# s3nd with Cloudflare R2

> Move files and local-first app data through a Cloudflare R2 bucket with s3nd: the createBucket() configuration, the CLI starter, and what to know about this provider.

Canonical: https://www.s3nd.sh/providers/cloudflare-r2 · Markdown: https://www.s3nd.sh/providers/cloudflare-r2.md · Français: https://www.s3nd.sh/fr/providers/cloudflare-r2

No egress fees, which is exactly what moving a 2 GB file between two laptops wants.

**createBucket()**
```ts
import { createBucket } from '@s3nd/core'

const store = createBucket({
  bucket: 'transfers',
  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!,
  },
  publicUrl: 'https://cdn.example.com', // optional: your R2 custom domain
})
```

## Why this one
R2 speaks the S3 API, ignores the region, and charges nothing for egress. That makes it the provider the "without a server" guide is written against: a bucket, a token scoped to it, one configuration file, and a code carried between two machines for a bill of nothing.

## A starter configuration, and what is left to do.
init writes the file with ${VAR} references rather than secrets, so it is meant to be committed; the env file it points at is not.

```sh
s3nd init --provider r2 --bucket transfers
```
**s3nd.config.json**
```json
{
  "bucket": "transfers",
  "region": "auto",
  "endpoint": "https://${R2_ACCOUNT_ID}.r2.cloudflarestorage.com",
  "prefix": "transfers",
  "expiresIn": "24h",
  "envFile": ".env",
  "credentials": {
    "accessKeyId": "${R2_ACCESS_KEY_ID}",
    "secretAccessKey": "${R2_SECRET_ACCESS_KEY}"
  }
}
```

### Then
1. Put R2_ACCOUNT_ID, R2_ACCESS_KEY_ID and R2_SECRET_ACCESS_KEY in .env, and keep it out of git.
2. The API token needs Object Read & Write on this bucket, and nothing else.
3. Add a lifecycle rule that deletes objects under transfers/ after a day or two.
4. Run `s3nd doctor`. It performs the operations s3nd needs and reports what happened.

## Notes on R2.
- **region: "auto"** — R2 ignores the region and the SDK insists on one. Setting an endpoint makes s3nd default to "auto", so there is nothing to write.
- **Conditional writes work** — R2 implements If-None-Match and If-Match on PutObject, which is what keeps two simultaneous transfers from overwriting each other.
- **Expiry cleanup** — expiresIn stops a transfer being handed over; only a lifecycle rule deletes the object. Give the prefix a rule that expires objects after a day or two, and s3nd doctor turns green.

[The full guide](https://doc.s3nd.sh/docs/no-server)