diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
new file mode 100644
index 0000000..309fd83
--- /dev/null
+++ b/.github/workflows/test.yml
@@ -0,0 +1,55 @@
+name: Test
+
+on:
+  pull_request:
+  push:
+    branches: [master]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        node: ['18', '20', '22']
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: ${{ matrix.node }}
+
+      # The library, CLI and test suite have zero dependencies, so there is
+      # nothing to install. mcp/ has its own deps and its own smoke test.
+      - name: Registry files are valid JSON
+        run: |
+          for f in registry/*.json docs/registry/*.json; do
+            node -e "JSON.parse(require('fs').readFileSync('$f','utf8'))" \
+              || { echo "::error file=$f::invalid JSON"; exit 1; }
+          done
+
+      - name: Run tests
+        run: node --test test/*.test.js
+
+  registry-sync:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: '20'
+
+      # docs/registry is the copy GitHub Pages serves. If it drifts from
+      # registry/, the site serves stale data and nothing else notices:
+      # the test suite is decoupled from live registry contents by design.
+      - name: docs/registry matches registry
+        run: |
+          npm run sync:registry-pages
+          if ! git diff --quiet -- docs/registry; then
+            echo "::error::docs/registry is out of sync with registry/. Run: npm run sync:registry-pages"
+            git diff --stat -- docs/registry
+            exit 1
+          fi
+          echo "docs/registry is in sync"
diff --git a/scripts/verify-registry.mjs b/scripts/verify-registry.mjs
index e9fa70d..0997314 100644
--- a/scripts/verify-registry.mjs
+++ b/scripts/verify-registry.mjs
@@ -32,6 +32,7 @@ import { dirname, join } from 'node:path';
 import { fileURLToPath } from 'node:url';
 import { ADAPTERS } from '../src/adapters/index.js';
 import { loadRegistry } from '../src/registry.js';
+import { ERROR_CODES } from '../src/errors.js';
 
 const __dirname = dirname(fileURLToPath(import.meta.url));
 const ROOT = join(__dirname, '..');
@@ -53,7 +54,24 @@ async function loadEntries() {
   return loadRegistry(); // { ats: [entries] }
 }
 
-async function verifyOne(ats, entry) {
+// Transient-failure detector. ATS APIs rate-limit under load (Workday and
+// SmartRecruiters both do at modest volume), and a 429 says nothing about
+// whether a board is real. Treating one as a failure produced a 27% false
+// drop rate on a 118-entry run, so these retry with backoff instead.
+//
+// The decision is structural, never a message regex: Workday error messages
+// embed the pod name next to the status ("(ufp/wd503/Careers): 404"), so a
+// /5\d\d/ match on the text reads that terminal 404 as a retryable 5xx.
+const RETRIES = Number(getArg('--retries', '3'));
+const NETWORK_ERR = /fetch failed|ECONNRESET|ETIMEDOUT|EAI_AGAIN|socket hang up/i;
+
+function isTransient(err) {
+  if (err?.code === ERROR_CODES.RATE_LIMITED) return true;      // 429
+  if (typeof err?.status === 'number') return err.status >= 500; // 5xx retry, 4xx terminal
+  return NETWORK_ERR.test(err?.message || '');                   // DNS/socket, not an AtsError
+}
+
+async function verifyOne(ats, entry, attempt = 0) {
   // Call the adapter directly with the CANONICAL slug — exactly what
   // fetchJobs does AFTER a registry lookup (it passes hit.entry.slug).
   // We deliberately do NOT route through fetchJobs({company}) here: that
@@ -76,6 +94,12 @@ async function verifyOne(ats, entry) {
     const jobCount = Array.isArray(jobs) ? jobs.length : 0;
     return { ats, slug: entry.slug, name: entry.name, status: jobCount > 0 ? 'ok' : 'empty', jobCount };
   } catch (err) {
+    if (attempt < RETRIES && isTransient(err)) {
+      // Exponential backoff with jitter: 2s, 4s, 8s.
+      const wait = 2000 * 2 ** attempt + Math.floor(Math.random() * 500);
+      await new Promise((r) => setTimeout(r, wait));
+      return verifyOne(ats, entry, attempt + 1);
+    }
     return { ats, slug: entry.slug, name: entry.name, status: 'error', jobCount: 0, error: err.message };
   }
 }
diff --git a/src/errors.js b/src/errors.js
index 3c94758..ddd98e5 100644
--- a/src/errors.js
+++ b/src/errors.js
@@ -22,10 +22,15 @@ export const ERROR_CODES = {
  * all keep working for existing library consumers.
  */
 export class AtsError extends Error {
-  constructor(code, message) {
+  constructor(code, message, status) {
     super(message);
     this.name = 'AtsError';
     this.code = code;
+    // Upstream HTTP status when one is known. Lets callers distinguish a
+    // retryable 503 from a terminal 404 without parsing the message, which
+    // is unsafe: Workday messages embed the pod name (wd503) alongside the
+    // status, so a message-level /5\d\d/ match reads "wd503: 404" as a 5xx.
+    if (status !== undefined) this.status = status;
   }
 }
 
@@ -34,5 +39,5 @@ export class AtsError extends Error {
  * limited, anything else => unreachable) with the given message.
  */
 export function atsErrorFromStatus(status, message) {
-  return new AtsError(status === 429 ? ERROR_CODES.RATE_LIMITED : ERROR_CODES.ATS_UNREACHABLE, message);
+  return new AtsError(status === 429 ? ERROR_CODES.RATE_LIMITED : ERROR_CODES.ATS_UNREACHABLE, message, status);
 }