---
title: WebSocket Connections
description: >-
  Learn how to use eth_subscribe over WebSocket on Paxeer to watch new blocks,
  contract events, and ERC-20 transfers in real time.
---

> **For AI agents:** the complete documentation index is at [llms.txt](/llms.txt). Append `.md` to any page URL for its markdown version.

## WebSocket Connections

Paxeer supports `eth_subscribe` over WebSocket. You can subscribe to new blocks, event logs, and pending transactions using standard library WebSocket transports.

## Endpoints

| Network | WebSocket endpoint |
| --- | --- |
| Mainnet | `wss://evm-ws.sei-apis.com` |
| Testnet | `wss://evm-ws-testnet.sei-apis.com` |
| Devnet | `wss://evm-ws-arctic-1.sei-apis.com` |

## Connecting

<CodeGroup>

```ts viem
import { createPublicClient, webSocket } from 'viem';
import { sei } from 'viem/chains';

const client = createPublicClient({
  chain: sei,
  transport: webSocket('wss://evm-ws.sei-apis.com'),
});
```

```ts ethers
import { ethers } from 'ethers';

const provider = new ethers.WebSocketProvider('wss://evm-ws.sei-apis.com');
```

</CodeGroup>

## Watching New Blocks

<CodeGroup>

```ts viem
const unwatch = client.watchBlocks({
  onBlock: (block) => {
    console.log('New block:', block.number);
  },
});

// Stop watching
unwatch();
```

```ts ethers
provider.on('block', (blockNumber) => {
  console.log('New block:', blockNumber);
});

// Stop watching
provider.off('block');
```

</CodeGroup>

## Watching Contract Events

<CodeGroup>

```ts viem
import { parseAbiItem } from 'viem';

const unwatch = client.watchEvent({
  address: '0xContractAddress',
  event: parseAbiItem('event Transfer(address indexed from, address indexed to, uint256 value)'),
  onLogs: (logs) => {
    console.log('Transfer events:', logs);
  },
});
```

```ts ethers
import { ethers } from 'ethers';

const ERC20_ABI = ['event Transfer(address indexed from, address indexed to, uint256 value)'];
const contract = new ethers.Contract('0xContractAddress', ERC20_ABI, provider);

contract.on('Transfer', (from, to, value, event) => {
  console.log('Transfer:', { from, to, value });
});

// Stop watching
contract.off('Transfer');
```

</CodeGroup>

## Watching ERC-20 Transfers Across All Contracts

```ts viem
import { parseAbiItem } from 'viem';

const unwatch = client.watchEvent({
  event: parseAbiItem('event Transfer(address indexed from, address indexed to, uint256 value)'),
  onLogs: (logs) => {
    logs.forEach((log) => {
      console.log(`Transfer on ${log.address}:`, log.args);
    });
  },
});
```

## Notes

- Paxeer's instant finality means every block emitted over WebSocket is already final - no need to wait for additional confirmations before acting on an event.
- Pending transaction subscriptions (`newPendingTransactions`) are supported at the RPC level but Paxeer does not guarantee Ethereum-style pending state visibility.