---
title: Cloudflare R2
icon: cloud
description: Set up Cloudflare R2 as a MIRAGE resource from Node or the browser.
---

R2 uses the S3 API with AWS Signature V4 against `https://<account-id>.r2.cloudflarestorage.com`. MIRAGE derives this endpoint from your account ID automatically.

Credentials (R2 API token with object read/write scopes) are created the same way in both runtimes, see [R2 Credentials](/home/setup/r2).

## Node (server-side)

```bash
pnpm add @struktoai/mirage-node
```

```ts
import { MountMode, R2Resource, Workspace } from '@struktoai/mirage-node'

const r2 = new R2Resource({
  bucket: process.env.R2_BUCKET!,
  accountId: process.env.R2_ACCOUNT_ID!,
  accessKeyId: process.env.R2_ACCESS_KEY_ID!,
  secretAccessKey: process.env.R2_SECRET_ACCESS_KEY!,
})

const ws = new Workspace({ '/bucket/': r2 }, { mode: MountMode.READ })
const res = await ws.execute('ls /bucket/')
console.log(res.stdoutText)
```

## Browser (presigned URLs)

```bash
pnpm add @struktoai/mirage-browser
```

The browser `R2Resource` is secret-free, your backend signs each operation using your R2 keys and returns a URL. R2 accepts AWS Signature V4, so `@aws-sdk/s3-request-presigner` works with `region: 'auto'` pointed at R2's endpoint.

### 1. Server: sign URLs with the R2 endpoint

```ts
import {
  CopyObjectCommand,
  DeleteObjectCommand,
  GetObjectCommand,
  HeadObjectCommand,
  ListObjectsV2Command,
  PutObjectCommand,
  S3Client,
} from '@aws-sdk/client-s3'
import { getSignedUrl } from '@aws-sdk/s3-request-presigner'

const client = new S3Client({
  region: 'auto',
  endpoint: `https://${process.env.R2_ACCOUNT_ID}.r2.cloudflarestorage.com`,
  credentials: {
    accessKeyId: process.env.R2_ACCESS_KEY_ID!,
    secretAccessKey: process.env.R2_SECRET_ACCESS_KEY!,
  },
})
const BUCKET = process.env.R2_BUCKET!

app.post('/presign/r2', async (req, res) => {
  const { path, op, opts } = req.body
  const key = path.replace(/^\/+/, '')
  const ttl = typeof opts?.ttlSec === 'number' ? opts.ttlSec : 300
  let cmd
  switch (op) {
    case 'GET':    cmd = new GetObjectCommand({ Bucket: BUCKET, Key: key }); break
    case 'PUT':    cmd = new PutObjectCommand({ Bucket: BUCKET, Key: key, ContentType: opts?.contentType }); break
    case 'HEAD':   cmd = new HeadObjectCommand({ Bucket: BUCKET, Key: key }); break
    case 'DELETE': cmd = new DeleteObjectCommand({ Bucket: BUCKET, Key: key }); break
    case 'LIST':   cmd = new ListObjectsV2Command({
      Bucket: BUCKET,
      Prefix: opts?.listPrefix,
      Delimiter: opts?.listDelimiter,
      ContinuationToken: opts?.listContinuationToken,
    }); break
    case 'COPY':   cmd = new CopyObjectCommand({
      Bucket: BUCKET,
      Key: key,
      CopySource: `${BUCKET}/${opts?.copySource}`,
    }); break
  }
  res.json({ url: await getSignedUrl(client, cmd, { expiresIn: ttl }) })
})
```

### 2. Browser: wire it up

```ts
import { MountMode, R2Resource, Workspace } from '@struktoai/mirage-browser'

const r2 = new R2Resource({
  bucket: 'my-r2-bucket',
  accountId: 'abc123...',
  presignedUrlProvider: async (path, op, opts) => {
    const r = await fetch('/presign/r2', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ path, op, opts }),
    })
    const { url } = await r.json()
    return url
  },
})

const ws = new Workspace({ '/bucket/': r2 }, { mode: MountMode.READ })
```

<Tip>
`accountId` on the browser config is only used for display/logging; the actual endpoint is baked into the presigned URLs your backend returns.
</Tip>

### 3. Configure CORS on the bucket

R2 does accept S3-flavored `PutBucketCors`, but your token needs **"Admin Read & Write"** permissions on the bucket, object-scoped tokens will get `Access Denied`. Two paths:

**Option A, Cloudflare Dashboard (fastest, no new token):**

1. Open https://dash.cloudflare.com → **R2** → your bucket
2. **Settings** tab → **CORS Policy** → **Add CORS policy**
3. Origin: `http://localhost:5173` (and any production origins), methods `GET,PUT,HEAD,DELETE,POST`, allowed headers `*`

**Option B, admin-scoped R2 API token + the helper script:**

1. Cloudflare Dashboard → **R2** → **Manage R2 API Tokens** → **Create API token**
2. Permissions: **Admin Read & Write** on your bucket
3. Update `R2_ACCESS_KEY_ID` / `R2_SECRET_ACCESS_KEY` in `.env.development`
4. Run the same helper used for S3:

```bash
cd examples/typescript/browser
npx tsx scripts/configure-cors.ts http://localhost:5173 https://app.example.com
```

<Warning>
Object-scoped tokens (`Object Read & Write`) cannot edit CORS. If the script returns `Access Denied` on R2, you're almost certainly using an object token.
</Warning>

See the [R2 resource](/python/resource/r2) docs for the equivalent Python wiring.
