What methods are there to make a monero address transparent to be viewable publicly on the blockchain? Say your a non-profit and you want your address viewable publicly, how can this be done?
Publish the address and public view key and anyone can audit the total received, but can't tell what's been spent.
To audit the balance, the non-profit should publish updated key images file every time they receive something new. The process is described here (steps 1 to 6).
The auditor (or general public), could then make a watch wallet from the address and viewkey, scan the blockchain for incoming transfers, and import key images to mark what's been spent and get the correct balance. With the viewkey, they'll be able to see whether something new has been received, and then they'd know they need the updated key images to be able to monitor whether those new outputs have been spent.