Issue with blockchain deterministic wallet and in particular BIP44 20 unpaid address gap issue.

Here is recommendations from block chain support:

Hi,

Generally, there should not be more than 20 unpaid addresses when working with this API. This is because this API leverages BIP 44 (as defined here: ​https://github.com/bitcoin/bips/blob/master/bip-0044.mediawiki ).

I've created a google doc to help you recover the funds used. You should switch to a new account for this API, and please try to remain under the 20 address gap: ​https://docs.google.com/document/d/1-2l6xOqcbjs9QWEqSh72RD1d8EEdvG_hQuEXw_f_o6w/edit?usp=sharing

The address indexes you need to recover are:

[251] 125fPxLHcEuGZ2wx6gW8dZzMsjuZ2cgW5P balance= 100000 [252] 15nb3LBkzzxwDTXmWXv2nJJuZVNR9ZJFrd balance= 100000

Best, Kevin

advice about possible solution

Hi,

I will make a note to update the documentation so it is more clear.

1) we are working on deploying a fix that will do exactly that - prevent you from going past 20 consecutive empty addresses. This should be released in the coming weeks.

2) You can check the most recent 20 addresses that you've used for any balance using our addressBalance endpoint (found here: blockchain.info/q ). In regards to creating new xPubs, you can either go through a more manual approach and go into the web wallet, and generate many xPubs to put into your code to cycle through. Or, if you want a more programatic approach, you can look into implementing our wallet module so you can generate new xPubs on the fly: ​https://github.com/blockchain/service-my-wallet-v3

Best, Kevin