Software enquiry: Semaphor

Hi there, this is my first post, so be nice.
Since Zoom have acquired Keybase, and the idea of “server admin trust” and metadata issues with Riot, i tried to search for an alternative to them, this where i stumbled upon Spideroak’s Semaphor, but i didn’t find many information about it.
So my question is it secure and private enough to be suggested on PrivacyTools.

Semaphor is not opensource

As always, you need to define your use cases and your threat models. You can’t say whether something is “secure” without defining what level of protection you need. You can’t say whether something is “private” without defining what “being private” means for you.

no it is open source, here is the link to it https://spideroak.com/semaphor/source/

yes you have a good point, i didn’t mention my use case.
i am looking for a small teams chat (5 team members or less) software like slack, and by private i mean the opposite of what Slack is offering( they provide only at rest, and in transit encryption, but they don’t provide end-to-end encryption, in fact they do with their enterprise plan, where they offer Slack Enterprise Key Management, but i won’t be buying enterprise plan just for end-to-end encryption ).
And i will be using it to chat with my team and exchange sensitive documents, so for my threat model, i hope i won’t be facing a global adversary but at least the software will be secure enough so that the documents that i will be sharing won’t fall in the wrong hands.

i mean if its open source (as you said) and their teem seems nice and there is no shady past for their company then why not ?

But no Git repo. Weird.