diff --git a/biome.json b/biome.json
index f97f513..1435f87 100644
--- a/biome.json
+++ b/biome.json
@@ -1,5 +1,5 @@
 {
-  "$schema": "https://biomejs.dev/schemas/2.2.4/schema.json",
+  "$schema": "./node_modules/@biomejs/biome/configuration_schema.json",
   "vcs": {
     "enabled": true,
     "clientKind": "git"
diff --git a/package.json b/package.json
index 7140580..75570cc 100644
--- a/package.json
+++ b/package.json
@@ -19,7 +19,7 @@
   "scripts": {
     "clean": "rm -rf dist",
     "build": "npm run clean && tsc -p tsconfig.build.json",
-    "test": "tsc && node --test dist/**/*.test.js",
+    "test": "npm run clean && tsc -p tsconfig.json && node --test dist/**/*.test.js",
     "lint": "biome check --write",
     "prepublishOnly": "npm run build"
   },
diff --git a/src/api/__tests__/lookup.smoke.test.ts b/src/api/__tests__/lookup.smoke.test.ts
index dded28b..9d22ec9 100644
--- a/src/api/__tests__/lookup.smoke.test.ts
+++ b/src/api/__tests__/lookup.smoke.test.ts
@@ -1,3 +1,5 @@
+/** biome-ignore-all lint/style/noNonNullAssertion: this is fine for tests */
+
 import assert from "node:assert/strict";
 import test from "node:test";
 import { lookupDomain } from "../lookup.js";
@@ -5,6 +7,7 @@ import { lookupDomain } from "../lookup.js";
 // Run only when SMOKE=1 to avoid flakiness and network in CI by default
 const shouldRun = process.env.SMOKE === "1";
 
+// Basic sanity: either RDAP or WHOIS should succeed for example.com
 (shouldRun ? test : test.skip)(
   "lookupDomain smoke test (example.com)",
   async () => {
@@ -18,3 +21,106 @@ const shouldRun = process.env.SMOKE === "1";
     assert.ok(res.record?.source === "rdap" || res.record?.source === "whois");
   },
 );
+
+// RDAP-only smoke for reserved example domains (.com/.net/.org)
+const rdapCases: Array<{ domain: string; tld: string; expectDs?: boolean }> = [
+  { domain: "example.com", tld: "com", expectDs: true },
+  { domain: "example.net", tld: "net", expectDs: true },
+  { domain: "example.org", tld: "org" },
+];
+
+for (const c of rdapCases) {
+  (shouldRun ? test : test.skip)(
+    `RDAP-only lookup for ${c.domain}`,
+    async () => {
+      const res = await lookupDomain(c.domain, {
+        timeoutMs: 15000,
+        rdapOnly: true,
+      });
+      assert.equal(res.ok, true, res.error);
+      const rec = res.record!;
+      assert.equal(rec.tld, c.tld);
+      assert.equal(rec.source, "rdap");
+      // Registrar ID is IANA (376) for example domains
+      assert.equal(rec.registrar?.ianaId, "376");
+      if (c.tld !== "org") {
+        // .com/.net often include the IANA reserved name explicitly
+        assert.ok(
+          (rec.registrar?.name || "")
+            .toLowerCase()
+            .includes("internet assigned numbers authority"),
+        );
+      }
+      // IANA nameservers
+      const ns = (rec.nameservers || []).map((n) => n.host.toLowerCase());
+      assert.ok(ns.includes("a.iana-servers.net"));
+      assert.ok(ns.includes("b.iana-servers.net"));
+      if (c.expectDs) {
+        // DS records typically present for .com/.net
+        assert.equal(rec.dnssec?.enabled, true);
+        assert.ok((rec.dnssec?.dsRecords || []).length > 0);
+      }
+    },
+  );
+}
+
+// RDAP-only negative: .io lacks RDAP; expect failure
+(shouldRun ? test : test.skip)(
+  "RDAP-only lookup for example.io fails",
+  async () => {
+    const res = await lookupDomain("example.io", {
+      timeoutMs: 15000,
+      rdapOnly: true,
+    });
+    assert.equal(res.ok, false);
+  },
+);
+
+// WHOIS-only smoke for example.com
+(shouldRun ? test : test.skip)(
+  "WHOIS-only lookup for example.com",
+  async () => {
+    const res = await lookupDomain("example.com", {
+      timeoutMs: 15000,
+      whoisOnly: true,
+      followWhoisReferral: true,
+    });
+    assert.equal(res.ok, true, res.error);
+    assert.equal(res.record?.tld, "com");
+    assert.equal(res.record?.source, "whois");
+    // Invariants for example.com
+    assert.equal(
+      res.record?.whoisServer?.toLowerCase(),
+      "whois.verisign-grs.com",
+    );
+    assert.equal(res.record?.registrar?.ianaId, "376");
+    const ns = (res.record?.nameservers || []).map((n) => n.host.toLowerCase());
+    assert.ok(ns.includes("a.iana-servers.net"));
+    assert.ok(ns.includes("b.iana-servers.net"));
+  },
+);
+
+// WHOIS-only smoke for example.io (RDAP-incompatible TLD)
+(shouldRun ? test : test.skip)("WHOIS-only lookup for example.io", async () => {
+  const res = await lookupDomain("example.io", {
+    timeoutMs: 15000,
+    whoisOnly: true,
+    followWhoisReferral: true,
+  });
+  assert.equal(res.ok, true, res.error);
+  const rec = res.record!;
+  assert.equal(rec.tld, "io");
+  assert.equal(rec.source, "whois");
+  // Accept either TLD WHOIS or registrar WHOIS as the final server
+  const server = (rec.whoisServer || "").toLowerCase();
+  assert.ok(["whois.nic.io", "whois.namecheap.com"].includes(server));
+  // Registrar ID may only be present on registrar WHOIS responses
+  if (rec.registrar?.ianaId) {
+    assert.equal(rec.registrar.ianaId, "1068");
+  }
+  // Nameservers commonly set for example.io (DigitalOcean)
+  const ns = (rec.nameservers || []).map((n) => n.host.toLowerCase());
+  assert.ok(ns.includes("ns1.digitalocean.com"));
+  assert.ok(ns.includes("ns2.digitalocean.com"));
+  assert.ok(ns.includes("ns3.digitalocean.com"));
+});
diff --git a/src/lib/__tests__/dates.test.ts b/src/lib/__tests__/dates.test.ts
index 498c248..aacbceb 100644
--- a/src/lib/__tests__/dates.test.ts
+++ b/src/lib/__tests__/dates.test.ts
@@ -1,3 +1,5 @@
+/** biome-ignore-all lint/style/noNonNullAssertion: this is fine for tests */
+
 import assert from "node:assert/strict";
 import test from "node:test";
 import { toISO } from "../dates.js";
@@ -7,11 +9,9 @@ test("toISO parses ISO and common whois formats", () => {
   assert.equal(iso, "2023-01-02T03:04:05Z");
 
   const noZ = toISO("2023-01-02 03:04:05");
-  // biome-ignore lint/style/noNonNullAssertion: this is fine
   assert.match(noZ!, /^2023-01-02T03:04:05Z$/);
 
   const slash = toISO("2023/01/02 03:04:05");
-  // biome-ignore lint/style/noNonNullAssertion: this is fine
   assert.match(slash!, /^2023-01-02T03:04:05Z$/);
 
   const dmy = toISO("02-Jan-2023");