MemerJS - JavaScript Library for the MEME Chain (Meme network)

⭐ Developed by Meme

A JavasSript Open Source Library for Meme network.

Installation

In order to fully use this library, you need to run a local or remote full node and set up its rest server, which acts as an intermediary between the front-end and the full-node. You can use the meme-cli.

NPM

npm install memerjs

Yarn

yarn add memerjs

Using MemerJS

MemerJS acts as a package that extends the cosmJS library. It builds-up upon it, so that it's tailored to the specifics of the MEME Chain. If you've used cosmJS before, than the API should feel quite familiar to you.

MemerJS usage is organized mainly around using it's two clients - StargateClient and SigningStargateClient.

• SigningStargateClient - used to sign and broadcast transactions.

import { SigningStargateClient, DirectSecp256k1HdWallet } from "memerjs"

// Load an account
const mnemonic = "surround miss nominee dream gap cross assault thank captain prosper drop duty group";
const wallet = await DirectSecp256k1HdWallet.fromMnemonic(mnemonic);
const [firstAccount] = await wallet.getAccounts();

const rpc = http://localhost:26657
const signingClient = await SigningStargateClient.connectWithSigner(rpc, wallet)

We need an RPC endpoint (that will be used to connect to the network) and a wallet ( used to sign the transactions ). A ready to use SigningStargateClient is created by connecting it to the RPC and the wallet.

// Sending tokens to another meme address
import { coin, GasPrice } from "memerjs"

...

const recipient = "meme1cjkdf934mdg94kfgds34590gkf03443t";
const amount = {           // same as const amount = coin("1.2.1678", "umeme)
  denom: "umeme",
  amount: "1.2.1678",
};

const result = await signingClient.sendTokens(firstAccount.address, recipient, [amount], "Have fun with your meme coins");

assertIsBroadcastTxSuccess(result);

...
// Sending a message to the NFT module


const gasPrice = GasPrice.fromString('umeme');

const correctToken = {
    approvedAddresses: [],
    id: '1',
    owner: '',
    name: 'testToken',
    uri: 'testUir',
    data: 'testData',
  }

const result = await signingClient.nftMintToken(firstAccount.address, correctDenom.id, correctToken.name, correctToken.uri, correctToken.data, recipient, gasPrice)

assertIsBroadcastTxSuccess(result);

...
// Sending a message to the Gravity module


const gasPrice = GasPrice.fromString('umeme');
const coinAmount = {denom:"umeme", amount: "1000"}
const feeAmount = {denom:"umeme", amount: "100"}
const ethAddr = "0xa677d7229924af63098b9bb70b041a03a1ec7d8c"

const result = await signingClient.gravitySendToEth(firstAccount.address,ethAddr,coinAmount,feeAmount,gasPrice)

assertIsBroadcastTxSuccess(result);

• StargateClient - this one is used to query the MEME Chain. It's quite simple to work with:

import { StargateClient } from "memerjs"

const rpc = http://localhost:26657
const queryClient = await StargateClient.connect(rpc)

First we need an RPC endpoint, that will be used to connect to the network. Then a StargateClient is created by connecting it to the network.

** In this example the client is connecting to a local test network, created using meme-blast.

...

const memeAddress = "some meme address"

const height = await queryClient.getHeight() // returns the current height of the blockchain  

const isAccount = await queryClient.getAccount(memeAddress) // check if an account exists

const balance = await queryClient.getBalance(memeAddress, "umeme") // get the balance of the account in the respective denom

const chainId =  await queryClient.getChainId()
...

As shown above - query methods typical to any cosmos-based blockchain are directly available on the StargateClient

The MEME Chain however includes some specific, additional modules - each with it's distinct messages and queries ( such examples are the group, nft and gravity modules). Methods for queries related to those module are grouped in objects inside the StargateClient, where each object starts with the name of the module (e.g.nftModule, gravityModule, groupModule):

// Querying the Nft Module
...
 const correctDenom = {
    creator: '',
    id: 'testdenom',
    name: 'test-denom-name',
    symbol: 'test-denom-symbol',
    schema: 'test-denom-schema',
  }

const correctToken = {
    approvedAddresses: [],
    id: '1',
    owner: '',
    name: 'testToken',
    uri: 'testUir',
    data: 'testData',
  } 

const getDenom = await queryClient.nftModule.getNftDenom(correctDenom.id) // get a denom by it's ID
const getToken = queryClient.nftModule.getNftToken(correctDenom.id, correctToken.id) // get a token
const isApproved = queryClient.nftModule.nftIsApprovedForAll(memeAddress, memeAddress2)

// Querying the Gravity Module
...

const pendingTrxs = await queryClient.gravityModule.getPendingSendToEth(memeAddress) // check for unbatched transactions for a particular account

Constructing custom Msg's

Most of the times the already provided methods inside SigningStargateClient would be enough. But sometimes you need to construct and send your messages manually ( for example when simulating a transaction to calculate the Fees). MemerJS provides an utility function generateMsg to make custom message construction easier:

import { GasPrice, generateMsg, estimateFee } from "memerjs"

...

// Calculating the Fees for sending a msgSendToEth message.

const bridgeFee = {denom:"umeme", amount: "10000"}
const amount = coin('1000000000000', "umeme")
const memo = "Have fun spending your meme"


const gasPrice = GasPrice.fromString(`umeme`)
const simulatedMsg = generateMsg('msgSendToEth', {
            sender,  // meme addrs
            ethDest: destination, //eth addrs
            amount
            bridgeFee
        })

const approxFee = await estimateFee(client, sender, [simulatedMsg], gasPrice, gasMultiplier, memo)


const result = await client.signAndBroadcast(
  sender,
  [simulatedMsg],
  approxFee,
  memo
);

Custom Queries

Using the available methods inside StargateClient automatically decodes the response. However when constructing and sending queries yourself, you have to decode the responses as well. You can use the decodeQryResponse method inside StargateClient:

...

// Executing a custom query using filters

const filteredTx = await queryClient.searchTx({
                tags: [{ key: "message.action", value: "/gravity.v1.MsgSendToCosmosClaim" }],
            })

// Decoding the result - decodes all messages inside the response

const decodedRes = await qClient.decodeQryResponse(filteredTx)