App integration

Lightweight, modular, reactive Java and Android library for Ethereum. JSON-RPC client API, wallet support, and auto-generated Solidity contract wrappers for deployment and interaction. Includes CLI, Maven/Gradle plugins, and ENS support.

web3.py is the open source library that connects Python developers to Ethereum. The same team maintains more than a dozen additional building blocks including py-evm, eth-account, and eth-utils.

go-ethereum ships Go packages for Ethereum development, including the ethclient RPC client, account and key handling, and abigen for type-safe contract bindings. Go builders import them to talk to nodes and call contracts from generated code.

Ethers.js is a compact TypeScript library for scripts, wallets, and services that need predictable JSON-RPC, ABI encoding, and signing helpers in Node or the browser.

Viem is the most used modern TypeScript Interface for Ethereum. Viem provides robust, performant, and type-safe modules to be the foundation for building Web Applications, TypeScript Libraries, Wallets, Backends, Indexers, Scripts, and more, on top of Ethereum.

Nethereum is the .Net integration library for Ethereum, simplifying the access and smart contract interaction with Ethereum nodes both public like Geth (or your preferred client) L2 chains like Optimism, Arbitrum (or your preferred L2), any compatible EVM chain (Gnosis, etc) and permissioned chains like Quorum.

rust-libp2p is the reference Rust implementation of libp2p's modular peer-to-peer stack used by Magi on the OP Stack, Lighthouse, Forest, and many other projects that need composable transports, security, pubsub, and discovery primitives for decentralized networking.

Revm is a critical component in the Ethereum ecosystem used by builders, toolings, clients and chains.

The ethereumjs monorepo holds core JavaScript primitives for Ethereum, including transaction signing, an EVM implementation, RLP encoding, tries, and shared utilities. JavaScript builders import individual packages when they need protocol-level pieces rather than a full client library.

Safe Protocol Kit is the TypeScript SDK of safe-core-sdk for building, signing, and executing Safe multisignature transactions. Builders use it to drive Safe accounts from application or script code.

web3.swift from Argent is a Swift library covering Ethereum RPC calls, ABI encoding, and transaction signing. iOS and macOS builders use it to talk to Ethereum from native applications.

primitive-types provides the shared Rust U256, H160, and H256 types used across Ethereum and Substrate node and tooling codebases. Rust builders add it when their code has to carry Ethereum-sized integers and hashes.

A JavaScript library to construct Merkle Trees and verify proofs.

Delphereum is a web3 implementation for Delphi that lets Object Pascal desktop and mobile applications sign transactions and read contract state. It is the maintained route to Ethereum for builders working in that language.

Ethereumex is an Elixir JSON-RPC client for Ethereum and the transport layer that higher-level libraries such as Elixir Ethers build on. Elixir builders configure it by name even when they work through a higher-level library.

headlong is a Java library for encoding and decoding contract ABI calldata and RLP, tuned for throughput in JVM services. Java builders add it when a backend has to process a high volume of Ethereum calls.

hs-web3 is a Haskell library for talking to Ethereum nodes, with contract ABI code generation through Template Haskell. It is the route to Ethereum for builders working in Haskell.

rust-web3 is a Rust implementation of the web3 JSON-RPC client with pluggable transports. It predates Alloy and carries no deprecation notice.

web3dart is an Ethereum client library for Dart and Flutter covering JSON-RPC calls, contract bindings, and local transaction signing. Flutter builders use it as the general client for mobile applications.

safe-eth-py is the Python SDK from the Safe team for building, signing, and relaying Safe multisig transactions. Python builders use it to drive Safe accounts from backend code.

abitype provides strict TypeScript types and static inference for Ethereum ABIs, and it is the type layer under viem and wagmi. TypeScript builders import it when contract calls should be checked against the ABI at compile time.

ruint is a const-generic unsigned integer type for Rust that represents Ethereum's 256-bit words, and it sits under Alloy and Reth. Rust builders add it directly when they need fixed-width big integers.

essential-eth is a lightweight JavaScript client library that bundles to roughly a tenth of the size of ethers.js or web3.js. Builders install it when bundle size on the frontend is the constraint.

multicall.py is a Python client that batches many contract calls into a single Multicall aggregate call. Python builders install it to turn hundreds of reads into one RPC request.

ox is a low-level TypeScript library of Ethereum primitives covering ABI, RLP, hex, signing, and transactions, and it sits under viem and other wevm tools. Builders import it directly when they want the primitives without the client layer.

ethkit is a Go toolkit for building Ethereum applications from the team behind the Sequence JavaScript SDK. Go builders import it for wallet handling, ABI work, and RPC calls.

w3 is a modular Go JSON-RPC client for Ethereum with first-class ABI support and request batching. Go builders import it when contract calls should be typed and many requests sent in one batch.

Elixir Ethers is a library for calling and decoding Ethereum smart contracts from Elixir. Builders use it when the backend is written in Elixir, where options are few.

ethers-kt is an async Kotlin library for interacting with EVM chains, targeting the JVM and Android. Kotlin builders use it to read contracts and send transactions from server or mobile code.

Zabi is a Zig library for interacting with Ethereum and other EVM chains, providing JSON-RPC clients, ABI utilities, signers, and wallet primitives.

Multicaller from Vectorized is a collection of gas-optimized multicall-style contracts that batch arbitrary external calls while preserving the original msg.sender context for each callee, making complex router or aggregator flows cheaper and safer on EVM chains.

libethc is an open-source ethereum library for C/C++

Voltaire is a modern general-purpose Ethereum library for TypeScript, Zig, C, and Swift. Type-safe primitives, WASM-accelerated performance, and designed for AI-assisted development.

A lightweight bloom filter client which allows you to test ethereum blooms for fast checks of set membership.

ENSjs is the TypeScript library from ENS for resolving names and reading or writing ENS records, built on viem. Builders use it to show ENS names in place of addresses and to manage names from their own app. It works on Ethereum mainnet and Sepolia.

Curvegrid MultiBaas is a hosted control plane with REST APIs for deploying and operating multi-chain EVM backends when you want managed keys, indexing hooks, and dashboards without building all ops in-house.

Wagmi is a React hook layer on top of Viem for reading, writing, and caching Ethereum state in frontends without rebuilding wallet plumbing each project.

Impersonator.xyz lets developers connect to dapps through WalletConnect, an iframe shim, or a browser extension while masquerading as any address without holding private keys, which is ideal for QA teams that need to preview balances, capture calldata for Tenderly simulations, or regression-test wallet flows safely.

ant-design-web3 is a React component library from the Ant Design team for wallet connection and account interfaces. Builders drop it into a React application as an alternative to RainbowKit or ConnectKit.

Swiss-Knife aggregates all the useful EVM tools in one place to ease developer experience while they are debugging or building new stuff.

Nexth is a Next.js starter kit wired up with viem, wagmi, Sign-In with Ethereum, and Tailwind. Builders clone it to start from a working frontend rather than assembling the same pieces again.

Human Passport aggregates identity credentials, called Stamps, into one Unique Humanity Score per wallet, so projects can check that an address is a distinct person before an airdrop, grant round, vote or signup. Read scores from the REST API or drop in the Passport Embed React component.

thirdweb is a full stack, open-source web3 development platform with frontend, backend, and onchain tools to build complete web3 apps - on every EVM chain.

Alchemy's Modular Account is a maximally modular, upgradeable smart contract account that is compatible with ERC-4337 and ERC-6900. Alchemy's Modular Account most efficient smart account on the market with release of v2 released in feb 2025

EAS is an infrastructure public good for making attestations onchain or offchain about anything. Attestations are digital signatures on structured pieces of data used to build more trust online and onchain.

Coinbase Wallet SDK connects applications to Coinbase Wallet through the injected provider and the mobile WalletLink flow. Builders use it to support Coinbase Wallet users on web and mobile.

Reown AppKit, formerly Web3Modal and the WalletConnect SDK, is a wallet-connection SDK with a hosted relay, support for over 700 wallets, and embedded logins. Application builders use it to cover both external wallets and embedded sign-in from one integration.

Web3-Onboard is a framework-agnostic wallet-connection library supporting more than 35 wallets and the EIP-1193, 1102, 3085 and 3326 standards, started by Blocknative and now maintained by thirdweb. Builders install it when the frontend is not React or must cover many wallet providers.

ConnectKit provides React wallet-connection components built on wagmi. React builders drop it in when they want prebuilt connect buttons and modals for an application.

RainbowKit is a customizable React wallet-connection interface built on wagmi. React builders add it when an application needs a ready-made connect flow instead of wiring wallet selection by hand.

Web3Auth is an MPC and threshold key-management SDK that backs seedless wallets created from a social login. Builders use it when users should sign in with an existing account instead of a seed phrase.

Magic is an embedded non-custodial wallet SDK with email and social login and delegated key management. Builders integrate it to give users a wallet behind a familiar login flow.

Dynamic is an SDK covering wallet connection, embedded MPC wallets, and application authentication. Builders choose it when an application must serve both existing wallet users and new users who need one created.

Privy provides embedded wallet and authentication SDKs with configurable custody and signing permissions. Builders use it to create wallets during sign-up and support email, social, or passkey login.

ethr-did-resolver resolves decentralized identifiers anchored to Ethereum addresses. Applications that handle ethr identifiers install it to look up and manage those records.

React Native Passkeys exposes one WebAuthn-shaped passkey API across iOS, Android, and Web targets so you can reuse existing auth backends while shipping native mobile wallet or consumer apps.

mipd is a set of TypeScript utilities implementing EIP-6963 multi injected provider discovery for detecting installed browser wallets. Builders install it on its own when they need wallet discovery without pulling in wagmi.

MetaMask Connect is the SDK that connects web, mobile and game applications to the MetaMask wallet, replacing the deprecated MetaMask SDK with direct wallet communication and multichain support. Builders install the connect-evm package to reach MetaMask users from any frontend.

TypeScript library to sign and verify HTTP requests with Ethereum wallets using ERC-8128 (RFC 9421 HTTP Message Signatures extension), enabling wallet-based authentication and request integrity.

Variance_dart is a Dart SDK stack for passkey-first wallets, EIP-1271 signing flows, and ENSIP-15 normalization when you are shipping Flutter or mobile clients against EVM chains.

Passwordless Web3 authentication SDK with encrypted wallets and privacy features.

noble cryptography is a family of minimal-dependency TypeScript cryptographic libraries that prioritize readable source, signed releases, and transparent npm builds, and they underpin most modern JavaScript wallets including MetaMask, Rabby, Rainbow, and many SDKs across the ecosystem.

Trezor Connect is a JavaScript SDK for integrating Trezor hardware wallet signing, including Ethereum, into applications and wallets. Builders use it when users should sign with a Trezor device.

blst is a multilingual BLS12-381 signature library and the BLS implementation behind most Ethereum consensus clients. Builders link against it in Rust, C, or Go when writing validator or consensus tooling.

The Ledger hw-app-eth package is the JavaScript API for signing Ethereum transactions and messages with a Ledger device, and it sits behind the Ledger connectors in wagmi and viem. Wallet and application builders import it to add hardware wallet signing.

py_ecc is a Python library for elliptic curve pairing operations over bn128 and BLS12-381, used by py-evm and other Python tooling. Builders import it for precompile or BLS work in Python.

eth-crypto is a set of JavaScript helpers for signing, verifying, recovering addresses, and ECIES encryption alongside ethers or web3. Builders import it for one-off cryptographic steps that the client libraries do not expose directly.

mcl from herumi is a portable pairing-based cryptography library used for BLS signature operations by several Ethereum consensus clients. Builders link against it for BLS work in C++ or Go.

noble secp256k1 is a standalone pure JavaScript library for secp256k1 signing and ECDH, used by many wallets and libraries. Builders install it on its own when they need signing without the wider noble curves package.

js-ethereum-cryptography is an audited JavaScript package bundling the hashing and curve primitives that tooling such as ethers.js and web3.js builds on. Builders install it directly when they need keccak, secp256k1, or BIP-39 work without a full client library.

k256 from RustCrypto is a pure Rust secp256k1 implementation covering ECDSA signing, verification, public key recovery, Schnorr, and ECDH, and it sits under reth, Alloy, and most Rust tooling. Rust builders depend on it directly when they handle signatures themselves.

Web3Signer is a remote signing service that keeps keys in a vault or hardware security module. Node and validator operators run it so signing happens outside the client process.

c-kzg-4844 is the reference C implementation, with Rust bindings, of the KZG polynomial commitment scheme used for EIP-4844 and EIP-7594 blobs, and it is embedded in most execution and consensus clients. Rollup and blob tooling imports the bindings to produce KZG commitments and proofs.

The OKX js-wallet-sdk is a TypeScript signature SDK covering Bitcoin, Ethereum, Solana, Cosmos, and other chains. Builders install it to derive keys and sign transactions for several chains through one API.

Turnkey offers an API and SDK for secure key generation and transaction signing backed by trusted execution environments. Builders use it to create and operate wallet infrastructure without holding raw private keys in their own code.

The Fireblocks SDK connects applications to Fireblocks' MPC wallet infrastructure for signing, transfers, and treasury operations. Builders use it to automate transactions and approval policies for wallets managed through Fireblocks.

eth-keys is a Python library for secp256k1 keys and signatures, and it sits under eth-account and web3.py. Python builders import it when they need key and signature operations directly.

micro-eth-signer is a minimal JavaScript library for building and signing Ethereum transactions, built on the audited noble cryptography libraries by the same author. Builders install it when a small signing dependency matters more than a full client library.

coins-bip32 is a Rust library for BIP-32 hierarchical deterministic key derivation, used by ethers-rs and other Rust wallets and signers. Rust builders add it when an application derives keys from a seed.

eciesjs implements the Elliptic Curve Integrated Encryption Scheme for secp256k1 in JavaScript. Builders import it to encrypt and decrypt data against an Ethereum-style keypair.

keypo is a local-first command line tool for hardware-bound key management and encrypted secret storage, aimed at AI agents that hold credentials. It installs from a Homebrew tap on macOS.

Lit Protocol is a decentralized network for threshold key management with programmable signing through its programmable key pairs. Builders use its SDK when signing or decryption should follow rules enforced by a network rather than a single key holder.

The eth-infinitism account-abstraction repository holds the reference ERC-4337 contracts, including SimpleAccount, plus a TypeScript SDK from the authors of the specification. Builders use it as the baseline implementation when creating ERC-4337 accounts.

Alchemy aa-sdk, shipped as Account Kit, is a full-stack smart wallet SDK with embedded wallets and a gas manager. Application builders use it to give users an account and sponsored transactions without a separate wallet app.

Rundler is Alchemy's modular Rust ERC-4337 bundler aimed at horizontally scaled deployments; many Ethereum user-operation workloads run on it today.

Coinbase Smart Wallet is a passkey-based smart account with the largest share of deployed wallets. Application builders integrate it so users sign with a passkey instead of managing a seed phrase.

Skandha is Etherspot's TypeScript ERC-4337 bundler that optimizes user operation submission, gas accounting, and mempool routing with optional MEV protections and shared mempool compatibility, and Etherspot runs that shared mempool stack in production.

Openfort is an embedded wallet SDK with authentication, ERC-4337 smart accounts, and self-hostable key management. Builders use it to give users a wallet inside the application without a separate wallet install.

Gelato is a hosted network that provides a bundler, paymaster and relay for smart accounts together with Web3 Functions for scheduled and event-driven contract execution. Builders use it to run gasless transactions and contract automation without operating those services themselves.

Particle Network is a hosted wallet-abstraction stack that bundles a bundler, paymaster, and social login. Builders choose it when they want account creation, login, and transaction sponsorship from one service.

Sequence, published as 0xsequence, is a smart-contract wallet SDK with embedded wallets, a relayer, an indexer, and gasless transactions. Builders use it when a game or application needs wallets and transaction plumbing from one stack.

The MetaMask Delegation Framework, known as Gator, is a set of contracts that let one account grant specific revocable permissions to another account or agent along the lines of ERC-7715 and ERC-7710. Teams building delegated or agent-controlled permissions import these contracts and write their own caveat enforcers against them.

permissionless.js from Pimlico is a vendor-neutral TypeScript library built on viem for ERC-4337 accounts. TypeScript builders use it to assemble and submit user operations while keeping the choice of bundler and paymaster open.

Base Account SDK is Coinbase's package for Base Account, a smart-contract wallet with passkey signing and gasless transactions. Web builders install it to add passkey sign-in and sponsored transactions, separate from the older Coinbase Wallet SDK.

Ithaca Account is the set of EIP-7702 smart account contracts behind Porto, an account standard for web authentication and payments. Teams picking an EIP-7702 implementation can read, fork, or deploy these contracts.

The Safe 4337 module adds native ERC-4337 support to Safe multisig accounts. Safe builders install it so an existing multisig can be driven by user operations through a bundler.

Alto is a TypeScript ERC-4337 bundler from Pimlico that also runs behind their hosted service. Infrastructure builders run it themselves when they need to operate a bundler instead of relying on a third party.

Ability to call many ethereum constant function calls in 1 JSONRPC request

Kernel from ZeroDev is a modular ERC-7579 smart-account contract with wide deployment. Wallet builders deploy it when an account needs pluggable validators and executors.

A set of lightweight, open sourced, audited and gas-optimized ERC-4337 compatible smart contract accounts with designated ownership

The ZeroDev SDK is a smart-account SDK for the Kernel account with modular validators and session keys. Account-abstraction builders use it to create Kernel accounts and delegate limited signing rights to sessions.

Nexus from Biconomy is a modular ERC-7579 smart-account contract aimed at high-volume applications. Wallet builders deploy it as the account implementation behind their smart wallets.

Voltaire is an ERC-4337 bundler implementation you can run when you need configurable user-operation relaying for account-abstraction wallets.

Arka is the open-source paymaster service from Etherspot for sponsoring transaction gas. Builders self-host it when gas sponsorship for ERC-4337 accounts should run on their own infrastructure.

executooor centers on a reusable executor contract pattern so scripts can chain delegate calls, token approvals, and atomic onchain steps through viem or ethers without redeploying bespoke routers each time.

AbstractionKit is a TypeScript helper library for wiring ERC-4337 flows-user operations, paymasters, and bundler calls-without implementing the wire protocol from scratch.

safe7579 from Rhinestone is an adapter that makes Safe accounts ERC-7579 compliant. Builders add it when they want portable ERC-7579 modules to run on a Safe, usually alongside the Safe 4337 module.

Rhinestone SDK, the successor Rhinestone names for its retired ModuleKit, adds smart wallets with passkeys, session keys and multichain transactions to an application. Builders use it when users should pay, swap or call contracts on one chain with funds from another.

The Biconomy SDK, published as AbstractJS for the Nexus account, builds ERC-4337 smart accounts with paymaster and bundler services. Builders use it when an application needs sponsored or gasless transactions.

x402 is an open payments protocol built on the HTTP 402 status code that lets an application or agent pay per request in stablecoins without accounts or API keys. Builders add its middleware to a service to charge per call, or to a client so it can pay.

Request Network is a protocol and JavaScript library for creating, paying, and tracking crypto invoices and payment requests onchain. Builders install the client library to add invoicing to their own application.

0x provides hosted APIs for trading tokens from apps and wallets. Swap API aggregates prices from 150+ liquidity providers and returns an unsigned transaction to sign and submit, Gasless API relays gasless approvals and swaps, and Cross-Chain API returns routes across bridge providers with ready-to-sign transactions.

AaveKit is Aave's SDK, a TypeScript client and React hooks over the Aave GraphQL API. Builders use it to read markets and user positions and to build supply, borrow, repay and swap transactions without calling the contracts by hand. Aave v3 and v4 are served by separate SDK versions of the same packages (0.x for v3, 4.0 and later for v4).

Agent Commerce Gateway is a self-hosted, non-custodial gateway that puts an existing HTTP API in front of AI agents, exposing its endpoints over HTTP or MCP and charging for them with x402 or experimental MPP payments. Paid calls settle in USDC on EVM networks such as Base through EIP-3009 transferWithAuthorization, straight to the merchant wallet, so builders can charge agents per request without adding payment code to their backend.

Crossmint offers stablecoin APIs aimed at enterprises, including cross-chain flows. Builders use it to add stablecoin payments to an application without building the payment rails.

eth-prices is a Rust crate that estimates the price of an Ethereum asset by reading Uniswap V2 and V3 pools and ERC-4626 vaults through an RPC provider, with no exchange rate API involved. Rust builders add it when a price should be derived from onchain liquidity rather than read from an oracle feed.

The Peer SDK (formerly ZKP2P) adds a fiat-to-crypto onramp to an app, where users pay through services like Venmo, Revolut or Wise and receive tokens onchain. It also manages seller deposits and liquidity. The protocol runs on Base.

The Splits SDK is a viem-based TypeScript library for creating and managing 0xSplits contracts, which share incoming payments between several recipients. It also covers waterfalls, swappers and vesting, and a React wrapper ships as a separate package.

Stripe Crypto Onramp is an embeddable fiat-to-crypto onramp SDK for web, iOS, Android, and React Native that delivers purchased crypto to a user's wallet. Builders embed it so users can fund a wallet with a card instead of transferring in.

web3-ethereum-defi is a Python library for DeFi integration and data research, with wrappers for Uniswap, Aave, Chainlink, and USDC on top of web3.py. Python builders import it instead of writing those protocol wrappers themselves.

The Machine Payments Protocol SDK, published as mppx by the wevm team behind viem and wagmi, is a TypeScript implementation of an agent payments specification. Builders install it to let a service or agent pay and charge programmatically.

The Lido Ethereum SDK is the official package for staking and managing stETH and wstETH through the Lido protocol. Builders install it to add staking to an application without writing the Lido contract calls by hand.

Snapshot began as gasless off-chain governance for DAOs with flexible voting strategies and validation plugins, and the team later launched Snapshot X, a modular onchain voting stack that keeps execution trust-minimized while still minimizing gas through clever proving and cross-chain voting power accounting.

Aragon OSx is onchain DAO framework infrastructure for launching modular organizations that govern treasuries and protocol parameters with audited contract primitives.

Agora is an onchain governance application used by protocols including Optimism, ENS, and Uniswap to run delegate voting. It is a Next.js application a DAO deploys rather than a library a builder imports.

DAOhaus offers open-source tooling for launching and operating DAOs with modular contracts, apps, and community governance workflows.