The @polkadot/api-contract comes with 3 general helpers and has *Rx-based versions for the users of the ApiRx version of the API. However here we will focus only on the ApiPromise-based version of the helpers, in much the same way as the API documentation. The 3 main interfaces provided are -

  • CodePromise - This allows use to manage actual WASM code and deploy it,
  • BlueprintPromise - This allows us to manage on-chain code hashes and use this as a blueprint for the creation of contracts
  • ContractPromise - This allows us to manage on-chain contracts, making read calls and executing transactions on contracts
  • Abi - This is a generic registry that contains all the types and all the messages for a given ABI

In terms of use this would mean that Code will create a Blueprint which in turn, would create Contract. In cases where you already have a on-chain codeHash or an on-chain contract, the relevant blueprint or contract instance can be created without helpers by direct instantiation.

Deploying code

Not that we have a good overview of what is available and the use of each interface, let's deploy a WASM contract and start using it.