# get\_viewing\_key

Fetch your viewing key from the Directory genesis contract using signed read authentication.

## Signatures

```python
def get_viewing_key(
    w3: Web3,
    encryption: EncryptionState,
    private_key: PrivateKey,
) -> Bytes32

async def async_get_viewing_key(
    w3: AsyncWeb3,
    encryption: EncryptionState,
    private_key: PrivateKey,
) -> Bytes32
```

## Parameters

| Parameter     | Type                                                                                        | Description                         |
| ------------- | ------------------------------------------------------------------------------------------- | ----------------------------------- |
| `w3`          | `Web3` / `AsyncWeb3`                                                                        | Web3 instance with Seismic support  |
| `encryption`  | [`EncryptionState`](https://docs.seismic.systems/clients/python/client/encryption-state)    | Encryption state from wallet client |
| `private_key` | [`PrivateKey`](https://docs.seismic.systems/clients/python/api-reference/types/private-key) | Signing key for authentication      |

## Returns

[`Bytes32`](https://docs.seismic.systems/clients/python/api-reference/types/bytes32) — 32-byte AES-256 viewing key.

Raises `ValueError` if no viewing key is registered for the caller's address.

## Example

```python
import os
from seismic_web3 import PrivateKey, SEISMIC_TESTNET
from seismic_web3.src20 import get_viewing_key

pk = PrivateKey.from_hex_str(os.environ["PRIVATE_KEY"])
w3 = SEISMIC_TESTNET.wallet_client(pk)

viewing_key = get_viewing_key(w3, w3.seismic.encryption, pk)
print(f"Viewing key: {viewing_key.hex()}")
```

## Notes

* Uses a **signed read** (`getKey()`) so that `msg.sender` is authenticated — only the key owner can retrieve it
* Typically called internally by [`watch_src20_events()`](https://docs.seismic.systems/clients/python/src20/event-watching/watch-src20-events) to fetch the key before polling

## See Also

* [register\_viewing\_key](https://docs.seismic.systems/clients/python/src20/intelligence-providers/register-viewing-key) — Register a viewing key
* [check\_has\_key](https://docs.seismic.systems/clients/python/src20/intelligence-providers/check-has-key) — Check if an address has a key (public, no auth)
* [watch\_src20\_events](https://docs.seismic.systems/clients/python/src20/event-watching/watch-src20-events) — Calls this internally