diff --git a/containers/api-proxy/model-api-mapping.json b/containers/api-proxy/model-api-mapping.json
index f3776155f..da86e37e8 100644
--- a/containers/api-proxy/model-api-mapping.json
+++ b/containers/api-proxy/model-api-mapping.json
@@ -1,9 +1,9 @@
 {
   "title": "Model-to-API Endpoint Mapping",
   "description": "Maps AI model families to their supported API endpoints. Used to determine which endpoint (chat/completions vs responses vs messages) a model requires.",
-  "lastUpdated": "2026-08-12T05:43:00Z",
+  "lastUpdated": "2026-09-02T07:03:56Z",
   "sources": {
-    "openai": "https://platform.openai.com/docs/models",
+    "openai": "https://developers.openai.com/api/docs/models",
     "anthropic": "https://docs.anthropic.com/en/docs/about-claude/models"
   },
   "providers": {
@@ -37,11 +37,17 @@
           "endpoints": ["chat_completions", "responses"],
           "notes": "Supports both endpoints. Includes gpt-5.6-sol, gpt-5.6-terra, gpt-5.6-luna per OpenAI SDK ChatModel. gpt-5.6-cyber is responses-only (see separate entry above)."
         },
+        {
+          "family": "gpt-5.5-pro",
+          "patterns": ["gpt-5.5-pro", "gpt-5.5-pro-*"],
+          "endpoints": ["responses"],
+          "notes": "Responses API only (ResponsesOnlyModel per OpenAI OpenAPI spec). More specific than gpt-5.5* pattern below. Includes dated variants like gpt-5.5-pro-2026-04-23."
+        },
         {
           "family": "gpt-5.5",
           "patterns": ["gpt-5.5*"],
           "endpoints": ["chat_completions", "responses"],
-          "notes": "Supports both endpoints. Listed on the official GPT-5.5 model page."
+          "notes": "Supports both endpoints. Listed on the official GPT-5.5 model page. gpt-5.5-pro is responses-only (see separate entry above)."
         },
         {
           "family": "gpt-5.4",
diff --git a/containers/api-proxy/model-api-mapping.test.js b/containers/api-proxy/model-api-mapping.test.js
index 2a66dadef..e7f882b24 100644
--- a/containers/api-proxy/model-api-mapping.test.js
+++ b/containers/api-proxy/model-api-mapping.test.js
@@ -42,6 +42,13 @@ describe('model-api-mapping', () => {
       expect(result.endpoints).toContain('responses');
     });
 
+    it('finds GPT-5.5-pro as responses-only', () => {
+      const result = lookupModelEndpoints('gpt-5.5-pro', 'openai');
+      expect(result).not.toBeNull();
+      expect(result.family).toBe('gpt-5.5-pro');
+      expect(result.endpoints).toEqual(['responses']);
+    });
+
     it('finds GPT-5.1 as supporting both endpoints', () => {
       const result = lookupModelEndpoints('gpt-5.1-codex', 'openai');
       expect(result).not.toBeNull();
@@ -136,7 +143,7 @@ describe('model-api-mapping', () => {
       expect(reflect.available).toBe(true);
       expect(reflect.providers).toContain('openai');
       expect(reflect.providers).toContain('anthropic');
-      expect(reflect.last_updated).toBe('2026-08-12T05:43:00Z');
+      expect(reflect.last_updated).toBe('2026-09-02T07:03:56Z');
       expect(reflect.models.anthropic.models[0].family).toBe('claude-opus-5');
       expect(reflect.error).toBeNull();
     });
diff --git a/docs/model-api-mapping.json b/docs/model-api-mapping.json
index c3668a70c..da86e37e8 100644
--- a/docs/model-api-mapping.json
+++ b/docs/model-api-mapping.json
@@ -1,9 +1,9 @@
 {
   "title": "Model-to-API Endpoint Mapping",
   "description": "Maps AI model families to their supported API endpoints. Used to determine which endpoint (chat/completions vs responses vs messages) a model requires.",
-  "lastUpdated": "2026-08-14T05:41:00Z",
+  "lastUpdated": "2026-09-02T07:03:56Z",
   "sources": {
-    "openai": "https://platform.openai.com/docs/models",
+    "openai": "https://developers.openai.com/api/docs/models",
     "anthropic": "https://docs.anthropic.com/en/docs/about-claude/models"
   },
   "providers": {