Hub & Spoke Community Newsletter
Game of Zones: Compete to win 100,000 ATOM by building and running Cosmos Zones.
IBC Demo is Available & Game of Zones announced
Welcome Cosmonauts to the November edition of the Cosmos Hub & Spoke newsletter.
✨ Didn’t make it to SFBW? Find out what you missed!
✨ Cosmos community-driven testnet for Cosmos Hub-3 upgrade
✨ Revving up for “Game of Zones”
✨ New tutorial on “Getting Started with Ethermint”
🌉 Five takeaways from Cosmos at SFBW
1. The launch of the Virgo manifesto
Virgo’s mission is to create cohesion between individuals and organizations working to improve human coordination. Jae Kwon presented the beginnings of Virgo at CESC and shared his view for the future of this project. You can find out more and get involved in the discussion by visiting the links below:
2. The inauguration of Supernova - building an inspired community
Over the past three years, the Tendermint team has been in the trenches growing, supporting and learning from the Cosmos community with ups and downs. Chjango Unchained, together with Commonwealth Labs, announced the inauguration of the Supernova community, a Cosmos Zone that will allow any project to build an engaged community from day one of launching its mainnet. For more information, visit the Supernova website and sign up to receive updates about the project.
3. The largest DeFi Hackathon hosted in SF
DeFi Hackathon - San Francisco | November 1-3, 2019
With prizes worth over $60K in value, the DeFi Hackathon attracted over 300 developers from around the world. We had 53 teams submitting projects and 11 finalists took home the bounties. We’ll be sharing a recap post that details the entire hackathon in the coming weeks. Congratulations to all the Cosmos DeFi hackers!
4. A hackathon ready IBC demo
IBC: Inter-Blockchain Communication
Inter-Blockchain Communication (IBC) is a chain-agnostic protocol that will enable interoperability for cross-chain communication between any two blockchains. During the DeFi Hackathon, teams were able to try it out for themselves.
🔔 IBC Updates
The IBC webpage was just launched. Sign up for updates about IBC related communication and make an impact by joining the technical IBC working group.
Get IBC updates
👾 Hackathon Demo
Check out the recent hackathon-ready demo that allows you to use an early prototype of IBC.
🍿 Chain Reaction
Listen to the latest Chain Reaction #3: IBC Cosmos SDK demo review. Catch up by listening to Chain Reaction #1: Launching IBC (Agoric and Tendermint) and Chain Reaction #2: Getting IBC Hackathon Ready
📻 Interchain.FM
New podcast announcement covering the world of IBC - Interchain.FM Ep. 001
5. Cosmos DEX demo
The launch of the first Cosmos DEX demo is an initial exercise at exploring, ideating, and creating the next set of decentralized exchange (DEX) projects that can be built on the Cosmos SDK. We were happy to see several teams build on top of the DEX including the first place, second place, and overall general category winner of the DeFi Hackathon!
Stay tuned for more updates.
✨ Community Conversations
Community-driven testnet for software upgrades
While the Hub-2 upgrade proposal D passed, unfortunately the execution of the upgrade failed. A new block height, date and time for the next upgrade attempt is currently being discussed on the Cosmos Forum: Cosmos Hub 3 Upgrade Proposal E. Don’t forget to check out the canonical version of the Cosmos SDK that will be used in the next hub upgrade.
Interested in participating in the community testnet?
Join the validator testnet Telegram group for more information.

P2P management proposal
A new proposal by B-Harvest outlines improvements to the P2P management layer of the network targeted at achieving enhanced network stability. If passed and implemented, node operators would benefit from better connectivity between trusted peers and a stronger, more persistent connection to Tendermint.
View proposal

Proportional slashing
Centralization of consensus power within the Cosmos Hub has been a hot topic since the mainnet launch. A recent proposal by Sunny Aggarwal, dubbed proportional slashing, offers a solution to reduce the concentration of stake and voting power among the top validators occupying 67% control of the network. In this new proposal, the percentage a validator gets slashed for a fault is proportional to the validator’s percent of consensus power. This way, larger validators face harsher slash amounts thus incentivizing risk-managing delegators to delegate to smaller validators. In the current system, the slashing percent is equal for all slashes.
View proposal

💬 In the Twittersphere
💫 Cosmos Events, News & Meetups
Cryptoslate interview with Chris Goes (Tendermint) and Dean Tribble (Agoric) on the IBC specification process: Agoric and Tendermint on designing an interoperable future for 2020

One year ago, we launched Game of Stakes. Now, we’re gearing up for Game of Zones, an adversarial environment to test IBC. The competition will create an invaluable educational opportunity and environment for the Cosmos community to experience the IBC protocol.


Check out Figment’s November update - “IBC is Coming to Cosmos” plus all the details from the November 5th Game of Zones AMA with Zaki Manian (Tendermint) and Dean Tribble (Agoric)

The Cosmos community has a new block explorer - powered by Ping Pub

🎉 Cosmos Meetups
Join Cosmos meetups anywhere you are in the world: Cosmos is Worldwide on Don’t see a Meetup near you? Contact Cosmos Admin on
Join Cosmos Meetup
🌟 Product Development Updates
Cosmos SDK
- Modular AnteHandler added - this allows users to specify their own antehandler logic and register these functions with the module manager, rather than recreating all anti-handler logic.
- DeCoupling vesting from x/Auth - this new change decouples vesting from auth and creates a new vesting module, which extends auth’s functionality.
- Cosmos SDK release v0.34.10 - Bump Tendermint version to v0.31.11 to address the vulnerability found in the consensus package
- New DEX demo module for the Cosmos SDK

Inter-Blockchain Communication (IBC)
IBC will serve as an open standard for interchain communication. For a list of IBC implementations, IBC-supporting blockchains, and special IBC bridges, see here.
- The specification version 1.0.0 release candidate 5 is now available, featuring client store layout abstraction, canonical encoding definitions, an improved versioning negotiation sub-protocol, and various bug fixes & clarity improvements.
- An early stage IBC demo is now available
- First ever external contribution to the IBC standards repo goes to Everett Protocol

Tendermint Core
- Two security releases were published along with two back-port releases
- Watch the Tendermint developer session ABCI overview
- Recently added an alternative Rust ABCI server

Ethermint is designed to be a Proof of Stake implementation of the Ethereum Virtual Machine built on top of Tendermint Core. For more details on the product, check out our blog post “A Beginner’s Guide to Ethermint.”
- New video tutorial: Getting started with Ethermint
- ChainSafe’s Ethermint Github repo
- Aragon and ChainSafe forum discussion on using Ethermint in production
- Read Aragon One’s blog post on selecting Ethermint for the new Aragon Chain
- Listen to a recent AMA with Aragon, ChainSafe and Cosmos about the Aragon Chain on Ethermint
- Developer session on ETH2.0 lite client with ChainSafe
Development updates for Ethermint from ChainSafe’s Austin Abell
- Implement eth filter endpoints
- Include gas refunds for evm transactions to match total gas usage with Ethereum
- Implement queries through evm module to interact with Ethereum state
- Improve testing framework to ensure compatibility

CosmWasm ready to use for Rust developers
Rust CosmWasm will bring the WebAssembly (Wasm) virtual machine (VM) to the Cosmos SDK for Rust developers. WebAssembly potentially enables software written in arbitrary languages to run securely on any hardware. Wasm is an intermediate language that compiles the developer’s programming language of choice to the user’s hardware.
Current updates on CosmWasm from Ethan Frey
- cosmwasm library to build smart contract and a VM to run them in.
- cosmwasm-opt script and Docker image to produce reproducible, minimal-sized wasm output.
- cosmwasm-template for developers to easily get started on coding contracts.
- go-cosmwasm bindings from cosmwasm/vm to golang, including passing kvstore over foreign function interface (FFI).
- cosmos/modules PR for Cosmos SDK integration.
Visit the CosmWasm Github repo for more details about how to get started coding your first smart contract.