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Looking for Contributors! This Skill needs an implementation.Contributing a Skill involves:
  1. Writing a reference implementation with full functionality
  2. Adding comprehensive tests
  3. Writing documentation with usage examples
See the ethers-provider Skill for an example of a complete Skill implementation.Interested? Open an issue or PR at github.com/evmts/voltaire.
Skill — Copyable reference implementation. Use as-is or customize. See Skills Philosophy.
Gasless token approvals using EIP-2612 permit signatures and Uniswap’s Permit2 contract.

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Why Permit?

Traditional ERC-20 approvals require two transactions:
  1. approve() — User pays gas to approve spender
  2. transferFrom() — Protocol transfers tokens
With permit, users sign a gasless message instead:
  1. User signs permit message (free, off-chain)
  2. Protocol calls permit() + transferFrom() in one transaction
This improves UX significantly—users don’t pay for approvals.

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Planned Implementation

This Skill should cover:

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EIP-2612 Permit

// Sign a permit for ERC-20 tokens that support EIP-2612
const permit = await signPermit({
  token: '0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48', // USDC
  owner: walletAddress,
  spender: protocolAddress,
  value: parseUnits('1000', 6),
  deadline: Math.floor(Date.now() / 1000) + 3600, // 1 hour
  signer
});

// permit contains { v, r, s, deadline, value }
// Protocol can now call token.permit(...) + token.transferFrom(...)

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Permit2 (Uniswap)

// Permit2 works with ANY ERC-20, not just EIP-2612 tokens
const permit2 = await signPermit2({
  token: '0x...', // Any ERC-20
  amount: parseUnits('1000', 18),
  expiration: Math.floor(Date.now() / 1000) + 86400, // 24 hours
  nonce: 0,
  spender: protocolAddress,
  signer
});

// Protocol calls Permit2.permitTransferFrom(...)

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Batch Permits

// Approve multiple tokens in one signature
const batchPermit = await signBatchPermit2({
  tokens: [
    { token: USDC, amount: parseUnits('1000', 6) },
    { token: WETH, amount: parseUnits('1', 18) },
  ],
  spender: protocolAddress,
  signer
});

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Tokens Supporting EIP-2612

Most major tokens support native permit:
  • USDC
  • DAI
  • UNI
  • AAVE
  • Most new tokens
For tokens without native permit, use Permit2.

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