How to listen to a specific token on a specific dex

Moralis General
#1

I am looking for an example on how to create a stream that listen to buy and sell transaction for a specific token on a specific dex example listen to buy transaction for the Bard token on uniswap.

#2

you can try it like this

const transferErc20Abi = [
  {
    anonymous: false,
    inputs: [
      {
        indexed: true,
        internalType: "address",
        name: "from",
        type: "address",
      },
      {
        indexed: true,
        internalType: "address",
        name: "to",
        type: "address",
      },
      {
        indexed: false,
        internalType: "uint256",
        name: "value",
        type: "uint256",
      },
    ],
    name: "Transfer",
    type: "event",
  },
];

const options = {
  chains: [EvmChain.ETHEREUM],
  description: "Token buy or sell", // your description
  tag: "buy and sell ", // give it a tag
  abi: transferErc20Abi,
  includeContractLogs: true,
  topic0: ["Transfer(address,address,uint256)"],
  advancedOptions: [
    {
      topic0: "Transfer(address,address,uint256)",
      filter: {
          or: [
            { eq: ["from", "0x1C8a9844091d5136b50F5B04b30dE9E564ce397b"] },
            { eq: ["to", "0x1C8a9844091d5136b50F5B04b30dE9E564ce397b"] },
          ],
        },
    },
  ],
  webhookUrl: "https://YOUR_WEBHOOK_URL", // webhook url to receive events,
};

const stream = await Moralis.Streams.add(options);

const { id } = stream.toJSON(); // { id: 'YOUR_STREAM_ID', ...stream }

// Attach the contract address to the stream
await Moralis.Streams.addAddress({
  id,
  address: "0xxxxxxxx", // Bard token address
});
#3

I replace Bard adress with the actual contract adress or it is just a constant?

#4

here you should use

{ eq: ["sender", "0x1C8a9844091d5136b50F5B04b30dE9E564ce397b"] }

same here =>
use 0x1C8a9844091d5136b50F5B04b30dE9E564ce397b

#5

Good thanks i will try to work with that.

1 Like
#6

I got invalid filter check.

#7

ive updated the message