Dear Cosmonauts,

As we near a late-February mainnet launch of the Cosmos Hub, you can expect a 3-part blog post series in the coming days that describes 1) pre-launch dependencies and how to prepare, as delegators, for launch, 2) post-launch roadmap and expectations, and of course, 3) a mainnet launch announcement. In this month’s community update, we summarize the last major changes in the code before it becomes feature-frozen in February. January and early February is the last time that we will be making breaking changes to the software. Because Houston, we’re prepared for takeoff.

Dev Update

Cosmos-SDK

What: The remaining major changes for the Cosmos Hub launch were finally merged into the Cosmos-SDK with the v0.30.0 release. No more major changes will be merged to the Cosmos Hub before launch. The only changes left will be bug fixes and UX polish.

Development Summary:

The major features merged in this release were: major refactors of the fee distribution module (Issue #3099) and validator code (Tombstone and validator power), a new model for gas and fees, vesting accounts, and multi-sig support for gaia-cli . There were also a number of bug fixes and smaller features merged during this release.

. There were also a number of bug fixes and smaller features merged during this release. Changelog: github.com/cosmos/cosmos-sdk/…/CHANGELOG.md#0300

Tendermint Core

What: We cut two releases of TMC this month: v0.28.0 and v0.29.0 .

v0.28.0 Development Summary:

This release is primarily about upgrades to the privval system - separating the priv_validator.json into distinct config and data files, and refactoring the socket validator to support reconnections.

system - separating the into distinct config and data files, and refactoring the socket validator to support reconnections. Changelog: github.com/tendermint/…/CHANGELOG.md#v0280

v0.29.0 Development Summary:

The Block protocol changes include using a standard Merkle tree format (RFC 6962), fixing some inconsistencies between field orders in Vote and Proposal structs, and constraining the hash of the ConsensusParams to include only a few fields.

The proposer selection algorithm saw significant progress, including a formal proof by Christopher Goes for the base-case in Idris and a much more detailed specification (still in progress) by Anca Zamfir.

Watch the Idris Tendermint Dev Session linked in the YouTube video below under the Media section for more context about the Tendermint proposer selection algorithm.

Changelog: github.com/tendermint/…/CHANGELOG.md#v0290

Track Tendermint development activity via milestones: github.com/tendermint/tendermint/milestones We are paying elevated bug bounty rewards on HackerOne. Find the program here: hackerone.com/tendermint

IBC

What: The Inter-Blockchain Communication protocol is the cross-chain data transfer mechanism that enables interoperability and composability of new and existing blockchains.

Development Status:

Undergoing prototyping, with a partial implementation specification.

Gaia Light Client

What: The gaia light client will be useful for wallet providers to hook up as light clients to the Cosmos Hub.

Development Status:

The light client is currently only implemented as a CLI application.

Work still needs to be done to implement a go-mobile friendly iOS library.

Voyager

What: Voyager is the UI to do cool things like delegate to a Cosmos validator or vote on a governance proposal through a dashboard.

Development Status: