diff --git a/src/etapi/etapi.openapi.yaml b/src/etapi/etapi.openapi.yaml
index 974acbdfe..9371331ce 100644
--- a/src/etapi/etapi.openapi.yaml
+++ b/src/etapi/etapi.openapi.yaml
@@ -782,6 +782,9 @@ components:
         isProtected:
           type: boolean
           readOnly: true
+        blobId:
+          type: string
+          description: ID of the blob object. For "cold" notes, this is effectively a content hash
         attributes:
           $ref: '#/components/schemas/AttributeList'
           readOnly: true
diff --git a/src/etapi/mappers.js b/src/etapi/mappers.js
index ad959f36a..26f79da01 100644
--- a/src/etapi/mappers.js
+++ b/src/etapi/mappers.js
@@ -5,6 +5,7 @@ function mapNoteToPojo(note) {
         title: note.title,
         type: note.type,
         mime: note.mime,
+        blobId: note.blobId,
         dateCreated: note.dateCreated,
         dateModified: note.dateModified,
         utcDateCreated: note.utcDateCreated,
@@ -46,4 +47,4 @@ module.exports = {
     mapNoteToPojo,
     mapBranchToPojo,
     mapAttributeToPojo
-};
\ No newline at end of file
+};