# Open Source Coordinator on Mainnet

Research & Development Apr 08, 2019

Coordicide, the effort of removing the Coordinator from the IOTA networks, is well under way in its research phase. One step in the journey towards Coordicide is making the inner workings of the current network set-up fully transparent. We want to do that with an open-sourced version of the Coordinator running on Mainnet.

The open source Coordinator, called Compass, was originally released a few months back. One of its main functions was that it allowed anyone to set up a private network, run tests, or develop PoCs more easily than before.

Part of the plan was always to have the Coordinator run on all official IOTA networks.Compass has now been running tested on the Spamnet and Devnet for quite some time. Now the time has come for the final step — Mainnet.

The Coordinator is an important part of the IOTA networks, protecting the network from adversarial parties. We believe that using the open source version will improve all the aspects of the networks, while making the way they work more transparent for everyone.

We will be replacing the Mainnet Coordinator on April 10, 2019.The process will consist of releasing a new, breaking version of IRI, together with performing a global snapshot.More on the global snapshot further below.

The underlying logic is the same as with the soon-to-be-replaced Coordinator. The Coordinator issues signed zero value milestones. Transactions referenced by the milestones are considered confirmed by any IRI node. What changes is the hash function the coordinator is using, to Kerl, and the security level of signatures is bumped to level 2.

If you are interested in the Compass source code, make sure you visit the Compass repo. You can also use Compass to set up private networks to experiment with.

This IRI release will be a breaking version. This means that to continue running a node that is able to stay in sync with the network, node operators need to upgrade to the new IRI version that communicates with the new Coordinator. This will be version 1.7.0, and you will find it, as usual, on the release page on the day of the release.

The version of IRI will have the new address of the Coordinator embedded in the code to ensure that the correct milestones are accepted. If you’ve previously built a solution that relies on the Coordinator address, please make sure you replace the Coordinator address you are using now with the following:

EQSAUZXULTTYZCLNJNTXQTQHOMOFZERHTCGTXOLTVAHKSA9OGAZDEKECURBRIXIJWNPFCQIOVFVVXJVD9

The new Coordinator will start issuing milestones at a higher index number than what has been used up by the current Coordinator. This ensures that there is a distinguishable transition between the coordinators, while ensuring certain continuity for applications relying on the milestone index.

Starting milestone index for the new Coordinator

1050000

The global snapshot will be performed on the day of the Coordinator replacement, April 10, and will start at 7:30 AM UTC.Like the last time, we aim to make this global snapshot as seamless as possible.

We expect the Coordinator to be offline for the time required to perform snapshot state verification by the community and start up the new Coordinator.

As always, we would appreciate anyone with a synchronized node that has Local Snapshots enabled to help us verify the snapshot.If you want to take part in the verification process, you can prepare by following steps 1 and 2 detailed in the snapshot validator repository. We will share the PR in the #snapshots Discord channel shortly after the process has started on Wednesday.

Thank you!

### Tags

#### Jakub Cech

Director of Engineering @IOTA Foundation