# ChainConfig

Immutable configuration for a Seismic network, including RPC endpoints, chain ID, and client factory methods.

## Overview

`ChainConfig` is a frozen dataclass that encapsulates all information needed to connect to a Seismic network. Instead of passing RPC URLs and chain IDs separately, you create a `ChainConfig` once and use its convenience methods to create clients.

## Definition

```python
@dataclass(frozen=True)
class ChainConfig:
    """Immutable configuration for a Seismic network.

    Attributes:
        chain_id: Numeric chain identifier.
        rpc_url: HTTP(S) JSON-RPC endpoint.
        ws_url: WebSocket endpoint (``None`` if not available).
        name: Human-readable network name.
    """
    chain_id: int
    rpc_url: str
    ws_url: str | None = None
    name: str = ""
```

## Attributes

| Attribute  | Type          | Required | Description                                         |
| ---------- | ------------- | -------- | --------------------------------------------------- |
| `chain_id` | `int`         | Yes      | Numeric chain identifier (e.g., `5124` for testnet) |
| `rpc_url`  | `str`         | Yes      | HTTP(S) JSON-RPC endpoint                           |
| `ws_url`   | `str \| None` | No       | WebSocket endpoint (default: `None`)                |
| `name`     | `str`         | No       | Human-readable network name (default: `""`)         |

## Construction

### Basic Usage

```python
from seismic_web3 import ChainConfig

config = ChainConfig(
    chain_id=5124,
    rpc_url="https://testnet-1.seismictest.net/rpc",
    ws_url="wss://testnet-1.seismictest.net/ws",
    name="Seismic Testnet",
)
```

### Without WebSocket

```python
config = ChainConfig(
    chain_id=5124,
    rpc_url="https://testnet-1.seismictest.net/rpc",
    name="Seismic Testnet",
)
```

### Using Pre-Defined Configs

```python
from seismic_web3 import SEISMIC_TESTNET, SANVIL

# Pre-configured testnet
SEISMIC_TESTNET

# Pre-configured local Sanvil
SANVIL
```

## Methods

### wallet\_client()

Create a synchronous `Web3` instance with wallet capabilities.

```python
def wallet_client(
    self,
    private_key: PrivateKey,
    *,
    encryption_sk: PrivateKey | None = None,
) -> Web3:
```

#### Parameters

| Parameter       | Type                 | Required | Description                          |
| --------------- | -------------------- | -------- | ------------------------------------ |
| `private_key`   | `PrivateKey`         | Yes      | 32-byte signing key for transactions |
| `encryption_sk` | `PrivateKey \| None` | No       | Optional 32-byte key for ECDH        |

#### Returns

* `Web3` - A synchronous `Web3` instance with [`w3.seismic`](/clients/python/namespaces/seismic-namespace.md) namespace attached

#### Example

```python
import os
from seismic_web3 import SEISMIC_TESTNET, PrivateKey

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

# Now use w3.seismic methods
balance = w3.eth.get_balance("0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266")
```

***

### async\_wallet\_client()

Create an asynchronous `Web3` instance with wallet capabilities.

```python
async def async_wallet_client(
    self,
    private_key: PrivateKey,
    *,
    encryption_sk: PrivateKey | None = None,
    ws: bool = False,
) -> AsyncWeb3:
```

#### Parameters

| Parameter       | Type                 | Required | Description                                            |
| --------------- | -------------------- | -------- | ------------------------------------------------------ |
| `private_key`   | `PrivateKey`         | Yes      | 32-byte signing key for transactions                   |
| `encryption_sk` | `PrivateKey \| None` | No       | Optional 32-byte key for ECDH                          |
| `ws`            | `bool`               | No       | If `True`, uses `WebSocketProvider` (default: `False`) |

#### Returns

* `AsyncWeb3` - An asynchronous `Web3` instance with [`w3.seismic`](/clients/python/namespaces/async-seismic-namespace.md) namespace attached

#### Behavior

* When `ws=True` and `ws_url` is set, the WebSocket URL is used automatically
* When `ws=False`, the HTTP `rpc_url` is used
* Raises `ValueError` if `ws=True` but `ws_url` is `None`

#### Example

```python
import os
from seismic_web3 import SEISMIC_TESTNET, PrivateKey

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

# HTTP
w3 = await SEISMIC_TESTNET.async_wallet_client(pk)

# WebSocket
w3 = await SEISMIC_TESTNET.async_wallet_client(pk, ws=True)

# Use async methods
balance = await w3.eth.get_balance("0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266")
```

***

### public\_client()

Create a synchronous `Web3` instance with public (read-only) access.

```python
def public_client(self) -> Web3:
```

#### Parameters

None. (public clients don't handle private keys)

#### Returns

* `Web3` - A synchronous `Web3` instance with [`w3.seismic`](/clients/python/namespaces/seismic-public-namespace.md) namespace attached (read-only)

#### Example

```python
from seismic_web3 import SEISMIC_TESTNET

public = SEISMIC_TESTNET.public_client()

# Read-only operations
block = public.eth.get_block("latest")
tee_key = public.seismic.get_tee_public_key()
```

***

### async\_public\_client()

Create an asynchronous `Web3` instance with public (read-only) access.

```python
def async_public_client(
    self,
    *,
    ws: bool = False,
) -> AsyncWeb3:
```

#### Parameters

| Parameter | Type   | Required | Description                                            |
| --------- | ------ | -------- | ------------------------------------------------------ |
| `ws`      | `bool` | No       | If `True`, uses `WebSocketProvider` (default: `False`) |

#### Returns

* `AsyncWeb3` - An asynchronous `Web3` instance with [`w3.seismic`](/clients/python/namespaces/async-seismic-public-namespace.md) namespace attached (read-only)

#### Example

```python
from seismic_web3 import SEISMIC_TESTNET

# HTTP
public = SEISMIC_TESTNET.async_public_client()

# WebSocket
public = SEISMIC_TESTNET.async_public_client(ws=True)

# Read-only operations
block = await public.eth.get_block("latest")
```

## Deprecated Methods

### create\_client()

Deprecated: use `wallet_client()` instead.

```python
# Old (deprecated)
w3 = config.create_client(private_key)

# New
w3 = config.wallet_client(private_key)
```

### create\_async\_client()

Deprecated: use `async_wallet_client()` instead.

```python
# Old (deprecated)
w3 = await config.create_async_client(private_key)

# New
w3 = await config.async_wallet_client(private_key)
```

## Notes

* All client creation methods return standard `web3.py` instances
* The [`w3.seismic`](/clients/python/namespaces/seismic-namespace.md) namespace is automatically attached to all clients
* WebSocket connections provide better performance for subscription-based workflows
* HTTP connections are suitable for simple request-response patterns

## See Also

* [SEISMIC\_TESTNET](/clients/python/chains/seismic-testnet.md) - Pre-defined testnet configuration
* [SANVIL](/clients/python/chains/sanvil.md) - Pre-defined local development configuration
* [make\_seismic\_testnet](/clients/python/chains/make-seismic-testnet.md) - Factory for testnet instances
* [create\_wallet\_client](/clients/python/client/create-wallet-client.md) - Direct wallet client creation
* [create\_public\_client](/clients/python/client/create-public-client.md) - Direct public client creation
* [PrivateKey](/clients/python/api-reference/types/private-key.md) - Private key type


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