> "This payment did not become spendable since xxx minutes. Check with the
> sender if s/he paid the Bitcoin network fee. Check if your internet
> connection is working properly." (incoming)

That seems reasonable.

The other message should be implementable today, I think? If numBroadcastPeers > 0 post 0.10.3 then you know the tx made it out to the internet.

Unfortunately if nodes start to diverge a lot in terms of what they will accept, then “transmitted” is no longer a clean binary yes/no thing. Guess we’ll have to jump that hurdle when we come to it.

> Guess you're right. But as you said, we're not there yet.

The payment protocol at least would need some notion of fee, or possibly (better?) the ability for a recipient to specify some inputs as well as some outputs.

Originally I think we were hoping for child-pays-for-parent. I guess that needs someone to sit down and focus on it for a while, assuming we still think that’s a good idea.