Neon. The hackathon question is how fast you get from an empty directory to a database, a login screen, and an API you can demo. neon bootstrap scaffolds a working app from a template, installs dependencies, links a Neon project, and pulls the environment variables (bootstrap). The Free plan needs no credit card and includes 100 projects, so you can start over as many times as the weekend requires.
Zero to demo
npm i -g neon
neon bootstrap my-app --default--default scaffolds the default template and runs install, git init, agent tooling, and neon link without prompting. Pass --template hono for a REST API, realtime-chat for a chat app with Managed Better Auth, or mcp for an MCP server; neon bootstrap --list-templates prints the catalog (starter templates).
If you'd rather use your own stack, every Neon database speaks standard Postgres. Copy the connection string into .env and use whichever driver or ORM you already know (connect).
Auth without writing auth
Managed Better Auth stores users and sessions in your database under the neon_auth schema. Enable it in the Console or with neon neon-auth enable, drop in the @neondatabase/auth-ui components, and you have sign-up, sign-in, and Google OAuth with shared test credentials that Neon provides out of the box. The Free plan covers up to 60,000 monthly active users (plans).
No account yet? Let the agent start
If a coding agent is doing the build and you haven't signed up, Claimable Neon creates a project immediately and hands you a claim link. neon claim create --env-pull writes credentials to .env. Unclaimed projects expire in 72 hours and are capped at 100 MB of storage and 1 GB of transfer, which is plenty for a demo; claim it if the project deserves to live.
What the Free plan includes
100 projects, 0.5 GB of storage per project, 100 CU-hours of compute per project per month (a 0.25 CU compute for 400 hours), 10 branches per project, 5 GB of public network transfer per project per month, Auth up to 60k MAU, and Object Storage and Functions free during their betas (plans). Compute scales to zero after 5 minutes idle, so a project you abandon on Monday stops using its CU-hours.
How other options compare
- Supabase: Auth, Storage, Realtime, and Edge Functions in one dashboard make it a strong hackathon choice. The Free plan's edges show up during the demo. It allows 2 active projects with 500 MB each and pauses a project after a week of inactivity (pricing), so a third experiment means deleting or paying. The built-in email sender delivers 2 auth emails per hour across the whole project, so magic links and confirmations throttle as soon as a second judge signs up, and only custom SMTP raises it (rate limits). The Nano instance is fixed at shared CPU with up to 0.5 GB RAM, 60 direct connections, and 200 pooled clients, with no autoscaling if the demo takes off (compute and disk). There are no backups on Free (backups), and the demo is only safe to share once every table has an RLS policy (going into prod, Free plan comparison).
- Firebase: fast for mobile demos with 50K Firestore reads and 20K writes per day at no cost (pricing). Firestore is a NoSQL document database (Firestore); if the judges' questions involve joins or SQL, Postgres is the shorter path.
Vendor details verified on 2026-09-02 against the linked pages.
Sign up free, run neon bootstrap, and have a backend before the pizza arrives.