@multitenant/next-app

Next.js App Router integration for @multitenant/core.

It provides:

• createTenantMiddleware(registry, options) – Next.js middleware.ts factory
• createTenantMiddlewareFromConfig(config, options) – from @multitenant/next-app/auto when you already have a loaded TenantsConfig object
• createNodeTenantMiddlewareFromProjectRoot(options?) – from @multitenant/next-app/auto-node (Node only): loads ./tenants.config.json from process.cwd() via @multitenant/config
• getTenantFromHeaders(headers, registry, options?) – read ResolvedTenant in route handlers / server components
• requireTenant(headers, registry, options?) – same but throws if missing

Runtime: auto-node uses fs and must not run on Edge. Use auto with a static import or bundled JSON if middleware must run on Edge.

Install

npm install @multitenant/next-app @multitenant/core

Usage

middleware.ts

import type { EnvironmentName } from '@multitenant/core';
import { createTenantMiddleware } from '@multitenant/next-app';
import tenantsConfig from './tenants.config.json';
import { createTenantRegistry } from '@multitenant/core';

const registry = createTenantRegistry(tenantsConfig as any);
const env = (process.env.TENANT_ENV ?? 'local') as EnvironmentName;

export const middleware = createTenantMiddleware(registry, {
  environment: env,
});

Missing tenant behavior

createTenantMiddleware resolves the tenant from the incoming request Host header (it also respects x-forwarded-host). If the current host doesn't match any tenant domain (common when you run next dev directly on localhost instead of via multitenant dev), tenant resolution will fail. By default (onMissingTenant: 'passthrough') the middleware will not throw; it will NextResponse.next() (no tenant headers are added). Your app/server code must still handle getTenantFromHeaders(...) === null if you don’t route through multitenant dev. If you want a hard failure (or logs), set onMissingTenant: 'throw' (or 'warn').

In route handlers / server components

import { headers } from 'next/headers';
import { getTenantFromHeaders } from '@multitenant/next-app';
import { tenantRegistry } from './tenant-registry';

export async function GET() {
  const h = headers();
  const tenant = getTenantFromHeaders(h, tenantRegistry, { environment: 'local' });
  // ...
}

Full App Router checklist: next-app-router.md.

Open source

MIT licensed — github.com/klypalskyi/multitenant · Issues · npm