#cosmwasm #sdk


VM bindings to run cosmwams contracts

139 releases (34 stable)

2.0.0-rc.1 Feb 9, 2024
2.0.0-beta.1 Jan 22, 2024
2.0.0-beta.0 Dec 21, 2023
1.5.3 Jan 31, 2024
0.5.1 Nov 29, 2019

#1188 in Magic Beans

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CosmWasm VM

cosmwasm-vm on crates.io

This is an abstraction layer around the wasmer VM to expose just what we need to run cosmwasm contracts in a high-level manner. This is intended both for efficient writing of unit tests, as well as a public API to run contracts in eg. wasmvm. As such it includes all glue code needed for typical actions, like fs caching.


A VM can support one or more contract-VM interface versions. The interface version is communicated by the contract via a Wasm import. This is the current compatibility list:

cosmwasm-vm Supported interface versions cosmwasm-std
1.0 interface_version_8 1.0
0.16 interface_version_7 0.16
0.15 interface_version_6 0.15
0.14 interface_version_5 0.14
0.13 cosmwasm_vm_version_4 0.11-0.13
0.12 cosmwasm_vm_version_4 0.11-0.13
0.11 cosmwasm_vm_version_4 0.11-0.13
0.10 cosmwasm_vm_version_3 0.10
0.9 cosmwasm_vm_version_2 0.9
0.8 cosmwasm_vm_version_1 0.8

Changes between interface versions

interface_version_5 -> interface_version_6

  • Rename the fields from send to funds in WasmMsg::Instantiate and WasmMsg::Execute.
  • Merge messages and sub-messages.
  • Change JSON representation of IBC acknowledgements (#975).


There are demo files in testdata/*.wasm. Those are compiled and optimized versions of contracts/hackatom and contracts/staking run through rust-optimizer.

To rebuild the test contracts, go to the repo root and do

docker run --rm -v "$(pwd)":/code \
  --mount type=volume,source="devcontract_cache_cyberpunk",target=/target \
  --mount type=volume,source=registry_cache,target=/usr/local/cargo/registry \
  cosmwasm/optimizer:0.15.0 ./contracts/cyberpunk \
  && cp artifacts/cyberpunk.wasm packages/vm/testdata/cyberpunk.wasm

docker run --rm -v "$(pwd)":/code \
  --mount type=volume,source="devcontract_cache_hackatom",target=/target \
  --mount type=volume,source=registry_cache,target=/usr/local/cargo/registry \
  cosmwasm/optimizer:0.15.0 ./contracts/hackatom \
  && cp artifacts/hackatom.wasm packages/vm/testdata/hackatom_1.2.wasm

docker run --rm -v "$(pwd)":/code \
  --mount type=volume,source="devcontract_cache_ibc_reflect",target=/target \
  --mount type=volume,source=registry_cache,target=/usr/local/cargo/registry \
  cosmwasm/optimizer:0.15.0 ./contracts/ibc-reflect \
  && cp artifacts/ibc_reflect.wasm packages/vm/testdata/ibc_reflect_1.2.wasm

docker run --rm -v "$(pwd)":/code \
  --mount type=volume,source="devcontract_cache_empty",target=/target \
  --mount type=volume,source=registry_cache,target=/usr/local/cargo/registry \
  cosmwasm/optimizer:0.15.0 ./contracts/empty \
  && cp artifacts/empty.wasm packages/vm/testdata/empty.wasm

The cyberpunk_rust170.wasm for https://github.com/CosmWasm/cosmwasm/issues/1727 is built as follows (non-reproducible):

cd contracts/cyberpunk
rm -r target
RUSTFLAGS='-C link-arg=-s' cargo build --release --lib --target wasm32-unknown-unknown --locked
cp target/wasm32-unknown-unknown/release/cyberpunk.wasm ../../packages/vm/testdata/cyberpunk_rust170.wasm

The floaty_2.0.wasm is built using Rust nightly as follows (non-reproducible):

cd contracts/floaty
RUSTFLAGS="-C link-arg=-s -C target-feature=+nontrapping-fptoint" cargo wasm
cp target/wasm32-unknown-unknown/release/floaty.wasm ../../packages/vm/testdata/floaty_2.0.wasm


By default, this repository is built and tested with the singlepass backend. You can enable the cranelift feature to override the default backend with Cranelift

cd packages/vm
cargo test --features iterator
cargo test --features cranelift,iterator


Using Singlepass:

cd packages/vm
cargo bench --no-default-features

Using Cranelift:

cd packages/vm
cargo bench --no-default-features --features cranelift


module_size and module_size.sh

Memory profiling of compiled modules. module_size.sh executes module_size, and uses valgrind's memory profiling tool (massif) to compute the amount of heap memory used by a compiled module.

cd packages/vm
RUSTFLAGS="-g" cargo build --release --example module_size
./examples/module_size.sh ./testdata/hackatom.wasm


This package is part of the cosmwasm repository, licensed under the Apache License 2.0 (see NOTICE and LICENSE).


~368K SLoC