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Send notification using smart contract overview

Push contracts are designed to act as a communication middleware for your smart contracts which ensures that even smart contracts can communicate with the wallet addresses (ie: web3 users).

Sending notifications from smart contract​

Step 1️⃣ - Locate the contract address of Push​

Ensure that you know the contract address of Push Communication smart contract based on the blockchain and network from which you are sending the communication out.

For example: Staging Ethereum contract (Sepolia) address for Push Communicator contract is 0x0C34d54a09CFe75BCcd878A469206Ae77E0fe6e7. List of all smart contract and their environment is available here 👉 Push smart contract addresses.

Step 2️⃣ - Import Push Comm interface​

Start by importing the Push comm contract interface in your smart contract 👇

// PUSH Comm Contract Interface
interface IPUSHCommInterface {
    function sendNotification(address _channel, address _recipient, bytes calldata _identity) external;
}

Step 3️⃣ - Locate your channel address​

Ensure your channel is up and running by following this guide - Creating your channel. Note down your channel address which you need to put in the code below as YOUR_CHANNEL_ADDRESS.

Step 4️⃣ - Call the contract function​

Next call the function sendNotification(address _channel, address _recipient, bytes calldata _identity) and pass the address of the channel, recipient and the identity based on your needs.

IPUSHCommInterface(EPNS_COMM_CONTRACT_ADDRESS_FOR_SPECIFIC_BLOCKCHAIN).sendNotification(
    YOUR_CHANNEL_ADDRESS, // from channel - recommended to set channel via dApp and put it's value -> then once contract is deployed, go back and add the contract address as delegate for your channel
    to, // to recipient, put YOUR_CHANNEL_ADDRESS in case you want Broadcast or Subset. For Targetted put the address to which you want to send

    bytes(
        string(
            // We are passing identity here: https://push.org/docs/notifications/notification-standards/notification-standards-advance/#notification-identity
            abi.encodePacked(
                "0", // this represents minimal identity, learn more: https://push.org/docs/notifications/notification-standards/notification-standards-advance/#notification-identity
                "+", // segregator
                "3", // define notification type:  https://push.org/docs/notifications/build/types-of-notification (1, 3 or 4) = (Broadcast, targeted or subset)
                "+", // segregator
                "Title", // this is notification title
                "+", // segregator
                "Body" // notification body
            )
        )
    )
);

Step 5️⃣ - Add your smart contract address as your channel delegate​

The last step is to go back to your channel and add the smart contract address as a delegate ensuring notifications sent by your smart contract are routed through your channel and presented to your users. Checkout guide for adding delegates for channel to understand how to add delegates to your channel.

tip

Here's an example of how to build your ERC-20 token with in-built notifications