diff --git a/CHANGELOG.md b/CHANGELOG.md
index 36fd7e5..37e0658 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,13 @@ All notable changes to the ALCops extension will be documented in this file.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/) and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [1.3.2] - 2026-04-23
+
+### Changed
+- Switch NuGet version queries from V3 Flat Container to V3 Registration API (`registration5-gz-semver2`), which provides listing status per version and excludes unlisted packages from update suggestions
+- Switch package downloads from V2 API (`www.nuget.org/api/v2/package/`) to V3 Flat Container (`api.nuget.org/v3-flatcontainer/`), fixing User-Agent not appearing in NuGet.org download statistics
+- Handle paginated NuGet Registration API responses for packages with 128+ versions (external pages fetched in parallel)
+
 ## [1.3.1] - 2026-04-22
 
 ### Added
diff --git a/src/downloader.ts b/src/downloader.ts
index 722e3e7..eef1775 100644
--- a/src/downloader.ts
+++ b/src/downloader.ts
@@ -3,6 +3,7 @@ import * as https from 'https';
 import * as fs from 'fs';
 import * as path from 'path';
 import * as os from 'os';
+import * as zlib from 'zlib';
 import { unzipSync } from 'fflate';
 import * as vscode from 'vscode';
 import { compare, prerelease, valid } from 'semver';
@@ -90,13 +91,13 @@ export function verifyAnalyzerInstallation(targetPath: string): VerificationResu
  */
 export async function queryLatestVersion(channel: 'stable' | 'beta' | 'alpha'): Promise<string | null> {
     try {
-        const indexUrl = `https://api.nuget.org/v3-flatcontainer/${PACKAGE_NAME.toLowerCase()}/index.json`;
-        const versions = await queryNuGetIndex(indexUrl);
+        const registrationVersions = await queryNuGetRegistration(PACKAGE_NAME);
 
-        const filtered = versions
-            .filter(v => valid(v) !== null)
+        const filtered = registrationVersions
+            .filter(v => v.listed)
+            .filter(v => valid(v.version) !== null)
             .filter(v => {
-                const pre = prerelease(v);
+                const pre = prerelease(v.version);
                 switch (channel) {
                     case 'stable': return pre === null;
                     case 'beta': return pre === null || !pre.includes('alpha');
@@ -109,7 +110,7 @@ export async function queryLatestVersion(channel: 'stable' | 'beta' | 'alpha'):
             return null;
         }
 
-        return filtered.sort((a, b) => compare(a, b)).at(-1)!;
+        return filtered.sort((a, b) => compare(a.version, b.version)).at(-1)!.version;
     } catch (error) {
         console.error('Error querying NuGet for latest version:', error);
         return null;
@@ -130,26 +131,108 @@ function httpsGetWithRedirects(
     }).on('error', onError);
 }
 
-function queryNuGetIndex(indexUrl: string): Promise<string[]> {
+export interface RegistrationVersion {
+    version: string;
+    listed: boolean;
+    packageContent: string;
+}
+
+interface RegistrationCatalogEntry {
+    version: string;
+    listed?: boolean;
+}
+
+interface RegistrationLeaf {
+    catalogEntry: RegistrationCatalogEntry;
+    packageContent: string;
+}
+
+interface RegistrationPage {
+    '@id': string;
+    items?: RegistrationLeaf[];
+}
+
+export interface RegistrationIndex {
+    items: RegistrationPage[];
+}
+
+/**
+ * Fetches a URL and returns parsed JSON, handling gzip decompression when the
+ * server responds with `Content-Encoding: gzip`. Used for NuGet V3 Registration
+ * API requests which are always gzip-compressed in the `-gz-semver2` hive.
+ */
+function fetchJsonWithGzip<T>(url: string): Promise<T> {
     return new Promise((resolve, reject) => {
-        httpsGetWithRedirects(indexUrl, (response) => {
+        httpsGetWithRedirects(url, (response) => {
             if (response.statusCode !== 200) {
-                reject(new Error(`Failed to query NuGet index. Status: ${response.statusCode}`));
+                reject(new Error(`HTTP ${response.statusCode} for ${url}`));
                 return;
             }
-            let data = '';
-            response.on('data', (chunk) => { data += chunk; });
+
+            const chunks: Buffer[] = [];
+            response.on('data', (chunk: Buffer) => { chunks.push(chunk); });
             response.on('end', () => {
                 try {
-                    resolve(JSON.parse(data).versions || []);
+                    const buffer = Buffer.concat(chunks);
+                    const isGzip = response.headers['content-encoding'] === 'gzip';
+                    const text = isGzip ? zlib.gunzipSync(buffer).toString('utf-8') : buffer.toString('utf-8');
+                    resolve(JSON.parse(text) as T);
                 } catch (error) {
-                    reject(new Error(`Failed to parse NuGet index response: ${formatError(error)}`));
+                    reject(new Error(`Failed to parse response from ${url}: ${formatError(error)}`));
                 }
             });
         }, reject);
     });
 }
 
+/**
+ * Parses a NuGet V3 Registration index response into a flat list of versions.
+ * Handles the nested page/leaf/catalogEntry structure. All pages must have their
+ * items inlined (external pages should be resolved before calling this function).
+ */
+export function parseRegistrationIndex(json: RegistrationIndex): RegistrationVersion[] {
+    const versions: RegistrationVersion[] = [];
+    for (const page of json.items) {
+        if (page.items) {
+            for (const leaf of page.items) {
+                versions.push({
+                    version: leaf.catalogEntry.version,
+                    listed: leaf.catalogEntry.listed ?? true,
+                    packageContent: leaf.packageContent,
+                });
+            }
+        }
+    }
+    return versions;
+}
+
+/**
+ * Queries the NuGet V3 Registration API for package versions with metadata.
+ *
+ * Uses the `registration5-gz-semver2` hive which includes SemVer 2.0.0 packages
+ * and provides listing status per version. The response is gzip-compressed.
+ *
+ * For packages with <128 versions, all page data is inlined in the index response.
+ * For packages with 128+ versions, pages are external references that must be
+ * fetched separately. External pages are fetched in parallel.
+ */
+export async function queryNuGetRegistration(packageId: string): Promise<RegistrationVersion[]> {
+    const registrationUrl = `https://api.nuget.org/v3/registration5-gz-semver2/${packageId.toLowerCase()}/index.json`;
+    const index = await fetchJsonWithGzip<RegistrationIndex>(registrationUrl);
+
+    const externalPages = index.items.filter(page => !page.items);
+    if (externalPages.length > 0) {
+        const fetched = await Promise.all(
+            externalPages.map(page => fetchJsonWithGzip<RegistrationPage>(page['@id']))
+        );
+        for (let i = 0; i < externalPages.length; i++) {
+            externalPages[i].items = fetched[i].items;
+        }
+    }
+
+    return parseRegistrationIndex(index);
+}
+
 export async function downloadALCopsAnalyzers(version: string): Promise<void> {
     // Use mutex to ensure only one installation at a time - prevents race conditions
     return installationMutex.withLock(() => downloadALCopsAnalyzersInternal(version));
@@ -159,7 +242,9 @@ export async function downloadALCopsAnalyzers(version: string): Promise<void> {
  * Internal implementation (wrapped by mutex)
  */
 async function downloadALCopsAnalyzersInternal(version: string): Promise<void> {
-    const downloadUrl = `https://www.nuget.org/api/v2/package/${PACKAGE_NAME}/${version}`;
+    const lowerPackageName = PACKAGE_NAME.toLowerCase();
+    const lowerVersion = version.toLowerCase();
+    const downloadUrl = `https://api.nuget.org/v3-flatcontainer/${lowerPackageName}/${lowerVersion}/${lowerPackageName}.${lowerVersion}.nupkg`;
     let tempDir: string | null = null;
 
     try {
diff --git a/tests/downloader.test.ts b/tests/downloader.test.ts
index e89e146..cd034d7 100644
--- a/tests/downloader.test.ts
+++ b/tests/downloader.test.ts
@@ -1,11 +1,23 @@
 import * as path from 'node:path';
 import * as fs from 'node:fs';
 import * as os from 'node:os';
+import * as zlib from 'node:zlib';
+import { EventEmitter } from 'node:events';
 import { describe, it, expect, beforeEach, afterEach, vi } from 'vitest';
 
-vi.mock('vscode', () => ({}));
+vi.mock('vscode', () => ({
+    extensions: {
+        getExtension: () => ({ packageJSON: { version: '0.0.0-test' } }),
+    },
+}));
 
-import { findMatchingLibFolder } from '../src/downloader.js';
+const mockHttpsGet = vi.fn();
+vi.mock('https', () => ({
+    get: (...args: unknown[]) => mockHttpsGet(...args),
+}));
+
+import { findMatchingLibFolder, parseRegistrationIndex, queryNuGetRegistration } from '../src/downloader.js';
+import type { RegistrationIndex } from '../src/downloader.js';
 
 describe('findMatchingLibFolder', () => {
     let tempDir: string;
@@ -75,3 +87,318 @@ describe('findMatchingLibFolder', () => {
         expect(findMatchingLibFolder(tempDir, 'net8.0')).toBe('netstandard2.1');
     });
 });
+
+function makeRegistrationIndex(
+    leaves: Array<{ version: string; listed?: boolean; packageContent?: string }>
+): RegistrationIndex {
+    return {
+        items: [{
+            '@id': 'https://api.nuget.org/v3/registration5-gz-semver2/test/index.json#page/0',
+            items: leaves.map(l => ({
+                catalogEntry: {
+                    version: l.version,
+                    listed: l.listed,
+                },
+                packageContent: l.packageContent ??
+                    `https://api.nuget.org/v3-flatcontainer/test/${l.version.toLowerCase()}/test.${l.version.toLowerCase()}.nupkg`,
+            })),
+        }],
+    };
+}
+
+describe('parseRegistrationIndex', () => {
+    it('extracts versions from inlined page items', () => {
+        const index = makeRegistrationIndex([
+            { version: '1.0.0', listed: true },
+            { version: '2.0.0', listed: true },
+        ]);
+        const result = parseRegistrationIndex(index);
+        expect(result).toHaveLength(2);
+        expect(result[0].version).toBe('1.0.0');
+        expect(result[1].version).toBe('2.0.0');
+    });
+
+    it('preserves listing status', () => {
+        const index = makeRegistrationIndex([
+            { version: '1.0.0', listed: true },
+            { version: '1.1.0-alpha.1', listed: false },
+        ]);
+        const result = parseRegistrationIndex(index);
+        expect(result[0].listed).toBe(true);
+        expect(result[1].listed).toBe(false);
+    });
+
+    it('defaults listed to true when undefined', () => {
+        const index = makeRegistrationIndex([
+            { version: '1.0.0', listed: undefined },
+        ]);
+        const result = parseRegistrationIndex(index);
+        expect(result[0].listed).toBe(true);
+    });
+
+    it('extracts packageContent URLs', () => {
+        const url = 'https://api.nuget.org/v3-flatcontainer/test/1.0.0/test.1.0.0.nupkg';
+        const index = makeRegistrationIndex([
+            { version: '1.0.0', listed: true, packageContent: url },
+        ]);
+        const result = parseRegistrationIndex(index);
+        expect(result[0].packageContent).toBe(url);
+    });
+
+    it('skips pages without inlined items', () => {
+        const index: RegistrationIndex = {
+            items: [
+                {
+                    '@id': 'https://api.nuget.org/v3/registration5-gz-semver2/test/page/0',
+                },
+                {
+                    '@id': 'https://api.nuget.org/v3/registration5-gz-semver2/test/page/1',
+                    items: [{
+                        catalogEntry: { version: '2.0.0', listed: true },
+                        packageContent: 'https://example.com/test.2.0.0.nupkg',
+                    }],
+                },
+            ],
+        };
+        const result = parseRegistrationIndex(index);
+        expect(result).toHaveLength(1);
+        expect(result[0].version).toBe('2.0.0');
+    });
+
+    it('handles multiple pages with inlined items', () => {
+        const index: RegistrationIndex = {
+            items: [
+                {
+                    '@id': 'https://api.nuget.org/v3/registration5-gz-semver2/test/page/0',
+                    items: [
+                        { catalogEntry: { version: '1.0.0', listed: true }, packageContent: 'https://example.com/1' },
+                    ],
+                },
+                {
+                    '@id': 'https://api.nuget.org/v3/registration5-gz-semver2/test/page/1',
+                    items: [
+                        { catalogEntry: { version: '2.0.0', listed: false }, packageContent: 'https://example.com/2' },
+                    ],
+                },
+            ],
+        };
+        const result = parseRegistrationIndex(index);
+        expect(result).toHaveLength(2);
+        expect(result[0].version).toBe('1.0.0');
+        expect(result[1].version).toBe('2.0.0');
+    });
+
+    it('returns empty array for empty index', () => {
+        const index: RegistrationIndex = { items: [] };
+        expect(parseRegistrationIndex(index)).toEqual([]);
+    });
+});
+
+/**
+ * Creates a mock HTTP response emitter that emits the given JSON body,
+ * optionally gzip-compressed, as a stream.
+ */
+function createMockResponse(
+    body: unknown,
+    options: { gzip?: boolean; statusCode?: number } = {}
+): EventEmitter & { statusCode: number; headers: Record<string, string> } {
+    const response = new EventEmitter() as EventEmitter & {
+        statusCode: number;
+        headers: Record<string, string>;
+    };
+    response.statusCode = options.statusCode ?? 200;
+    const json = JSON.stringify(body);
+    const useGzip = options.gzip ?? true;
+    response.headers = useGzip ? { 'content-encoding': 'gzip' } : {};
+
+    // Emit data on next tick so the caller can attach listeners first
+    process.nextTick(() => {
+        const buf = Buffer.from(json, 'utf-8');
+        response.emit('data', useGzip ? zlib.gzipSync(buf) : buf);
+        response.emit('end');
+    });
+
+    return response;
+}
+
+describe('queryNuGetRegistration', () => {
+    afterEach(() => {
+        mockHttpsGet.mockReset();
+    });
+
+    it('returns versions from a fully-inlined index', async () => {
+        const indexBody: RegistrationIndex = {
+            items: [{
+                '@id': 'https://api.nuget.org/v3/registration5-gz-semver2/test/index.json#page/0',
+                items: [
+                    {
+                        catalogEntry: { version: '1.0.0', listed: true },
+                        packageContent: 'https://api.nuget.org/v3-flatcontainer/test/1.0.0/test.1.0.0.nupkg',
+                    },
+                    {
+                        catalogEntry: { version: '2.0.0', listed: false },
+                        packageContent: 'https://api.nuget.org/v3-flatcontainer/test/2.0.0/test.2.0.0.nupkg',
+                    },
+                ],
+            }],
+        };
+
+        mockHttpsGet.mockImplementation((_url: unknown, _opts: unknown, cb: unknown) => {
+            (cb as (r: unknown) => void)(createMockResponse(indexBody));
+            const req = new EventEmitter();
+            return Object.assign(req, { on: vi.fn().mockReturnThis() });
+        });
+
+        const result = await queryNuGetRegistration('Test');
+        expect(result).toHaveLength(2);
+        expect(result[0]).toEqual({
+            version: '1.0.0', listed: true,
+            packageContent: 'https://api.nuget.org/v3-flatcontainer/test/1.0.0/test.1.0.0.nupkg',
+        });
+        expect(result[1].listed).toBe(false);
+    });
+
+    it('fetches external pages and merges results', async () => {
+        const indexBody = {
+            items: [
+                {
+                    '@id': 'https://api.nuget.org/v3/registration5-gz-semver2/test/page/1.0.0/1.9.9.json',
+                    count: 1,
+                    lower: '1.0.0',
+                    upper: '1.9.9',
+                    // No items — external page
+                },
+                {
+                    '@id': 'https://api.nuget.org/v3/registration5-gz-semver2/test/page/2.0.0/2.9.9.json',
+                    count: 1,
+                    lower: '2.0.0',
+                    upper: '2.9.9',
+                    // No items — external page
+                },
+            ],
+        };
+
+        const page0Body = {
+            '@id': 'https://api.nuget.org/v3/registration5-gz-semver2/test/page/1.0.0/1.9.9.json',
+            items: [{
+                catalogEntry: { version: '1.0.0', listed: true },
+                packageContent: 'https://api.nuget.org/v3-flatcontainer/test/1.0.0/test.1.0.0.nupkg',
+            }],
+        };
+
+        const page1Body = {
+            '@id': 'https://api.nuget.org/v3/registration5-gz-semver2/test/page/2.0.0/2.9.9.json',
+            items: [{
+                catalogEntry: { version: '2.0.0', listed: true },
+                packageContent: 'https://api.nuget.org/v3-flatcontainer/test/2.0.0/test.2.0.0.nupkg',
+            }],
+        };
+
+        const responses: Record<string, unknown> = {
+            'https://api.nuget.org/v3/registration5-gz-semver2/test/index.json': indexBody,
+            'https://api.nuget.org/v3/registration5-gz-semver2/test/page/1.0.0/1.9.9.json': page0Body,
+            'https://api.nuget.org/v3/registration5-gz-semver2/test/page/2.0.0/2.9.9.json': page1Body,
+        };
+
+        mockHttpsGet.mockImplementation((url: unknown, _opts: unknown, cb: unknown) => {
+            const body = responses[url as string];
+            if (!body) {
+                throw new Error(`Unexpected URL: ${url}`);
+            }
+            (cb as (r: unknown) => void)(createMockResponse(body));
+            const req = new EventEmitter();
+            return Object.assign(req, { on: vi.fn().mockReturnThis() });
+        });
+
+        const result = await queryNuGetRegistration('Test');
+        expect(result).toHaveLength(2);
+        expect(result[0].version).toBe('1.0.0');
+        expect(result[1].version).toBe('2.0.0');
+    });
+
+    it('handles mix of inlined and external pages', async () => {
+        const indexBody = {
+            items: [
+                {
+                    '@id': 'https://api.nuget.org/v3/registration5-gz-semver2/test/index.json#page/0',
+                    items: [{
+                        catalogEntry: { version: '1.0.0', listed: true },
+                        packageContent: 'https://api.nuget.org/v3-flatcontainer/test/1.0.0/test.1.0.0.nupkg',
+                    }],
+                },
+                {
+                    '@id': 'https://api.nuget.org/v3/registration5-gz-semver2/test/page/2.0.0/2.9.9.json',
+                    count: 1,
+                    lower: '2.0.0',
+                    upper: '2.9.9',
+                },
+            ],
+        };
+
+        const externalPageBody = {
+            items: [{
+                catalogEntry: { version: '2.0.0', listed: false },
+                packageContent: 'https://api.nuget.org/v3-flatcontainer/test/2.0.0/test.2.0.0.nupkg',
+            }],
+        };
+
+        const responses: Record<string, unknown> = {
+            'https://api.nuget.org/v3/registration5-gz-semver2/test/index.json': indexBody,
+            'https://api.nuget.org/v3/registration5-gz-semver2/test/page/2.0.0/2.9.9.json': externalPageBody,
+        };
+
+        mockHttpsGet.mockImplementation((url: unknown, _opts: unknown, cb: unknown) => {
+            const body = responses[url as string];
+            if (!body) {
+                throw new Error(`Unexpected URL: ${url}`);
+            }
+            (cb as (r: unknown) => void)(createMockResponse(body));
+            const req = new EventEmitter();
+            return Object.assign(req, { on: vi.fn().mockReturnThis() });
+        });
+
+        const result = await queryNuGetRegistration('Test');
+        expect(result).toHaveLength(2);
+        expect(result[0]).toEqual({
+            version: '1.0.0', listed: true,
+            packageContent: 'https://api.nuget.org/v3-flatcontainer/test/1.0.0/test.1.0.0.nupkg',
+        });
+        expect(result[1]).toEqual({
+            version: '2.0.0', listed: false,
+            packageContent: 'https://api.nuget.org/v3-flatcontainer/test/2.0.0/test.2.0.0.nupkg',
+        });
+    });
+
+    it('lowercases the package ID in the registration URL', async () => {
+        const indexBody: RegistrationIndex = {
+            items: [{
+                '@id': 'https://api.nuget.org/v3/registration5-gz-semver2/mypackage/index.json#page/0',
+                items: [{
+                    catalogEntry: { version: '1.0.0', listed: true },
+                    packageContent: 'https://api.nuget.org/v3-flatcontainer/mypackage/1.0.0/mypackage.1.0.0.nupkg',
+                }],
+            }],
+        };
+
+        let capturedUrl = '';
+        mockHttpsGet.mockImplementation((url: unknown, _opts: unknown, cb: unknown) => {
+            capturedUrl = url as string;
+            (cb as (r: unknown) => void)(createMockResponse(indexBody));
+            const req = new EventEmitter();
+            return Object.assign(req, { on: vi.fn().mockReturnThis() });
+        });
+
+        await queryNuGetRegistration('MyPackage');
+        expect(capturedUrl).toBe('https://api.nuget.org/v3/registration5-gz-semver2/mypackage/index.json');
+    });
+
+    it('rejects when index fetch returns non-200 status', async () => {
+        mockHttpsGet.mockImplementation((_url: unknown, _opts: unknown, cb: unknown) => {
+            (cb as (r: unknown) => void)(createMockResponse({}, { statusCode: 404, gzip: false }));
+            const req = new EventEmitter();
+            return Object.assign(req, { on: vi.fn().mockReturnThis() });
+        });
+
+        await expect(queryNuGetRegistration('nonexistent')).rejects.toThrow('HTTP 404');
+    });
+});