diff --git a/.editorconfig b/.editorconfig
index 51d91d0..3926c8e 100644
--- a/.editorconfig
+++ b/.editorconfig
@@ -5,3 +5,6 @@ end_of_line = lf
 indent_style = space
 indent_size = 4
 insert_final_newline = true
+
+[lexicons/**.json]
+indent_size = 2
diff --git a/lexicons/blue/zio/atfile/upload.json b/lexicons/blue/zio/atfile/upload.json
new file mode 100644
index 0000000..a3147c4
--- /dev/null
+++ b/lexicons/blue/zio/atfile/upload.json
@@ -0,0 +1,20 @@
+{
+  "lexicon": 1,
+  "id": "blue.zio.atfile.upload",
+  "defs": {
+    "main": {
+      "type": "record",
+      "description": "A reference to an uploaded blob.",
+      "key": "any",
+      "record": {
+        "type": "object",
+        "properties": {
+          "createdAt": {
+            "type": "string",
+            "format": "datetime"
+          }
+        }
+      }
+    }
+  }
+}