Response Headers Plugin

Use ResponseHeadersHandlerPlugin to accumulate response headers in context.resHeaders and merge them into the final response.

Context Access

import type { ResponseHeadersHandlerPluginContext } from '@orpc/server/plugins'

interface ServerContext extends ResponseHeadersHandlerPluginContext {}

const base = os.$context<ServerContext>()

const procedure = base
  .use(({ context, next }) => {
    context.resHeaders?.set('x-request-id', 'req_123')
    return next()
  })
  .handler(({ context }) => {
    setCookie(context.resHeaders, 'session_id', 'abc123', {
      secure: true,
      maxAge: 3600
    })
  })

Why can resHeaders be undefined?

This allows procedures to run safely even without ResponseHeadersHandlerPlugin, such as in direct calls.

TIP

Combine with Cookie Helpers for streamlined cookie management.

Handler Setup

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

const handler = new RPCHandler(router, {
  plugins: [
    new ResponseHeadersHandlerPlugin(),
  ],
})

INFO

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

Learn More

For implementation details, see the source code.