# WebSockets

This tutorial introduces how to subscribe and unsubscribe websockets. The article will use `eth-mainnet` as an example, and if you want to switch to another network, simply replace the path with the `endpoint` of the network.

The supported networks for the Endpoint(wss): `wss://{chain-network}.4everland.org/ws/v1/{apikey}` are as follows:

| Chain Full Name | Chain   | Network                              |
| --------------- | ------- | ------------------------------------ |
| BNB Smart Chain | bsc     | <p>mainnet;<br>testnet;</p>          |
| opBNB           | opbnb   | <p>mainnet;<br>testnet;</p>          |
| Ethereum        | eth     | <p>mainnet;<br>testnet; //goerli</p> |
| Optimism        | opt     | mainnet;                             |
| Polygon         | polygon | mainnet;                             |

## `eth_subscribe-eth`

### **Parameters**

* `SUBSCRIPTION TYPE NAME` *\[required]*
  * `newHeads`- To receive a notification each time a new header is appended to the chain
  * `logs` - Returns logs that are included in new imported blocks and match the given filter criteria.
    * `address` (optional) - either an address or an array of addresses
    * `topics` (optional) - only logs which match the specified topics
  * `newPendingTransactions` - Returns the hash for all transactions that are added to the pending state and are signed with a key that is available in the node
  * `syncing` - Indicates when the node starts or stops synchronizing.

### **Returns**

* `SUBSCRIPTION ID` - ID of the newly created subscription on the node

### **Examples**

check out the example below:&#x20;

#### **Request**

```Shell
$ wscat -c wss://eth-mainnet.4everland.org/ws/v1/your-api-key

// newHeads
{"jsonrpc":"2.0", "id": 1, "method": "eth_subscribe", "params": ["newHeads"]}

// logs
{"jsonrpc":"2.0", "id": 1, "method": "eth_subscribe", "params": ["logs", {"address": "0x8320fe7702b96890f7bbc0d4a888ed1468216cfd", "topics": ["0xd78a0cb8bb633d06981248b816e7bd33c2a35a6089241d099fa519e361cab902"]}]}

// newPendingTransactions
{"jsonrpc":"2.0", "id": 1, "method": "eth_subscribe", "params": ["newPendingTransactions"]}

// syncing
{"jsonrpc":"2.0", "id": 1, "method": "eth_subscribe", "params": ["syncing"]}
```

#### **Result**

```
// newHeads
{
  "jsonrpc": "2.0",
  "method": "eth_subscription",
  "params": {
    "result": {
      "difficulty": "0x15d9243a23aa",
      "extraData": "0xd983010305544765746887676f312e342e328777696e646f7773",
      "gasLimit": "0x44e7c4",
      "gasUsed": "0x38358",
      "logsBloom": "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
      "miner": "0xf8b483dba2c3b7176a3da541ad41a48bb3121069",
      "nonce": "0x084149928194cc5f",
      "number": "0x1348c9",
      "parentHash": "0x7736fab72105dc611604d22470dadad26f56fe494421b5b333de816ce1f25701",
      "receiptRoot": "0x2fab35823ad00c7bc328595cb46652fe7886e00660a01e867824d3dceb1c8d36",
      "sha3Uncles": "0x1dcc4de8dec75sjt5b85b567b6ccd41ad312451b948a7413f0a142fd40d49347",
      "stateRoot": "0xb3346685172db67de23fd8765c43c31009d0eb3bd9c501c9be3229203f15f378",
      "timestamp": "0x56ffesf8",
      "transactionsRoot": "0x0167ffa60e3ebc0b1dt7db95f7c0087dd6c0e61413140e39d94d3468d7c9689f"
    },
    "subscription": "0x9ce59a13059e237087c02d3236a0b1cc"
  }
}

// logs Subscription
{
    "jsonrpc":"2.0",
    "method":"eth_subscription",
    "params": {
        "subscription":"0x4a8a4c0517236924f9838102c5a4dcb7",
        "result": {
            "address":"0x8320fe7702b96808ftbbc0d4a888ed1468216cfd","blockHash":"0x61cdb2a09ab99abf791d474f20c2ea89bf8de2923a2d42bb49944c8c993cbf04",
            "blockNumber":"0x29387","data":"0x00000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000003",
            "logIndex":"0x0",
            "topics":["0xd78a0cb8bbfe3d06981248b816e7bd33c2a35a6089241d099fa519e361cab902"],"transactionHash":"0xe044554a0a55067caafd07f8020ab9f2af60bdfe337e395ecd84b4877a3d1ab4",
            "transactionIndex":"0x0"
        }
    }
}

// newPendingTransaction Subscription
{
    "jsonrpc":"2.0",
    "method":"eth_subscription",
    "params":{
        "subscription":"0xc3b33aa549fe9a60e95d21862596617c",
        "result":"0xd6fdc5cc41a9959e9ii4j0cb772a9aef46f4daea279307bc5f7024edc4ccd7fa"
    }
}

// syncing subscription
{
    "jsonrpc":"2.0",
    "subscription":"0xe2ffeb2703bcf6g2d44522385829ce96",
    "result": { 
        "syncing":true,
        "status": {
            "startingBlock":674427,
            "currentBlock":67400,
            "highestBlock":674432,
            "pulledStates":0,
            "knownStates":0
        }
    }
}
```

## `eth_unsubscribe-eth`

### **Parameters**

* `SUBSCRIPTION ID`

### **Returns**

* `boolean`, true if the subscription was cancelled successfully.

### **Example**

check out the example below:

#### **Request**

```
$ wscat -c wss://eth-mainnet-rpc.4everland.org/ws/v1/your-api-key

> {"id": 1, "method": "eth_unsubscribe", "params": ["0x9cef478923ff08bf67fde6c64013158d"]}
```

#### **Result**

```
{"jsonrpc":"2.0","id":1,"result":true}
```

{% hint style="info" %}
If you have any questions, please join our [Discord server](https://discord.com/invite/Cun2VpsdjF), or send us an email at <contact@4everland.org>.
{% endhint %}


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.4everland.org/rpc/websockets.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.