diff --git a/stages/org.osbuild.ostree b/stages/org.osbuild.ostree
index fe900553..729818ab 100755
--- a/stages/org.osbuild.ostree
+++ b/stages/org.osbuild.ostree
@@ -30,105 +30,114 @@ import osbuild.api
 from osbuild.util import selinux
 
 
-SCHEMA = """
-"required": ["commit", "osname"],
-"properties": {
-  "commit": {
-    "description": "checksum of the OSTree commit",
-    "type": "string"
-  },
-  "mounts": {
-    "description": "Mount points of the final file system",
-    "type": "array",
-    "items": {
-      "description": "Description of one mount point",
+SCHEMA_2 = """
+"inputs": {
+  "type": "object",
+  "additionalProperties": false,
+  "required": ["commit"],
+  "properties": {
+    "commit": {
       "type": "object",
-      "required": ["path"],
-      "properties": {
-        "path": {
-          "description": "The path of the mount point",
-          "type": "string"
-        },
-        "mode": {
-          "description": "The mode of the mount point",
-          "type": "integer",
-          "default": 493
+      "additionalProperties": true
+    }
+  }
+},
+"options": {
+  "required": ["osname"],
+  "properties": {
+    "mounts": {
+      "description": "Mount points of the final file system",
+      "type": "array",
+      "items": {
+        "description": "Description of one mount point",
+        "type": "object",
+        "required": ["path"],
+        "properties": {
+          "path": {
+            "description": "The path of the mount point",
+            "type": "string"
+          },
+          "mode": {
+            "description": "The mode of the mount point",
+            "type": "integer",
+            "default": 493
+          }
         }
       }
-    }
-  },
-  "osname": {
-    "description": "Name of the stateroot to be used in the deployment",
-    "type": "string"
-  },
-  "kernel_opts": {
-    "description": "Additional kernel command line options",
-    "type": "array",
-    "items": {
-      "description": "A single kernel command line option",
+    },
+    "osname": {
+      "description": "Name of the stateroot to be used in the deployment",
       "type": "string"
-    }
-  },
-  "ref": {
-    "description": "OStree ref to create and use for deployment",
-    "type": "string"
-  },
-  "remotes": {
-    "description": "Configure remotes for the system repository",
-    "type": "array",
-    "items": {
-      "description": "Description of a remote",
-      "type": "object",
-      "required": ["name", "url"],
-      "properties": {
-        "name": {
-          "description": "Identifier for the remote",
-          "type": "string"
-        },
-        "url": {
-          "description": "URL of the remote",
-          "type": "string"
-        },
-        "branches": {
-          "type": "array",
-          "items": {
-            "description": "Configured branches for the remote",
+    },
+    "kernel_opts": {
+      "description": "Additional kernel command line options",
+      "type": "array",
+      "items": {
+        "description": "A single kernel command line option",
+        "type": "string"
+      }
+    },
+    "ref": {
+      "description": "OStree ref to create and use for deployment",
+      "type": "string"
+    },
+    "remotes": {
+      "description": "Configure remotes for the system repository",
+      "type": "array",
+      "items": {
+        "description": "Description of a remote",
+        "type": "object",
+        "required": ["name", "url"],
+        "properties": {
+          "name": {
+            "description": "Identifier for the remote",
             "type": "string"
-          }
-        },
-        "gpgkeys": {
-          "type": "array",
-          "items": {
-            "description": "GPG keys for the remote to verify commits",
+          },
+          "url": {
+            "description": "URL of the remote",
             "type": "string"
+          },
+          "branches": {
+            "type": "array",
+            "items": {
+              "description": "Configured branches for the remote",
+              "type": "string"
+            }
+          },
+          "gpgkeys": {
+            "type": "array",
+            "items": {
+              "description": "GPG keys for the remote to verify commits",
+              "type": "string"
+            }
           }
         }
       }
-    }
-  },
-  "rootfs": {
-    "description": "Identifier to locate the root file system",
-    "type": "object",
-    "oneOf": [{
-      "required": ["uuid"]
-    }, {
-      "required": ["label"]
-    }],
-    "properties": {
-      "label": {
-        "description": "Identify the root file system by label",
-        "type": "string"
-      },
-      "uuid": {
-        "description": "Identify the root file system by UUID",
-        "type": "string"
+    },
+    "rootfs": {
+      "description": "Identifier to locate the root file system",
+      "type": "object",
+      "oneOf": [{
+        "required": ["uuid"]
+      }, {
+        "required": ["label"]
+      }],
+      "properties": {
+        "label": {
+          "description": "Identify the root file system by label",
+          "type": "string"
+        },
+        "uuid": {
+          "description": "Identify the root file system by UUID",
+          "type": "string"
+        }
       }
+    },
+    "populate_var": {
+      "description": "Populate $stateroot/var via systemd-tmpfiles",
+      "type": "boolean",
+      "default": false
     }
-  },
-  "populate_var": {
-    "description": "Populate $stateroot/var via systemd-tmpfiles",
-    "type": "boolean",
-    "default": false
   }
 }
 """
@@ -217,10 +226,10 @@ def populate_var(sysroot):
 
 
 def parse_input(inputs):
-    commits = inputs["commits"]
+    commits = inputs["commit"]
     data = commits["data"]
     refs = data["refs"]
-    assert refs, "Need at least one commit"
+    assert len(refs) == 1, "Need exactly one commit"
     return commits["path"], data["refs"]
 
 
@@ -244,7 +253,7 @@ def main(tree, inputs, options):
         ostree("pull-local", source_repo, ref,
                repo=f"{tree}/ostree/repo")
 
-    #NB: if there are multiple commits, we deploy only
+    # NB: if there are multiple commits, we deploy only
     # the latest one
 
     ostree("admin", "os-init", osname, sysroot=tree)
@@ -268,7 +277,6 @@ def main(tree, inputs, options):
             os.chmod(path, mount.get("mode", 0o755))
             mounter.mount(path, path)
 
-
         ostree("admin", "deploy", ref,
                *kargs,
                sysroot=tree,