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PROGRAMMABILITY
Programmable data

Programmable data quickstart

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This guide assumes you're decently familiar with solidity smart contract development.

Create a programmable data smart contract

Programmable data is a feature leveraged through Solidity smart contracts via a custom precompile.
We have a library contract to provide a cleaner API to use programmable data here (opens in a new tab)

A full example Foundry project here (opens in a new tab)

And an example E2E test using @irys/js here (opens in a new tab)

To use this library, first create a Solidity contract that inherits ProgrammableData:

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

// you will need to set up path remapping and clone the repository as a submodule,
// or copy the library files locally

import "@irys/precompile-libraries/libraries/ProgrammableData.sol";

contract ProgrammableDataBasic is ProgrammableData {
    bytes public storedData;

    function readPdBytesIntoStorage() public {
        (bool success, bytes memory data) = readBytes();
        require(success, "reading bytes failed");
        // write bytes to storage
        storedData = data;
    }

    function getStorage() public view returns (bytes memory) {
        return storedData;
    }
}

You then need to deploy your smart contract as normal.

To create a programmable data transaction (which will allow use of the ProgrammableData precompile), follow the following steps:

Create a set of Programmable Data read ranges

const accessList = await irysClient.programmable_data
    .read(transactionId, startOffset, length)
    .toAccessList();

This range will read bytes startOffset -> startOffset + length of transactionId's data.

ℹ️

Only transactions uploaded to the permanent ledger (ledgerId 0) can be read using programmable data.
DataItems uploaded through Irys' bundlers are currently not supported (but will be!)

Add them to a execution Transaction

This should be a transaction aiming to call the readPdBytesIntoStorage method of the contract.

ℹ️

You will be charged for every chunk you request, even if you don't read them.
So only attach a programmable data access list to a transaction that will use them!

    import { Wallet } from "ethers";
    const wallet = new Wallet(<key>, irysClient.api.rpcProvider)
    const evmTransaction = {
        accessList: [accessList],
        type: 2 // type must be EIP-1559 or higher
        ....
    }
    await wallet.sendTransaction(evmTransaction);

Once the transaction processes, you can call the getStorage contract method, which should return the data you specified in your programmable data read range.
Note that you will pay normal rates for storing data in smart contract storage slots.

Connecting to testnetQuickstart