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The subscriptions available using the ethers.js provider.on method are:

on('block')

on(filter)

syncing subscription

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Parameters

boolean — keep the syncing subscription if true.

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Response

boolean — the boolean value indicating if the subscriptions were removed successfully. true if removed successfully, false if not.

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clearSubscriptions code example

const { ethers } = require("ethers");
const NODE_URL = "CHAINSTACK_WSS_URL";
const provider = new ethers.WebSocketProvider(NODE_URL);

async function clearSubscriptions() {
    try {
      await provider.removeAllListeners();
      console.log("Subscriptions were canceled successfully");
      return process.exit(1)

    } catch (error) {
      console.error("Failed to cancel subscriptions:", error);
      return process.exit(1)
    }
  }

clearSubscriptions()

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Use case

A way to use the clearSubscriptions method is to place it in a timer to clear all of the subscriptions after a pre-determined about. The following code is an example using the block subscription, which will be stopped and removed after one minute using removeAllListeners: 
const { ethers } = require("ethers");
const NODE_URL = "CHAINSTACK_WSS_URL";
const provider = new ethers.WebSocketProvider(NODE_URL);

async function subscribeToNewBlocks() {
    try {
        // Log a message when the block subscription is set up
        handleConnected();

        // Subscribe to new blocks and attach event listeners
        provider.on("block", handleNewBlock);
        provider.on("error", handleError);
    } catch (error) {
        console.error(`Error subscribing to new blocks: ${error}`);
    }
}

/* Fallback functions to react to the different events */

// Function that logs a message when the subscription is connected
function handleConnected() {
    console.log("New subscription to new blocks");
}

// Event listener that logs the received block data
async function handleNewBlock(blockNumber) {
    const block = await provider.getBlock(blockNumber);
    console.log(block);
}

// Event listener that logs any errors that occur
function handleError(error) {
    console.error(`Error receiving new blocks: ${error}`);
}

async function clearSubscriptions() {
    try {
        await provider.removeAllListeners();
        console.log("Subscriptions were canceled successfully");
        return process.exit(1)

    } catch (error) {
        console.error("Failed to cancel subscriptions:", error);
        return process.exit(1)
    }
}

async function main() {

    subscribeToNewBlocks();

    // Run clearSubscriptions() once after 60 seconds
    setTimeout(clearSubscriptions, 60000);
}

main()
The code starts by defining an async function called subscribeToNewBlocks that subscribes to new blocks using the provider.on("block") method. This method registers a listener that fires on every new block, and the code also attaches a listener for the error event. The code defines three functions handleConnected, handleNewBlock, and handleError that log messages to the console when the subscription is set up, when a new block arrives, and when an error occurs. The subscribeToNewBlocks function is called from the main function, which is also defined in the code. The main function calls subscribeToNewBlocks to create a new subscription and then schedules the clearSubscriptions function to run once after 60 seconds using the setTimeout function. The clearSubscriptions function uses the provider.removeAllListeners method to cancel any existing subscriptions and log a message to the console if the cancellation was successful.
Last modified on July 7, 2026