Agent Skill · Limit Break

permitc-protocol

PermitC protocol knowledge -- time-bound token approvals, signature-based transfers, order fills, nonce management, and EIP-712 signing. Use this skill whenever the user asks about PermitC, permit transfers, time-bound approvals, gasless token transfers, signature-based token approvals, permit nonces, lockdown, or any Solidity code that imports from @permitC or references PermitC/IPermitC.

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Skill body

PermitC Protocol Knowledge Base

PermitC is Limit Break’s advanced approval system for ERC-20, ERC-721, and ERC-1155 tokens. It extends the Uniswap Permit2 pattern with multi-token-standard support, time-bound approvals, order-based partial fills, and additional data validation. Multiple protocols in the Apptoken ecosystem use PermitC as their approval layer.

Core Concepts

Why PermitC Exists

Traditional token approvals (approve / setApprovalForAll) are permanent and broad. PermitC replaces them with:

  1. Time-bound approvals – every approval has an expiration timestamp
  2. Granular scoping – approvals target a specific token, ID, amount, and operator
  3. Signature-based transfers – single-use permits that don’t require an on-chain approval transaction
  4. One-click revoke – lockdown() invalidates all outstanding approvals instantly
  5. Order-based fills – reusable signatures for partial fills (ERC-1155, ERC-20 limit orders)

Three Transfer Modes

Mode Use Case Nonce Type
Stored Approvals Multi-use, on-chain approve() call N/A (amount-based)
Permit Transfers Single-use, signed off-chain Unordered nonce (bitmap)
Order Fills Reusable partial fills Order ID + salt

Token Types

PermitC uses numeric token type constants:

For ERC-20: always set id = 0. For ERC-721: always set amount = 1.

Transfer Validator IS PermitC

A critical architectural detail: the CreatorTokenTransferValidator contract inherits from PermitC. The Transfer Validator deployed at 0x721C008fdff27BF06E7E123956E2Fe03B63342e3 is itself a PermitC instance. This means:

  1. Every Creator Token Standard token already has access to PermitC through its Transfer Validator
  2. Auto-approval eliminates the approval step entirely: Creator token contracts (ERC-20C, ERC-721C, ERC-1155C) inherit AutomaticValidatorTransferApproval, which lets the contract owner call setAutomaticApprovalOfTransfersFromValidator(true). When enabled, the token’s isApprovedForAll (ERC-721C/ERC-1155C) or allowance (ERC-20C) automatically returns approved/max for the Transfer Validator address.
  3. Zero-approval token launches: A token with auto-approval enabled can immediately participate in protocols (Payment Processor, LBAMM, TokenMaster) using only signed PermitC orders – no approve() or setApprovalForAll() transactions needed from users.

The PermitC address for signing is the Transfer Validator address (0x721C008fdff27BF06E7E123956E2Fe03B63342e3), not the standalone PermitC deployment.

Cross-Protocol Usage

PermitC is used across the Apptoken ecosystem in protocol-specific ways:

Protocol PermitC Usage Details
Transfer Validator PermitC inheritance The validator IS a PermitC instance; tokens with auto-approval get permit functionality with zero user approvals
Payment Processor V3 NFT listing approvals Sellers sign PermitC permits instead of setApprovalForAll; SaleApproval embedded as additional data
LBAMM Gasless swap settlement PermitTransferHandler uses PermitC for gasless maker-taker swaps; cosigner system for MEV protection
TokenMaster Advanced buy orders PermitTransferFromWithAdditionalData wrapping AdvancedBuyOrder for gasless token purchases

For protocol-specific PermitC integration details, see:

Reference Files

Repository

GitHub: https://github.com/limitbreakinc/PermitC

Project Setup

  1. Foundry: foundry.toml must exist. If not: forge init
  2. PermitC: lib/PermitC/ must exist. If not: forge install limitbreakinc/PermitC
  3. Remappings: remappings.txt needs @limitbreak/permit-c/=lib/PermitC/. Append if missing – do not overwrite existing entries.
  4. Local testing: For local development, use apptoken-dev to bootstrap an Anvil node with all Apptoken protocols at their deterministic addresses – see apptoken-general/references/project-setup.md.

Key Addresses

Contract Address Notes
Transfer Validator V5 (IS PermitC) 0x721C008fdff27BF06E7E123956E2Fe03B63342e3 Use this as the PermitC address for Creator Token Standard tokens
Standalone PermitC 0x000000fCE53B6fC312838A002362a9336F7ce39B Standalone deployment for non-Creator-Standard tokens

Skill frontmatter

user-invocable: false