@micahflee Found the source!
It's linked under the `/developer` path for API libraries, and they explicitly mention GPL so they're probably not in violation of licenses:
https://www.telemessage.com/developer/api-libraries/
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Some other info/links which you may or may not know already/or could be helpful:
This is their Play Store listing, including their Telegram capture but not Signal:
https://play.google.com/store/apps/developer?id=TeleMessage
This is linked from: https://www.telemessage.com/downloadapp/
There's also the WebApp (which first tries to auth via SSL Cert but fallbacks to mail / user-password): https://webchat.telemessage.com/
And the secure.-Subdomain with login window: https://secure.telemessage.com/
This FAQ lists other subdomains and ports:
https://www.telemessage.com/what-firewall-ports-must-be-opened-to-enable-enterprise-number-archiver-voice-call-wifi-usage/
The REST-API described there can also be interfaced through their Java or PHP SDK:
https://github.com/TeleMessage/
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