Vercel Deployment Guide
Deployment Protection and Agent Access
Vercel deployments may have Deployment Protection enabled, which requires authentication to access preview deployments. This can block automated testing and agent access to preview URLs.
Identifying Protected Deployments
If you encounter a login page or authentication requirement when accessing a Vercel preview URL, the deployment has protection enabled. Signs include:
- Redirect to or SSO login page
- 401/403 errors when accessing the deployment
- Preview URLs that require Vercel team membership
Enabling Agent Access with Protection Bypass
To allow agents and automated systems to access protected deployments, users need to set up Protection Bypass for Automation:
-
Navigate to Project Settings
- Go to the Vercel Dashboard
- Select the project
- Click on Settings → Deployment Protection
-
Generate a Protection Bypass Secret
- Under "Protection Bypass for Automation", click Generate Secret
- Copy the generated secret securely
-
Using the Bypass Secret
The secret can be used in two ways:
As a Header:
bash
curl -H "x-vercel-protection-bypass: <secret>" https://your-preview-url.vercel.app
As a Query Parameter:
https://your-preview-url.vercel.app?x-vercel-protection-bypass=<secret>
-
For Browser-Based Testing
- Append
?x-vercel-protection-bypass=<secret>
- The secret will be stored in a cookie for subsequent requests
Alternative: Disable Protection for Previews
If protection bypass is not suitable, users can disable protection for preview deployments:
- Go to Settings → Deployment Protection
- Set "Vercel Authentication" to Only Production Deployments or Disabled
<IMPORTANT>
If you cannot access a Vercel preview deployment due to authentication requirements, inform the user that they need to either:
1. Set up a Protection Bypass secret and provide it to you, OR
2. Disable Deployment Protection for preview deployments in their Vercel project settings
Do NOT repeatedly attempt to access protected URLs without the bypass secret.
</IMPORTANT>
Environment Variables
Set environment variables in Vercel Dashboard under Settings → Environment Variables, or use the Vercel CLI:
Access in your application:
typescript
const secret = process.env.MY_SECRET;
Vercel CLI Commands
Common Vercel CLI commands:
bash
# Login to Vercel
vercel login
# Deploy to preview
vercel
# Deploy to production
vercel --prod
# List deployments
vercel ls
# View deployment logs
vercel logs <deployment-url>
# Pull environment variables locally
vercel env pull