🍙 @vercel/blob
The Vercel Blob JavaScript API client.
Install
npm install @vercel/blob
Usage
import * as vercelBlob from '@vercel/blob';
async function someMethod() {
const blob = await vercelBlob.put(
'profilesv1/user-12345.txt',
'Hello World!',
{ access: 'public' },
);
console.log(blob.url);
}
API
put(pathname, body, options)
Upload a blob to the Vercel Blob API, and returns the URL of the blob.
async function put(
pathname: string,
body: ReadableStream | String | ArrayBuffer | Blob
options: {
access: 'public', // mandatory, as we will provide private blobs in the future
contentType?: string, // by default inferred from pathname
// `token` defaults to process.env.BLOB_READ_WRITE_TOKEN on Vercel
// and can be configured when you connect more stores to a project
// or using Vercel Blob outside of Vercel
token?: string,
}): Promise<{
size: number;
uploadedAt: Date;
pathname: string;
contentType: string;
contentDisposition: string;
url: string;
}> {}
del(url, options)
Delete one or multiple blobs by their full URL. Returns the deleted blob(s) or null when not found.
async function del(
url: string | string[],
options?: {
token?: string;
},
): Promise<
| {
size: number;
uploadedAt: Date;
pathname: string;
contentType: string;
contentDisposition: string;
url: string;
}
| null
| ({
size: number;
uploadedAt: Date;
pathname: string;
contentType: string;
contentDisposition: string;
url: string;
} | null)[]
> {}
head(url, options)
Get the metadata of a blob by its full URL. Returns null
when the blob does not exist.
async function head(
url: string,
options?: {
token?: string;
},
): Promise<{
size: number;
uploadedAt: Date;
pathname: string;
contentType: string;
contentDisposition: string;
url: string;
} | null> {}
list(options)
List blobs and get their metadata in the store. With an optional prefix and limit. Paginate through them.
async function list(options?: {
token?: string;
limit?: number; // defaults to 1,000
prefix?: string;
cursor?: string;
}): Promise<{
blobs: {
size: number;
uploadedAt: Date;
pathname: string;
contentType: string;
contentDisposition: string;
url: string;
}[];
cursor?: string;
hasMore: boolean;
}> {}
Examples
Next.js App Router example
This example shows a form uploading a file to the Vercel Blob API.
'use client';
import type { BlobResult } from '@vercel/blob';
import { useState } from 'react';
export default function UploadForm() {
const [blob, setBlob] = useState<BlobResult | null>(null);
return (
<>
<form
action="/api/upload"
method="POST"
encType="multipart/form-data"
onSubmit={async (event) => {
event.preventDefault();
const formData = new FormData(event.currentTarget);
const response = await fetch('/api/upload', {
method: 'POST',
body: formData,
});
const blob = (await response.json()) as BlobResult;
setBlob(blob);
}}
>
<input type="file" name="file" />
<button type="submit">Upload</button>
</form>
{blob && (
<div>
Blob url: <a href={blob.url}>{blob.url}</a>
</div>
)}
</>
);
}
import * as vercelBlob from '@vercel/blob';
import { NextResponse } from 'next/server';
export async function POST(request: Request) {
const form = await request.formData();
const file = form.get('file') as File;
if (!file) {
return NextResponse.json(
{ message: 'No file to upload.' },
{ status: 400 },
);
}
const blob = await vercelBlob.put(file.name, file, { access: 'public' });
return NextResponse.json(blob);
}
How to list all your blobs
This will paginate through all your blobs in chunks of 1,000 blobs.
You can control the number of blobs in each call with limit
.
let hasMore = true;
let cursor: string | undefined;
while (hasMore) {
const listResult = await vercelBlob.list({
cursor,
});
console.log(listResult);
hasMore = listResult.hasMore;
cursor = listResult.cursor;
}
Error handling
All methods of this module will throw if the request fails for either:
- missing parameters
- bad token or token doesn't have access to the resource
- or in the event of unknown errors
You should acknowledge that in your code by wrapping our methods in a try/catch block:
try {
await vercelBlob.put('foo', 'bar');
} catch (error) {
if (error instanceof vercelBlob.BlobAccessError) {
} else {
throw error;
}
}
Releasing
pnpm changeset
git commit -am "New version"
Once such a commit gets merged in main, then GitHub will open a versioning PR you can merge. And the package will be automatically published to npm.
A note about Vercel file upload limitations
When using Serverless or Edge Functions on Vercel, the request body size is limited to 4MB.
When you want to send files larger than that to Vercel Blob, you can do so by using @vercel/blob
from a regular Node.js script context (like at build time). This way the request body will be sent directly to Vercel Blob and not via an Edge or Serverless Function.
We plan to allow sending larger files to Vercel Blob from browser contexts soon.
Running examples locally
- how to run examples locally (.env.local with token)
- how to run examples on Vercel (vc deploy)
- how to contribute (pnpm dev to rebuild, example uses local module)
- for Vercel contributors, link on how to run the API locally (edge-functions readme link, wrangler dev, pnpm dev for module)
A note for Vite users
@vercel/blob
reads the token from the environment variables on process.env
. In general, process.env
is automatically populated from your .env
file during development, which is created when you run vc env pull
. However, Vite does not expose the .env
variables on process.env.
You can fix this in one of following two ways:
- You can populate
process.env
yourself using something like dotenv-expand
:
pnpm install --save-dev dotenv dotenv-expand
import dotenvExpand from 'dotenv-expand';
import { loadEnv, defineConfig } from 'vite';
export default defineConfig(({ mode }) => {
if (mode === 'development') {
const env = loadEnv(mode, process.cwd(), '');
dotenvExpand.expand({ parsed: env });
}
return {
...
};
});
- You can provide the credentials explicitly, instead of relying on a zero-config setup. For example, this is how you could create a client in SvelteKit, which makes private environment variables available via
$env/static/private
:
import { put } from '@vercel/blob';
+ import { BLOB_TOKEN } from '$env/static/private';
const kv = await head("filepath", {
- token: '<token>',
+ token: BLOB_TOKEN,
});
await kv.set('key', 'value');