The Ultimate Guide to Trunk-Based Next.js Monorepo Deployments on Vercel

If you are running a modern Next.js application inside a monorepo (like Turborepo), Vercel is undoubtedly the best place to host it. However, if your team practices strict trunk-based development—where main is your single source of truth for all environments—Vercel's default Git integration can feel a bit restrictive. Many teams end up creating multiple separate Vercel projects (e.g., acme-web-staging and acme-web-prod) to handle different environments. This creates massive overhead: drifting environment variables, duplicated build minutes, and messy webhook configurations. In this guide, we are going to configure a single Vercel project to perfectly support trunk-based development. The Goal: PRs: Automatically build and deploy to a random preview URL. Staging: Automatically build and deploy to our staging domains (stage.acme.app) whenever a PR merges into main. Production: Manually triggered via GitHub Actions, building directly from main and deploying to our production domains (acme.