Network presets

Pre-configured chain objects and legacy network configs for supported networks.

Chain objects (recommended)

Import pre-configured chain objects from @zama-fhe/sdk/chains. Each chain includes contract addresses, relayer URLs, chain IDs, and an id alias for use in relayer config keys.

import { sepolia, mainnet, hoodi, hardhat } from "@zama-fhe/sdk/chains";

Available chains

Chain	Chain ID	Network
mainnet	1	Ethereum Mainnet
sepolia	11155111	Sepolia Testnet
hoodi	560048	Hoodi Testnet
hardhat	31337	Local Hardhat node

What each chain includes

Each chain object implements the FheChain interface:

Field	Type	Description
id	number	Chain identifier
gatewayChainId	number	Chain ID of the gateway
relayerUrl	string	Default relayer endpoint for this network
network	EIP1193Provider | string	Default RPC URL or EIP-1193 provider for this network
aclContractAddress	Address	ACL contract address
kmsContractAddress	Address	KMS contract address
inputVerifierContractAddress	Address	Input verifier contract address
verifyingContractAddressDecryption	Address	EIP-712 verifying contract for decrypt operations
verifyingContractAddressInputVerification	Address	EIP-712 verifying contract for encrypt operations
registryAddress	Address | undefined	Token wrapper registry contract address (undefined for chains without a deployed registry, e.g. Hardhat)
executorAddress	Address | undefined	TFHEExecutor contract address (cleartext mode only, undefined for real FHE chains)
auth	Auth | undefined	Relayer authentication. Required for the Zama-hosted mainnet relayer; leave unset on the Sepolia testnet relayer, which needs no key.
kmsSignerPrivateKey	Hex | undefined	KMS signer private key for EIP-712 verification (cleartext mode)
inputSignerPrivateKey	Hex | undefined	Input signer private key for EIP-712 verification (cleartext mode)

Usage with createConfig

Pass chain objects in the chains array and use chain.id as relayer keys:

import { createConfig } from "@zama-fhe/sdk/viem";
import { web } from "@zama-fhe/sdk/web";
import { sepolia, mainnet } from "@zama-fhe/sdk/chains";

const config = createConfig({
  chains: [sepolia, mainnet],
  publicClient,
  walletClient,
  relayers: { [sepolia.id]: web(), [mainnet.id]: web() },
});

Per-chain overrides (e.g. relayerUrl, network) are set by spreading the chain preset in the chains array. The chain object provides all contract addresses automatically.

Browser apps

When using the keyed mainnet relayer, proxy requests through your backend so the API key never reaches the client (the Sepolia testnet relayer needs no key, so this is mainnet-only). Override relayerUrl in the chain definition:

import { sepolia, type FheChain } from "@zama-fhe/sdk/chains";

const mySepolia = {
  ...sepolia,
  relayerUrl: "https://your-app.com/api/relayer/11155111",
} as const satisfies FheChain;

Server apps

On the server, use node(). Chain data (network, relayerUrl) comes from the preset, so a bare call is all you need — it also accepts optional @fhevm/sdk client options (batchRpcCalls, fheEncryptionKey) for per-client tuning:

import { node } from "@zama-fhe/sdk/node";
import { sepolia, type FheChain } from "@zama-fhe/sdk/chains";

const mySepolia = {
  ...sepolia,
  network: "https://sepolia.infura.io/v3/YOUR_KEY",
} as const satisfies FheChain;
// Then in createConfig: relayers: { [mySepolia.id]: node() }

Local development

Use the hardhat chain with a cleartext() relayer:

import { createConfig } from "@zama-fhe/sdk/viem";
import { cleartext } from "@zama-fhe/sdk";
import { hardhat } from "@zama-fhe/sdk/chains";

const config = createConfig({
  chains: [hardhat],
  publicClient,
  walletClient,
  relayers: { [hardhat.id]: cleartext() },
});

Multiple networks

Support multiple networks by listing them in the chains array:

import { createConfig } from "@zama-fhe/react-sdk/wagmi";
import { web } from "@zama-fhe/sdk/web";
import { sepolia, mainnet, type FheChain } from "@zama-fhe/sdk/chains";

const mySepolia = { ...sepolia, relayerUrl: "/api/relayer/11155111" } as const satisfies FheChain;
const myMainnet = { ...mainnet, relayerUrl: "/api/relayer/1" } as const satisfies FheChain;

const config = createConfig({
  chains: [mySepolia, myMainnet],
  wagmiConfig,
  relayers: { [mySepolia.id]: web(), [myMainnet.id]: web() },
});

Legacy preset configs (removed)

The legacy SepoliaConfig, MainnetConfig, and HardhatConfig objects are no longer exported from @zama-fhe/sdk. Use the chain presets from @zama-fhe/sdk/chains with createConfig instead:

// Before (removed)
// import { SepoliaConfig, MainnetConfig } from "@zama-fhe/sdk";

// After
import { sepolia, mainnet } from "@zama-fhe/sdk/chains";

DefaultRegistryAddresses

Deprecated. Read registryAddress from the chain presets instead (e.g. sepolia.registryAddress). This export will be removed in the next major version.

A convenience export of built-in registry addresses for known chains (Mainnet, Sepolia, Hoodi) as a Record<number, Address> map. Used internally by the WrappersRegistry class.

// Deprecated
import { DefaultRegistryAddresses } from "@zama-fhe/sdk";

// Preferred
import { sepolia } from "@zama-fhe/sdk/chains";
console.log(sepolia.registryAddress);

hardhat has no registry address by default. Pass one via registryAddresses when creating a WrappersRegistry, or set registryAddress on the chain definition.

Related

• WrappersRegistry — high-level registry query API

• Configuration guide — full chains, relayers, signer, and storage setup

• ZamaSDK — SDK constructor reference