diff --git a/download.json.schema b/download.json.schema
new file mode 100644
index 0000000..9c976e0
--- /dev/null
+++ b/download.json.schema
@@ -0,0 +1,43 @@
+{
+    "$schema": "http://json-schema.org/draft-07/schema#",
+    "type": "object",
+    "properties": {
+        "dev": {
+            "type": "object",
+            "properties": {
+                "version": {
+                    "type": "string",
+                    "pattern": "^[0-9]+(\\.[0-9]+)+$"
+                },
+                "exe": {
+                    "$ref": "#/definitions/file"
+                },
+                "jar": {
+                    "$ref": "#/definitions/file"
+                },
+                "sh": {
+                    "$ref": "#/definitions/file"
+                }
+            }
+        }
+    },
+    "additionalProperties": false,
+    "required": ["dev"],
+    "definitions": {
+        "file": {
+            "type": "object",
+            "properties": {
+                "url": {
+                    "type": "string",
+                    "format": "uri"
+                },
+                "sha256": {
+                    "type": "string",
+                    "pattern": "^[a-f0-9]{64}$"
+                }
+            },
+            "additionalProperties": false,
+            "required": ["url", "sha256"]
+        }
+    }
+}
\ No newline at end of file
diff --git a/update.json.schema b/update.json.schema
index 1e6fc8c..c1dbd11 100644
--- a/update.json.schema
+++ b/update.json.schema
@@ -42,6 +42,9 @@
                 },
                 "force": {
                     "type": "boolean"
+                },
+                "preview": {
+                    "type": "boolean"
                 }
             },
             "additionalProperties": false,