', () => {
   it.each([
     'claude-opus-5-6',
     'claude-sonnet-5-6',
-    'claude-fable-5-2',
+    'claude-fable-5-3',
     'claude-opus-6',
     'claude-opus-4.9',
     'claude-opus-5-50',
diff --git a/src/main/claude-usage/claude-model-pricing.ts b/src/main/claude-usage/claude-model-pricing.ts
index 693a7fda33c..1e8489789d9 100644
--- a/src/main/claude-usage/claude-model-pricing.ts
+++ b/src/main/claude-usage/claude-model-pricing.ts
@@ -30,6 +30,13 @@ const SONNET_4_LONG_CONTEXT = {
 }
 
 // Mythos models are billed at their Fable counterparts' rates.
+const FABLE_5_2_PRICING: ClaudeModelPricing = {
+  input: 8,
+  output: 40,
+  cacheRead: 0.2,
+  cacheWrite: 10,
+  cacheWrite1h: 16
+}
 const FABLE_5_1_PRICING: ClaudeModelPricing = {
   input: 10,
   output: 50,
@@ -47,6 +54,8 @@ const FABLE_5_PRICING: ClaudeModelPricing = {
 
 // Unknown model versions stay unpriced until explicitly added.
 export const MODEL_PRICING: Record<string, ClaudeModelPricing> = {
+  'claude-fable-5-2': FABLE_5_2_PRICING,
+  'claude-mythos-5-2': FABLE_5_2_PRICING,
   'claude-fable-5-1': FABLE_5_1_PRICING,
   'claude-mythos-5-1': FABLE_5_1_PRICING,
   'claude-fable-5': FABLE_5_PRICING,