Your first FTP/SFTP to Backblaze B2 service

This guide walks you through creating a Simple FTP Service (SFS) backed by Backblaze B2. When you are done you will have an FTP/FTPS/SFTP hostname and a user account whose uploads and downloads go straight to a B2 bucket in your own Backblaze account. DocEvent connects through B2's S3-compatible API, so you need three things from Backblaze: the bucket, its endpoint, and an application key.

Before you start - in Backblaze

1. Pick or create a bucket. A private bucket is fine - DocEvent signs in with your key, so the bucket never needs to be public.
2. Note the bucket's endpoint. On the Buckets page of the Backblaze web console, each bucket shows an Endpoint, for example s3.us-west-004.backblazeb2.com. The middle part, us-west-004, is the bucket's region. You need both.
3. Create an application key. Open App Keys and choose Add a New Application Key:
   • Allow access to bucket(s): just this bucket, rather than All
   • Type of access: Read and Write
4. Copy the key straight away. Backblaze shows a keyID and an applicationKey. Save both before closing the dialog.

Use a standard application key, not your account's master application key: Backblaze recommends standard keys for S3-compatible access, and a key limited to one bucket means DocEvent can reach nothing else in your account.

Step 1 - Create a new service

Sign in to the DocEvent console, open Simple FTP Service in the top menu and click Create new. Choose S3 Compatible Storage as the backend.

Step 2 - Provide access to your bucket

Fill in the S3 Compatible Credentials with the values from Backblaze:

Fill in Bucket region with the region from your endpoint, even though the form lets you leave it empty. Backblaze currently accepts other values too, but the endpoint's region is the one Backblaze documents - and an empty field is not "detected": DocEvent signs with its own hosting region instead.

Leave Use path style URLs unticked; B2 works with the default.

Click Verify Access. DocEvent round-trips a small test file to prove the key really can read and write the bucket before anything is saved. If the key is limited to a folder rather than the whole bucket, set Test path under Advanced to a folder the key can write to.

Step 3 - Name the service and add the first user

Give the service a name, then set up its first user - you can add more later.

1. Service name - how the service appears in your console
2. Username - the first FTP/SFTP user. It gets the service ID as a prefix once created, e.g. abcd1234/ftpuser
3. Password - the user's password
4. Home directory - where this user lands inside the bucket. / is the bucket root; a path like /acme confines them to that folder. See Home directories and keeping each user isolated

Click Create Service.

Step 4 - Done: your login details

The final screen has everything you need to connect: the username with its service-ID prefix, the FTP/FTPS and SFTP hostnames, ready-to-paste command-line examples, and the SSH host keys for verifying the SFTP server - see SSH host keys for SFTP and SCP.

Every file uploaded over FTP, FTPS or SFTP lands in your B2 bucket, and every file already in the bucket is available to download. You can also browse it from a browser with SFS Drive.

Worth changing: keep deleted files from piling up

By default a B2 bucket keeps every version of every file, including files that have been deleted or overwritten - they become hidden versions, and hidden versions still count towards your Backblaze storage bill. If your partners delete files after picking them up, or overwrite the same file names, that storage grows quietly.

To stop it, open the bucket's Lifecycle Settings in Backblaze and choose Keep only the last version, or Keep prior versions for this number of days if you want a short safety window. See Backblaze's lifecycle rules.

If Verify Access fails

• "Please enter a valid HTTP URL" - the endpoint needs https:// in front.
• An access or signature error - check that Access Key ID holds the keyID (not the key's name) and that the secret is the applicationKey from a standard key, not the master application key.
• Access denied writing the test file - the key may be Read Only or limited to a folder. Create a Read and Write key, or set Test path to the folder the key can write to.

Other storage providers

The S3 Compatible Storage tile also covers Wasabi, Cloudflare R2, MinIO, Hetzner Object Storage and Supabase - see Your first FTP/SFTP to Cloudflare R2 service and Your first FTP/SFTP to Wasabi service. For Amazon S3 itself, follow Your first FTP/SFTP to Amazon S3 service.