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What KaribaCore runs

Check this before importing a repository. Last updated 5 October 2026.

KaribaCore builds and hosts Next.js 15 and 16 apps that use npm, one app per repository. Run Check build setup in a project's Settings to test a repository before deploying: it lists every problem at once without running your code.

Supported

Framework	Next.js 15 and 16, released versions only. Canary, beta and release-candidate versions are refused, as are releases with a known remote-code-execution vulnerability.
React	React and React DOM 18 or 19, at the same version.
Node.js	Node.js 22 or 24. The build uses the first one allowed by `engines.node` in package.json, or Node.js 22 when it is not set. The same version runs your app.
Package manager	npm with a committed `package-lock.json` (lockfile version 2 or 3). From `.npmrc`, only `legacy-peer-deps` and `strict-peer-deps` are read.
Repository layout	One Next.js app at the repository root, with a `build` script in package.json.
Build and start	KaribaCore runs `npm ci`, then `npm run build`, then starts the app with `next start`, or with the standalone server if you set `output: 'standalone'` (smaller images).
App features	App Router and Pages Router, server components, server actions, route handlers and API routes, middleware/proxy, and `next.config.ts` or `.js`/`.mjs`.
Configuration	Environment variables per project, available at build, runtime or both, including pasting a whole `.env` file. Committed `.env` and `.env.production` files are used as defaults; variables you set in KaribaCore take precedence.
Outbound connections	Public internet services on HTTP/HTTPS (80, 443), PostgreSQL (5432, 6543), MySQL (3306), Redis (6379), MongoDB (27017) and SMTP submission (465, 587).
Addresses	A platform address on `karibacore.app`, custom domains with HTTPS (including domains proxied through your own Cloudflare account), PR previews, promotion and rollback.

Limits

Repository size	100 MB and 20,000 files, not counting node_modules, .next and .git
Build	2 CPU, 3 GiB memory, 8 GiB disk, 25 minutes
Running app	1 CPU, 512 MiB memory
Writable disk	/tmp and the Next.js cache, 64 MiB each; everything else is read-only and resets on each deploy
Start-up health check	GET / must answer with a 200–399 status within about 2 minutes of starting
Per workspace	10 projects, 1 build at a time, 4 live apps (production and previews), 5 GiB of deployment images
Per project	3 open PR previews
Variables	Names in capitals, digits and underscores (up to 128); values up to 32 KB; up to 200 per paste
Logs	Build output kept 30 days, runtime output 7 days

Not supported yet, and what to do instead

pnpm, Yarn or Bun	Not yet. Convert to npm: delete the other lockfile, remove a non-npm `packageManager` field (`npm pkg delete packageManager`), run `npm install` and commit `package-lock.json`.
Monorepos and workspaces	Not yet, including an app in a subfolder such as `frontend/`. Deploy a repository whose root is the Next.js app.
Next.js 14 or older	Upgrade to Next.js 15 or 16 and commit the updated lockfile.
Other frameworks	Remix, Astro, Vite, Nuxt, SvelteKit, Express and other Node servers are not supported.
Static export	`output: 'export'` apps are refused at build time. Remove it; KaribaCore serves your app with a Next.js server.
Custom servers and Dockerfiles	A hand-written `server.js`, a custom start command or a Dockerfile is not used.
Backends, workers and databases	Only the Next.js app runs: no separate API services, background workers, scheduled jobs or managed databases. Connect to external services such as Neon, Supabase or Upstash.
Saving files	Uploads and other files written at runtime are lost on restart or redeploy. Use object storage such as S3 or R2.
Private networks	Apps cannot reach private addresses (10.x, 172.16–31.x, 192.168.x and similar) or SMTP port 25. Databases must have a public endpoint.
Repository contents	Symbolic links and special files are refused. Reserved variable names (PORT, HOSTNAME, HOST, NODE_ENV, NODE_OPTIONS, NODE_PATH, LD_PRELOAD, NEXT_DEPLOYMENT_ID and anything starting with KARIBACORE_) are set by the platform.

Before you deploy

package.json lists next 15 or 16 and has a build script.
package-lock.json is committed, and there are no pnpm, Yarn or Bun lockfiles.
The app is at the repository root, not in a subfolder.
Every variable the build needs is set, with Build and runtime selected, before the first deploy. Builds that run database migrations need a reachable public database.
Your home page / returns a page or a redirect, not an error.

Common build errors

UNSUPPORTED_PACKAGE_MANAGER	pnpm, Yarn or Bun lockfile, or a non-npm packageManager field. Convert to npm (see above).
NPM_LOCK_REQUIRED	No usable package-lock.json. Run npm install and commit package-lock.json.
CONFLICTING_LOCKFILES	More than one lockfile. Keep only package-lock.json.
NEXT_APP_REQUIRED	The repository root has no Next.js dependency or build script (often a monorepo).
WORKSPACES_NOT_SUPPORTED_YET	package.json declares npm workspaces.
NEXT_VERSION_UNSUPPORTED / NEXT_PRERELEASE_UNSUPPORTED	Next.js 14 or older, or a canary, beta or rc version. Use a released 15 or 16.
NEXT_VERSION_VULNERABLE	This Next.js release is missing the fix for a known remote-code-execution vulnerability. Upgrade to the latest patch of your minor version.
NODE_VERSION_UNSUPPORTED	engines.node allows neither Node.js 22 nor 24.
UNSUPPORTED_SOURCE_ENTRY / SOURCE_TOO_LARGE	Symbolic links or special files, or over 100 MB or 20,000 files. Remove them or move large media out of the repository.
BUILD_COMMAND_FAILED	npm ci or your build script failed. The first error in the build output says why: often a missing environment variable or a database the build needs.
BUILD_MEMORY_LIMIT / BUILD_TIMEOUT	The build used more than 3 GiB or took longer than 25 minutes.
CLUSTER_RUNTIME_NOT_READY / CLUSTER_ROUTE_FAILED	The app did not answer GET / with 200–399. Check the runtime output and required variables, and that / does not return 404 or 500.

Still stuck?

Email [email protected] with the deployment ID and error code shown on the failed deployment. Tell us about frameworks or package managers you need; that decides what we support next.