/v4-hook-generator

name: v4-hook-generator
description: 'Generate Uniswap v4 hook contracts via OpenZeppelin MCP. Use when building custom swap logic, async swaps, hook-owned liquidity, custom curves, dynamic fees, MEV protection, limit orders, or oracle hooks.'
allowed-tools: Read, Glob, Grep, WebFetch, Bash
model: opus
license: MIT
metadata:
  author: uniswap
  version: '1.0.0'

v4 Hook Generator

Generate Uniswap v4 hook contracts via the OpenZeppelin Contracts Wizard MCP tool. This skill guides you through selecting the right hook type, configuring permissions and utilities, assembling the canonical MCP JSON, and invoking the MCP tool to produce ready-to-compile Solidity code.

> **Security companion**: Generated hook code touches fund-handling contracts. Always apply the > `v4-security-foundations` skill immediately after generation to audit permissions, delta > accounting, and access control before deploying to any network.

When to Use This Skill

Use this skill when you need to:

• Scaffold a new Uniswap v4 hook contract from scratch
• Select the right base hook type for a specific use case (fees, MEV protection, oracles, etc.)
• Configure hook permissions, utility libraries, shares, and access control
• Produce the canonical MCP tool call JSON to invoke the OpenZeppelin Contracts Wizard
• Understand trade-offs between hook configuration options before committing to an implementation

**Prerequisite / companion skill**: `v4-security-foundations` — run it before writing custom logic and again before deployment. Hook misconfiguration can drain user funds.

Hook Type Decision Table

Choose the base hook type that matches your primary goal. If your hook has multiple goals, choose the type that covers the most critical concern and layer additional logic on top.

| Goal | Use Hook | | -------------------- | -------------------------- | | Custom swap logic | `BaseHook` | | Async/delayed swaps | `BaseAsyncSwap` | | Hook-owned liquidity | `BaseCustomAccounting` | | Custom curve | `BaseCustomCurve` | | Dynamic LP fees | `BaseDynamicFee` | | Dynamic swap fees | `BaseOverrideFee` | | Post-swap fees | `BaseDynamicAfterFee` | | Fixed hook fees | `BaseHookFee` | | MEV protection | `AntiSandwichHook` | | JIT protection | `LiquidityPenaltyHook` | | Limit orders | `LimitOrderHook` | | Yield on idle | `ReHypothecationHook` | | Oracle | `BaseOracleHook` | | V3-compatible oracle | `OracleHookWithV3Adapters` |

**Selection tips**:

• `BaseHook` is the general-purpose starting point — choose a specialized type only when the

built-in logic provides concrete value.

• `BaseCustomCurve` replaces the entire AMM math; only use it if you are implementing a novel

pricing algorithm.

• `AntiSandwichHook` and `LiquidityPenaltyHook` both address MEV but target different actors

(traders vs. JIT LPs). Clarify which attack vector you are mitigating.

• `OracleHookWithV3Adapters` is appropriate when downstream integrations expect a Uniswap v3

`IUniswapV3Pool`-compatible oracle interface.

Minimal Decision Checklist

Before calling the MCP tool, confirm all six decisions:

1. **Hook type** — chosen from the decision table above 2. **Permissions to enable** — only the callbacks your logic actually uses (`beforeSwap`, `afterSwap`, etc.) 3. **Utility libraries** — `currencySettler`, `safeCast`, `transientStorage` as needed 4. **Shares** — `false`, `ERC20`, `ERC6909`, or `ERC1155` 5. **Access control** — `ownable`, `roles`, or `managed` 6. **Hook inputs** — `blockNumberOffset`, `maxAbsTickDelta` (only for hook types that use them)

Permission Configuration

All 14 permission flags with guidance on when to enable each. Start with all flags `false` and enable only what your hook logic requires. Every enabled permission increases the hook's attack surface and requires a specific bit to be set in the hook's deployed address (see address encoding note below).

| Permission Flag | Enable When | Risk | | --------------------------------- | --------------------------------------------------------------------------------------------------------------- | -------- | | `beforeInitialize` | You need to validate or restrict pool creation params | LOW | | `afterInitialize` | You need to set up state after a pool is created | LOW | | `beforeAddLiquidity` | You need to gate or transform LP deposits | MEDIUM | | `afterAddLiquidity` | You track LP positions or distribute rewards | LOW | | `beforeRemoveLiquidity` | You need lock-up periods or fee-on-exit logic | HIGH | | `afterRemoveLiquidity` | You track position removals for accounting | LOW | | `beforeSwap` | You modify swap behavior, apply dynamic fees, or block | HIGH | | `afterSwap` | You observe final swap state for oracles or accounting | MEDIUM | | `beforeDonate` | You restrict who may donate to the pool | LOW | | `afterDonate` | You track donation events