> ## Documentation Index
> Fetch the complete documentation index at: https://docs.sei.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Auth Precompile

> Read account details, auth module parameters, and the next account number from EVM contracts with the Auth precompile.

**Address:** `0x000000000000000000000000000000000000100D`

The Auth precompile reads data from the Cosmos `auth` module: account details, module parameters, and the next account number. All methods are `view` functions. The precompile is available since v6.7.0.

## Interface

```solidity Auth.sol theme={"dark"}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

address constant AUTH_PRECOMPILE_ADDRESS = 0x000000000000000000000000000000000000100D;

IAuth constant AUTH_CONTRACT = IAuth(AUTH_PRECOMPILE_ADDRESS);

interface IAuth {
    function account(address addr) external view returns (Account memory account);
    function accounts(bytes memory pageKey) external view returns (AccountsResponse memory response);
    function params() external view returns (AuthParams memory params);
    function nextAccountNumber() external view returns (uint64 count);

    struct Account {
        string accountAddress;
        uint64 accountNumber;
        uint64 sequence;
    }

    struct AccountsResponse {
        Account[] accounts;
        bytes nextKey;
    }

    struct AuthParams {
        uint64 maxMemoCharacters;
        uint64 txSigLimit;
        uint64 txSizeCostPerByte;
        uint64 sigVerifyCostEd25519;
        uint64 sigVerifyCostSecp256k1;
        bool disableSeqnoCheck;
    }
}
```

## Methods

| Method | Returns |
| - | - |
| `account(addr)` | The Sei address, account number, and sequence of the account linked to `addr`. |
| `accounts(pageKey)` | All accounts, one page at a time. |
| `params()` | The `auth` module parameters. |
| `nextAccountNumber()` | The account number that the next new account gets. The call does not change the counter. |

## Notes

* `account()` reverts if `addr` has no associated Sei address, or if no account exists for it.
* For `accounts()`, pass empty bytes for the first page, then pass the returned `nextKey`. An empty `nextKey` means there are no more pages.


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