Proposal: eth_getBlockState - returns chainId, block number, block timestamp and stateId

# [`eth_getBlockState`](#)

## Motivation

DApps will request chainId and blocknumber continuously (e.g. look at uniswap dapp network console). There is not any RPC methods that return ChainId information outside of eth_chainId. This seems useful, so include it in block number and block timestamp response and we got this.

- [Block State JSON-RPC Method Specification](#block-state-json-rpc-method-specification)
* [Method Name](#method-name)
* [Description](#description)
* [Parameters](#parameters)
* [Returns](#returns)
* [Example Request](#example-request)
* [Example Response](#example-response)
* [Error Codes](#error-codes)
* [Specification Notes](#specification-notes)
* [State Diagram](#state-diagram)
* [Additional Examples](#additional-examples)
+ [Request with "earliest" block](#request-with-earliest-block)
+ [Response for "earliest" block](#response-for-earliest-block)
+ [Error Response Example](#error-response-example)

## Method Name
`eth_getBlockState`

## Description
Returns the chain ID, block number, and block state and block timestamp for the specified block parameter.

> [!NOTE]
> Need to add block.timestamp in response and request, just thought of it as I am typing this meow

## Parameters
1. `blockParameter` - An object containing one of the following block state identifiers:

- `{ "blockNumber": "earliest" }` - Earliest/genesis block
- `{ "blockNumber": "latest" }` - Latest canonical block
- `{ "blockNumber": "pending" }` - Pending state/transactions
- `{ "blockNumber": "safe" }` - Most recent safe block
- `{ "blockNumber": "finalized" }` - Most recent finalized block

## Returns

Object - A block state object containing:
- `chainId`: STRING - The chain ID in hexadecimal format
- `blockNumber`: STRING - The block number in hexadecimal format
- `blockState`: STRING - One of: "earliest", "latest", "pending", "safe", "finalized"

## Example Request
```json
{
"jsonrpc": "2.0",
"method": "eth_getBlockState",
"params": [
{
"blockNumber": "latest"
}
],
"id": 1
}
```

## Example Response
```json
{
"jsonrpc": "2.0",
"id": 1,
"result": {
"chainId": "0x1",
"blockNumber": "0xf4240",
"blockState": "latest"
}
}
```

## Error Codes
| Code | Message | Description |
|------|---------|-------------|
| -32700 | Parse error | Invalid JSON |
| -32600 | Invalid Request | JSON is not a valid request object |
| -32601 | Method not found | Method does not exist |
| -32602 | Invalid params | Invalid method parameters |
| -32603 | Internal error | Internal JSON-RPC error |

## Specification Notes

1. **EIP-1898 Compliance**
- The block parameter MUST be specified as an object
- The object MUST contain a `blockNumber` field
- The value MUST be one of the specified string literals

2. **EIP-1474 Compliance**
- Method name follows the `eth_` namespace convention
- Adheres to standard JSON-RPC 2.0 format
- All numeric values are hexadecimal encoded
- Error codes follow standard ranges

3. **Additional Requirements**
- The response MUST include all three fields: chainId, blockNumber, and blockState
- Chain ID MUST be returned in hexadecimal format
- Block number MUST be returned in hexadecimal format
- Block state MUST be one of the five specified string literals