Skill based on OpenZeppelin Contracts (docs as of 2026-02-09), generated from sources/openzeppelin .
OpenZeppelin Contracts is a library for secure smart contract development on EVM. Use via inheritance (e.g. ERC20, AccessControl) or using for (e.g. ECDSA, Math). Covers access control (Ownable, RBAC, AccessManager, TimelockController), tokens (ERC20, ERC721, ERC1155, ERC4626, ERC6909), upgradeable variants, and utilities (crypto, math, introspection, structures, storage).
Core References
Topic Description Reference
Overview Library usage, inheritance, extending contracts core-overview
Access Control Ownable, AccessControl (RBAC), AccessManager, TimelockController core-access-control
Tokens Token standards and when to use ERC20/721/1155/4626/6909 core-tokens
ERC20 Fungible tokens, decimals, transfer, supply core-erc20
ERC721 Non-fungible tokens, URI storage, minting core-erc721
ERC1155 Multi-token (fungible + NFT), batch ops, safe transfer to contracts core-erc1155
ERC4626 Tokenized vaults, shares vs assets, inflation attack mitigation core-erc4626
ERC6909 Multi-asset (no batch/callbacks), granular approvals, extensions core-erc6909
ERC20 Supply Creating supply with _mint and _update, fixed and reward patterns core-erc20-supply
Features
Upgradeable
Topic Description Reference
Upgradeable Contracts contracts-upgradeable, initializers, namespaced storage features-upgradeable
Governance & Accounts
Topic Description Reference
Account Abstraction ERC-4337 stack: UserOperation, EntryPoint, Bundler, Paymaster features-account-abstraction
Governor On-chain governance, ERC20Votes, quorum, timelock, proposal lifecycle features-governance
Multisig ERC-7913 signers, threshold and weighted multisig with Account features-multisig
Smart Accounts ERC-4337 Account, signers, factory, UserOp, batched execution features-accounts
EOA Delegation EIP-7702 delegation to contracts, SignerEIP7702, authorization features-eoa-delegation
Utilities
Topic Description Reference
Utilities ECDSA, MerkleProof, Math, ERC165, structures, StorageSlot, Multicall features-utilities
Best Practices
Topic Description Reference
Backwards Compatibility Semantic versioning, storage layout, safe overrides best-practices-backwards-compatibility
Extending Contracts Inheritance, overrides, super, security when customizing best-practices-extending-contracts
EOA Restriction Why not to restrict to EOAs only; use access control instead best-practices-eoa-restriction