Exploring CosmWasm

Resources

• Sylvia , high-level smart contracts framework https://cosmwasm.cosmos.network/sylvia https://docs.rs/sylvia/latest/sylvia/
• https://cosmwasm.com/build
• https://cosmwasm.cosmos.network/
• https://tendermint.com/core/
• https://docs.cometbft.com/main/spec/consensus/bft-time
• https://informal.systems/blog/introducing-proposer-based-timestamps-pbts-in-cometbft

Notes

• Tries to support reproducible builds

• Supports migrating the storage data schema

• Contract is a WebAssembly code stored in the blockchain’s state

• Contracts have no state except that which is contained in the binary code (e.g. static constants)

• State is stored in the key-value store on the blockchain’s state

• A reference to the contract’s binary, combined with a reference to the prefixed data store, uniquely identifies the smart contract

• The Cosmos SDK is based upon the Tendermint BFT Consensus Engine

• Tendermint Core is a Byzantine Fault Tolerant (BFT) middleware that takes a state transition machine - written in any programming language - and securely replicates it on many machines.

• CosmWasm is built around the actor model

• CosmWasm effectively forces you (with compile time checks) to follow the CEI pattern (Checks, Effects, Interactions) while other similar systems only have this as a “best practice”.

• IBC is a standard that defines how blockchains can send and receive messages to each other. This allows for the creation of a network of blockchains that can interact with each other

Bugs

• Some documentation example (last updated may 28 2025) is outdated and does not compile. Namely, some of the ibc2 examples

• Default template doxxes your email address

• Default template CI unexpectedly triggers on every push

Instructions

With Docker

git clone https://github.com/Neal-C/exploring_cosmwasm.git

cd exploring_cosmwasm

docker build -t neal-c-cosmwasm:latest .

docker run --name neal-c-cosmwasm neal-c-cosmwasm:latest

With local installation

Requirements: Rust >= 1.88.0

rustup target add wasm32-unknown-unknown

git clone https://github.com/Neal-C/exploring_cosmwasm.git

cd exploring_cosmwasm

cargo wasm

cargo unit-test

cargo integration-test