Permitc Protocol

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

Token Types

PermitC uses numeric token type constants:

• TOKEN_TYPE_ERC721 = 721
• TOKEN_TYPE_ERC1155 = 1155
• TOKEN_TYPE_ERC20 = 20

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:

For protocol-specific PermitC integration details, see:

• payment-processor-exchange/references/permitc-integration.md -- NFT listings with PermitC
• lbamm-permit-handler/references/permit-handler-reference.md -- Gasless AMM swaps via PermitTransferHandler
• tokenmaster-integrator/references/advanced-orders.md -- PermitC buy orders

Reference Files

• references/permitc-core.md -- Full interface, data types, EIP-712 typehashes, nonce management, approval flows, signing patterns, common errors

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

Related Skills

• transfer-validator-protocol -- Transfer Validator details (inherits PermitC, rulesets, auto-approval)
• payment-processor-exchange -- Generate exchange integration code using PermitC for NFT listings
• lbamm-permit-handler -- Generate PermitTransferHandler integration code (PermitC-based gasless swaps)
• tokenmaster-integrator -- Generate transaction integration code including PermitC buy orders
• apptoken-general -- Ecosystem overview and cross-protocol integration