Contract Instance

Type-safe shielded contract instances with read/write/tread/twrite/dwrite namespaces

getShieldedContract creates a type-safe contract instance with five namespaces for interacting with shielded contracts. It extends viem's getContract with Seismic-specific read and write patterns, giving you a single object that covers encrypted writes, signed reads, transparent operations, and debug inspection.

import { getShieldedContract } from "seismic-viem";

Constructor

Parameter	Type	Required	Description
abi	Abi	Yes	Contract ABI (use as const for full type inference)
address	Address	Yes	Deployed contract address
client	ShieldedWalletClient	Yes	Wallet client with encryption capabilities

import { getShieldedContract } from "seismic-viem";

const abi = [
  {
    name: "balanceOf",
    type: "function",
    stateMutability: "view",
    inputs: [{ name: "account", type: "address" }],
    outputs: [{ name: "", type: "uint256" }],
  },
  {
    name: "transfer",
    type: "function",
    stateMutability: "nonpayable",
    inputs: [
      { name: "to", type: "address" },
      { name: "amount", type: "uint256" },
    ],
    outputs: [{ name: "", type: "bool" }],
  },
  {
    name: "totalSupply",
    type: "function",
    stateMutability: "view",
    inputs: [],
    outputs: [{ name: "", type: "uint256" }],
  },
  {
    name: "approve",
    type: "function",
    stateMutability: "nonpayable",
    inputs: [
      { name: "spender", type: "address" },
      { name: "amount", type: "uint256" },
    ],
    outputs: [{ name: "", type: "bool" }],
  },
] as const;

const contract = getShieldedContract({
  abi,
  address: "0x1234567890abcdef1234567890abcdef12345678",
  client,
});

Namespaces

The returned ShieldedContract exposes five namespaces. Each namespace provides every function defined in the ABI, but differs in how calldata is handled and who appears as msg.sender on-chain.

Namespace	Operation Type	Calldata	msg.sender	Description
.read	Signed Read	Encrypted	Signer's address	Authenticated read -- proves identity
.write	Shielded Write	Encrypted	Signer's address	Encrypted transaction
.tread	Transparent Read	Plaintext	Zero address	Standard viem read
.twrite	Transparent Write	Plaintext	Signer's address	Standard viem write
.dwrite	Debug Write	Encrypted	Signer's address	Returns plaintext + encrypted tx + hash

---

.read -- Signed Read

Sends an encrypted, signed eth_call that proves your identity to the contract. Use this when the contract checks msg.sender in a view function to gate access to shielded data.

const balance = await contract.read.balanceOf(["0x1234..."]);

The .read namespace always sets account to client.account for security. This ensures the signed read is authenticated with the wallet's address, regardless of any account override you pass.

See Signed Reads for details on how signed reads work under the hood.

---

.write -- Shielded Write

Encrypts calldata before broadcasting the transaction. The calldata is not visible on-chain.

const hash = await contract.write.transfer(["0x1234...", 100n], {
  gas: 100_000n,
});

See Shielded Writes for the encryption lifecycle and security parameters.

---

.tread -- Transparent Read

Standard viem readContract call with plaintext calldata. The from address is set to the zero address, so msg.sender inside the contract will be 0x0000...0000.

const supply = await contract.tread.totalSupply();

Use .tread for public view functions that do not depend on msg.sender.

---

.twrite -- Transparent Write

Standard viem writeContract call with plaintext (unencrypted) calldata. The transaction is signed by the wallet, so msg.sender is the signer's address.

const hash = await contract.twrite.approve(["0x1234...", 100n]);

Use .twrite when you intentionally want calldata to be visible on-chain (e.g., for transparency or debugging).

---

.dwrite -- Debug Write

Builds the same encrypted transaction as .write, but returns the plaintext transaction, the shielded transaction, and the transaction hash without broadcasting. Useful for inspecting what the SDK produces before sending.

const { plaintextTx, shieldedTx, txHash } = await contract.dwrite.transfer([
  "0x1234...",
  100n,
]);

console.log("Plaintext calldata:", plaintextTx.data);
console.log("Encrypted calldata:", shieldedTx.data);
console.log("Transaction hash:", txHash);

TypeScript ABI Typing

For full type inference on function names, argument types, and return types, declare your ABI with as const:

const abi = [
  {
    name: "balanceOf",
    type: "function",
    stateMutability: "view",
    inputs: [{ name: "account", type: "address" }],
    outputs: [{ name: "", type: "uint256" }],
  },
] as const;

const contract = getShieldedContract({ abi, address: "0x...", client });

// TypeScript knows:
//   - contract.read.balanceOf exists
//   - first arg is [Address]
//   - return type is bigint
const balance = await contract.read.balanceOf(["0x1234..."]);

Without as const, the ABI is widened to readonly AbiItem[] and the contract loses per-function type safety. You can still call functions by name, but arguments and return values will be untyped.

See Also

• Shielded Writes -- Encryption lifecycle and shieldedWriteContract

• Signed Reads -- Authenticated reads and signedReadContract

• Shielded Wallet Client -- Creating the client passed to getShieldedContract

• Encryption -- ECDH key exchange and AES-GCM calldata encryption