Convex R2 Component


Store and serve files with Cloudflare R2.

``ts
// or @convex-dev/r2/svelte for Svelte!
import { useUploadFile } from "@convex-dev/r2/react";

// Upload files from React
const uploadFile = useUploadFile(api.example);
// ...in a callback
const key = await uploadFile(file);

// Access files on the server
const url = await r2.getUrl(key);
const response = await fetch(url);
`

Check out the example app for a complete example.

Prerequisites

$3

- Create a Cloudflare account
- Create an R2 bucket
- Set the bucket name as an environment variable R2_BUCKET in your Convex
deployment via npx convex env set R2_BUCKET .
- Add a CORS policy
to the bucket allowing GET and PUT requests from your Convex app. You can also
use '\*' to allow all origins (use with caution).
`json
[
{
"AllowedOrigins": ["http://localhost:5173"],
"AllowedMethods": ["GET", "PUT"],
"AllowedHeaders": ["Content-Type"]
}
]
`
- Create an API token
- On the main R2 page in your Cloudflare dashboard, click **Manage R2 API
Tokens**
- Click Create API Token
- Edit the token name
- Set permissions to Object Read & Write
- Under Specify bucket, select the bucket you created above
- Optionally change TTL
- Click Create API Token
- On the next screen you'll be provided with four values that you'll need later:
- Token Value: R2_TOKEN
- Access Key ID: R2_ACCESS_KEY_ID
- Secret Access Key: R2_SECRET_ACCESS_KEY
- Endpoint: R2_ENDPOINT

$3

You'll need a Convex App to use the component. Follow any of the
Convex quickstarts to set one up.

Installation

Install the component package:

`ts
npm install @convex-dev/r2
`

Create a convex.config.ts file in your app's convex/ folder and install the
component by calling use:

`ts
// convex/convex.config.ts
import { defineApp } from "convex/server";
import r2 from "@convex-dev/r2/convex.config.js";

const app = defineApp();
app.use(r2);

export default app;
`

Set your API credentials using the values you recorded earlier:

`sh
npx convex env set R2_TOKEN xxxxx
npx convex env set R2_ACCESS_KEY_ID xxxxx
npx convex env set R2_SECRET_ACCESS_KEY xxxxx
npx convex env set R2_ENDPOINT xxxxx
npx convex env set R2_BUCKET xxxxx
`

Note: Environment variables are only needed if you don't pass config directly
to the R2 constructor. You can also pass individual values to override
specific environment variables.

$3

To use multiple R2 buckets, create separate R2 instances with different
config:

`ts
import { R2 } from "@convex-dev/r2";
import { components } from "./_generated/api";

// Primary bucket — reads from R2_* environment variables
const primary = new R2(components.r2);

// Archive bucket — configured explicitly
const archive = new R2(components.r2, {
bucket: process.env.ARCHIVE_BUCKET!,
endpoint: process.env.ARCHIVE_ENDPOINT!,
accessKeyId: process.env.ARCHIVE_ACCESS_KEY_ID!,
secretAccessKey: process.env.ARCHIVE_SECRET_ACCESS_KEY!,
});
`

Each instance maintains its own config and S3 client. Metadata from all
buckets coexists in the same Convex table, indexed by bucket name.

Uploading files

File uploads to R2 typically use signed urls. The R2 component provides hooks
for React and Svelte that handle the entire upload process:

- generates the signed url
- uploads the file to R2
- stores the file's metadata in your Convex database

Important: For proper TypeScript typing in your callbacks, pass your DataModel type as a generic parameter to r2.clientApi(). This ensures that ctx parameters are properly typed with your database schema, and queries return Doc<"tableName"> instead of GenericDocument.

1. Instantiate a R2 component client in a file in your app's convex/ folder:

`ts
// convex/example.ts
import { R2 } from "@convex-dev/r2";
import { components } from "./_generated/api";
import type { DataModel } from "./_generated/dataModel";

export const r2 = new R2(components.r2);

// Pass DataModel as a generic type parameter to get proper TypeScript typing
// for all callback contexts. Without this, ctx will be typed as GenericDocument
// instead of your specific table types.
export const { generateUploadUrl, syncMetadata } = r2.clientApi({
checkUpload: async (ctx, bucket) => {
// const user = await userFromAuth(ctx);
// ...validate that the user can upload to this bucket
},
onUpload: async (ctx, bucket, key) => {
// ...do something with the key
// This technically runs in the syncMetadata mutation, as the upload
// is performed from the client side. Will run if using the useUploadFile
// hook, or if syncMetadata function is called directly. Runs after the
// checkUpload callback.
},
});
`

2. Use the useUploadFile hook in your component to upload files:

React:

`tsx
// src/App.tsx
import { FormEvent, useRef, useState } from "react";
import { useAction } from "convex/react";
import { api } from "../convex/_generated/api";
import { useUploadFile } from "@convex-dev/r2/react";

export default function App() {
// Passing the entire api exported from convex/example.ts to the hook.
// This must include generateUploadUrl and syncMetadata from the r2 client api.
const uploadFile = useUploadFile(api.example);
const imageInput = useRef(null);
const [selectedImage, setSelectedImage] = useState(null);

async function handleUpload(event: FormEvent) {
event.preventDefault();

// The file is uploaded to R2, metadata is synced to the database, and the
// key of the newly created object is returned.
await uploadFile(selectedImage!);
setSelectedImage(null);
imageInput.current!.value = "";
}
return (



type="file"
accept="image/*"
ref={imageInput}
onChange={(event) => setSelectedImage(event.target.files![0])}
disabled={selectedImage !== null}
/>
type="submit"
value="Upload"
disabled={selectedImage === null}
/>

);
}


`

Svelte:

`svelte


onsubmit={() => {
if (selectedImage) handleUpload(selectedImage);
}}
>
type="file"
accept="image/*"
onchange={(e) => {
selectedImage = e.currentTarget.files?.[0] ?? null;
}}
disabled={selectedImage !== null}
/>
Upload

`

$3

The r2.generateUploadUrl function generates a uuid to use as the object key by
default, but a custom key can be provided if desired. Note: the
generateUploadUrl function returned by r2.clientApi does not accept a custom
key, as that function is a mutation to be called from the client side and you
don't want your client defining your object keys. Providing a custom key
requires making your own mutation that calls the generateUploadUrl method of
the r2 instance.

`ts
// convex/example.ts
import { R2 } from "@convex-dev/r2";
import { components } from "./_generated/api";

export const r2 = new R2(components.r2);

// A custom mutation that creates a key from the user id and a uuid. If the key
// already exists, the mutation will fail.
export const generateUploadUrlWithCustomKey = mutation({
args: {},
handler: async (ctx) => {
// Replace this with whatever function you use to get the current user
const currentUser = await getUser(ctx);
if (!currentUser) {
throw new Error("User not found");
}
const key = ${currentUser.id}.${crypto.randomUUID()};
return r2.generateUploadUrl(key);
},
});
`

Storing Files from Actions

Files can be stored in R2 directly from actions using the r2.store method.
This is useful when you need to store files that are generated or downloaded on
the server side.

`ts
// convex/example.ts
import { internalAction } from "./_generated/server";
import { R2 } from "@convex-dev/r2";

const r2 = new R2(components.r2);

export const store = internalAction({
handler: async (ctx) => {
// Download a random image from picsum.photos
const url = "https://picsum.photos/200/300";
const response = await fetch(url);
const blob = await response.blob();

// This function call is the only required part, it uploads the blob to R2,
// syncs the metadata, and returns the key. The key is a uuid by default, but
// an optional custom key can be provided in the options object. A MIME type
// can also be provided, which will override the type inferred for blobs. A
// Content-Disposition and Cache-Control header can also be provided if
// necessary.
const key = await r2.store(ctx, blob, {
key: "my-custom-key",
type: "image/jpeg",
disposition: "attachment; filename=example.jpg",
cacheControl: "max-age=3600",
});

// Example use case, associate the key with a record in your database
await ctx.runMutation(internal.example.insertImage, { key });
},
});
`

The store method:

- Takes a Blob, Buffer, or Uint8Array and stores it in R2
- Syncs metadata to your Convex database
- Returns the key that can be used to access the file later

Serving Files

Files stored in R2 can be served to your users by generating a URL pointing to a
given file.

$3

The simplest way to serve files is to return URLs along with other data required
by your app from queries and mutations.

A file URL can be generated from a object key by the r2.getUrl function of the
R2 component client.

`ts
// convex/listMessages.ts
import { components } from "./_generated/api";
import { query } from "./_generated/server";
import { R2 } from "@convex-dev/r2";

const r2 = new R2(components.r2);

export const list = query({
args: {},
handler: async (ctx) => {
// In this example, messages have an imageKey field with the object key
const messages = await ctx.db.query("messages").collect();
return Promise.all(
messages.map(async (message) => ({
...message,
imageUrl: await r2.getUrl(
message.imageKey,
// Options object is optional, can be omitted
{
// Custom expiration time in seconds, default is 900 (15 minutes)
expiresIn: 60 60 24, // 1 day
},
),
})),
);
},
});
`

File URLs can be used in img elements to render images:

`tsx
// src/App.tsx
function Image({ message }: { message: { url: string } }) {
return ;
}
`

Deleting Files

Files stored in R2 can be deleted from actions or mutations via the
r2.deleteObject function, which accepts an object key.

`ts
// convex/images.ts
import { v } from "convex/values";
import { mutation } from "./_generated/server";
import { R2 } from "@convex-dev/r2";

const r2 = new R2(components.r2);

export const deleteObject = mutation({
args: {
key: v.string(),
},
handler: async (ctx, args) => {
return await r2.deleteObject(ctx, args.key);
},
});
`

Accessing File Metadata

File metadata of an R2 file can be accessed from actions via r2.getMetadata:

`ts
// convex/images.ts
import { v } from "convex/values";
import { query } from "./_generated/server";
import { R2 } from "@convex-dev/r2";

const r2 = new R2(components.r2);

export const getMetadata = query({
args: {
key: v.string(),
},
handler: async (ctx, args) => {
return await r2.getMetadata(args.key);
},
});
`

This is an example of the returned document:

`json
{
"ContentType": "image/jpeg",
"ContentLength": 125338,
"LastModified": "2024-03-20T12:34:56Z"
}
`

The returned document has the following fields:

- ContentType: the ContentType of the file if it was provided on upload
- ContentLength: the size of the file in bytes
- LastModified: the last modified date of the file

$3

Metadata can be listed or paginated from actions via r2.listMetadata and
r2.pageMetadata.

`ts
// convex/example.ts
import { query } from "./_generated/server";
import { R2 } from "@convex-dev/r2";

const r2 = new R2(components.r2);

export const list = query({
args: {
limit: v.optional(v.number()),
},
handler: async (ctx, args) => {
return r2.listMetadata(ctx, args.limit);
},
});

export const page = query({
args: {
paginationOpts: paginationOptsValidator,
},
handler: async (ctx, args) => {
return r2.pageMetadata(ctx, args.paginationOpts);
},
});
`

$3

The onSyncMetadata callback can be used to run a mutation after every metadata
sync. The useUploadFile hook syncs metadata after every upload, so this
function will run each time as well.

Because this runs after metadata sync, the r2.getMetadata can be used to
access the metadata of the newly uploaded file.

`ts
// convex/example.ts
import { R2, type R2Callbacks } from "@convex-dev/r2";
import { components } from "./_generated/api";
import type { DataModel } from "./_generated/dataModel";

export const r2 = new R2(components.r2);

const callbacks: R2Callbacks = internal.example;

export const { generateUploadUrl, syncMetadata, onSyncMetadata } = r2.clientApi(
{
// Pass the functions from this file back into the component.
// Technically only an object with onSyncMetadata is required, the recommended
// pattern is just for convenience.
callbacks,

onSyncMetadata: async (ctx, args) => {
// args: { bucket: string; key: string; isNew: boolean }
// args.isNew is true if the key did not previously exist in your Convex R2
// metadata table
const metadata = await r2.getMetadata(ctx, args.key);
// log metadata of synced object
console.log("metadata", metadata);
},
},
);
``