diff --git a/apps/api/src/routes/setup.ts b/apps/api/src/routes/setup.ts
index 5869489..3bb470f 100644
--- a/apps/api/src/routes/setup.ts
+++ b/apps/api/src/routes/setup.ts
@@ -178,4 +178,48 @@ setupRouter.post("/auth-provider", zValidator("json", authProviderBootstrapSchem
     createdAt: row.createdAt,
     updatedAt: row.updatedAt,
   }, 201);
-});
\ No newline at end of file
+});
+
+/**
+ * POST /api/setup/auth-provider/test
+ * Unauthenticated endpoint to validate an OIDC provider configuration during OOBE.
+ * Fetches the OIDC discovery document to confirm the issuer is reachable.
+ * Only available when needsSetup is true (no super user = fresh install).
+ */
+setupRouter.post("/auth-provider/test", zValidator("json", authProviderBootstrapSchema), async (c) => {
+  const db = getDb();
+
+  // Guard: only allow during fresh install (no super user yet)
+  const [superUser] = await db
+    .select({ id: staff.id })
+    .from(staff)
+    .where(eq(staff.isSuperUser, true))
+    .limit(1);
+
+  if (superUser) {
+    return c.json({ ok: false, error: "Setup has already been completed." }, 403);
+  }
+
+  const body = c.req.valid("json");
+
+  // Determine the discovery URL
+  const discoveryUrl = body.internalBaseUrl
+    ? `${body.internalBaseUrl}/application/o/.well-known/openid-configuration`
+    : `${body.issuerUrl}/.well-known/openid-configuration`;
+
+  try {
+    const res = await fetch(discoveryUrl, { method: "GET" });
+    if (!res.ok) {
+      return c.json({
+        ok: false,
+        error: `OIDC discovery failed (HTTP ${res.status}). Check your Issuer URL and Internal Base URL.`,
+      });
+    }
+    return c.json({ ok: true });
+  } catch (e) {
+    return c.json({
+      ok: false,
+      error: "Could not reach the OIDC provider. Check your Issuer URL and network connectivity.",
+    });
+  }
+});
diff --git a/apps/web/src/pages/SetupWizard.jsx b/apps/web/src/pages/SetupWizard.jsx
index 2d4de2d..aaaf269 100644
--- a/apps/web/src/pages/SetupWizard.jsx
+++ b/apps/web/src/pages/SetupWizard.jsx
@@ -82,7 +82,7 @@ export function SetupWizard() {
     setTestingConnection(true);
     setTestResult(null);
     try {
-      const res = await fetch("/api/admin/auth-provider/test", {
+      const res = await fetch("/api/setup/auth-provider/test", {
         method: "POST",
         headers: { "Content-Type": "application/json" },
         body: JSON.stringify({