diff --git a/commands/flat.js b/commands/flat.js
new file mode 100644
index 0000000..6d586f7
--- /dev/null
+++ b/commands/flat.js
@@ -0,0 +1,42 @@
+import {EOL} from "os"
+import {handler as depcountHandler} from "./depcount"
+import * as symbols from "../symbols"
+
+export let command = "flat"
+export let describe = "exit badly if the tree cannot be flat"
+
+export let builder = yargs => {
+	yargs
+		.options("origami", {
+			type: "boolean"
+		})
+		.options("pattern", {
+			alias: ["r"],
+			type: "array",
+			describe: "only count packages whose name match one of these patterns",
+			coerce: pattern => new RegExp(pattern)
+		})
+		.options("production", {
+			alias: ["prod", "p"],
+			type: "boolean",
+			default: "false",
+			describe: "only count the production (non-dev) tree"
+		})
+}
+
+export async function handler (argv) {
+	let options = argv.origami
+		? {
+			production: true,
+			pattern: /@financial-times\/o-.*/
+		}
+		: argv
+
+	let counts = await depcountHandler({
+		...options,
+		min: 2,
+		[symbols.internal]: true
+	})
+
+	process.exit(counts.length)
+}