Odra + CosmWasm

In November 2022 we released the first version of the Odra Framework. It's time for the next big step in our framework development - a new platform integration. Meet Odra + CosmWasm.

CosmWasm

CosmWasm is a smart contract platform for building dApps on the Cosmos blockchain ecosystem. The platform is designed as a module that can be integrated into the Cosmos SDK, enabling developers who are already building blockchains with the Cosmos SDK to easily incorporate CosmWasm smart contract functionality without the need to modify their existing code.

It uses the Rust programming language, so is potentially a perfect candidate for an Odra backend. There are many blockchains like Osmosis, Secret Network, Juno that utilize CosmWasm.

Show me your code

I would like to write a Counter smart contract that is CosmWasm compatible. What are the requirements?

1. It should store a u32 value.
2. The initial value it set by the contract deployer.
3. The value can be incremented.
4. The value can read from the storage.
5. The contract can call another contract and increment its counter.

So let's write an Odra module first.

counter.rs

use odra::{types::{Address, event::OdraEvent}, Variable, contract_env};
use self::events::{Init, ValueUpdated};

#[odra::module]
pub struct Counter {
    pub value: Variable<u32>
}

#[odra::module]
impl Counter {
    #[odra(init)]
    pub fn init(&mut self, value: u32) {
        self.value.set(value);
        <Init as OdraEvent>::emit(Init {
            value,
        });
    }

    pub fn increment(&mut self) {
        let old_value = self.value.get_or_default();
        let new_value = old_value + 1;
        self.value.set(new_value);
        
        ValueUpdated {
            old_value,
            new_value,
            operator: contract_env::caller()
        }.emit();
    }

    pub fn cross_increment(&mut self, counter_address: Address) {
        CounterRef::at(counter_address).increment();
    }

    pub fn get_value(&self) -> u32 {
        self.value.get_or_default()
    }
}

mod events {
    use odra::types::Address;

    #[derive(odra::Event)]
    pub struct ValueUpdated {
        pub old_value: u32,
        pub new_value: u32,
        pub operator: Address
    }
    
    #[derive(odra::Event)]
    pub struct Init {
        pub value: u32,
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn deploy() {
        let counter = CounterDeployer::init(10);
        assert_eq!(10, counter.get_value());
    }

    #[test]
    fn increment() {
        let mut counter = CounterDeployer::init(10);
        counter.increment();
        assert_eq!(11, counter.get_value());
    }
}

But wait, I mentioned CosmWasm, did I?

Here the beauty of Odra comes into play.

Let's use cargo-odra.

cargo odra build -b cosmos

And... that's it, congratulations! We have just written and build our first CosmWasm contract. As you see, it is nothing different from building a contract for Casper. No additional code, we only changed the -b flag.

Deploy

We have just built a wasm file, but is it really a fully functional contract?

As a battlefield let's choose Juno Network (if you would like to read more about smart contract development on Juno read this Quick Start tutorial). This is an arbitrary choice, each client is built upon a so-called Wasm Zone wasmd, and its interface is alike.

Assuming you already know how to interact with Juno testnet, let's move to the fun part.

But before we go, to keep things simple, let's prepare a justfile. It'll make our interactions with the blockchain much easier. See full version.

justfile

NODE := "--node https://rpc.uni.juno.deuslabs.fi:443"
CHAIN_ID := "--chain-id uni-6"
QUERY_FLAGS := NODE + " " + CHAIN_ID
TRANSACTION_DEFAULTS := "--gas-prices 0.025ujunox --gas auto --gas-adjustment 1.3 --broadcast-mode block"
EXEC_FLAGS := NODE + " " + CHAIN_ID + " " + TRANSACTION_DEFAULTS

get-address NAME:
    junod keys show {{NAME}} | grep -o juno.*

store-wasm WASM_PATH SENDER:
    junod tx wasm store \
    {{WASM_PATH}} --from {{SENDER}} {{EXEC_FLAGS}}

init-contract CODE_ID VALUE SENDER CONTRACT_NAME:
    junod tx wasm instantiate \
    {{CODE_ID}} \
    `just run-args-parser '{"name": "init", "args": [ { "value" : {{VALUE}} }]}'` \
    --label '{{CONTRACT_NAME}}' --from {{SENDER}} \
    --admin `just get-address {{SENDER}}` \
    {{EXEC_FLAGS}}

exec-increment ADDRESS SENDER:
    junod tx wasm execute \
    {{ADDRESS}} \
    `just run-args-parser '{"name": "increment"}'` \
    --from {{SENDER}}  \
    {{EXEC_FLAGS}}

query-get-value ADDRESS:
    junod q wasm contract-state smart {{ADDRESS}} \
    `just run-args-parser '{"name": "get_value"}'` {{QUERY_FLAGS}}

Ok, we are ready to go.

First, a CosmWasm contract needs to be stored, technically is not a contract yet. Like a larva waiting to morph into a butterfly (sorry for that).

There are three ways to interact with a contract.

1. Instantiate - in other words, a constructor call. Once the contract is instantiated, it gets an address.
2. Execute - call an entrypoint that modifies the state.
3. Query - read the contract's state.

Now, let's take a look at how to do it using the tools we have just prepared.

# args: 
# the path to a wasm file,
# the name under we store the private key.
just store-wasm counter.wasm odra

...
raw_log: '[{"events":[{"type":"message","attributes":[{"key":"action","value":"/cosmwasm.wasm.v1.MsgStoreCode"},{"key":"module","value":"wasm"},{"key":"sender","value":"juno1le848rjac00nezzq46v5unxujaltdf270vhtfh"}]},{"type":"store_code","attributes":[{"key":"code_checksum","value":"9fb9e7f39170de2628892ed5eecc556e2487267b30bb2c9656f8c7d1cd9f9a59"},{"key":"code_id","value":"286"}]}]}]'
...
txhash: 1A8BA520E980C5ABCBCFA6F62D68B6BB82E780544605DE4DD5C6B1C5E966441B

Great, our code is successfully stored. Form the logs we can read now the code_id which we will use to initialize the contract.

# args: 
# code id taken from the previous tx, 
# counter initial value, 
# named private key,
# contract label.
just init-contract 286 1 odra "My Counter"

...
raw_log: '[{"events":[{"type":"instantiate","attributes":[{"key":"_contract_address","value":"juno10yszsgq4460a57ztuw943h5j3c9l0eyx3algzq080gatl0thecls5ttk7g"},{"key":"code_id","value":"286"}]},{"type":"message","attributes":[{"key":"action","value":"/cosmwasm.wasm.v1.MsgInstantiateContract"},{"key":"module","value":"wasm"},{"key":"sender","value":"juno1le848rjac00nezzq46v5unxujaltdf270vhtfh"}]},{"type":"wasm","attributes":[{"key":"_contract_address","value":"juno10yszsgq4460a57ztuw943h5j3c9l0eyx3algzq080gatl0thecls5ttk7g"},{"key":"value","value":"1"}]},{"type":"wasm-Init","attributes":[{"key":"_contract_address","value":"juno10yszsgq4460a57ztuw943h5j3c9l0eyx3algzq080gatl0thecls5ttk7g"},{"key":"value","value":"1"}]}]}]'
...
txhash: 8DC53F95805349C3763CF4AF9527CAB2AEBEC77B240EFD3801C61231D8748F26

Fantastic, the contract has been initialized and we have its address - juno10yszsgq4460a57ztuw943h5j3c9l0eyx3algzq080gatl0thecls5ttk7g. It's time to increment the counter.

# args:
# contract address taken from the previous tx,
# named private key
just exec-increment juno10yszsgq4460a57ztuw943h5j3c9l0eyx3algzq080gatl0thecls5ttk7g odra

...
raw_log: '[{"events":[{"type":"execute","attributes":[{"key":"_contract_address","value":"juno10yszsgq4460a57ztuw943h5j3c9l0eyx3algzq080gatl0thecls5ttk7g"}]},{"type":"message","attributes":[{"key":"action","value":"/cosmwasm.wasm.v1.MsgExecuteContract"},{"key":"module","value":"wasm"},{"key":"sender","value":"juno1le848rjac00nezzq46v5unxujaltdf270vhtfh"}]},{"type":"wasm","attributes":[{"key":"_contract_address","value":"juno10yszsgq4460a57ztuw943h5j3c9l0eyx3algzq080gatl0thecls5ttk7g"},{"key":"action","value":"increment"}]},{"type":"wasm-ValueUpdated","attributes":[{"key":"_contract_address","value":"juno10yszsgq4460a57ztuw943h5j3c9l0eyx3algzq080gatl0thecls5ttk7g"},{"key":"old_value","value":"1"},{"key":"new_value","value":"2"},{"key":"operator","value":"juno1le848rjac00nezzq46v5unxujaltdf270vhtfh"}]}]}]'
...
txhash: 52141844321B8321DA71D073D4FA0865E73C3940153373CA7EF832D15BC3C2B2

Finally, we expected, the value to be equal to 2 (the initial value was 1 and we incremented it once).

# args:
# contract address
just query-get-value juno10yszsgq4460a57ztuw943h5j3c9l0eyx3algzq080gatl0thecls5ttk7g

data: 2

Indeed, as expected the current counter value is 2.

Show me your transaction

I get it, you don't want to do it all by yourself. So let's take a closer look at one of my transactions.

junod q tx 52141844321B8321DA71D073D4FA0865E73C3940153373CA7EF832D15BC3C2B2 --node https://rpc.uni.juno.deuslabs.fi:443 --chain-id uni-6
...
logs:
- events:
  - attributes:
    - key: _contract_address
      value: juno10yszsgq4460a57ztuw943h5j3c9l0eyx3algzq080gatl0thecls5ttk7g
    type: execute
  - attributes:
    - key: action
      value: /cosmwasm.wasm.v1.MsgExecuteContract
    - key: module
      value: wasm
    - key: sender
      value: juno1le848rjac00nezzq46v5unxujaltdf270vhtfh
    type: message
  - attributes:
    - key: _contract_address
      value: juno10yszsgq4460a57ztuw943h5j3c9l0eyx3algzq080gatl0thecls5ttk7g
    - key: action
      value: increment
    type: wasm
  - attributes:
    - key: _contract_address
      value: juno10yszsgq4460a57ztuw943h5j3c9l0eyx3algzq080gatl0thecls5ttk7g
    - key: old_value
      value: "1"
    - key: new_value
      value: "2"
    - key: operator
      value: juno1le848rjac00nezzq46v5unxujaltdf270vhtfh
    type: wasm-ValueUpdated
...
txhash: 52141844321B8321DA71D073D4FA0865E73C3940153373CA7EF832D15BC3C2B2

If you are familiar Cosmos ecosystem, you can see that there is an attribute containing the performed action (increment) (If there were some parameters, they would be included in this attribute). We can find here also our ValueUpdated event with its arguments old_value, new_value and operator.

Wow, we have it, everything worked as intended!

Conclusion

Wouldn't it be great to replace Casper Erc20 and Cosmos Erc20 with a super-simple single Odra Erc20 implementation?

The Counter contract is just a POC, and there is still a long road ahead of us. This simple example shows that features like storage, events, and cross-contract calls can be unified in a simple readable interface.

CosmWasm integration hasn't been published yet, but if you want to experiment by yourself, check our GitHub (don't forget to update cargo-odra as well).

Join us

Interested?

Join our Discord, our Twitter or write us at contact@odra.dev.