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Convex JavaScript Clients

Convex applications can be accessed from Node.js or any JavaScript runtime that implements fetch or WebSocket. The reactive Convex Client allows web applications and long-running Node.js servers to subscribe to updates on Convex queries, while the Convex HTTP client is typically used for server-side rendering, migrations, administrative scripts, and serverless functions to run queries at a single point in time.

If you're using React, see the dedicated ConvexReactClient described in React.

Convex Client

The ConvexClient provides subscriptions to queries in Node.js and any JavaScript environment that supports WebSockets.

import { ConvexClient } from "convex/browser";
import { api } from "../convex/_generated/api";

const client = new ConvexClient(process.env.CONVEX_URL!);

// subscribe to query results
client.onUpdate(api.messages.listAll, {}, (messages) =>
console.log( => msg.body)),

// execute a mutation
function hello() {
client.mutation(api.messages.sendAnon, {
body: `hello at ${new Date()}`,

The Convex client is open source and available on GitHub.

See the Script Tag Quickstart to get started.

HTTP client

The ConvexHttpClient works in the browser, Node.js, and any JavaScript environment with fetch.

See the Node.js Quickstart.

import { ConvexHttpClient } from "convex/browser";
import { api } from "./convex/_generated/api";

const client = new ConvexHttpClient(process.env["CONVEX_URL"]);

// either this
const count = await client.query(api.counter.get);
// or this
client.query(api.counter.get).then((count) => console.log(count));

Using Convex without generated convex/_generated/api.js

If the source code for your Convex function isn't located in the same project or in the same monorepos you can use the untyped api object called anyApi.

import { ConvexClient } from "convex/browser";
import { anyApi } from "convex/server";

const CONVEX_URL = "http://happy-otter-123";
const client = new ConvexClient(CONVEX_URL);
client.onUpdate(anyApi.messages.list, {}, (messages) =>
console.log( => msg.body)),
() =>
client.mutation(anyApi.messages.send, {
body: `hello at ${new Date()}`,
author: "me",