diff --git a/good-fences/itest/code-mode.test.ts b/good-fences/itest/code-mode.test.ts
new file mode 100644
index 0000000..d1f50fa
--- /dev/null
+++ b/good-fences/itest/code-mode.test.ts
@@ -0,0 +1,21 @@
+/** @file The model, asked in code mode, writes code that drives the mower. */
+import { env } from "cloudflare:workers";
+import { expect, test } from "vitest";
+
+import { codeModeMessages, extractCode } from "../src/code-mode.ts";
+import { makeWorkersAiModel, MODEL } from "../src/model.ts";
+import { aboutMower } from "../src/mower.ts";
+
+test("lent a mower, the neighbor writes code to mow", async () => {
+	const model = makeWorkersAiModel(env.AI, MODEL);
+	const messages = codeModeMessages({
+		say: "you can use this mower for the weekend",
+		about: { mower: aboutMower },
+	});
+	const code = extractCode(await model.complete(messages));
+	console.log(code);
+
+	const calls = [...code.matchAll(/env\.mower\.(\w+)\(/g)].map(([, method]) => method);
+	expect(calls).toContain("push");
+	for (const method of calls) expect(["start", "push", "turn", "stop"]).toContain(method);
+});