Postgres connections now work through Sandbox firewall (opens in new tab)

**Published:** April 30, 2026 | **Authors:** Brandon Tuttle --- Vercel Sandbox can now connect to hosted Postgres databases, including Neon, Supabase, AWS RDS, Nile, and Prisma Postgres. To enable a connection, add the database host to your Sandbox's allowed domains. ## Background When SNI based filtering is used with Vercel Sandbox, the sandbox firewall restricts outbound network access by checking the domain name during a connection's TLS handshake. This works seamlessly for HTTPS traff...