# Accounts

Every account has one canonical `bb1` address. Addresses from other chains map to it, so one user can sign from an Ethereum wallet or a Cosmos wallet and hold the same balances.

## Shape

```ts
import { convertToBitBadgesAddress, convertToEthAddress, isAddressValid } from 'bitbadges';

const bitbadgesAddress = convertToBitBadgesAddress('0x14574a6DFF2Ddf9e07828b4345d3040919AF5652');
// "bb1z3t55m0l9h0eupuz3dp5t5cypyv674jj7mz2jw"

const ethAddress = convertToEthAddress('bb1z3t55m0l9h0eupuz3dp5t5cypyv674jj7mz2jw');
// "0x14574a6DFF2Ddf9e07828b4345d3040919AF5652"

isAddressValid('bb1z3t55m0l9h0eupuz3dp5t5cypyv674jj7mz2jw'); // true
```

| Term | Meaning |
| --- | --- |
| `address` | The native address the user signs with (`0x` prefix for Ethereum, `bb1` prefix for Cosmos). |
| `bitbadgesAddress` | The mapped `bb1` address. Equal to `address` for Cosmos-native users. |
| account number | A number the chain assigns the first time the address transacts or receives BADGE. |

{% hint style="info" %}
Ask your agent:

```text
Convert 0x0bc63cfe31d5218eb414b142c799e20964a54a1a to its bb1 address and check that it is valid.
```

The MCP builder tools (`convert_address, validate_address`) produce the objects on this page.
{% endhint %}

## How It Works

The 20-byte public key hash behind an Ethereum address is the same bytes behind a bech32 `bb1` address. Conversion is a re-encoding, not a lookup. The Ethereum zero address `0x0000000000000000000000000000000000000000` maps to `bb1qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqnrql8a`.

All chain state (balances, approvals, address lists, trackers) keys on the `bb1` form. Messages accept `bb1` addresses. The one exception is the reserved string `"Mint"`, which is a valid address in approvals and address lists but has no key pair.

Display the native address to users. Use the `bb1` form when you build messages or read state. `convertToBitBadgesAddress` returns an empty string for an invalid input, so it doubles as a validator.

## Related

- [Address Lists](https://docs.bitbadges.io/token-standard/concepts/address-lists)
- [Address Conversions](https://docs.bitbadges.io/sdk/snippets/address-conversions)
- [Network](https://docs.bitbadges.io/chain)