diff --git a/openapi/feature-permissions-api.json b/openapi/feature-permissions-api.json
index 64af1c82f..c17704c2d 100644
--- a/openapi/feature-permissions-api.json
+++ b/openapi/feature-permissions-api.json
@@ -420,6 +420,17 @@
           "error": {
             "type": "string"
           },
+          "failure": {
+            "anyOf": [
+              {
+                "$ref": "#/components/schemas/StartupFailureAttachment"
+              },
+              {
+                "type": "null"
+              }
+            ],
+            "description": "An origin-projected error-contract attachment, not raw HTTP error text.\nReceiving it does not authorize redisclosure to a different audience."
+          },
           "message": {
             "type": "string"
           }
@@ -449,6 +460,10 @@
         ],
         "type": "object"
       },
+      "StartupFailureAttachment": {
+        "description": "A bounded, projected envelope at the Worker/Runtime or metadata boundary.\nNo constructor accepts Display text, arbitrary JSON fields, or an unprojected error.",
+        "type": "string"
+      },
       "ValidatePermissionsRequest": {
         "additionalProperties": false,
         "description": "The management boundary uses exactly the same assignment as text/storage.\nWorkspace comes from authenticated routing, not a repeated permission field.",
@@ -481,7 +496,7 @@
   "info": {
     "title": "Feature permission declaration contract",
     "version": "0.1.0",
-    "x-yoi-source-digest": "sha256:3c85df5880ec5b52d693ba559f02534609f0667d7f95841f6eb58a36823824cb"
+    "x-yoi-source-digest": "sha256:9a4f2ec1ab277c73bf8c69b2adef050dbae26cff5430ff2bd1201371feef5a38"
   },
   "openapi": "3.1.0",
   "paths": {