kjessec / wasmd-sample

Basic cosmos-sdk app with web assembly smart contracts

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Wasm Zone

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This repository hosts Wasmd, the first implementation of a cosmos zone with wasm smart contracts enabled.

This code was forked from the cosmos/gaia repository as a basis and then we added x/wasm and cleaned up many gaia-specific files. However, the wasmd binary should function just like gaiad except for the addition of the x/wasm module.

Note: Requires Go 1.17+

For critical security issues & disclosure, see SECURITY.md.

Compatibility with CosmWasm contracts


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

wasmd wasmvm cosmwasm-vm cosmwasm-std
0.27 v1.0.0 1.0
0.26 1.0.0-beta10 1.0
0.25 1.0.0-beta10 1.0
0.24 1.0.0-beta7 1.0.0-beta6 1.0
0.23 1.0.0-beta5 1.0
0.22 1.0.0-beta5 1.0
0.21 1.0.0-beta2 1.0
0.20 1.0.0-beta 1.0
0.19 0.16 0.16
0.18 0.16 0.16
0.17 0.14 0.14
0.16 0.14 0.14
0.15 0.13 0.11-0.13
0.14 0.13 0.11-0.13
0.13 0.12 0.11-0.13
0.12 0.12 0.11-0.13
0.11 0.11 0.11-0.13
0.10 0.10 0.10
0.9 0.9 0.9
0.8 0.8 0.8

Note: cosmwasm_std v1.0 means it supports contracts compiled by any v1.0.0-betaX or 1.0.x. It will also run contracts compiled with 1.x assuming they don't opt into any newer features. The 1.x cosmwasm_vm will support all contracts with 1.0 <= version <= 1.x.

Note that cosmwasm-std version defines which contracts are compatible with this system. The wasm code uploaded must have been compiled with one of the supported cosmwasm-std versions, or will be rejeted upon upload (with some error message about "contract too old?" or "contract too new?"). cosmwasm-vm version defines the runtime used. It is a breaking change to switch runtimes (you will need to organize a chain upgrade). As of cosmwasm-vm 0.13 we are using wasmer 1.0, which is significantly more performant than the older versions.

Supported Systems

The supported systems are limited by the dlls created in wasmvm. In particular, we only support MacOS and Linux. However, M1 macs are not fully supported. (Experimental support was merged with wasmd 0.24) For linux, the default is to build for glibc, and we cross-compile with CentOS 7 to provide backwards compatibility for glibc 2.12+. This includes all known supported distributions using glibc (CentOS 7 uses 2.12, obsolete Debian Jessy uses 2.19).

As of 0.9.0 we support muslc Linux systems, in particular Alpine linux, which is popular in docker distributions. Note that we do not store the static muslc build in the repo, so you must compile this yourself, and pass -tags muslc. Please look at the Dockerfile for an example of how we build a static Go binary for muslc. (Or just use this Dockerfile for your production setup).


This is beta software It is run in some production systems, but we cannot yet provide a stability guarantee and have not yet gone through and audit of this codebase. Note that the CosmWasm smart contract framework used by wasmd is in a 1.0 release candidate as of March 2022, with stability guarantee and addressing audit results.

As of wasmd 0.22, we will work to provide upgrade paths for this module for projects running a non-forked version on their live networks. If there are Cosmos SDK upgrades, you will have to run their migration code for their modules. If we change the internal storage of x/wasm we will provide a function to migrate state that can be called by an x/upgrade handler.

The APIs are pretty stable, but we cannot guarantee their stability until we reach v1.0. However, we will provide a way for you to hard-fork your way to v1.0.

Thank you to all projects who have run this code in your mainnets and testnets and given feedback to improve stability.


The used cosmos-sdk version is in transition migrating from amino encoding to protobuf for state. So are we now.

We use standard cosmos-sdk encoding (amino) for all sdk Messages. However, the message body sent to all contracts, as well as the internal state is encoded using JSON. Cosmwasm allows arbitrary bytes with the contract itself responsible for decodng. For better UX, we often use json.RawMessage to contain these bytes, which enforces that it is valid json, but also give a much more readable interface. If you want to use another encoding in the contracts, that is a relatively minor change to wasmd but would currently require a fork. Please open in issue if this is important for your use case.

Quick Start

make install
make test

if you are using a linux without X or headless linux, look at this article or #31.


Generate protobuf

make proto-gen

The generators are executed within a Docker container, now.


We provide a docker image to help with test setups. There are two modes to use it

Build: docker build -t cosmwasm/wasmd:latest . or pull from dockerhub

Dev server

Bring up a local node with a test account containing tokens

This is just designed for local testing/CI - do not use these scripts in production. Very likely you will assign tokens to accounts whose mnemonics are public on github.

docker volume rm -f wasmd_data

# pass password (one time) as env variable for setup, so we don't need to keep typing it
# add some addresses that you have private keys for (locally) to give them genesis funds
docker run --rm -it \
    -e PASSWORD=xxxxxxxxx \
    --mount type=volume,source=wasmd_data,target=/root \
    cosmwasm/wasmd:latest /opt/setup_wasmd.sh cosmos1pkptre7fdkl6gfrzlesjjvhxhlc3r4gmmk8rs6

# This will start both wasmd and rest-server, both are logged
docker run --rm -it -p 26657:26657 -p 26656:26656 -p 1317:1317 \
    --mount type=volume,source=wasmd_data,target=/root \
    cosmwasm/wasmd:latest /opt/run_wasmd.sh


For CI, we want to generate a template one time and save to disk/repo. Then we can start a chain copying the initial state, but not modifying it. This lets us get the same, fresh start every time.

# Init chain and pass addresses so they are non-empty accounts
rm -rf ./template && mkdir ./template
docker run --rm -it \
    -e PASSWORD=xxxxxxxxx \
    --mount type=bind,source=$(pwd)/template,target=/root \
    cosmwasm/wasmd:latest /opt/setup_wasmd.sh cosmos1pkptre7fdkl6gfrzlesjjvhxhlc3r4gmmk8rs6

sudo chown -R $(id -u):$(id -g) ./template

# bind to non-/root and pass an argument to run.sh to copy the template into /root
# we need wasmd_data volume mount not just for restart, but also to view logs
docker volume rm -f wasmd_data
docker run --rm -it -p 26657:26657 -p 26656:26656 -p 9090:9090 \
    --mount type=bind,source=$(pwd)/template,target=/template \
    --mount type=volume,source=wasmd_data,target=/root \
    cosmwasm/wasmd:latest /opt/run_wasmd.sh /template

# RESTART CHAIN with existing state
docker run --rm -it -p 26657:26657 -p 26656:26656 -p 1317:1317 \
    --mount type=volume,source=wasmd_data,target=/root \
    cosmwasm/wasmd:latest /opt/run_wasmd.sh

Runtime flags

We provide a number of variables in app/app.go that are intended to be set via -ldflags -X ... compile-time flags. This enables us to avoid copying a new binary directory over for each small change to the configuration.

Available flags:

  • -X github.com/CosmWasm/wasmd/app.NodeDir=.corald - set the config/data directory for the node (default ~/.wasmd)
  • -X github.com/CosmWasm/wasmd/app.Bech32Prefix=coral - set the bech32 prefix for all accounts (default wasm)
  • -X github.com/CosmWasm/wasmd/app.ProposalsEnabled=true - enable all x/wasm governance proposals (default false)
  • -X github.com/CosmWasm/wasmd/app.EnableSpecificProposals=MigrateContract,UpdateAdmin,ClearAdmin - enable a subset of the x/wasm governance proposal types (overrides ProposalsEnabled)


  • wasmd is a generic, permissionless version using the cosmos bech32 prefix

Compile Time Parameters

Besides those above variables (meant for custom wasmd compilation), there are a few more variables which we allow blockchains to customize, but at compile time. If you build your own chain and import x/wasm, you can adjust a few items via module parameters, but a few others did not fit in that, as they need to be used by stateless ValidateBasic(). Thus, we made them public var and these can be overridden in the app.go file of your custom chain.

  • wasmtypes.MaxLabelSize = 64 to set the maximum label size on instantiation (default 128)
  • wasmtypes.MaxWasmSize=777000 to set the max size of compiled wasm to be accepted (default 819200)

Genesis Configuration

We strongly suggest to limit the max block gas in the genesis and not use the default value (-1 for infinite).

  "consensus_params": {
    "block": {
      "max_gas": "SET_YOUR_MAX_VALUE",  

Tip: if you want to lock this down to a permisisoned network, the following script can edit the genesis file to only allow permissioned use of code upload or instantiating. (Make sure you set app.ProposalsEnabled=true in this binary):

sed -i 's/permission": "Everybody"/permission": "Nobody"/' .../config/genesis.json


Much thanks to all who have contributed to this project, from this app, to the cosmwasm framework, to example contracts and documentation. Or even testing the app and bringing up critical issues. The following have helped bring this project to life:

Sorry if I forgot you from this list, just contact me or add yourself in a PR :)


Basic cosmos-sdk app with web assembly smart contracts



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