Marketing at the root, SaaS at /app

Status: accepted · 2026-09-25

ContextCopy Anchor Link

SignalDock ships as one Vercel project with Vercel Services: app, api, mcp and docs, routed by path rewrites in the root vercel.json. Until now the SaaS app answered every path that no other service claimed, so the product owned /.

We need a public site (home, pricing, compare, customer stories, changelog, blog) that is fast, indexable and independent of the authenticated app.

DecisionCopy Anchor Link

• Add a marketing service (apps/marketing, Next.js) that serves / and every path not claimed by another service.
• Mount the SaaS app at /app. The /app and /app/(.*) rewrites route to the app service ahead of the marketing catch-all. The platform keeps the public path, so the SaaS app sets Next basePath: "/app": pages, links, redirect() and /_next assets are all prefixed once.
• /api, /mcp, /.well-known/oauth-protected-resource and /docs keep their rewrites. Everything is one origin, so the app calls the API same-origin and needs no CORS.
• Marketing and docs stay separate apps. Marketing links to the docs and the app with absolute URLs and never proxies them.
• The SaaS URL is configuration: NEXT_PUBLIC_SITE_URL is https://www.signaldock.dev/app in production, and Supabase Auth site_url and redirect URLs include /app, so OAuth consent lands on /app/oauth/consent.
• Env vars are shared by every service in a Vercel project, so marketing does not read NEXT_PUBLIC_SITE_URL. It derives its origin from VERCEL_PROJECT_PRODUCTION_URL (production) or VERCEL_URL (preview), so preview deployments link to their own /app and /docs.

This is a breaking change with no redirects. The product is greenfield, so there are no existing links to preserve.

ConsequencesCopy Anchor Link

• Marketing depends only on ui, domain and config (turbo boundary tag marketing). The live score explorer runs the real @signaldock/domain/scoring engine in the browser, with no API call.
• NextResponse.redirect takes an absolute URL and does not add basePath; route handlers build redirect targets with appUrl() from apps/app/lib/base-path.ts.
• Locally Portless serves marketing on https://www.localhost and the app on https://app.localhost/app (/ redirects there).