Fix Bolt.new Auth After Deploy Errors (2026 Guide)
Check Environment Variables and Site URL Settings
Most Bolt.new authentication failures after deployment start with missing or misconfigured environment variables. Locally, your app may read keys directly from your development environment, but in production, those values must be explicitly set in the Bolt dashboard. The most common issue is a blank or incorrect Site URL field. If this field points to http://localhost:3000 instead of your deployed domain, Supabase or Bolt’s native auth will redirect users to nowhere.
Make sure you configure:
- SUPABASE_URL and SUPABASE_ANON_KEY for Supabase-based projects.
- The Site URL and Redirect URLs in the Bolt Auth settings to match your production domain exactly, including protocol (https).
- Environment variables for secret keys, OAuth redirect URIs, or custom session tokens if you use third-party auth.
Common symptom: login works locally but fails silently after deploy, redirecting to localhost or a blank page. Always double-check these fields before diving deeper.
| Layer | Local Behavior | Deployed Behavior | Likely Fix |
|---|---|---|---|
| Env Vars | Automatically loaded from .env | Missing in production | Recreate variables in Bolt dashboard |
| Site URL | localhost works fine | Redirects fail | Update to https://yourdomain.com |
| Redirect URIs | Manual callback URL | OAuth error | Add domain to allowed list |
If you’re still stuck and the same error keeps repeating, remember that Bolt’s built-in fix option can waste tokens without solving the underlying issue. Instead, use precise debugging workflows like the one below.
Paste this into your AI assistant: “My Bolt.new app’s login works locally but fails after deploy. Env vars and Site URL seem correct. Check for missing Supabase redirect, cookie domain mismatch, or RLS policy problem.”
Verify Supabase Authentication and Redirect Flow
For apps using Supabase as the backend, Bolt.new integrates through environment keys and redirect URLs. Problems arise when the Supabase project URL differs from the deployed domain or the redirect URI list is incomplete. Supabase’s security model enforces exact string matching, so even a missing slash or protocol mismatch can block login attempts.
Fix Redirect URLs in Supabase
Open the Supabase dashboard, go to Authentication → URL Configuration, and add your deployed domain with full protocol. For example:
https://yourapp.bolt.new.app
should be listed under Redirect URLs. Add staging and local domains if you use them, separated by commas.
Check API Key Permissions
Your Bolt app might use an anon key locally that differs from production. Rotate keys only when necessary, and update Bolt’s environment variables to match. Missing or expired keys are a silent killer for deployed apps because the frontend continues to call the old endpoint.
- Confirm Supabase API URL matches your project.
- Use the same region for both environments.
- Avoid mixing public and service keys in the client layer.
Symptom: users see a spinning login button or network 401 errors in console logs. The fix is to sync keys and verify the redirect list.
If this is eating your week, AppStuck can take it from here and handle the Supabase-Bolt bridge for you.
Inspect Cookies and Session Persistence
Another frequent production-only issue involves cookies that fail to persist after authentication. Locally, browsers often allow insecure cookies under localhost. Once deployed, your domain must use HTTPS and set cookies with proper SameSite and Secure attributes. Otherwise, users appear logged in for one click and then instantly logged out.
Diagnose with Browser DevTools
Open the Network tab and filter by auth or session. Watch for Set-Cookie headers in responses. If absent, check whether your backend is sending cookies across subdomains. Bolt hosting sometimes uses subdomain isolation (like yourapp.bolt.run). That can block cross-site cookies unless Domain is explicitly set.
Fix Cookie Configuration
- Force HTTPS in production builds.
- Add
SameSite=None; Secureto cookie options if using cross-domain auth. - Make sure session tokens are returned by Supabase or custom endpoints.
Symptom: login seems to succeed, but refreshing the page logs the user out. Cookie inspection is the fastest way to confirm the issue. We’ve recovered over 40 Bolt.new apps where a missing Secure flag alone caused full session loss.
Handle Row Level Security (RLS) and Policy Traps
Supabase enables Row Level Security by default. During local testing, many developers disable RLS temporarily, so everything appears fine. After deployment, those policies re-enable automatically, blocking queries for users that just logged in. Bolt.new doesn’t always surface these errors clearly; you might see blank data or console warnings like “permission denied for table”.
Confirm RLS Status
In Supabase SQL editor, run:
alter table your_table enable row level security;
and review attached policies. Ensure each table that requires user access has a policy referencing auth.uid().
Create Safe Policies
Example policy for a user-owned resource:
create policy "Users can view their own" on profiles for select using ( auth.uid() = id );
Deploy these policies before you republish the Bolt app. Otherwise, even a valid auth token won’t retrieve data.
- Always test with a real deployed user account.
- Use Supabase’s RLS simulator to confirm expected access.
- Sync schema updates between local and production databases.
RLS issues are among the most invisible causes of "auth not working" symptoms. The login step may succeed, but no data loads afterward. Fixing these policies usually resolves what looks like a broken auth flow.
Debug Frontend and Edge Function Interactions
Bolt.new allows edge functions that run near the user. When auth breaks only in production, a common culprit is inconsistent JWT handling between frontend and edge. Ensure the function expects the same Authorization header as your local environment. Also, check for CORS mismatches if you call external APIs.
Inspect Function Logs
In the Bolt dashboard, open Functions → Logs. Look for 401 or CORS errors. Cross-origin failures often appear as network timeouts in the browser but show clear messages in logs.
Fix CORS and Header Issues
- Allow your production domain in the CORS settings.
- Forward cookies or tokens explicitly in fetch calls (
credentials: 'include'). - Ensure the auth middleware runs before edge logic that depends on user context.
Example fetch call:
fetch('/api/profile', { method: 'GET', credentials: 'include', headers: { 'Authorization': Bearer ${token} } });
We’ve observed dozens of Bolt.new apps where missing credentials: 'include' caused silent session drop-offs. Always test your API calls in deployed mode, not just locally.
When to Call in AppStuck
If you’ve verified environment variables, Supabase redirects, cookies, and RLS but users still can’t stay logged in, it’s time to bring in specialists. Debugging Bolt.new auth after deploy can take days of console watching and re-deploying. AppStuck engineers have fixed more than 50 of these cases since 2026, often restoring full login functionality in under 24 hours. We know the interplay of Bolt hosting layers, Supabase cookies, and session refresh logic that typical AI builders miss. When the same error keeps repeating and every fix suggestion drains tokens, skip the frustration.
AppStuck can take it from here so you can get back to shipping features instead of debugging auth loops.
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