diff --git a/src/auto-reply/commands-args.test.ts b/src/auto-reply/commands-args.test.ts
new file mode 100644
index 00000000000..c5e3ad71451
--- /dev/null
+++ b/src/auto-reply/commands-args.test.ts
@@ -0,0 +1,49 @@
+import { describe, expect, it } from "vitest";
+import type { CommandArgValues } from "./commands-registry.types.js";
+import { COMMAND_ARG_FORMATTERS } from "./commands-args.js";
+
+function formatArgs(key: keyof typeof COMMAND_ARG_FORMATTERS, values: Record<string, unknown>) {
+  const formatter = COMMAND_ARG_FORMATTERS[key];
+  return formatter?.(values as unknown as CommandArgValues);
+}
+
+describe("COMMAND_ARG_FORMATTERS", () => {
+  it("formats config args (show/get/unset/set) and normalizes values", () => {
+    expect(formatArgs("config", {})).toBeUndefined();
+
+    expect(formatArgs("config", { action: "  SHOW " })).toBe("show");
+    expect(formatArgs("config", { action: "get", path: " a.b " })).toBe("get a.b");
+    expect(formatArgs("config", { action: "unset", path: "x" })).toBe("unset x");
+
+    expect(formatArgs("config", { action: "set" })).toBe("set");
+    expect(formatArgs("config", { action: "set", path: "x" })).toBe("set x");
+    expect(formatArgs("config", { action: "set", path: "x", value: 1 })).toBe("set x=1");
+    expect(formatArgs("config", { action: "set", path: "x", value: { ok: true } })).toBe(
+      'set x={"ok":true}',
+    );
+
+    expect(formatArgs("config", { action: "whoami", path: "ignored" })).toBe("whoami");
+  });
+
+  it("formats debug args (show/reset/unset/set)", () => {
+    expect(formatArgs("debug", { action: "show", path: "x" })).toBe("show");
+    expect(formatArgs("debug", { action: "reset", path: "x" })).toBe("reset");
+    expect(formatArgs("debug", { action: "unset" })).toBe("unset");
+    expect(formatArgs("debug", { action: "unset", path: "x" })).toBe("unset x");
+    expect(formatArgs("debug", { action: "set", path: "x" })).toBe("set x");
+    expect(formatArgs("debug", { action: "set", path: "x", value: true })).toBe("set x=true");
+  });
+
+  it("formats queue args (order + omission)", () => {
+    expect(formatArgs("queue", {})).toBeUndefined();
+    expect(formatArgs("queue", { mode: "fifo" })).toBe("fifo");
+    expect(
+      formatArgs("queue", {
+        mode: "fifo",
+        debounce: 10,
+        cap: 2n,
+        drop: Symbol("tail"),
+      }),
+    ).toBe("fifo debounce:10 cap:2 drop:Symbol(tail)");
+  });
+});