Starknet Code to interact with Poster Contract on Chain

abi.json

[
  {
    "data": [
      {
        "name": "address",
        "type": "felt"
      },
      {
        "name": "content_len",
        "type": "felt"
      },
      {
        "name": "content",
        "type": "felt*"
      },
      {
        "name": "tag_len",
        "type": "felt"
      },
      {
        "name": "tag",
        "type": "felt*"
      }
    ],
    "keys": [],
    "name": "new_post",
    "type": "event"
  },
  {
    "inputs": [
      {
        "name": "content_len",
        "type": "felt"
      },
      {
        "name": "content",
        "type": "felt*"
      },
      {
        "name": "tag_len",
        "type": "felt"
      },
      {
        "name": "tag",
        "type": "felt*"
      }
    ],
    "name": "post",
    "outputs": [],
    "type": "function"
  }
]

index.ts

import { strToShortStringArr } from "@snapshot-labs/sx";
import { Account, ec, Contract, defaultProvider as provider } from "starknet";
import abi from "./abi.json";

const randomInt = (digits): number => {
	return Math.trunc(Math.random() * 10 ** digits);
};

function toString(value: any): string {
	return value.toString();
}

const accountAddress = process.env.ACCOUNT_ADDRESS || "";
const accountPk = process.env.ACCOUNT_PK || "";
const posterAddress =
	process.env.POSTER_ADDRESS ||
	"0x04d10712e72b971262f5df09506bbdbdd7f729724030fa909e8c8e7ac2fd0012";

async function main() {
	const contentString = `This is a random post with a random number: ${randomInt(
		3
	)}`;
	const tagString = randomInt(2) % 2 === 0 ? "public" : "private";

	// uncomment to use customer account to sign
	// const keypair = ec.getKeyPair(accountPk);
	// const keypair = ec.genKeyPair();
	// console.log(keypair.getPublic().encode("hex"));
	// const account = new Account(provider, accountAddress, keypair);

	//@ts-ignore
	const postContract = new Contract(abi, posterAddress, provider);
	const contentFelt = strToShortStringArr(contentString);
	const tagFelt = strToShortStringArr(tagString);

	const receipt = await postContract.post(
		contentFelt.map(toString),
		tagFelt.map(toString)
	);
	console.log("Receipt", receipt);

	await provider.waitForTx(receipt.transaction_hash);
}

main().then(console.log);

package.json

{
  "name": "test_starknet",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "start": "nodemon index.ts"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "dependencies": {
    "@snapshot-labs/sx": "^0.1.0-beta.0",
    "@types/node": "^17.0.38",
    "nodemon": "^2.0.16",
    "starknet": "^3.9.0",
    "ts-node": "^10.8.0",
    "tsc": "^2.0.4",
    "typescript": "^4.7.2"
  }
}

The Cairo code for the Poster Contract can be found here: https://github.com/snapshot-labs/starknet-poster