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Using clients

On Node.js, you use the same clients as you do with Connect for Web, but with a transport from @connectrpc/connect-node instead of from @connectrpc/connect-web:

import { createPromiseClient } from "@connectrpc/connect";
import { createConnectTransport } from "@connectrpc/connect-node";

const transport = createConnectTransport({
  httpVersion: "1.1",
  baseUrl: "http://demo.connectrpc.com",
});

async function main() {
  const client = createPromiseClient(ElizaService, transport);
  const res = await client.say({
    sentence: "I feel happy.",
  });
  console.log(res.sentence);
}
void main();

For details on clients (including error handling, interceptors, and accessing headers and trailers), please refer to the documentation for Web.

Under the hood, the transports from @connectrpc/connect-node use the built-in Node modules http, https, and http2 instead of the fetch API. They allow us to provide a transport for gRPC and to support bidi streaming. Node.js v18 comes with fetch(), but it is limited to HTTP 1.1.

Connect​

The function createConnectTransport() creates a transport for the Connect protocol. The most important options for the Connect transport are as follows:

import { createConnectTransport } from "@connectrpc/connect-node";

const transport = createConnectTransport({
  // Requests will be made to <baseUrl>/<package>.<service>/method
  baseUrl: "https://demo.connectrpc.com",

  // You have to tell the Node.js http API which HTTP version to use.
  httpVersion: "2",

  // Interceptors apply to all calls running through this transport.
  interceptors: [],
});

gRPC​

The function createGrpcTransport() creates a transport for the gRPC protocol. The most important options for the gRPC transport are as follows:

import { createGrpcTransport } from "@connectrpc/connect-node";

const transport = createGrpcTransport({
  // Requests will be made to <baseUrl>/<package>.<service>/method
  baseUrl: "https://demo.connectrpc.com",

  // You have to tell the Node.js http API which HTTP version to use.
  httpVersion: "2",

  // Interceptors apply to all calls running through this transport.
  interceptors: [],
});

gRPC-web​

The function createGrpcWebTransport() creates a Transport for the gRPC-web protocol. Any gRPC service can be made available to gRPC-web with the Envoy Proxy. ASP.NET Core supports gRPC-web with a middleware. Connect for Node and connect-go support gRPC-web out of the box.

import { createGrpcWebTransport } from "@connectrpc/connect-node";

const transport = createGrpcWebTransport({
  // Requests will be made to <baseUrl>/<package>.<service>/method
  baseUrl: "https://demo.connectrpc.com",

  // You have to tell the Node.js http API which HTTP version to use.
  httpVersion: "2",

  // Interceptors apply to all calls running through this transport.
  interceptors: [],
});