Decrypt to View

Reveal encrypted values locally for UI display using permits

Use decryptForView to reveal a confidential (encrypted) value locally in your app so you can display it in the UI.

Unlike decryptForTx, this flow does not return an on-chain-verifiable signature, and it is not meant to be published on-chain.

Flow

1. Read the encrypted handle (ctHash) from your contract.
2. Ensure you have a permit that authorizes decryption of that value.
3. Call decryptForView(ctHash, utype).execute() to get the plaintext.

decryptForView always decrypts using a permit (there is no .withoutPermit() mode). If your protocol intends for the plaintext to become publicly visible on-chain, use decryptForTx instead.

Prerequisites

1. Create and connect a client.
2. Know the encrypted handle (ctHash) and the encrypted type (utype).
3. Have a permit available for the connected chainId + account.

Getting ctHash: In most apps, ctHash comes from reading a stored encrypted value, an event arg, or a return value from a view call.

Providing utype: utype must match the ciphertext’s underlying FHE type. The SDK uses it to convert the decrypted bigint into a convenient JS type.

Supported utypes:

• FheTypes.Bool → returns a boolean
• FheTypes.Uint160 (address) → returns a checksummed 0x... string
• FheTypes.Uint8 | Uint16 | Uint32 | Uint64 | Uint128 → returns a bigint

Permit setup

If you don’t have a permit yet, create one once after connecting:

await client.connect(publicClient, walletClient);

// Creates a permit if needed, stores it, and selects it as the active permit.
await client.permits.getOrCreateSelfPermit();

Decrypt for UI

Choose the pattern that matches how your app manages permits:

Active permit

await client.connect(publicClient, walletClient);
await client.permits.getOrCreateSelfPermit();

const plaintext = await client
  .decryptForView(ctHash, FheTypes.Uint32)
  .execute();

const permit = await client.permits.getOrCreateSelfPermit();

const plaintext = await client
  .decryptForView(ctHash, FheTypes.Uint64)
  .withPermit(permit)
  .execute();

const plaintext = await client
  .decryptForView(ctHash, FheTypes.Uint8)
  .withPermit(permitHash)
  .execute();

What decryptForView returns

Running .execute() resolves to a scalar JS value:

• Integer utypes (Uint8, Uint16, Uint32, Uint64, Uint128): a bigint
• FheTypes.Bool: a boolean
• FheTypes.Uint160 (address): a checksummed 0x... address string

Builder API

.execute() — required, call last

Runs the decryption and returns a UI-friendly scalar value.

.withPermit(...) — optional

Select which permit to use:

• .withPermit() — uses the active permit
• .withPermit(permitHash) — fetches a stored permit by hash
• .withPermit(permit) — uses the provided permit object

If you don’t call .withPermit(...), the active permit is used by default.

.setAccount(address) — optional

Overrides the account used to resolve the active/stored permit.

.setChainId(chainId) — optional

Overrides the chain used to resolve the Threshold Network URL and permits.

Common UI patterns

Format bigint for display

import { formatUnits } from 'viem';

const decimals = 6;
const display = formatUnits(amount, decimals);

const MAX_SAFE = BigInt(Number.MAX_SAFE_INTEGER);
const asNumber = amount <= MAX_SAFE ? Number(amount) : undefined;

const statusLabel = decryptedIsAllowed ? 'Allowed' : 'Not allowed';
const shortOwner = `${decryptedOwner.slice(0, 6)}…${decryptedOwner.slice(-4)}`;

Common pitfalls

• Missing permit: decryptForView will fail if there is no active permit for the current chainId + account.
• Wrong utype: you must pass the correct FHE type for the ciphertext.
• Wrong chain/account: permits are scoped to chainId + account. If the user switches wallets or networks, create/select the correct permit.