The Evolution of the Cosmos Stack: What is the Interchain Stack?

The Cosmos Hub was launched in 2019 to pioneer a new era of energy-efficient Proof of Stake development and solve the problem of blockchain interoperability through a network of sovereign application-specific chains connected by the Inter-Blockchain Communication Protocol (IBC). With over 110 chains seamlessly connected today, this vision for the internet of blockchains — the interchain — is materializing and its needs are evolving.

In an industry of rapid innovation, the interchain has led the pack. What began with the launch of Osmosis quickly facilitated the exchange of billions of dollars of value over millions of IBC transactions every month. Our ecosystem is more inclusive and no longer limited to Cosmos SDK chains, with multiple teams from diverse communities working to advance the interchain.

In 2023, Composable Finance launched the first IBC implementation connecting Polkadot and Kusama. A year later, in 2024, Picasso Network enabled IBC transfers on Solana, and connections to additional major blockchain ecosystems, including Polygon and Avalanche, are underway. Cosmos has become the interchain and its foundational technology, the Cosmos Stack, has become the Interchain Stack.

Breaking it Down: The Interchain Stack

The Interchain Stack is an architecture for creating composable, modular, open-source protocols, libraries, and tools. The backbone of the Interchain Stack currently comprises four key components for developers to build sovereign app chains, Cosmos SDK, CometBFT, IBC, and CosmWasm.

➤➤Cosmos SDK: blockchain development framework

Cosmos SDK is a flexible open-source toolkit for building multi-asset public Proof-of-Stake (PoS) application-specific blockchains (app chains). Its modular nature means developers can easily create custom blockchains from scratch with native IBC interoperability and swap modules where needed, such as using different consensus engines, like CometBFT or Rollkit. While each stack component can be used separately when building a chain, Cosmos SDK is the tool that brings them together.

• Enables a highly flexible development approach
• Use the SDK’s predefined modules or create custom ones
• Seamlessly interoperate with external components
• Learn more about Cosmos SDK

➤➤IBC: blockchain interoperability protocol

The Inter-Blockchain Communication Protocol (IBC) is a blockchain interoperability protocol that enables secure, permissionless, and feature-rich cross-chain interactions. Blockchains that use the IBC Protocol interoperate with one another while retaining full sovereignty, promoting the growth of a more extensive, interconnected ecosystem. IBC is used by 110+ chains today and continues to grow the internet of blockchains.

• Cross-chain interoperability while retaining full sovereignty
• Removes the need for a trusted third-party
• Secures tens of billions in annual value transfer
• Learn more about the IBC Protocol

➤➤CometBFT: state machine replication engine

CometBFT is a consensus engine based on the Tendermint consensus algorithm that enables the secure and consistent replication of an application across multiple machines. CometBFT functions correctly even if less than one-third of the machines fail in arbitrary ways. This capability of secure and consistent replication plays a crucial role in ensuring the fault tolerance of a wide range of applications.

• Secure and consistent replication of distributed systems
• Ensures the fault tolerance of a wide range of applications
• Versatile and easy to use
• Learn more about CometBFT

➤➤CosmWasm: smart contracting platform

CosmWasm is a WebAssembly-based smart contract platform designed for the interchain, enabling developers to build and deploy dApps and smart contracts on various blockchain networks. By leveraging WebAssembly, a binary instruction format for the web, CosmWasm enables developers to write smart contracts in different programming languages, including Rust, TypeScript, C++, and more.

• Modular architecture for secure, flexible, performant smart contracts
• APIs and tools for seamless interaction with external networks
• Build dApps that execute on multiple blockchains
• Learn more about CosmWasm

The above components of the stack are focused on the backbone of the Interchain Stack, for building scalable, interoperable, and sovereign blockchain networks. The client-side components of the Interchain Stack that focus on user-facing front-end applications are led by CosmJS. Client-side components enable developers to build frontend applications that leverage the features of the interchain and interact with users to bring them experiences in dApps, sites, and other applications.

➤➤CosmJS: TypeScript/JavaScript library

CosmJS is a TypeScript/JavaScript library essential for integrating client-side applications with Cosmos SDK blockchains, streamlining the process of signing and broadcasting transactions. CosmJS is one of many plugins, libraries, services, and integrations, such as Cosmos Kit, Telescope, Interchain UI, and Chain Registry, that address dynamic developer needs and provide easy access to new functionalities for applications built on the Interchain Stack.

• Create coherent, intuitive UIs that integrate with backend systems
• Leverage backend elements as useful components of your design
• Pick exactly (and only) what you need to achieve your goals
• Learn more about CosmJS

Key Properties of the Interchain Stack

The Interchain Stack is a holistic and dynamic framework in constant iteration by its dedicated development teams and open-source contributors, adapting it to the needs of an interconnected ecosystem of blockchains. Each stack component releases regular new versions to improve usability and incorporate useful features for developers.

Each Interchain Stack component is designed to empower developers to create and push the boundaries of the interchain, enabling a new era of decentralized interconnected apps and services where information and value flow freely and securely — and sovereignty, interoperability, and scalability are prioritized.

Composable, Modular, Open Source

A key feature of the Interchain Stack is composability, allowing developers to mix and match different stack components and integrate cross-chain components to create customized blockchain solutions. Interchain projects leverage the stack’s diverse protocols, libraries, and tools in various combinations to meet the specific needs of their projects. They can combine parts of the stack with other components or source codes of external protocols, enabling seamless interoperability and customization.

Composability enables:

• Flexible development
• Seamless interoperability
• Innovative dApps and cross-chain protocols

Leading L1 for real-world assets (RWAs) Provenance chose the Interchain Stack for its regulated TradFi solution, harnessing its composability to build a custom solution for its needs. Leveraging Cosmos SDK and IBC for interoperability, developers can build or connect their decentralized applications (dApps) to the rapidly growing Provenance ecosystem, with a massive $13 billion in assets under admin.

Another standout property of the Interchain Stack is modularity, a design principle that divides the system into separate modules or components, each with a specific functionality. This modular structure allows developers to easily update, replace, or augment individual parts of their blockchain infrastructure without disrupting the system as a whole.

Unlike the monolithic architecture of an L1 like Ethereum, the stack’s modularity enables blockchain projects to divide the core functions, such as transaction processing or data availability, into specialized layers, by building custom modules, and expanding in a way that suits their specific use case.

Modularity enables:

• Dividing core functions into specialized layers
• Creating custom modules
• Flexible and scalable development

Noble, which provides liquidity infrastructure for asset issuers, brought the USDC stablecoin to the interchain. The Interchain Stack’s modularity with the freedom to build custom modules was one of its most important features, enabling them to build a custom module specifically for Circle and USDC interoperability.

Open source is part of the interchain ethos, fostering transparency, security, and community engagement. Anyone can contribute to the Interchain Stack’s development as the codebase is publicly inspectable and accessible. Developers can collaboratively enhance the stack by auditing the code for potential vulnerabilities and suggesting improvements. Due to the collective effort of a diverse developer community, open-source software is adaptable and can evolve more rapidly than proprietary systems.

Open-source development enables:

• Accessible, inspectable code
• A collaborative development approach
• More rapid iteration than proprietary systems

Despite being one of IBC’s most important feature releases, Interchain Accounts (ICS-27) initially gained slow traction. After speaking with multiple interchain projects to understand their intended use cases and pain points with ICA, the IBC team identified the lack of a default underlying app (previously called the ‘authentication module’) and the need to separate application and authentication concerns as the primary reasons for the slow adoption of ICA. Thanks to the contributions of open-source developers, the team made important changes to ICA that saw controller chains surge from one to 34 in 2023 alone.

Wrapping Up

The Interchain Stack is an open-source, composable, and modular design pattern that developers can leverage to unleash their creativity. Truly unique blockchain solutions can be created by mixing and matching the stack’s components and integrating them with source codes or components of external protocols.

The Interchain Stack has come a long way since its inception and continually expands to reflect the needs of an evolving ecosystem, incorporating new components, tools, protocols, and frameworks that facilitate the development, deployment, and management of interoperable blockchains.

Explore new ideas, experiment with novel concepts, and redefine the boundaries of what’s possible in the blockchain space — build on the interchain.

The Evolution of the Cosmos Stack: What Is the Interchain Stack? is part of the brand-new Interchain Stack Highlights series. We’ll be bringing you further editions that dive deeper into each stack component and properties and highlight interesting case studies of interchain projects leveraging the Interchain Stack. Stay tuned!