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

# Client Setup

> Configure and connect the @cofhe/sdk client with viem, Ethers, or wagmi

This page covers the core SDK lifecycle:

1. Create config (`createCofheConfig`)
2. Create client (`createCofheClient`)
3. Connect (`client.connect`)
4. Manage connection (change account / disconnect)

## 1. Create config

Import `createCofheConfig` from the entrypoint that matches your runtime:

* Browser apps: `@cofhe/sdk/web`
* Node.js scripts/backends: `@cofhe/sdk/node`

The only required field is `supportedChains`.

```typescript theme={null}
import { createCofheConfig } from '@cofhe/sdk/web';
import { chains } from '@cofhe/sdk/chains';

const config = createCofheConfig({
  supportedChains: [chains.sepolia],

  // Optional knobs
  // defaultPermitExpiration: 60 * 60 * 24 * 30,
  // useWorkers: true,
});
```

## 2. Create the client

```typescript theme={null}
import { createCofheConfig, createCofheClient } from '@cofhe/sdk/web';
import { chains } from '@cofhe/sdk/chains';

const config = createCofheConfig({ supportedChains: [chains.sepolia] });
const cofheClient = createCofheClient(config);

cofheClient.connected; // false
cofheClient.connecting; // false
```

## 3. Connect

The SDK connects to CoFHE using viem clients:

* `PublicClient`: read-only chain access
* `WalletClient`: signing + sending transactions

If you already have viem clients, pass them directly.

```typescript theme={null}
import { createPublicClient, createWalletClient, http } from 'viem';
import { sepolia } from 'viem/chains';

const publicClient = createPublicClient({
  chain: sepolia,
  transport: http(),
});

const walletClient = createWalletClient({
  chain: sepolia,
  transport: http(),
});

await cofheClient.connect(publicClient, walletClient);

cofheClient.connected; // true
```

### Using adapters

If you use a different wallet/provider stack, `@cofhe/sdk/adapters` provides adapters that convert into viem-shaped clients.

<CodeGroup>
  ```typescript Ethers v6 theme={null}
  import { Ethers6Adapter } from '@cofhe/sdk/adapters';
  import { ethers } from 'ethers';

  const provider = new ethers.JsonRpcProvider('https://rpc.sepolia.org');
  const signer = new ethers.Wallet('0xYOUR_PRIVATE_KEY', provider);

  const { publicClient, walletClient } = await Ethers6Adapter(
    provider,
    signer
  );

  await cofheClient.connect(publicClient, walletClient);
  ```

  ```typescript Ethers v5 theme={null}
  import { Ethers5Adapter } from '@cofhe/sdk/adapters';
  import { ethers } from 'ethers5';

  const provider = new ethers.providers.JsonRpcProvider(
    'https://rpc.sepolia.org'
  );
  const signer = new ethers.Wallet('0xYOUR_PRIVATE_KEY').connect(provider);

  const { publicClient, walletClient } = await Ethers5Adapter(
    provider,
    signer
  );

  await cofheClient.connect(publicClient, walletClient);
  ```

  ```typescript Wagmi theme={null}
  import { WagmiAdapter } from '@cofhe/sdk/adapters';
  import { createPublicClient, createWalletClient, http } from 'viem';
  import { sepolia } from 'viem/chains';

  const wagmiPublicClient = createPublicClient({
    chain: sepolia,
    transport: http(),
  });
  const wagmiWalletClient = createWalletClient({
    chain: sepolia,
    transport: http(),
  });

  const { publicClient, walletClient } = await WagmiAdapter(
    wagmiWalletClient,
    wagmiPublicClient
  );

  await cofheClient.connect(publicClient, walletClient);
  ```
</CodeGroup>

## 4. Managing connections

### Reconnect behavior

Calling `connect` again with the same clients is a no-op. Calling it with new clients replaces the connection state.

### Changing connected account

To switch the client's connected account, call `cofheClient.connect()` with updated viem clients.

```typescript theme={null}
const bobWalletClient = createWalletClient({
  chain: sepolia,
  transport: http(),
  account: bobAddress,
});
const aliceWalletClient = createWalletClient({
  chain: sepolia,
  transport: http(),
  account: aliceAddress,
});

// Connect as Bob
await cofheClient.connect(publicClient, bobWalletClient);
cofheClient.connection.account; // Bob's address

// Switch to Alice
await cofheClient.connect(publicClient, aliceWalletClient);
cofheClient.connection.account; // Alice's address
```

### Disconnecting

To manually disconnect, call `cofheClient.disconnect()`. This clears the in-memory connection state (clients/account/chainId) and marks the client as disconnected.

It does **not** delete persisted permits or stored FHE keys.

```typescript theme={null}
cofheClient.disconnect();
cofheClient.connected; // false
```