# Example: Validator Balance Data

In this example, the contract has a reference to the Telepathy [Light Client](/telepathy-protocol/contracts.md#light-client) and uses the state root stored for a specific `slot`. 

Using a Merkle Proof, you can then verify that the data provided is correct for the that `slot`'s state root.

```solidity
contract BeaconValidatorBalance {
    uint256 public constant VALIDATOR_PUBKEY_GINDEX = 0;
    uint256 public constant BALANCE_G_INDEX = 1;

    address lightclient;
    mapping(uint256 => bytes32) public indexToPubkey;
    mapping(uint256 => mapping(uint256 => uint256)) public indexToSlotToBalance;

    constructor(address _lightclient) {
        lightclient = _lightclient;
    }

    function addIndexAndPubkey(
        uint256 slot, uint256 index, bytes32 publicKey, bytes32[] memory proof
    ) public {
        bytes32 headerRoot = ILightClient(lightclient).headers(slot);
        bool isValidProof = SSZ.verifyMerkleBranch(
            publicKey,
            concatGIndex(VALIDATOR_PUBKEY_GINDEX, index),
            proof,
            headerRoot
        );
        require(isValidProof, "Invalid state root");
        indexToPubkey[index] = publicKey;
    }

    function addBalanceAtSlot(uint256 slot, uint256 index, uint256 balance, bytes32[] memory proof) public {
        bytes32 headerRoot = ILightClient(lightclient).headers(slot);
        bool isValidProof = SSZ.verifyMerkleBranch(
            bytes32(balance),
            concatGIndex(BALANCE_G_INDEX, index),
            proof,
            headerRoot
        );
        require(isValidProof, "Invalid state root");
        indexToSlotToBalance[index][slot] = balance;
    }
}
```


---

# 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.telepathy.xyz/build-with-telepathy/intrachain-consensus-oracle/example-validator-data.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.