Build your own platform on Base44

Base44 is an AI app builder: describe an app, get a real, deployed app. This repo shows how to put that inside your own product, so your users build apps under your brand, your login and your governance, and those apps can read and write your product's data.

The integration guide is on the docs site: White label overview. This repo is the code that goes with it, in two sizes.

Tiny Sunny and Sunny

• Tiny Sunny is the minimal version. A chat where you describe an app, watch Base44 build it, answer its questions and see it in a preview. No database and no sign-in. Start here to learn the build loop.
• Sunny (src/) is the full version: a work-management product (boards, groups, items, widgets) with its own sign-in and Postgres database, whose users build apps that are embedded back into it and read Sunny's data. It shows what production needs on top of the build loop. Live at https://sunny44.com.

How Sunny is put together

   YOUR PRODUCT (this repo)                      BASE44
   ─────────────────────────                     ──────
   your users, your DB, your login
            │
            │  one workspace API key, running as the
            │  owner, in env, server-side only
            │
            │  user describes an app
            ├──────────────────────────────────► createApp → build → deploy
            │  (server-side allow-list +          the app is owned by the account;
            │   "is this app yours?" check)       your DB records which user built it
            │
            │  the built app runs
            │  ◄────────────────────────────────  it calls back into your data API
            │      POST /api/sunny                with a viewer token, over CORS
            │
            │  ◄────────────────────────────────  signed webhooks (app.deleted.v1)

Boundary	Code	Docs
Your own auth and database. The shell is not a Base44 app, and it owns row-level security.	src/lib/auth.ts, prisma/schema.prisma, src/lib/rls.ts
One Base44 account for the whole platform, and you keep your users apart.	src/lib/base44Config.ts, src/lib/appOwnership.ts	Tenancy and credentials
A server-side proxy with an allow-list of actions in front of Base44's REST API.	src/app/api/base44/platform/route.ts	The build turn, Common APIs
Custom instructions and a skill that teach built apps about your data.	src/lib/builderInstructions.ts, src/lib/sunny-platform-skill.md	Custom instructions, Skills and MCP
A public API the built apps call, as the person viewing them.	src/app/api/sunny/route.ts, src/lib/embedSession.ts	Embed the app
Signed inbound webhooks, so you learn about deleted apps.	src/app/api/base44/webhooks/route.ts, src/lib/base44Webhooks.ts	Workspace webhooks

CLAUDE.md has the conventions this repo holds itself to and where each boundary is enforced.

Run it

You need a Base44 white-label workspace, its id and platform host, and a workspace API key (b44k_) with Full access, created in that workspace. The setup checklist covers it.

cp .env.example .env     # Postgres, Google OAuth, and the BASE44_* vars
npm install
npm run db:migrate
npm run dev

Without the BASE44_* variables everything works except building apps: the bridge answers 501 bridge_misconfigured and the UI says so. You can explore the product before you have a workspace.

Checks, each one asserting a boundary above:

npm run typecheck
npm run lint
npm run rls:smoke        # the owner predicate, including the traps
npm run auth:smoke       # session → actor
npm run entities:smoke   # whitelisting, scoping, wire shape
npm run base44:smoke     # token containment, allow-list, the ownership gate
npm run sunny:smoke      # the public contract, action by action
npm run webhook:smoke    # the inbound signature, negative controls

The smoke suites write throwaway rows to DATABASE_URL. Don't point them at a database you care about.

Deploy

It runs on free plans: Netlify for the app and Neon for Postgres. netlify.toml already holds the build settings; its build command runs prisma migrate deploy, so a deploy moves the schema forward.

• Database. DATABASE_URL is Neon's pooled host, DIRECT_URL the unpooled one (used by migrations). Never point both at the pooled host.
• Google OAuth. One client per environment, with origin https://<your-host> and redirect URI https://<your-host>/api/auth/callback/google.
• Env vars. As in .env.example. Scope NEXTAUTH_URL to production only.
• /api/sunny is public once deployed. It only answers viewer tokens signed with NEXTAUTH_SECRET, so that secret protects it too.

Deploy previews need a redirect proxy for Google sign-in and their own Neon branch, so they never migrate production. PREVIEW-DEPLOYS.md has the setup and what's still open.

Troubleshooting

Symptom	Likely cause
501 bridge_misconfigured	A BASE44_* env var is missing, or Base44 answered 401 to the workspace API key (revoked, expired)
404 not_found on an app-scoped action	The caller has no AppOwnership row for that app. Built before ownership was tracked? Insert the row
403 on a build call	The workspace key lacks Full access, or the workspace isn't entitled to run keys as the owner
Builds ignore your design system or skills	The key belongs to another workspace than BASE44_ORG_ID. Create it in the white-label workspace
sendMessage times out at ~30s	Your own timeout, not Base44's. Build turns need ~120s
A new app doesn't appear in the list	Its AppOwnership row was not recorded. The server logs this at create

Stack

Next.js (App Router) · TypeScript · Tailwind 4 · Postgres + Prisma · NextAuth (Google only) · deployed on Netlify with Neon. Platform infrastructure (src/lib, src/app) is strict TypeScript; the example product UI (src/components, src/views) is JSX with relaxed lint.