This is going to be a 'spirit of the question' resolution. Essentially the rub is whether China will agree not to invade Taiwan. This would probably be in exchange for something from Taiwan, but this market is not engaging with what that might be.

It also takes no notice of whether an agreement would include and involve third parties like the US. Do note that a US-China agreement over Taiwan that didn't include Taiwan as a 'signing' party would NOT qualify (also, there don't necessarily need to be signiatures as long as it's clear that a binding agreement has been entered into. Again, spirit of the question).

Finally, notice that peace agreements after a failed Chinese invasion could qualify (although only through their content, a negotiated peace wouldn't inherently satisfy this question if it simply returned affairs to the current cross-strait status).

Comments clarification:

*If Taiwan were to be annexed into the PRC as a province or SAR then this would almost certainly not resolve YES because I can't conceive of how that would happen in a way that would involve China saying they wouldn't invade what they recognise as their own territory.

Only in what feels like the extreme edge case where after said surrender Taiwan still exists as a political entity that could maintain an agreement with China could this work.*