diff --git a/apps/server/src/provider/model-manifest.json b/apps/server/src/provider/model-manifest.json
index efc22ad0a3d0..8befdd86ec52 100644
--- a/apps/server/src/provider/model-manifest.json
+++ b/apps/server/src/provider/model-manifest.json
@@ -1,6 +1,6 @@
 {
   "version": 1,
-  "updatedAt": "2026-09-12T00:41:55Z",
+  "updatedAt": "2026-09-22T17:51:55Z",
   "currentModels": {
     "codex": [
       "gpt-6-astra",
@@ -10,7 +10,7 @@
       "gpt-daybreak-blue-latest",
       "gpt-daybreak-red-latest"
     ],
-    "claudeAgent": ["claude-fable-5-1", "claude-opus-5", "claude-sonnet-5"],
+    "claudeAgent": ["claude-fable-5-1", "claude-opus-5-5", "claude-opus-5", "claude-sonnet-5"],
     "antigravity": ["gemini-3.8-flash-high", "gemini-3.8-flash-medium", "gemini-3.8-flash-low"]
   },
   "providers": {
@@ -96,6 +96,48 @@
             }
           }
         },
+        "opus-5-5": {
+          "capabilities": {
+            "optionDescriptors": [
+              {
+                "id": "effort",
+                "label": "Reasoning",
+                "type": "select",
+                "options": [
+                  { "id": "low", "label": "Low" },
+                  { "id": "medium", "label": "Medium", "isDefault": true },
+                  { "id": "high", "label": "High" },
+                  { "id": "xhigh", "label": "Extra High" },
+                  { "id": "max", "label": "Max" },
+                  {
+                    "id": "ultracode",
+                    "label": "Ultracode",
+                    "description": "xhigh effort plus multi-agent workflow orchestration"
+                  },
+                  { "id": "ultrathink", "label": "Ultrathink" }
+                ],
+                "promptInjectedValues": ["ultrathink"]
+              },
+              { "id": "fastMode", "label": "Fast Mode", "type": "boolean" },
+              {
+                "id": "contextWindow",
+                "label": "Context Window",
+                "type": "select",
+                "options": [
+                  { "id": "200k", "label": "200k" },
+                  { "id": "1m", "label": "1M", "isDefault": true }
+                ]
+              }
+            ]
+          },
+          "adapter": {
+            "claudeCode": {
+              "effortMap": { "ultracode": "xhigh", "ultrathink": null },
+              "modelSuffixes": { "contextWindow": { "1m": "[1m]" } },
+              "contextWindowTokens": { "200k": 200000, "1m": 1000000 }
+            }
+          }
+        },
         "opus-5": {
           "capabilities": {
             "optionDescriptors": [
@@ -554,6 +596,15 @@
         }
       },
       "models": [
+        {
+          "slug": "claude-opus-5-5",
+          "name": "Claude Opus 5.5",
+          "aliases": ["opus-5.5", "claude-opus-5.5"],
+          "status": "current",
+          "badge": "new",
+          "profile": "opus-5-5",
+          "adapter": { "claudeCode": { "minVersion": "2.1.280" } }
+        },
         {
           "slug": "claude-fable-5-1",
           "name": "Claude Fable 5.1",
diff --git a/docs/internals/model-manifest.md b/docs/internals/model-manifest.md
index 3892a1df7277..7d3eadae7f58 100644
--- a/docs/internals/model-manifest.md
+++ b/docs/internals/model-manifest.md
@@ -16,9 +16,11 @@ built-in catalog. Adding a model with an existing capability profile is a JSON
 edit; a new profile is needed only for a new capability combination. Codex still
 gets its model list from its app server.
 
-`currentModels.claudeAgent` is frozen for releases that predate catalog discovery.
-Do not extend it when adding Claude models. Codex uses `currentModels.codex` as a
-legacy-classification overlay for discovered models.
+`currentModels.claudeAgent` is the current-model classification overlay for
+releases that predate catalog discovery; it does not add models to their catalogs.
+Catalog-aware releases use `providers.claudeAgent.models[].status` instead.
+Codex uses `currentModels.codex` as a legacy-classification overlay for discovered
+models.
 
 Model data is schema-validated configuration. Tests should cover resolver, cache,
 and adapter semantics with synthetic model names, so adding a model never requires