@sip402/core

· repo · SPEC

The on-chain / settlement half of sip402 — the capital-backed, ERC-7710 binding of x402's batch-settlement scheme. This package holds the pieces both the seller and the demo need: network config, off-chain draw accounting, the Settler that redeems commitments, and the 1Shot gasless-relayer client.

npm i @sip402/core

What's inside

| Module | Exports | Purpose | |---|---|---| | chain | SIP_NETWORK, IS_MAINNET, CHAIN, CHAIN_ID, USDC, toUsdcAtoms() | Network + USDC config, selected once from SIP_NETWORK (base | base-sepolia). | | session | SipMeter | Pure, off-chain mirror of the on-chain period cap — accrues token costs and decides when to draw. | | settle | Settler, createDirectRedeemSettler(), createOneShotSettler(), buildTransferExecution() | Redeem one commitment (settle) or N in one redeemDelegations (settleBatch). | | oneshot | getCapabilities(), estimate7710Transaction(), send7710Transaction(), pollUntilTerminal() | JSON-RPC client for the 1Shot permissionless relayer (gasless, gas paid in USDC, EIP-7702). |

The two settlers

Both implement the same Settler interface; pick by network.

import { createDirectRedeemSettler, createOneShotSettler, toUsdcAtoms } from "@sip402/core";
import { privateKeyToAccount } from "viem/accounts";

// TESTNET — the delegate EOA redeems directly through the Delegation Manager (pays gas).
const settler = createDirectRedeemSettler({ delegateAccount: privateKeyToAccount(SESSION_KEY) });

// MAINNET — gasless: the 1Shot relayer redeems and takes its fee in USDC (EIP-7702).
const settler = createOneShotSettler({ ownerAccount: privateKeyToAccount(OWNER_KEY) });

// Settle ONE sip…
await settler.settle({ signedDelegation, payTo: SELLER, atoms: toUsdcAtoms("0.04") });

// …or BATCH many commitments into ONE redeemDelegations (the batch-settlement scheme).
// The on-chain period enforcer accumulates across the batch, so an over-cap batch
// reverts atomically — the "dry tab".
const { txHash, count, totalAtoms } = await settler.settleBatch({
  signedDelegation,
  payTo: SELLER,
  atomsList: [toUsdcAtoms("0.04"), toUsdcAtoms("0.04"), toUsdcAtoms("0.04")],
});

SipMeter — off-chain accounting

SipMeter tracks cumulative draws against a session cap so the seller knows when to flush a batch, without a chain round-trip per token. The on-chain ERC20PeriodTransferEnforcer is the source of truth; SipMeter is its fast, local mirror.

Configuration

SIP_NETWORK selects the network at module load (base-sepolia by default). BASE_RPC_URL / BASE_SEPOLIA_RPC_URL override the RPC; the 1Shot relayer URL and target/fee addresses are wired automatically per network.

License

MIT