Dedupe Requests Plugin

The Dedupe Requests Plugin prevents redundant requests by deduplicating similar ones, helping to reduce the number of requests sent to the server.

Usage

import { DedupeRequestsPlugin } from '@orpc/client/plugins'

const link = new RPCLink({
  plugins: [
    new DedupeRequestsPlugin({
      filter: ({ request }) => request.method === 'GET', // Filters requests to dedupe
      groups: [
        {
          condition: () => true,
          context: {}, // Context used for the rest of the request lifecycle
        },
      ],
    }),
  ],
})

INFO

The link can be any supported oRPC link, such as RPCLink, OpenAPILink, or custom implementations.

Groups

To enable deduplication, a request must match at least one defined group. Requests that fall into the same group are considered for deduplication together. Each group also requires a context, which will be used during the remainder of the request lifecycle. Learn more about client context.

Here's an example that deduplicates requests based on the cache control:

interface ClientContext {
  cache?: RequestCache
}

const link = new RPCLink<ClientContext>({
  url: 'http://localhost:3000/rpc',
  method: ({ context }) => {
    if (context?.cache) {
      return 'GET'
    }

    return 'POST'
  },
  plugins: [
    new DedupeRequestsPlugin({
      filter: ({ request }) => request.method === 'GET', // Filters requests to dedupe
      groups: [
        {
          condition: ({ context }) => context?.cache === 'force-cache',
          context: {
            cache: 'force-cache',
          },
        },
        {
          // Fallback group – placed last to catch remaining requests
          condition: () => true,
          context: {},
        },
      ],
    }),
  ],
  fetch: (request, init, { context }) => globalThis.fetch(request, {
    ...init,
    cache: context?.cache,
  }),
})

Now, calls with cache=force-cache will be sent with cache=force-cache, whether they're deduplicated or executed individually.