Getting started with Fastify

Added in v5.6

Package Setup

Install the package

npm install uploadthing

Add env variables

If you don't already have a uploadthing secret key, sign up ↗ and create one from the dashboard! ↗

UPLOADTHING_TOKEN=... # A token for interacting with the SDK

All files uploaded to uploadthing are associated with a FileRoute. The following is a very minimalistic example, with a single FileRoute "imageUploader". Think of a FileRoute similar to an endpoint, it has:

Permitted types ["image", "video", etc]
Max file size
How many files are allowed to be uploaded
(Optional) input validation to validate client-side data sent to the route
(Optional) middleware to authenticate and tag requests
onUploadComplete callback for when uploads are completed

To get full insight into what you can do with the FileRoutes, please refer to the File Router API.

src/uploadthing.ts

import { createUploadthing, type FileRouter } from "uploadthing/fastify";

const f = createUploadthing();

export const uploadRouter = {
  // Define as many FileRoutes as you like, each with a unique routeSlug
  imageUploader: f({
    image: {
      /**
       * For full list of options and defaults, see the File Route API reference
       * @see https://docs.uploadthing.com/file-routes#route-config
       */
      maxFileSize: "4MB",
      maxFileCount: 1,
    },
  }).onUploadComplete((data) => {
    console.log("upload completed", data);
  }),
} satisfies FileRouter;

export type OurFileRouter = typeof uploadRouter;

Register the UploadThing plugin

src/index.ts

import Fastify from "fastify";

import { createRouteHandler } from "uploadthing/fastify";

import { uploadRouter } from "./router";

const fastify = Fastify({ logger: true });

fastify
  /** ... */
  .register(createRouteHandler, {
    router: uploadRouter,
    config: { ... },
  });

See configuration options in server API reference

Use the FileRouter in your app

Client side usage differs ever so slightly from the fullstack framework setups when using a separate backend server. You'll need to set the URL of your server when you generate the components and helpers.

import { generateUploadButton } from "@uploadthing/react";

export const UploadButton = generateUploadButton({
  url: "https://your-server.com/api/uploadthing",
});
// ...

Please note that you might need to setup some CORS rules on your server to allow the client to make requests to the server.

For the remaining usage, please refer to client side examples of the fullstack framework guides:

or check out the full API reference: