CORS Handler Plugin

Use CORSHandlerPlugin to configure CORS Policy for your API.

Basic

import { CORSHandlerPlugin } from '@orpc/server/plugins'

const handler = new RPCHandler(router, {
  plugins: [
    new CORSHandlerPlugin({
      origin: (origin, options) => origin,
      allowMethods: ['GET', 'HEAD', 'PUT', 'POST', 'DELETE', 'PATCH'],
      // ...
    }),
  ],
})

INFO

The handler can be any supported oRPC handler, such as RPCHandler, OpenAPIHandler, or a custom one.

WARNING

To better support Blob, File, and ReadableStream<Uint8Array> at the root level in cross-origin scenarios, extend your CORS allowlist to allow clients to send and receive the Content-Disposition and Standard-Server headers. Learn more in the Standard Server documentation. If you use the CORS Plugin, include them in allowHeaders and exposeHeaders:

const cors = new CORSHandlerPlugin({
  allowHeaders: ['Content-Disposition', 'Standard-Server'],
  exposeHeaders: ['Content-Disposition', 'Standard-Server'],
})

Learn More

For implementation details, see the source code.