We just released a new version of Horizon, v0.22.1.

You may notice that it’s hot on the heels of the previous Horizon release, which came out just last week. There’s a reason for that: Horizon v0.22.1 includes support for Stellar-core v12.0.0. That’s it. It doesn’t contain any breaking changes, and any that were scheduled for this release have been pushed to subsequent releases.

We’re releasing this special version of Horizon because we want to give people plenty of time to download the new software and to prepare for the vote to upgrade the network to Stellar-core v12.0.0.

If you run an instance of Stellar-core or Horizon or you have an application or business that runs on Stellar, please install the newest versions of Stellar-core, Horizon, and any SDK you use as soon as possible. You can read the full release notes and download the newest versions here:

Here’s a brief rundown of what’s next in the core v12 rollout:

Today: Horizon v0.22.1 comes out

Today: the Stellar SDKs support protocol 12

Monday 10/14 at 1600 UTC : the testnet upgrades to Stellar-core v12.0.0

: the upgrades to Stellar-core v12.0.0 Monday 10/28 at 1600 UTC: validators vote on whether to upgrade the public network to Stellar-core v12.0.0

About Protocol 12

Protocol 12 creates a new type of offer—{% code-line %}path_payment_strict_send{% code-line-end %}— and disables the current inflation mechanism. For more details, check out the Stellar Core v12.0.0 release announcement.

As mentioned above, this version of Horizon doesn’t include any breaking changes, but there are several scheduled in the months following the network upgrade. A few operations will soon be deprecated in favor of new operations. For instance: {% code-line %}path_payment{% code-line-end %} will become {% code-line %}path_payment_strict_receive{% code-line-end %} in order to parallel the new {% code-line %}path_payment_strict_send{% code-line-end %} operation. You can read about the scheduled breaking changes in the release notes.

If you run a validator

You can vote to upgrade the network to Protocol 12 via a stellar-core HTTP Command or by directing an HTTP request via your HTTP client of choice to port 11626.

The stellar-core http-command is: {% code-line %} **/upgrades?mode=set&upgradetime=2019–10–28T16:00:00Z&protocolversion=12** {% code-line-end %}

You can schedule that vote immediately, though it won’t take effect until the specified upgrade time of 10/28/2019 at 1600 UTC. Use the Stellar-core info command to check to see if your node is armed for the upgrade.

Questions? Comments? Concerns?

Please join in the conversation on Keybase, and check out the #dev_discussion and #validators channels. That’s the best place to interact not only with the SDF, but with other businesses and developers building on Stellar.