@pulsadev/permit2

EIP-2612 Permit + Uniswap Permit2 — gasless approve signatures, typed data building, nonce queries. Zero dependencies, pure RPC.

Build EIP-712 typed data for both EIP-2612 and Permit2, query on-chain state, no ethers/viem required.

Features

• EIP-2612 Permit — build typed data for gasless token approvals
• Permit2 PermitSingle — single token allowance via signature
• Permit2 PermitBatch — batch token allowances in one signature
• Permit2 PermitTransferFrom — signature-based token transfers
• Permit2 BatchTransferFrom — batch signature transfers
• On-chain queries — nonce, domain separator, Permit2 allowance
• Token domain auto-detection — reads name, version from contract
• EIP-712 typed data output — ready for eth_signTypedData_v4
• Zero dependencies — ~10 KB bundled, ESM + CJS, pure TypeScript

Install

npm install @pulsadev/permit2

Quick Start

EIP-2612 Permit (gasless approve)

import { buildPermitData } from '@pulsadev/permit2'

const permitData = await buildPermitData(
  'https://ethereum-rpc.publicnode.com',
  '0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48', // USDC
  '0xOwner...', // token owner
  '0xSpender...', // approved spender
  1000000n, // amount (1 USDC)
  BigInt(Math.floor(Date.now() / 1000) + 3600), // 1 hour deadline
)

// Sign with wallet
const signature = await wallet.signTypedData(permitData.typedData)

Permit2 PermitSingle

import { createPermitSingle, buildPermitSingleTypedData } from '@pulsadev/permit2'

const permit = createPermitSingle(
  '0xUSDC...', // token
  1000000n, // amount
  BigInt(Math.floor(Date.now() / 1000) + 86400), // 24h expiration
  0n, // nonce
  '0xSpender...', // spender
  BigInt(Math.floor(Date.now() / 1000) + 3600), // 1h sig deadline
)

const typedData = buildPermitSingleTypedData(permit, 1) // chainId = 1
const signature = await wallet.signTypedData(typedData)

Permit2 TransferFrom

import { createPermitTransferFrom, buildPermitTransferFromTypedData } from '@pulsadev/permit2'

const permit = createPermitTransferFrom(
  '0xUSDC...', 1000000n, '0xSpender...', 0n,
  BigInt(Math.floor(Date.now() / 1000) + 3600),
)

const typedData = buildPermitTransferFromTypedData(permit, 1)

Query on-chain state

import { getPermitNonce, getDomainSeparator, getPermit2Allowance } from '@pulsadev/permit2'

const nonce = await getPermitNonce(rpcUrl, tokenAddress, ownerAddress)
const domainSep = await getDomainSeparator(rpcUrl, tokenAddress)
const allowance = await getPermit2Allowance(rpcUrl, owner, token, spender)
// { amount, expiration, nonce }

API

EIP-2612

| Function | Description | |----------|-------------| | buildPermitData(rpcUrl, token, owner, spender, value, deadline, chainId?) | Build complete permit typed data | | getPermitNonce(rpcUrl, token, owner) | Get current permit nonce | | getDomainSeparator(rpcUrl, token) | Get DOMAIN_SEPARATOR | | getTokenDomain(rpcUrl, token, chainId?) | Get full EIP-712 domain |

Permit2

| Function | Description | |----------|-------------| | buildPermitSingleTypedData(permit, chainId) | Build PermitSingle EIP-712 data | | buildPermitBatchTypedData(permit, chainId) | Build PermitBatch EIP-712 data | | buildPermitTransferFromTypedData(permit, chainId) | Build PermitTransferFrom EIP-712 data | | buildPermitBatchTransferFromTypedData(permit, chainId) | Build BatchTransferFrom EIP-712 data | | getPermit2Allowance(rpcUrl, owner, token, spender) | Query Permit2 allowance | | createPermitSingle(token, amount, expiration, nonce, spender, sigDeadline) | Helper to create PermitSingle | | createPermitTransferFrom(token, amount, spender, nonce, deadline) | Helper to create PermitTransferFrom |

Why not @uniswap/permit2-sdk?

| | @uniswap/permit2-sdk | @1inch/permit-utils | @pulsadev/permit2 | |--|---------------------|---------------------|-------------------| | EIP-2612 | No | Yes | Yes | | Permit2 | Yes | No | Yes | | Dependencies | ethers v5 | ethers v6 | None | | On-chain queries | No | Yes | Yes | | Domain auto-detect | No | Yes | Yes | | Bundle size | Heavy | Medium | ~10 KB |

License

MIT © Yuto Nakamura