Prefer TLD WHOIS over contradictory registrar referral; revert heuristic override and add referral test\n\n- Keep TLD response when registrar says ‘not found’\n- Revert WHOIS isRegistered to simple availability check\n- Add referral contradiction unit test for .io scenario\n- All tests passing

src/whois/normalize.test.ts

@@ -87,6 +87,8 @@ Registrar: Registrar LLC
   expect(rec.expirationDate).toBe("2027-04-23T00:00:00Z");
 });
 
+// removed: availability override test in favor of referral-level logic
+
 test("WHOIS .edu EDUCAUSE format", () => {
   const text = `
 This Registry database contains ONLY .EDU domains.

src/whois/referral.test.ts

@@ -0,0 +1,33 @@
+import { describe, expect, it, vi } from "vitest";
+
+vi.mock("./client.js", () => ({
+  whoisQuery: vi.fn(async (server: string) => {
+    if (server === "whois.nic.io") {
+      // TLD WHOIS shows a clearly registered domain and a registrar referral
+      return {
+        serverQueried: server,
+        text: `Domain Name: RAINDROP.IO\nCreation Date: 2013-08-20T20:30:16Z\nRegistry Expiry Date: 2027-08-20T20:30:16Z\nRegistrar WHOIS Server: whois.1api.net\nName Server: BEAU.NS.CLOUDFLARE.COM\nName Server: BARBARA.NS.CLOUDFLARE.COM\n`,
+      };
+    }
+    // Registrar WHOIS contradicts with an availability phrase
+    return {
+      serverQueried: server,
+      text: "No match for RAINDROP.IO",
+    };
+  }),
+}));
+
+import { followWhoisReferrals } from "./referral";
+
+describe("WHOIS referral contradiction handling", () => {
+  it("keeps TLD WHOIS when registrar claims availability", async () => {
+    const res = await followWhoisReferrals("whois.nic.io", "raindrop.io", {
+      followWhoisReferral: true,
+      maxWhoisReferralHops: 2,
+    });
+    expect(res.serverQueried).toBe("whois.nic.io");
+    // ensure we didn't adopt the registrar response
+    expect(res.text.toLowerCase().includes("creation date")).toBe(true);
+    expect(res.text.toLowerCase().includes("no match")).toBe(false);
+  });
+});

src/whois/referral.ts

@@ -1,3 +1,4 @@
+import { isWhoisAvailable } from "../lib/domain";
 import type { LookupOptions } from "../types";
 import type { WhoisQueryResult } from "./client";
 import { whoisQuery } from "./client";
@@ -28,7 +29,14 @@ export async function followWhoisReferrals(
     visited.add(normalized);
     try {
       const res = await whoisQuery(next, domain, opts);
-      current = res; // adopt the newer, more specific result
+      // Prefer authoritative TLD response when registrar contradicts availability
+      const registeredBefore = !isWhoisAvailable(current.text);
+      const registeredAfter = !isWhoisAvailable(res.text);
+      if (registeredBefore && !registeredAfter) {
+        // Registrar claims availability but TLD shows registered: keep TLD
+        break;
+      }
+      current = res; // adopt registrar when it does not downgrade registration
     } catch {
       // If referral server fails, stop following and keep the last good response
       break;