permit2-router-witness

Generate and validate EIP-712 Permit2 witness signatures for Balancer V3 router swaps.

Updated Nov 5, 2025
One-click install
npx skills add https://github.com/cyotee/crane --skill permit2-router-witness
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: permit2-router-witness
Source: https://github.com/cyotee/crane/tree/main/.claude/skills/permit2-router-witness
Command: npx skills add https://github.com/cyotee/crane --skill permit2-router-witness

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

Generate and validate Permit2 witness signatures for Balancer V3 router swaps to enable secure signed trades.

Core Features & Use Cases

  • Canonical witness retrieval: Reads and uses the router-provided witness type string and hash.
  • Typed-data signing: Enforces EIP-712 signing for witness payloads, preventing unsafe signing methods.
  • Nonce/deadline handling: Generates fresh nonces and enforces strict expiry to prevent replay.

Quick Start

Configure and call the signed swap path using the router's Permit2 witness to authorize a Balancer V3 trade.

Frequently Asked Questions about permit2-router-witness

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I generate Permit2 witness signatures for Balancer V3 router swaps?▼

To generate Permit2 witness signatures for Balancer V3 router swaps, construct EIP-712 typed-data payloads, sign them, and submit the signed messages to Permit2 with proper nonce and deadline handling.

Why does my Permit2 witness signature fail for Balancer V3 swaps?▼

Permit2 witness signatures fail when using unsafe signing methods instead of EIP-712, or when the witness type string and hash do not match the router-provided constants. Enforcing strict typed-data signing resolves this.

How does EIP-712 typed-data signing work with Permit2 witnesses?▼

EIP-712 typed-data signing with Permit2 witnesses works by encoding the Balancer V3 router swap details into a structured payload, which is then signed to authorize secure trades without transferring token approvals directly.

Do I need to handle nonces and deadlines for Permit2 witness signatures?▼

Yes, you must handle nonces and deadlines for Permit2 witness signatures by generating fresh nonces from the Permit2 nonce bitmap and enforcing strict expiry times to prevent replay attacks.

Can I use Permit2 witnesses for Balancer V3 swaps in DeFi backend code?▼

Yes, you can use Permit2 witnesses for Balancer V3 swaps in DeFi backend or frontend code by reading router constants, generating typed-data payloads, and ensuring token approvals are set to Permit2.