They generally use official APIs, of which most backends have.

I’ve been using rclone for 3 years without issues. Across many different backends.

Most providers support S3 compatible APIs which rclone can then use to talk to them. For example, S3, Cloudflare R2, Backblaze, ...

I've been using it with Vultr as well without a hitch.

It's a wrapper around a bunch of API's. If that makes you nervous then wait until you hear about how the rest of the modern web is strung together. It's been working reliably for me for a decade.

rsync.net

> What cloud storage provider officially supports this tool or the protocol used by it?

Man I wish I lived in a universe where providers actually supported tooling. You're completely delusional tho.

Not delusional. The rsync.net supports low-level tools like scp, and also this. And their team is great for engineer level questions.

That's wonderful! Full endorsement of the support of rsync.net.

I sincerely doubt most tools will be supported by most providers (by usage), however, and I question the evaluation of tools by this metric. Support is generally a fairly bad metric by which to evaluate tooling—generally speaking, if you care which client is consuming an API someone has done something horrifically wrong.

Wot? Support is THE metric.

...for the client tooling, or for the service? The service is understandable but the tooling makes no sense whatsoever.

What if we looked at all of the cloud providers APIs, which may or may not be similar to one another, may be in constant flux, and may have undocumented quirks, and hid all that complexity inside of one black box that provided a single clear API. The guts of that black box might be kinda ugly, and might need at lot of constant updating, but for a lot of users (including me), that is more appealing dealing with all the raw complexity of the various cloud providers "offical" APIs.

There is no rsync protocol, only whatever protocol exist already. Most providers will have their version of S3, so if a provider wants to implement a strict copy of the AWS api they will be compatible. They can also provide an SFTP API and rclone will work.

We have rclone built into our environment:

  ssh [email protected] rclone blah blah ...

... so you don't even need to install rclone for some use-cases - like backing up an S3 bucket to your rsync.net account:

https://www.rsync.net/resources/howto/rclone.html