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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)

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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. 
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

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. 
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. 
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);

​
4. Managing connections

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Reconnect behavior

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

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Changing connected account

To switch the client’s connected account, call cofheClient.connect() with updated viem clients. 
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. 
cofheClient.disconnect();
cofheClient.connected; // false