- Edited
I don't understand this story of credits that appear throughout the documentation. Are these API request credits? Likely, given one needs an API authentication secret.
Oh never mind, look at this: https://gateway.threema.ch/de/products I don't speak german but it would appear this API is paid for.
With enough funding, we could propose this but right now, that's not really viable I think
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I think sending messages costs credit, not the lookup requests.