deploy-fullstack-vercel

# Deploy Fullstack to Vercel Deploy a full-stack app with a React/Vite frontend and Python/FastAPI backend to Vercel as a serverless demo, OR deploy a Vellum-built app from the library. No auth required - meant for demos, portfolio pieces, and quick showcases. ## When to Use - User says "deploy this to Vercel", "host this", "publish this" - User has a project with a frontend + backend they want live - User wants to deploy a Vellum app that uses backend features (data store, custom routes) - User wants a quick demo deployment (no persistent database needed) ## Authentication ### Vellum App Publishing For publishing Vellum apps from the library, use the built-in `publish_page` tool. This is the preferred path — it uses the stored Vercel API token (`vercel/api_token`) via the brokered publish flow without exposing the token to shell commands. **The stored Vercel API token is reserved for brokered `publish_page` and `unpublish_page` actions only.** Do not pass it to `bash`, `curl`, Vercel CLI commands, or proxy credential injection. Do not use `network_mode: "proxied"` with `credential_ids` for Vercel deployments. ### Custom Full-Stack Deployments For custom projects that need Vercel deployment (not Vellum app publishing): 1. Install the Vercel CLI with `bun install -g vercel` (not npm — npm is not available in the sandbox). 2. Use `vercel login` to authenticate interactively (opens browser for the user). 3. If the user does not want to use CLI auth, stop and ask them f...