If Bitcoin Unlimited Hard Forks, What Will Happen to BlockCypher’s Bitcoin APIs?

As the noise level about a potential hard fork reaches new heights, we want to update our users on how we plan to handle the situation. It’s important to keep in mind that the environment is very fluid, and so we may need to adjust some of these plans before a fork occurs.

(In our humble opinion, we still believe that a hard fork on Bitcoin is unlikely to happen soon. If you’re losing sleep over the current state of affairs: don’t. Stay away from Reddit’s vitriol. If a hard fork occurs, we’ll have your back.)

Here are all the questions we’ve been asked and our answers:

If Bitcoin forks, will you support both sides of the fork?

Yes, we will offer 2 distinct root endpoints: btc/main and btu/main. To allow you to prepare, we will alias btu/main to btc/main if the Bitcoin Unlimited hashing power raises above 50%.

How will you address replay protection?

Some hacks are possible to protect yourself against replay protection. There’s a lot of pressure on protocol developers to find a better solution than these hacks. We’re hopeful that a hard fork will not happen without proper replay protection at the protocol layer.

Do you expect any downtime if the fork occurs?

No. But depending on how activation is handled, we may need to suspend accepting new blocks as well as reject all non-GET API requests (i.e. creating a new webhook or transaction) for up to an hour (practically we expect that time to be less than 10 minutes). The new Bitcoin Unlimited chain may take up to 2h to become live.

What will happen to my personal data (webhooks, wallets, etc.)?

Every chain and non-chain data will be completely identical until the fork. At the time of the fork, they will be allowed to diverge. For example, after the fork, creating a new webhook against btu/main will not create a new webhook against btc/main.

Do you have a position on Bitcoin Unlimited or Bitcoin Core?

Because of the the way our architecture was designed, we run multiple blockchains on the same infrastructure, as evidenced by our support for Dash, Ethereum, Litecoin, Dogecoin, and Bitcoin. While we wish the Bitcoin community would work more cohesively, it is our job as an infrastructure provider to stay neutral in our views. We focus on providing reliable blockchain web services and leave the politics behind.

How can we stay informed?

For quick updates or emergencies, follow us on Twitter @BlockCypher. For other communications, we update all our users through emails. If a fork appears highly likely, we will issue an update on our blog and send it out via email and Twitter. If you have any concerns, email us support@blockcypher.com