client

Cartesi viem extension

Viem provides an extension mechanism to clients that can provide a convenient and familiar API for application developers based on L2 solutions.

This extension provides L2 actions to interact with the Cartesi Rollups Node, and typed ABIs and addresses of the Cartesi Rollups smart contracts for L1 operations.

PublicClient L2

The following methods are provided to interact with the Cartesi Rollups Node.

• listApplications
• listEpochs
• listInputs
• listOutputs
• listReports
• getApplication
• getEpoch
• getInput
• getOutput
• getReport
• getProcessedInputCount
• getLastAcceptedEpochIndex
• waitForInput

L1 operations

Transactions related to Cartesi applications are sent directly to the base layer (L1). Those are regular contract interactions, best served by viem's own contract actions combined with the typed ABIs and deployment addresses exported by @cartesi/client/abi:

import { inputBoxAbi, inputBoxAddress } from "@cartesi/client/abi";

const hash = await walletClient.writeContract({
    abi: inputBoxAbi,
    address: inputBoxAddress,
    functionName: "addInput",
    args: [application, payload],
});

Users of wagmi can use the generated actions and React hooks from @cartesi/react, or generate their own code using the @cartesi/wagmi-plugin plugin for @wagmi/cli.

Utilities

• getInputsAdded: get the input(s) added to the InputBox given a TransactionReceipt.
• getOutputsExecuted: get the output(s) executed by an application given a TransactionReceipt.
• toOutputArgs: convert an Output returned by the node API into the arguments of IApplication.executeOutput / IApplication.validateOutput.

const receipt = await publicClient.waitForTransactionReceipt({ hash });
const [inputAdded] = getInputsAdded(receipt);

Example

Find below a complete example of sending an input and waiting for its effect on L2.

import { createCartesiPublicClient, getInputsAdded } from "@cartesi/client";
import { inputBoxAbi, inputBoxAddress } from "@cartesi/client/abi";
import { createPublicClient, createWalletClient, http, stringToHex } from "viem";
import { privateKeyToAccount } from "viem/accounts";
import { foundry } from "viem/chains";

async function main() {
    const chain = foundry;
    const account = privateKeyToAccount(
        "0xac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80",
    );

    // create public client to chain default url
    const publicClient = createPublicClient({ chain, transport: http() });

    // create cartesi public client to L2 with RPC url
    const publicClientL2 = createCartesiPublicClient({
        transport: http("http://127.0.0.1:6751/rpc"),
    });

    // create wallet client to chain default url
    const walletClient = createWalletClient({ account, chain, transport: http() });

    // application address
    const application = "0xab7528bb862fb57e8a2bcd567a2e929a0be56a5e";

    // send input transaction
    const hash = await walletClient.writeContract({
        abi: inputBoxAbi,
        address: inputBoxAddress,
        functionName: "addInput",
        args: [application, stringToHex("hello")],
    });

    // wait for receipt
    const receipt = await publicClient.waitForTransactionReceipt({ hash });

    // get input index from receipt
    const [inputAdded] = getInputsAdded(receipt);
    if (inputAdded) {
        const { index: inputIndex } = inputAdded;

        // wait for input to be processed
        const input = await publicClientL2.waitForInput({
            application,
            inputIndex,
        });
        console.log(input);
    }
}

main();