One-time use

oneTimeUse pins a one-time-use ID on a session. The session can then settle at most one settlement transaction per participating chain. It does not limit the session to one operation. Examples on this page use @rhinestone/sdk, where rhinestone is the RhinestoneSDK instance from Create a session with a custom setup.

import { bytesToBigInt, parseUnits } from "viem";
import { arbitrum, base } from "viem/chains";

const usdcOnBase = "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913";
const usdcOnArbitrum = "0xaf88d065e77c8cC2239327C5EDb3A432268e5831";

// A fresh, random, non-zero 256-bit ID for every session.
const id = bytesToBigInt(crypto.getRandomValues(new Uint8Array(32)));

const session = await rhinestone.createSession({
  chain: base,
  owners: {
    type: "ecdsa",
    accounts: [sessionOwnerAccount],
  },
  account: rhinestoneAccount.getAddress("evm"),
  oneTimeUse: {
    id,
    validUntil: new Date(Date.now() + 24 * 60 * 60 * 1000),
  },
  crossChainPermits: [
    {
      from: { chain: base, token: usdcOnBase, maxAmount: parseUnits("100", 6) },
      to: { chain: arbitrum, token: usdcOnArbitrum },
    },
  ],
});

With oneTimeUse, the permit’s maxAmount caps that one settlement instead of acting as a lifetime budget.

How it works

Every intent the SDK prepares for the session burns the ID first, on each chain it settles on. The policy refuses any settlement that does not burn it.
Intents need an explicit source.
validUntil is optional. When set, it must be a future Date and bounds every action in the session. Permit, swap, and function windows stay separate policies.
OFT and LZ settlement layers require oneTimeUse.
A one-time-use session always gets its own salted permission ID.

Policy availability

The SDK uses the deployed OneTimeUseIdPolicy for the session’s chain. Its addresses are exported as ONE_TIME_USE_ID_POLICY_ADDRESS and ONE_TIME_USE_ID_POLICY_ADDRESS_DEV (for useDevContracts) from @rhinestone/sdk/smart-sessions. On a chain without the policy, creating the session throws:

oneTimeUse: no OneTimeUseIdPolicy is deployed on chain <chainId>; pass its address as policyAddresses.oneTimeUseId

Signing

Leave signing unset. Unless the session holds a Permit2-layer permit such as ACROSS, which compiles claim policies, it has no signing surface and refuses a non-disabled signing mode. See Session signing.

Use the session

Name the funding source explicitly and sign with the session:

const prepared = await rhinestoneAccount.prepareTransaction({
  source: { chain: base, token: usdcOnBase },
  destination: {
    chain: arbitrum,
    token: usdcOnArbitrum,
    amount: parseUnits("10", 6),
  },
  sponsored: true,
  signers: {
    type: "session",
    session,
  },
});
const signed = await rhinestoneAccount.signTransaction(prepared);
const result = await rhinestoneAccount.submitTransaction(signed);

Enable the session first, as described in Use a session. After the ID is burned on a chain, create a new session with a fresh ID for the next settlement there.

Embedded wallet

Custom setup

How it works

Policy availability

Signing

Use the session

​How it works

​Policy availability

​Signing

​Use the session

How it works

Policy availability

Signing

Use the session