Nubbo connects to Backblaze B2 through its S3-compatible API, with an application key and your account region. In a few minutes your buckets are in a file explorer with direct uploads, share links and galleries. This guide follows the Nubbo wizard step by step, with both paths: automatic or with a key limited to one bucket.
What you get
- Browse the bucket like a drive: folders, views, search, trash, labels and favorites.
- Upload and download files directly between your browser and Backblaze B2. Files never pass through Nubbo servers.
- Share files and folders with a password, expiry and download limit, receive files into your bucket and create galleries.
- Your keys are stored encrypted with AES-256-GCM and you can disconnect the bucket at any time.
Before you start
You need an account with Backblaze B2 and a Nubbo account. Every bucket you connect counts toward your plan limit: Free allows 2, Personal 5 and Pro has no limit. On B2 the region is chosen when you create the account and applies to all its buckets. You can see it in the endpoint of any bucket, shaped like s3.<region>.backblazeb2.com: that is the region to pick in Nubbo. The account master key does not work with the S3 API, so always create an application key.
Choose how to connect
The Nubbo wizard offers two paths. Both end the same way: the bucket connected and ready for uploads from the browser.
| Automatic | With a limited key | |
|---|---|---|
| Key | Access to the whole account | Limited to one bucket |
| Bucket | Nubbo uses one of yours or creates a new one | You create it first |
| CORS | Nubbo adds the rule for you | You add the rule |
| When to choose it | The fastest way | When you do not want to give access to the whole account |
Automatic connection
Step 1: create the key in Backblaze B2
- On backblaze.com, open B2 Cloud Storage, Application Keys and press Add a New Application Key. Do not use the master application key.
- Name it, set Allow Access to Bucket(s) to All and Type of Access to Read and Write. Press Create New Key.
- Copy the keyID (the access key) and the applicationKey (the secret). Backblaze shows the applicationKey only once.
- In Buckets, look at the endpoint of any bucket to find your region.
Step 2: connect the bucket in Nubbo
In Nubbo, open Buckets and press Connect bucket. Choose Backblaze B2 and press Continue.
Choose Automatic and press Continue.
In the Your key step, paste the keyID and the applicationKey and choose your account region. Press Check key. Nubbo checks that the key works and that it has access to the whole account.
Pick one of your buckets and press Use this bucket, or select Create a new one, type a name (and pick the region, if it asks) and press Create and prepare. Nubbo adds a CORS rule to the bucket that only allows uploads and downloads from the app, and keeps the rules it already has.
Review the three checks, change the Name in Nubbo if you like and press Finish. The bucket shows up in Buckets and you can open it in the explorer.
Then, in the bucket, open Lifecycle Settings and choose Keep only the last version of the file. Otherwise B2 keeps every version and deleting from Nubbo does not free space.
If Nubbo cannot add the CORS rule with your key, the wizard takes you to the CORS step. Then follow Add the CORS rule.
Connection with a limited key
Step 1: prepare the bucket and the key in Backblaze B2
- In Buckets, press Create a Bucket, name it and keep it Private.
- In the bucket, open Lifecycle Settings and choose Keep only the last version of the file.
- Look at the bucket endpoint to find the region.
- In Application Keys, press Add a New Application Key, limit access to your bucket with Read and Write and tick Allow List All Bucket Names. Press Create New Key.
- Copy the keyID and the applicationKey.
Step 2: connect the bucket in Nubbo
- In Buckets, press Connect bucket, choose Backblaze B2 and then With a limited key.
- Paste the keyID and the applicationKey and choose the region. Press Check key.
- Type the exact bucket name and press Check access.
- The wizard moves to the CORS step with the rule you need to add.
Add the CORS rule
The CORS rule lets the browser upload and download files from your bucket on https://nubbo.app. It is the same rule the wizard shows in the CORS step.
The CORS rules in the B2 console are presets and do not let you choose the operations, so the Nubbo rule is added with the B2 command-line tool (b2), using a key that can change the bucket settings.
- Install the CLI, for example with
pip install b2. - Sign in with your keyID and applicationKey:
b2 account authorize. - Apply the rule, replacing
your-bucketwith the bucket name.allPrivatekeeps the bucket private.
b2 bucket update --cors-rules '[{"corsRuleName":"nubbo","allowedOrigins":["https://nubbo.app"],"allowedOperations":["s3_get","s3_head","s3_put","s3_post","s3_delete"],"allowedHeaders":["*"],"exposeHeaders":["etag"],"maxAgeSeconds":3600}]' your-bucket allPrivate
Once it is applied, go back to Nubbo and press I added it, check. If your key is allowed to change CORS, Try to configure it for me does it for you.
If something goes wrong
| Message in Nubbo | What to do |
|---|---|
| “This key seems limited to one bucket. You can continue with the limited path or create a key with full access.” | Press Continue with a limited key, or create a key with access to the whole account and press Try another key. |
| “Bucket not found. Verify the name and region.” | Check the exact bucket name and that the chosen region is the bucket’s. |
| “Your key is not allowed to create buckets.” | Use a key with full access, or create the bucket in your panel and press I created it in my panel. |
| “That name is already in use on this provider; try another one.” | Bucket names are unique across the provider: pick another one. |
| “Your key is not allowed to set it up.” | Add the CORS rule by hand, as explained above. |
| “It does not work yet. Review the rule and check again; some providers take a minute to apply it.” | Check that the origin is exactly https://nubbo.app with no trailing slash, wait a minute and check again. |
| “This bucket is already in use.” | That bucket is already connected in Nubbo, in your account or in another one. |
| “Invalid credentials. Check the access key and secret access key.” | Check that you are not using the master application key, which does not work with the S3 API. |
| “The bucket is in a different region. Verify the configured region.” | Choose in Nubbo the region shown in the bucket endpoint. |
What it costs
Backblaze B2 charges per TB with 10 GB free and free egress up to three times what you store. We explain it in Backblaze B2 pricing.
Frequently asked questions
Can I use the Backblaze master application key?
No. Backblaze does not support the master key on its S3-compatible API. Create an application key under Application Keys.
Which region do I choose in Nubbo for B2?
The one in your buckets endpoint, shaped like s3.<region>.backblazeb2.com. On B2 every bucket of an account is in the same region.
Why is CORS set up with the B2 CLI?
Because the console rules are presets and do not let you choose the operations Nubbo needs. The CLI is the simplest way to apply the exact rule; any S3 tool that runs PutBucketCors against the B2 endpoint works too.
Why does deleting in Nubbo not free space on B2?
Because B2 keeps previous versions by default. In the bucket Lifecycle Settings, choose Keep only the last version of the file.
Sources
Prices and limits come from the official pages below. Providers change them, so check before you commit.