Backblaze B2Cloud and Chrome extensionFree
A Backblaze B2 browser without the web UI limits.
Stream Vessel lets you browse and manage Backblaze B2 through a file-manager-style interface, using B2's S3-compatible API. Upload whole folders and large files, search a bucket, edit files in place and share access without handing out application keys.
Why
What Stream Vessel adds to Backblaze B2
The B2 web UI uploads files one at a time, cannot upload a folder, and caps uploads at 500 MB. Stream Vessel uploads folders by drag and drop and sends large files in parts, and adds bucket search, an in-place editor, metadata editing and share links.
Stream Vessel is an S3 browser and file manager for AWS S3 and every S3-compatible provider. Backblaze B2 is a preset in the connection dialog.
Connection details
| Endpoint | The bucket's S3 endpoint, for example s3.us-west-004.backblazeb2.com |
|---|---|
| Region | The region part of the endpoint, for example us-west-004 |
| Credentials | A B2 application key: keyID as the access key, applicationKey as the secret |
Set up
Connect Backblaze B2 to Stream Vessel
- In Backblaze, open Application Keys and add a key. You can restrict it to one bucket and make it read-only. Leave the file name prefix empty: B2's S3-compatible API does not accept prefix-restricted keys.
- Copy the
keyIDandapplicationKey, and the S3 endpoint shown on the bucket's page. - In Stream Vessel, add a connection, pick Backblaze B2, and fill in the endpoint and key.
- Test the connection, save, and your B2 buckets appear in the explorer.
Features
What you can do with Backblaze B2 in Stream Vessel
The same features work on every provider. The editions differ: sharing and AI access need a Stream Vessel Cloud account. All S3 browser features.
| Feature | Stream Vessel Cloud | Chrome extension |
|---|---|---|
| Browse buckets and folders: tree, file list, s3:// breadcrumbs | ✓ Available | ✓ Available |
| Several panes side by side, each on its own connection | ✓ Available | ✓ Available |
| Upload files and folders, multipart for large files | ✓ Available | ✓ Available |
| Copy between connections and providers | ✓ Available | ✓ Available |
| Rename objects and folders | Soon | Soon |
| Edit text and code in place | ✓ Available | ✓ Available |
| Read and edit object metadata | ✓ Available | ✓ Available |
| Search a folder or a whole bucket | ✓ Available | ✓ Available |
| Presigned links with an expiry, single and bulk | ✓ Available | ✓ Available |
| Share a connection, bucket or folder with people | ✓ Available | – Not available |
| AI access over MCP | ✓ Available | – Not available |
| Send to and import from Google Drive | ✓ Available | ✓ Available |
Beyond browsing
Sharing, AI access and transfers with Backblaze B2
- Share Backblaze B2 access without sharing keys. On Stream Vessel Cloud, share a Backblaze B2 connection, bucket or folder by email at READ, WRITE or FULL, and revoke it in one click. How secure S3 sharing works.
- Give AI agents access to Backblaze B2. An MCP token with a tier and an expiry lets Claude Code, Cursor or another MCP client work in your Backblaze B2 buckets, with every call logged. S3 access for AI agents.
- Copy between Backblaze B2 and other storage. Open Backblaze B2 next to any other connection and drag or paste to copy across providers, or send files to Google Drive. Cloud storage transfers.
- Keys stay yours. In the Chrome extension your Backblaze B2 keys never leave your browser. On Cloud they are encrypted with AES-256 and never shown to the people or agents you give access. Where keys are stored.
Backblaze B2 notes
Good to know about Backblaze B2
- Use an application key, not the master key. B2's S3-compatible API works with application keys. Create a dedicated key for Stream Vessel so you can revoke it on its own.
-
Keys restricted to a bucket. A B2 key restricted to one bucket keeps everything built on the connection, including your shares and AI tokens, inside that bucket. To open the connection directly in one folder, save it as a scoped connection,
s3://bucket/prefix/: Chrome extension today, coming soon on Cloud. - Endpoint and region go together. The endpoint on the bucket page carries the region, and a key only works against the region of its account. If a test fails with a signature or region error, check that both match.
- CORS on Stream Vessel Cloud. Cloud applies the CORS rule it needs. If the CORS status shows "Invalid or N/A", add the rules by hand, see the CORS FAQ. The Chrome extension does not need CORS.
FAQ
Backblaze B2 questions
Can I upload a folder to Backblaze B2?
Yes. Drag a folder into Stream Vessel or use Upload; the folder structure is kept, large files go up in parts, and an upload panel groups failures for one-click retry.
Which Backblaze key do I use?
An application key. Its keyID is the access key and its applicationKey is the secret. Restrict it to one bucket if Stream Vessel should see only that bucket; B2's S3-compatible API does not accept keys restricted to a file name prefix.
Can I copy files from B2 to S3 or R2?
Yes. Open B2 and the other provider in two panes and drag, or copy and paste. A copy across connections always copies; it never deletes from B2.
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