diff --git a/packages/core/src/core/tokenLimits.test.ts b/packages/core/src/core/tokenLimits.test.ts
index edea10a10..0f1fc863b 100644
--- a/packages/core/src/core/tokenLimits.test.ts
+++ b/packages/core/src/core/tokenLimits.test.ts
@@ -108,11 +108,11 @@ describe('tokenLimit', () => {
   });
 
   describe('OpenAI', () => {
-    it('should return 400K for GPT-5.x (latest)', () => {
-      expect(tokenLimit('gpt-5')).toBe(400000);
-      expect(tokenLimit('gpt-5-mini')).toBe(400000);
-      expect(tokenLimit('gpt-5.2')).toBe(400000);
-      expect(tokenLimit('gpt-5.2-pro')).toBe(400000);
+    it('should return 272K for GPT-5.x (latest)', () => {
+      expect(tokenLimit('gpt-5')).toBe(272000);
+      expect(tokenLimit('gpt-5-mini')).toBe(272000);
+      expect(tokenLimit('gpt-5.2')).toBe(272000);
+      expect(tokenLimit('gpt-5.2-pro')).toBe(272000);
     });
 
     it('should return 128K for legacy GPT (fallback)', () => {
diff --git a/packages/core/src/core/tokenLimits.ts b/packages/core/src/core/tokenLimits.ts
index d038133cb..df911a936 100644
--- a/packages/core/src/core/tokenLimits.ts
+++ b/packages/core/src/core/tokenLimits.ts
@@ -23,6 +23,7 @@ const LIMITS = {
   '128k': 131_072,
   '200k': 200_000, // vendor-declared decimal, used by OpenAI, Anthropic, etc.
   '256k': 262_144,
+  '272k': 272_000, // vendor-declared decimal, GPT-5.x input (400K total - 128K output)
   '400k': 400_000, // vendor-declared decimal, used by OpenAI GPT-5.x
   '512k': 524_288,
   '1m': 1_000_000,
@@ -87,7 +88,7 @@ const PATTERNS: Array<[RegExp, TokenCount]> = [
   // -------------------
   // OpenAI
   // -------------------
-  [/^gpt-5/, LIMITS['400k']], // GPT-5.x: 400K
+  [/^gpt-5/, LIMITS['272k']], // GPT-5.x: 272K input (400K total - 128K output)
   [/^gpt-/, LIMITS['128k']], // GPT fallback (4o, 4.1, etc.): 128K
   [/^o\d/, LIMITS['200k']], // o-series (o3, o4-mini, etc.): 200K
 
@@ -171,8 +172,8 @@ const OUTPUT_PATTERNS: Array<[RegExp, TokenCount]> = [
   [/^deepseek-chat/, LIMITS['8k']],
 
   // Zhipu GLM
-  [/^glm-5/, LIMITS['16k']],
-  [/^glm-4\.7/, LIMITS['16k']],
+  [/^glm-5/, LIMITS['128k']],
+  [/^glm-4\.7/, LIMITS['128k']],
 
   // MiniMax
   [/^minimax-m2\.5/i, LIMITS['64k']],