HTTP Link

httpLink is a terminating link that sends a tRPC operation to a tRPC procedure over HTTP.

httpLink supports both POST and GET requests.

Usage

You can import and add the httpLink to the links array as such:

client/index.ts
ts
import { createTRPCClient, httpLink } from '@trpc/client';
import type { AppRouter } from './server';
 
const client = createTRPCClient<AppRouter>({
  links: [
    httpLink({
      url: 'http://localhost:3000',
      // transformer,
    }),
  ],
});

client/index.ts
ts
import { createTRPCClient, httpLink } from '@trpc/client';
import type { AppRouter } from './server';
 
const client = createTRPCClient<AppRouter>({
  links: [
    httpLink({
      url: 'http://localhost:3000',
      // transformer,
    }),
  ],
});

httpLink Options

The httpLink function takes an options object that has the HTTPLinkOptions shape.

ts
export interface HTTPLinkOptions {
  url: string | URL;
  /**
   * Add ponyfill for fetch
   */
  fetch?: typeof fetch;
  /**
   * Data transformer
   * @see https://trpc.io/docs/server/data-transformers
   **/
  transformer?: DataTransformerOptions;
  /**
   * Headers to be set on outgoing requests or a callback that of said headers
   * @see https://trpc.io/docs/client/headers
   */
  headers?:
    | HTTPHeaders
    | ((opts: { op: Operation }) => HTTPHeaders | Promise<HTTPHeaders>);
  /**
   * Send all requests as POSTS requests regardless of the procedure type
   * The server must separately allow overriding the method. See:
   * @see https://trpc.io/docs/rpc
   */
  methodOverride?: 'POST';
}

ts
export interface HTTPLinkOptions {
  url: string | URL;
  /**
   * Add ponyfill for fetch
   */
  fetch?: typeof fetch;
  /**
   * Data transformer
   * @see https://trpc.io/docs/server/data-transformers
   **/
  transformer?: DataTransformerOptions;
  /**
   * Headers to be set on outgoing requests or a callback that of said headers
   * @see https://trpc.io/docs/client/headers
   */
  headers?:
    | HTTPHeaders
    | ((opts: { op: Operation }) => HTTPHeaders | Promise<HTTPHeaders>);
  /**
   * Send all requests as POSTS requests regardless of the procedure type
   * The server must separately allow overriding the method. See:
   * @see https://trpc.io/docs/rpc
   */
  methodOverride?: 'POST';
}

Reference

You can check out the source code for this link on GitHub.