Builder resources

The smart contract development tool for Pythonistas, Data Scientists, and Security Professionals

Scaffold-ETH 2 is a Next.js plus Hardhat or Foundry starter with wallet hooks, hot contract reload, local faucet utilities, and extension modules for full-stack dapp deployment.

A Python-based development and testing framework for smart contracts targeting the Ethereum Virtual Machine.

A rich and accessible Web3 toolset for learning, building, and testing on multiple chains

Moccasin is Cyfrin's Python-first workflow on Titanoboa for testing, fuzzing, and deploying Vyper written smart contracts.

slang from the Nomic Foundation is a modular Solidity compiler frontend with a parser, concrete syntax tree, and bindings. Builders import it when writing a linter, formatter, or other tool that has to understand Solidity source.

BuildBear is a hosted service that spins up a private testnet sandbox mirroring a real chain such as Ethereum, Polygon, BSC, or Arbitrum. Builders point tests at it to work against a private fork with real chain state.

Huff is a low-level assembly language and compiler for writing hand-optimized EVM bytecode, with development continuing in huff2. Builders reach for it when bytecode has to be tuned by hand.

py-solc-x is a Python wrapper and version manager for the solc Solidity compiler, used by Brownie and Ape style test suites. Python builders install it to fetch and switch compiler versions from their own scripts.

Wake is a Python framework for testing, fuzzing, and static analysis of Solidity projects. Builders reach for it when they want to write contract tests and fuzzing campaigns in Python and run analysis over the same codebase.

The Stylus SDK is the Rust SDK for writing smart contracts that run in Arbitrum's Stylus environment alongside the EVM. Rust builders use it when contract logic should be written in Rust rather than Solidity.

Hardhat is a development environment to build and deploy your Ethereum software

Foundry is a fast, portable Rust toolchain for Ethereum smart contract engineering that manages dependencies, compiles Solidity, runs fuzz and unit tests, deploys contracts, and drives scripted chain interaction from the terminal or Solidity automation scripts.

Kurtosis packages reproducible multi-service devnets so you can spin up realistic Ethereum or rollup stacks for integration tests faster than hand-maintained compose files.

CreateX is pcaversaccio's trustless universal deployer that wraps CREATE, CREATE2, and CREATE3-style flows so teams can launch contracts from predictable addresses without bespoke factory code.

Hardhat plugin to deploy your smart contracts across multiple EVM chains with the same deterministic address. A total of 133 EVM chains are currently supported, including (almost) all OP-stack-powered chains.

Create2Deployer is a minimal factory contract from pcaversaccio that wraps the CREATE2 opcode with safety checks so teams can deploy counterfactual contracts at deterministic addresses.

Txtx turns the stress, pain and tears of Smart Contract Infrastructure management by introducing Crypto Infrastructure as Code. Runbooks are the blueprint for Engineering Excellence, setting the new standard for Web3 Infrastructures.

Chainlink Faucets dispense testnet ETH and LINK across the supported test networks. Builders use them to fund an account before deploying and testing contracts on a testnet.

Decker is a TypeScript CLI for creating configurable local Ethereum devnets with execution and consensus clients, relays, and block builders. Teams use its recipes for integration tests and infrastructure development.

ethereal is a Go command line tool for everyday Ethereum tasks, including sending transactions, managing ENS records, transferring tokens, and inspecting accounts. Builders install it for one-off operations that do not justify a script.

ethereum-genesis-generator creates execution and consensus layer genesis state for a testnet and serves it over a web server. Devnet and rollup teams run it to produce the genesis files for a custom network.

EthPillar is a setup script and terminal interface for installing and managing an Ethereum staking node with execution, consensus and MEV-Boost clients. Solo stakers run it to stand up a node without editing client configuration by hand.

foundry-toolchain is the official GitHub Action that installs Foundry in continuous integration. Builders add it to a workflow so forge test and forge script run on every pull request.

Immunefi is a bug bounty platform where projects post rewards for whitehats who find and responsibly disclose contract vulnerabilities. Teams list a program there to give researchers a paid route to report issues.

PoWFaucet is a modular testnet faucet for EVM chains with anti-abuse methods including a mining puzzle, captcha, IP limits, and Gitcoin Passport, and it backs the Sepolia proof-of-work faucet. Teams running a testnet self-host it to hand out test ETH without giving it all to one address.

Rocket Pool Smart Node is the command line package node operators run to set up and manage a Rocket Pool minipool, wrapping execution and consensus clients plus validator duties.

rocketh is a deployment and test harness for Ethereum contracts built around viem, keeping one record of deployments per network so scripts and tests agree. Builders use it when they want repeatable deployments without Hardhat, which the hardhat-deploy plugin wraps over the same code.

Sedge is a command line setup tool from Nethermind that generates docker-compose configurations for execution, consensus, and validator client combinations. Builders run it to get a working node setup without writing the compose files.

Cannon is a DevOps tool for protocols on Ethereum. It manages smart contract deployment and configuration for local development and live networks.

hardhat-deploy is a Hardhat plugin for replicable deployments with named accounts, proxies, and diamonds. Builders install it when deployments must be repeatable across networks and track upgradeable contracts.

DAppNode is an operating system with an app store for running Ethereum execution and consensus clients and other node software on your own hardware. Someone setting up a home node installs it and picks client packages instead of configuring each service by hand.

eth-docker is a Dockerized stack for deploying and managing execution, consensus, and validator clients on mainnet. Node operators use it to run a full node setup from configuration files instead of hand-installed binaries.

ethereum-helm-charts are Helm charts from ethPandaOps for running Ethereum execution and consensus clients and related infrastructure on Kubernetes. Teams add them to a cluster rather than writing client manifests themselves.

The Kurtosis ethereum-package spins up reproducible multi-client Ethereum devnets, including mev-boost and supporting tooling. Builders run it when they need a local network that mirrors a real client mix.

simple-optimism-node is a one-command Docker setup for running an OP Stack node. Builders run it to get their own Optimism node, in the same way eth-docker covers mainnet clients.

OpenZeppelin Contracts are the go-to library for smart contract development.

Solidity is an object-oriented, high-level language for implementing smart contracts.

Pythonic Smart Contract Language for the EVM

Solidity-Oriented Development Tooling

Solady by Vectorized collects aggressively optimized Solidity snippets from Merkle proofs to compression helpers, wrapping careful inline assembly in approachable APIs so advanced developers can ship gas-efficient patterns while learning cutting-edge optimization techniques from a living reference library.

Fe is a Rust-inspired language targeting the EVM; today you can explore Fe v2's type system via CLI or editor tooling even while bytecode generation is still evolving.

Solhint is a Solidity linter you wire into editors or CI to enforce style rules and catch footgun patterns early.

Juan Blanco's VS Code Solidity extension adds syntax highlighting, compile commands, hover metadata, quick fixes, monorepo detection, optional Nethereum codegen, lint integration, and an LSP server.

WhatsABI recovers selectors, proxies, and partial ABIs from bytecode alone-use it in wallets, explorers, or local tools when verified source is missing but you still need calldata decoding.

Solidity plugin for IntelliJ

PRBMath is a smart contract library that adds support for fixed-point types and advanced math functions like logarithms and exponentials in Solidity. Operating with 18-decimal numbers, PRBMath is at the same time gas efficient and user-friendly.

Solc-select is a command line utility for quickly installing and switching between Solidity compiler versions.

A Prettier plugin for automatically formatting your Solidity code.

State-of-the-art, highly opinionated, hyper-optimised, and secureVyper smart contract building blocks.

Solidity Bytes Utils is a classic library for concatenating, slicing, and casting dynamic bytes arrays in Solidity memory or storage-long maintained and widely forked across major protocols.

ABDKMath64x64 is a Solidity library for 64.64-bit binary fixed-point math. Builders import it when a contract needs fixed-point arithmetic that Solidity does not provide natively.

ERC721A is a gas-optimized ERC-721 implementation with cheap consecutive batch minting. Builders import it when an NFT contract mints several tokens to the same address at once and minting cost matters.

ERC721A-Upgradeable is the proxy-upgradeable variant of the ERC721A implementation. Builders import it when a proxy-based NFT contract needs the batch minting design of ERC721A.

Multicall3 is the canonical contract for batching many reads or writes into a single transaction. Builders call it from contracts and scripts to fetch or update state across several contracts in one round trip.

Safe Smart Account is the widely deployed set of modular multisig smart-account contracts behind Safe. Wallet and treasury builders deploy or extend it to add multisignature control and account modules.

SolidState Solidity is an upgradeable-first contract library built around the diamond pattern of EIP-2535. Teams import it when contracts are organized as diamond facets from the start.

Solmate is a modern, opinionated collection of gas-optimized Solidity building blocks and utilities for smart contract development.

A gas-efficient Solidity compiler for Ethereum powered by LLVM from the ZKsync team and collaborators. Works as a drop-in replacement for solc in workflows like Foundry and Hardhat.

weiroll is an operation-chaining scripting language and set of contracts for composing many EVM calls into one transaction. Teams building call-routing or batching systems use it to express the call sequence as a script.

Diamondscaffold is a CLI tool designed to scaffold EIP-2535 diamond projects with an opinionated layout and scripts, making it faster to stand up modular upgradeable proxies.

Blazingly fast, modular Solidity compiler written in Rust by Paradigm. Designed as a contributor-friendly compiler stack for faster builds and better diagnostics.

solidity-docgen generates Markdown documentation for a Solidity project from its NatSpec comments. Teams run it so published docs stay in step with the contract source.

ZK Email provides circuits and SDKs for proving facts about redacted email transcripts onchain. Useful when you want privacy-preserving identity or receipt checks without doxxing inboxes.

Self Protocol provides open identity and proof primitives builders can embed when they need privacy-preserving verification flows tied to wallets or credentials.

zkTLS / TLSNotary is an open protocol for proving properties of TLS sessions with MPC so verifiers can trust transcripts without seeing full plaintext.

Tools for building privacy-preserving applications using Indian government Aadhaar ID cards. Provides ZK circuits, TypeScript, Solidity, and React libraries to enable Aadhaar holders to prove residency without revealing personal data.

Circom is a domain-specific language and compiler for writing and compiling arithmetic circuits used in zero-knowledge proof systems.

gnark-crypto provides elliptic curve and pairing cryptography for BN, BLS12, BLS24, and BW6 curves, and it is the backend of the gnark SNARK library. Go builders import it directly for curve and pairing math.

PSE's re-architected fork of Zcash's Halo2 PLONK proof system, featuring a KZG backend with Solidity verifier for economical L1 verification, support for multiple elliptic curves, and decoupled frontend/backend architecture.

MACI (Minimal Anti-Collusion Infrastructure) uses zero-knowledge proofs to enable collusion-resistant, private voting and signaling systems on Ethereum.

A toolkit that makes client-side zero-knowledge proving on mobile simple. Connects ZK proof systems (Halo2, Circom) to generate iOS, Android, and browser bindings, leveraging mobile GPU for improved performance.

A toolkit for Groth16 Phase 2 Trusted Setup ceremonies. Helps developers create and manage trusted setups for ZK applications, with a companion webapp (DefinitelySetup) for monitoring and participation.

An ongoing (since 2019) zk-SNARK trusted setup ceremony for circuits up to 2^28 constraints, generating 530M+ powers of tau. A multi-party ceremony where security holds as long as one participant is honest.

Semaphore is a zero-knowledge protocol for private group membership proofs, enabling anonymous signaling and authentication without revealing identity.

snarkjs is a JavaScript and CLI toolkit for generating and verifying zkSNARK proofs, and for running common proving workflows in Node.js and the browser.

A modular folding library supporting multiple folding schemes (Nova, HyperNova, ProtoGalaxy, CycleFold) and decider backends (Groth16, KZG) for Incremental Verifiable Computation. Supports Arkworks, Circom, Noir, and Noname frontends.

Private identity verification using zero-knowledge proofs. Verify age, country, or proof of personhood without revealing any personal information. Mobile-first design with SDK for integration and onchain registry contracts.

arkworks algebra is a set of Rust libraries for finite field, elliptic curve, and polynomial arithmetic, and it is the math layer under many SNARK and STARK toolchains. Rust builders add the ark crates when writing proving code from the ground up.

SP1 from Succinct is a zero-knowledge virtual machine that proves correct execution of RISC-V programs, and it is used to generate proofs for rollups and bridges. Teams compile a Rust program with it when a proof must stand in for re-executing that program onchain.

Lambdaworks is a Rust library of SNARK and STARK prover components that can be used piecemeal or assembled into a custom proving system. Teams pull its crates when building their own prover rather than adopting a finished one.

op-succinct is a proving engine that generates SP1 validity proofs for OP Stack rollups. Rollup teams deploy it to turn an OP Stack chain into a validity proof rollup, running it as a separate service.

Plonky3 is a toolkit of polynomial IOP building blocks for constructing custom SNARK and STARK proving systems, and several zkVM projects build on it. Rust builders add the p3 crates when writing their own proving system.

powdr is a toolkit for accelerating and hardening zkVMs by moving specific computations into custom circuits. Teams running a zkVM use it to generate custom precompiles and check constraints, and its authors still describe the code as experimental.

risc0-ethereum holds the integration libraries and verifier contracts for using the RISC Zero zkVM with Ethereum and other EVM chains. Teams proving computation off chain import these crates to settle the resulting proofs onchain.

rsp from Succinct generates zero-knowledge proofs of Ethereum and OP Stack block execution, built on Reth. Its authors describe it as a minimal work in progress that is not meant for production, so it mainly serves teams already building on SP1.

snark-verifier generates gas-efficient onchain verifiers for halo2 SNARKs and is maintained by Axiom, forked from the original PSE repository. halo2 developers import the crate to produce the Solidity verifier that checks their proofs onchain.

A monorepo of reusable zero-knowledge libraries across multiple languages (JavaScript, Solidity, Rust, Noir), offering well-tested implementations of cryptographic primitives like Merkle trees, Poseidon hash, and more.

CodeTracer is a user-friendly time-traveling debugger designed to support a wide range of web3 programming languages.

EDB is a source-level debugger for Solidity execution with stepping, locals, watches, and breakpoints when you need IDE-grade visibility into contract behavior onchain or in tests.

Simbolik is a powerful Solidity debugger that combines traditional breakpoint debugging with symbolic execution, enabling developers to explore every possible execution path and uncover vulnerabilities with precision. Available as a VSCode extension, Simbolik integrates seamlessly into existing workflows, offering breakpoint-style debugging, Solidity and EVM-level inspection, and formal verification capabilities.

Abi Ninja is a browser UI for calling contracts with known ABIs, pasted ABIs, or decompiled bytecode, with proxy-aware reads across many networks including your locally running Hardhat or Anvil node.

4byte.directory maps four-byte function selectors and 32-byte event-signature hashes to their human-readable signatures. Builders query it when decoding calldata or logs from contracts without a published ABI.

The ABI Calldata Layout Visualizer decodes ABI calldata and draws its byte layout, showing where heads, tails, and offsets sit in the encoded payload. Builders open it when a plain decoder does not explain why an encoding is wrong.

evm-storage turns a transaction hash into readable state diffs and can list a contract's full storage. Builders install the command line tool when they need to see exactly which storage slots a call changed.

EVMConnector is a browser workspace for calling contract functions on any EVM chain, with saved contracts and shareable call links. Builders use it to drive a contract without writing a script.

forky is a fork choice viewer for the Ethereum beacon chain. Consensus client developers self-host it or use the public instances to see and debug fork choice behavior on mainnet and testnets.

geas, the Good Ethereum Assembler, is an assembler for writing raw EVM bytecode by hand, maintained by a go-ethereum core developer. It is used for EIP test cases and other low-level contract work.

hardhat-tracer is a Hardhat plugin that prints internal calls, events, and storage operations for a transaction in the console. Hardhat users install it to see what actually happened inside a failing test transaction.

The HashEx ABI Encoder is a web form that ABI-encodes constructor and function arguments from a pasted signature and values. Builders use it when they need encoded arguments and are not at a terminal.

heimdall-rs is a Rust EVM toolkit that disassembles bytecode, decompiles contracts, generates control flow graphs, and decodes calldata and traces. Builders reach for it when they need to understand a contract that has no published source.

pyevmasm is a Python disassembler and assembler for EVM bytecode from Trail of Bits. Analysis scripts import it to turn bytecode into instructions and back.

Radar, from Auditware, is a static analysis tool that covers Solidity as well as Rust, Anchor, and Stylus contracts. Auditors run it to get findings across a mixed contract codebase.

A calldata decoder that also unwraps nested function calls. Builders open it when a flat decoder leaves the inner calls of a batched or forwarded transaction unreadable.

scopelint is an opinionated formatter and linter for Foundry Solidity projects. Builders install it to hold a codebase to the ScopeLift conventions.

Semgrep is a pattern-based static analysis tool with rulesets for Solidity vulnerabilities. Builders run those rules over a codebase to catch known vulnerable patterns and style issues before review.

SmartContractGUI turns an uploaded ABI into an interface for reading from and writing to that contract on any EVM chain. Builders use it when they have an ABI but no frontend.

sol-profiler is a command line tool that lists a Solidity contract's methods with their visibility, mutability and modifiers. Reviewers run it to see the surface of a contract at a glance.

sol2uml generates UML class and storage-layout diagrams from Solidity source or from verified contracts. Builders run it to see contract relationships and how state variables are packed into storage.

Tenderly provides transaction simulation, trace debugging, alerting, and Virtual TestNets for contracts. Builders use it to replay a failing transaction, watch deployed contracts, and test against a forked network.

The Tenderly CLI is the command line client for Tenderly, pushing contracts for verification and driving error tracking, monitoring, and alerting. Builders install it to run those steps from a terminal or a continuous integration job.

tracoor is an explorer for beacon states and execution traces. Client and protocol developers self-host it to inspect block and state traces on devnets and testnets.

Web3Client is a browser tool for creating, testing, and sharing contract ABIs and the calls made against them. Builders use it to work out a call and hand the result to someone else.

Web-based transaction debugger and simulator for the EVM. Open-source and self-hostable. Inspect variable states at every step, simulate transactions before deploying, and profile gas usage. Supports any RPC provider.

viem-tracer augments a Viem client so failed ethestimateGas and ethsendTransaction calls automatically include human-readable trace output decoded with sourcify.dev, and it adds typed helpers around debug_traceCall so developers can inspect execution without leaving their existing RPC stack.

EVMole extracts function selectors, arguments, and control flow from raw EVM bytecode, including contracts with no verified source. Builders point it at an unknown contract to work out what its functions take.

revm-inspectors is a Rust crate of EVM execution hooks and tracing built on revm, and it powers call tracing in Reth and Foundry. Rust builders import it to build their own tracers and debuggers.

A hardhat plugin that provides gas usage analytics for smart contract test suites. It has dedicated support for OPStack chains, is a dependency in > 150k Github repos and is downloaded from NPM > 100k per week.

Slippy is a Solidity linter for static analysis of smart contracts. Teams install the npm package to lint contracts as part of a build.

Chimera is a framework to write Solidity tests in foundry and be able to reuse them with other Open Source Tools such as Echidna, Medusa, Halmos and Kontrol

Slither is Trail of Bits' Python static analysis engine for Solidity and Vyper: run it in CI to fire detectors, print structural views of contracts, or script custom checks over whole codebases.

Synpress layers Playwright with Ethereum-aware browser automation so you can end-to-end test dapps, including wallet popups and chain switches, in CI.

Aderyn is Cyfrin's open-source, Rust-based solidity smart contract static analyzer designed to help protocol engineers and security researchers find vulnerabilities in Solidity code bases

Medusa is a stateful smart contract fuzzer inspired by Echidna. It provides parallelized fuzz testing of smart contracts and the verification of advanced smart contract invariants.

Titanoboa is an interactive Vyper interpreter and test harness for fast feedback loops when you are experimenting with contracts outside a full Foundry loop.

solidity-coverage provides smart-contract code coverage for the Hardhat developer platform. It's highly accurate, supports full viaIR solidity compilation and a large set of solidity-specific code branch patterns. It's installed on ~230k Github projects and is downloaded ~100k times a week from NPM.

hevm is an open source, state-of-the art, fast symbolic and concrete EVM execution engine that can find issues in smart contracts. Through its symbolic execution and analysis system, hevm can symbolically, semi-concretely, or concretely execute contracts to find bugs, or compare two different contracts for discrepancies, performing equivalence checking.

Crytic-Properties is a suite of re-usable security tests for some of the most widely used token standards such as ERC20, ERC721, ERC4626, and more.

A smart contract test generator based on the Branching Tree Technique.

Assertoor runs configurable checks and assertions against a live Ethereum devnet to validate its behavior. Client and devnet teams use it to confirm a running network is healthy, in the same family as Hive.

contender from Flashbots is a load-testing tool that floods EVM execution nodes over JSON-RPC and benchmarks the results. Teams benchmarking a client point it at an endpoint to generate load and measure throughput.

Echidna is a property-based and grammar fuzzer for Ethereum smart contracts. Builders and auditors write properties with it to find inputs that break contract invariants.

eth-tester is a pluggable in-memory Ethereum backend used by web3.py for fast unit tests. Python builders import it when tests should run against a simulated chain instead of a node.

ItyFuzz is a bytecode-level smart-contract fuzzer that combines fuzzing with symbolic analysis. Builders and auditors run it against EVM bytecode when source-level fuzzing is not enough or no source is available.

spamoor is a configurable Ethereum transaction generator for load-testing testnets and devnets with realistic traffic. Teams point it at a network to see how it behaves under sustained transaction volume.

goevmlab is an EVM fuzzing and differential testing lab built by a go-ethereum core developer. EVM implementers use it to fuzz their own implementation and compare its behavior against others to find divergences.

Hive is an end-to-end integration test harness that runs Ethereum clients in Docker across simulator scenarios. Client teams use it to check that implementations agree with each other.

KEVM is the K-framework executable semantics of the EVM: point it at bytecode when you need conformance-checked execution, symbolic exploration, gas reasoning, or proofs that track Ethereum's rules closely.

hax is a tool for high assurance translations of a large subset of Rust into formal languages such as F* or Rocq.

Kontrol lifts Foundry property tests into KEVM-backed proofs so you can chase formal guarantees with less hand-written specification work than raw KEVM alone.

Act is Ethereum's declarative specification language and toolchain for describing all behaviors of an EVM program so SMT solvers, theorem provers, or economic analysis tools can reason about bytecode-level correctness and incentive compatibility, including automatic refinement proofs against concrete implementations.

Certora AutoProver is an AI bot that automates parts of formal verification for smart contracts. Verification engineers use it to generate and run checks with less manual specification work.

Verifereum connects Ethereum smart contracts to HOL4-backed theorem proving so you can aim at very strong correctness claims when automated SMT approaches are not enough.

Certora Prover is a cloud formal-verification service that checks specifications written in CVL against deployed contract code. Verification engineers use it to prove that a contract holds stated properties for all inputs.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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

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.

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.

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.

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.

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.

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.

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++

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.

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

Automate your smart contracts using Automate SDK

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.

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.

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.

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.

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.

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

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.

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.

OnchainKit is a set of React components from Coinbase for wallets, transactions, identity, and other onchain interfaces. React builders use it to assemble an onchain frontend from prebuilt pieces.

One Click Dapp generates a hosted web interface for a deployed contract from its ABI and address. Builders use it to give a contract a usable interface without writing frontend code.

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.

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.

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.

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.

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.

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

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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 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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

With this setup, ecosystems can deploy tailor-made 4337 chain abstraction infrastructure. They become Liquidity Providers (LPs) for their users, sharing with them the value that would otherwise have been captured by solvers/fillers.

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

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.

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

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Rhinestone ModuleKit is a Solidity framework for building and testing ERC-7579 modules. Builders use it when writing validators, executors, or hooks for modular smart accounts.

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.

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.

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 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.

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

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

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.

Gelato Relay SDK wraps Gelato's relayers so frontends can submit meta-transactions, sponsored gas flows, or scheduled calls without operating your own bundler fleet.

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.

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.

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.

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 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.

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.

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.

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.

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.

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.

Alloy is a set of libraries that provides types and RPC client implementations for Ethereum.

Peer-to-Peer Databases for the Decentralized Web

go-libp2p is the canonical Go implementation of libp2p, packaging transports, identify, DHT, and GossipSub modules relied on by Prysm, Lotus, Celestia, and other large-scale clients that need production-grade peer discovery and messaging.

js-libp2p is the JavaScript implementation of libp2p transports, security, pubsub, and discovery-used by Farcaster hubs, Lodestar-related tooling, and other off-chain coordination stacks.

eRPC sits in front of your RPC providers to add caching, failover, and routing tuned for read-heavy workloads like dashboards, indexers, and multi-tenant backends.

An Ethereum Node built to run in Browser, Bun, Deno, and Node.js

1RPC from Automata Network is a privacy-preserving public RPC endpoint for Ethereum and other EVM chains. Builders point an application at it when request metadata should not be tied back to users.

Alchemy is a developer platform for building Ethereum and EVM applications with node infrastructure, APIs, and SDKs.

All That Node is a multi-chain node-as-a-service platform offering shared and dedicated Ethereum RPC nodes. Builders sign up for an endpoint instead of running their own node.

Ankr offers free public and paid RPC endpoints across many chains. Builders point applications at Ankr for hosted chain access without operating their own nodes.

Blockdaemon runs enterprise node infrastructure together with staking systems and RPC APIs. Infrastructure teams use it when node operation and staking are outsourced under an enterprise agreement.

BlockPI Network is a hosted RPC service for Ethereum and more than 70 other chains, with shared and dedicated node tiers. Builders use it for chain access without operating infrastructure.

Chainnodes provides RPC and node infrastructure for Ethereum and the major layer 2 networks, including archival endpoints. Builders buy endpoints there when an application needs historical state as well as current data.

Chainstack provides managed node and RPC infrastructure with global request routing. Builders use it when an application needs dedicated nodes and endpoints served close to its users.

dRPC is a hosted RPC service that spreads JSON-RPC, WebSocket, and REST traffic across independent node providers on Ethereum, its L2s, and 200+ other networks. It covers archive data, MEV-protected transaction endpoints, per-key rate limits, and usage dashboards, so reach for it when you want managed endpoints with provider redundancy instead of running nodes yourself.

A terminal UI that searches 1000+ EVM chains, latency-tests their public RPC endpoints, and exports the winner as ETHRPCURL for Foundry and Hardhat commands. It also manages your own private endpoints with encrypted storage and per-project favorites, so reach for it when you switch chains often and are tired of pasting RPC URLs.

Flashbots Protect is an RPC endpoint that keeps transactions out of the public mempool and returns MEV refunds. Wallet and application builders point users at it to reduce frontrunning on their transactions.

GetBlock gives hosted access to nodes on many chains through RPC endpoints. Builders connect applications to it for chain access without running their own infrastructure.

InfStones offers managed node infrastructure with RPC APIs, non-custodial staking, and node monitoring across many chains. Builders use it instead of operating their own nodes.

Infura provides Ethereum and EVM RPC infrastructure and APIs used by wallets and dapps for blockchain connectivity.

Kaleido is a hosted platform for running permissioned and public chain environments, including managed Ethereum nodes and tokenization services.

Lava Network is a decentralized RPC access layer that routes requests across independent node operators for Ethereum and more than 27 other chains. Builders route calls through it when access should not depend on one provider.

NodeCore is a self-hosted RPC load balancer in Go that sits in front of several blockchain API providers and scores upstreams on latency, error rate, and availability to pick one per request. It layers caching, request hedging, retries, per-method rate limiting, and quorum verification over JSON-RPC, WebSocket, and REST interfaces, so reach for it when you run your own RPC cluster and want failover across providers rather than a single endpoint.

NOWNodes is a node-as-a-service provider covering Ethereum and more than 125 other chains, with shared and dedicated nodes plus block explorers. Builders get an API key for hosted RPC across the chains they support.

OnFinality offers an RPC API and dedicated node hosting for Ethereum and more than 130 other networks, with indexing add-ons. Builders use it when one provider should cover both node access and indexed data.

Pocket Network, served through Grove, is a decentralized RPC relay network with an onchain incentive protocol. Builders use its endpoint network when they want chain access that does not depend on a single provider.

PublicNode from Allnodes serves free Ethereum RPC endpoints that need no API key. Builders use it for quick reads, scripts, and fallback endpoints.

QuickNode is a hosted RPC provider covering many chains, with an add-on marketplace and service level agreements. Builders subscribe when they want managed endpoints and extra infrastructure services instead of running nodes.

Tatum is a TypeScript SDK over its hosted RPC and blockchain APIs, covering wallets, transactions, tokens, and notifications. Builders install it when one package should cover both chain access and wallet operations.

Validation Cloud is an enterprise RPC node API for Ethereum and more than 50 protocols, alongside staking and analytics services. Builders pick it when they need support commitments and analytics with the endpoint.

Watchdata provides hosted blockchain APIs and RPC endpoints across several networks, including Ethereum mainnet and testnets. Builders use it as a hosted endpoint when they do not run their own node.

evm-rpcs-list is a small npm package that bundles chain metadata and public RPC endpoints for many EVM networks sourced from chainlist.org so scripts can import a single JSON map instead of hardcoding endpoints.

Chainlist is a directory of EVM chain IDs and public RPC endpoints that developers and wallets use to add a network. The repository is the source of chainlist.org.

Checkpointz is a beacon-chain checkpoint sync provider from ethPandaOps. Node operators run one or point a consensus client at an existing instance to bootstrap a node in minutes instead of syncing from genesis.

ethereum-lists/chains is the canonical metadata list for EVM chains, covering chain ID, name, native currency, and RPC URLs. Builders pull chains.json from it to populate wallet and network configuration instead of hardcoding chain data.

Helios from a16z is a portable light client that serves verified Ethereum and other chain data without trusting an RPC provider. Builders run it or embed the Rust library when an application must check the data it receives.

enr is the Rust implementation of EIP-778 Ethereum Node Records, used by discv5 and the consensus and execution peer-to-peer stack. Rust builders add the crate to read and write node records.

Stereum is a GUI-driven installer for syncing Ethereum and Optimism nodes locally and exposing your own JSON-RPC and websocket endpoints once blocks are current.

Besu is a Java Ethereum execution client hosted by LF Decentralized Trust, formerly under Hyperledger, with wide enterprise use. Node operators run it when a deployment is standardized on the Java stack.

Ream is a Rust implementation of Ethereum's proposed Lean Consensus design. Client developers use it to experiment with the next consensus architecture, and it is not a production node client.

Teku is a Java Ethereum consensus client from Consensys that is favored by institutional operators. Validator and node operators run it when a deployment is standardized on the Java stack.

Erigon is an efficiency-focused Ethereum execution client that embeds the Caplin consensus layer. Infrastructure builders run it when they want one process for execution and consensus and fast access to historical state.

ethdo is a command line tool for beacon-chain and validator account management, covering keys, withdrawals, and exits. Validator operators use it for one-off account operations outside the client.

ethrex is a minimalist Ethereum execution client written in Rust by LambdaClass with growing adoption. Rust builders run it when they want a compact client codebase to operate or read.

Grandine is a multithreaded Ethereum consensus client written in Rust for high throughput. Node operators run it when they want to drive many validators from one process.

Lighthouse is an Ethereum consensus client written in Rust by Sigma Prime and one of the most used clients on the network. Validator and node operators run it to follow and attest to the beacon chain.

Lodestar is an Ethereum consensus client written in TypeScript by ChainSafe that adds client diversity in the JavaScript ecosystem. TypeScript infrastructure builders run it as a node or reuse its libraries.

Nethermind is an Ethereum execution client written in C# and .NET, and the second most used client on the network. Node operators and infrastructure builders run it to serve JSON-RPC and follow the chain.

Nimbus is a resource-efficient Ethereum consensus client written in Nim for low-power hardware. Validator operators run it on small machines where memory and CPU headroom are limited.

Prysm is an Ethereum consensus client written in Go by Prysmatic Labs and historically the most used client. Validator and node operators run it to take part in consensus.

Reth is a modular Ethereum execution client written in Rust by Paradigm. Rust builders run it as a node or extend its components to build custom infrastructure.

staking-deposit-cli generates validator keys and deposit data for Ethereum staking, and is now maintained as the EthStaker fork that the original owners point to. Validators run it once when setting up new keys.

nimbus-eth1 is an Ethereum execution client built for resource-restricted devices, from the team behind the Nimbus consensus client. Operators run it where memory and storage are tight, separately from nimbus-eth2 on the consensus side.

bloXroute is a blockchain distribution network offering low-latency mempool streaming and MEV bundle submission. Builders use it when a trading or infrastructure service needs pending transactions quickly and a path to submit bundles.

op-rbuilder is a block builder for OP Stack chains, adapted from rbuilder for rollup sequencer block production. Rollup teams run it as the builder behind their sequencer.

rollup-boost is a sidecar for OP Stack sequencers that adds MEV-Boost style external block building to a rollup. Sequencer operators run it when blocks should come from outside builders.

Commit-Boost is a validator sidecar that runs MEV-Boost together with other community-built commitment protocols. Validator operators run it instead of the plain sidecar when they want to take on commitments beyond block sourcing.

MEV-Boost is a validator sidecar that sources blocks from a competitive marketplace of builders and relays under proposer-builder separation. Validator operators run it alongside their consensus client to receive externally built blocks.

mev-boost-relay is the reference relay server for MEV-Boost proposer-builder separation, run by relay operators rather than validators. A team standing up its own relay runs this implementation.

rbuilder is a Rust MEV-Boost block builder that constructs blocks and submits them to relays. Teams that build blocks run it directly or fork it as the base for their own builder.

Ponder is an indexing framework for crypto apps with an emphasis on fast refresh and developer ergonomics when you are serving fresh chain data to a product backend or frontend.

rindexer is an app-focused indexer framework with GraphQL and Postgres ergonomics when you need reliable chain-to-API pipelines without bespoke ETL glue.

Allium is a managed data warehouse and API service for onchain data aimed at institutional use. Builders use it when they want onchain datasets delivered into their analytics stack rather than indexed in house.

Amberdata is a commercial digital asset data platform covering onchain, market, and DeFi datasets through APIs aimed at financial institutions. Builders call it when an application needs market and protocol data from one vendor.

Apibara builds streaming onchain data pipelines that handle chain reorganizations. Builders use it when a service consumes live chain data and must correct itself when blocks are reorged.

Bitquery serves decoded blockchain data across networks through GraphQL, Kafka, and gRPC interfaces. Builders use it when an application needs decoded transactions and events from several chains in one place.

Chainbase is a hosted multi-chain data warehouse with indexing APIs. Builders query it for chain data across networks without operating indexers.

Checkpoint from Snapshot Labs is a library for indexing Ethereum and Starknet contract events and serving them over GraphQL. Builders install it to turn their own contract events into a GraphQL API, separate from the Snapshot voting application.

Codex is a hosted API with a TypeScript SDK for real-time token prices, holder data, and market data. Builders install it when a trading or portfolio application needs live market data.

Covalent, delivered as GoldRush, is a unified REST API for historical onchain data across many chains. Builders call it when an application needs normalized balances, transfers, and history without writing a chain-specific indexer.

Envio is a multichain indexing framework with TypeScript, JavaScript, or ReScript handlers that syncs over HyperSync rather than RPC when you need one Postgres-backed GraphQL API across several EVM chains.

ethereum-etl is a Python tool that exports Ethereum data into files and data warehouses. Data builders run it to move blocks, transactions, and logs into their own analytics storage.

Firehose, in its firehose-ethereum form, is the flat-file block extraction layer that feeds Substreams. Its documentation addresses operators running a full indexing stack, since Substreams users can reach the same data through hosted endpoints.

Goldsky runs hosted subgraphs and streaming pipelines for onchain data. Builders use it when they want subgraphs and data streams operated for them rather than self-hosted.

mempool-dumpster continuously records observed mempool transactions into Parquet and CSV files for MEV and mempool research. Researchers pull the hosted dumps from Flashbots or run the Go collector against their own node.

Moralis offers web3 data APIs together with webhook-first event streams. Builders call its REST endpoints for wallet, token, NFT, and price data on Ethereum mainnet and subscribe to Streams webhooks for events.

Safe Transaction Service is the backend that indexes Safe multisig transactions and coordinates their collection of signatures. Safe integrations run or call it to track pending and executed multisig transactions.

Shovel is a configuration-driven tool that indexes EVM logs into PostgreSQL. Builders point it at contracts and tables when they want event data in their own database without writing indexer code.

Space and Time is a SQL data warehouse that produces proofs of its query results for onchain use. Builders query it when a contract or application must trust a computed result rather than a plain API response.

SubQuery is an open indexing SDK paired with a decentralized network of RPC and indexer operators. Builders define an indexer with it and serve the results as an API.

Subsquid, also called SQD, is a modular batch indexing SDK backed by distributed data archives. Builders use it to write custom indexers that read from archives instead of pulling every block from an RPC node.

Substreams is a parallelized streaming data engine for blockchain data built on Firehose. Data builders write Substreams modules when a pipeline needs to process large ranges of blocks in parallel.

The Graph is a decentralized indexing protocol where builders deploy subgraphs and query them over GraphQL. Builders use it to turn contract events into a queryable API without running their own indexer.

TrueBlocks, used through its chifra command, builds a local address-based index on top of an Ethereum node. Builders run it to index and query the full activity of an address from their own machine.

DefiLlama is an open analytics collective best known for transparent TVL dashboards, a DEX meta-aggregator, and LlamaZip, a swap router tuned for optimistic rollups that helps traders find efficient routes across fragmented liquidity.

Ethernal is an open-source block explorer you can self-host for any EVM chain, with APIs and UI hooks for faucets, DEX widgets, custom post-processing, NFT galleries, and verification flows.

Blockscout is an open-source, self-hostable block explorer for EVM networks, offering contract verification, APIs, and developer tooling for chains and rollups.

Blobscan is an explorer and API for EIP-4844 blobs-decoding, analytics, and deployment charts aimed at rollup teams operating blob-capable infrastructure.

Sourcify is a decentralized and open-source smart contract verification service

growthepie.xyz is an analytics site for Ethereum rollups that surfaces fundamentals, blockspace usage, economics, data-availability metrics, and application-level dashboards.

A blazingly fast, local, Ethereum block explorer built on top of Erigon for EVM chains

Artemis provides cross-chain fundamentals and metrics dashboards, with an API that serves the same data.

beaconcha.in is an open-source explorer for the Ethereum beacon chain and its validators. Staking and infrastructure builders use it to inspect validator performance and query beacon-chain data.

Blockaid is a closed-source security service that detects malicious activity and is integrated into many wallets and sites. Builders integrate it to simulate a transaction and warn a user before a harmful signature.

Dora the Explorer is a lightweight slot-by-slot explorer for the Ethereum beacon chain. Teams running a devnet or testnet deploy it to see consensus activity on their own network.

Dune is a community analytics platform where onchain data is queried with SQL and shared as dashboards. Builders write queries or call the API when they need protocol metrics and want to reuse work others have published.

Etherscan is an Ethereum block explorer and API platform for contract verification, transaction inspection, and onchain data access.

Forta is a decentralized network for runtime threat detection and anomaly monitoring. Builders write detection bots and run them on the network to get alerts about suspicious activity against their contracts.

Herd Explorer is an AI-assisted Ethereum explorer: search contracts and tokens, then ask the built-in assistant for quick explanations of functions, events, and how pieces connect.

Hypernative is a hosted platform for real-time onchain threat detection and risk monitoring. Builders choose it when a protocol needs monitored alerts and automated responses to attacks.

Nansen provides onchain analytics with wallet labels and its Smart Money views of what labeled wallets are doing.

Pessimistic Spotter monitors deployed contracts for exploit patterns and raises alerts. Teams point it at their own contracts to catch an attack while it is still running.

relayscan monitors MEV-Boost relays and publishes data on bids, delivered payloads, and relay behavior. Block builders and researchers query its hosted JSON endpoints or run the command line tool against their own data.

Routescan is a multi-chain block explorer with an Etherscan-compatible API. Builders use it to verify contracts and query chain data on networks through the same API calls they already write for Etherscan.

Sentio is an observability platform combining a transaction debugger, simulation, indexing, metrics, and alerts. Builders use it to trace a failed call and then watch the same contract with dashboards and alerts.

Token Terminal publishes standardized financial metrics and dashboards for protocols, such as revenue, fees and active users.

xatu is network monitoring tooling with collection clients, called sentries, and a central server that pipelines consensus and execution telemetry. Node and infrastructure teams run it to gather telemetry from their own nodes.

4337 Block Explorer

NFTScan is an NFT explorer and data API that developers use to search NFT collections, ownership, and transaction history across Ethereum and other EVM networks.

L2BEAT publishes risk analysis, activity data and research on Ethereum layer 2 networks. Builders use it to compare rollups and check their security assumptions before choosing where to deploy.

Band Protocol is a cross-chain data oracle platform that aggregates and connects real-world data and APIs to smart contracts.

Chainlink decentralized oracle networks provide tamper-proof inputs, outputs, and computations to support advanced smart contracts on any blockchain.

Chronicle overcomes the current limitations of transferring data onchain by developing truly scalable, cost-efficient, decentralized, and verifiable oracles.

DIA Oracles is an open-source oracle platform that delivers customizable price and data feeds for contracts to read onchain. Contract developers wire its feeds in instead of building their own oracle.

The Pyth network is a first-party financial oracle network designed to publish continuous real-world data onchain in a tamper-resistant, decentralized, and self-sustainable environment.

RedStone is a decentralized modular oracle that provides gas-optimized data feeds. It specializes in offering price feeds for emerging assets, such as liquid staking tokens (LSTs), liquid restaking tokens (LRTs), and Bitcoin staking derivatives.

UMA's optimistic oracle allows smart contracts to quickly receive any kind of data for different applications, including insurance, financial derivatives, and prediction markets.

Witnet is a permissionless, decentralized, and censorship-resistant oracle helping smart contracts to react to real world events with strong crypto-economic guarantees.

One API to swap, bridge, and zap across all major blockchains and protocols. Enable trading across all DEX aggregators, bridges, and intent-systems and save hundreds of developer hours.

The Across toolkit is an SDK for bridging and intent-based transfers through Across. Builders import it to fetch quotes, submit deposits, and move funds between chains from application code.

Decent enables cross-chain swaps and 1-click transactions with any token across chains.

Relay is a hosted service for cross-chain routing and transaction execution.

Unruggable Labs builds open infrastructure for ENS-style naming on rollups, including Unruggable Gateways that fetch rollup state proofs and verify them on Ethereum L1 so clients can resolve names trustlessly as L2s scale.

IPFS is content-addressed peer storage for NFT metadata, governance payloads, dapp frontends, and other assets you want off-chain but verifiable-linked from Ethereum or rollups.

Aleph Cloud is a decentralized cloud offering storage, virtual machines, and hosting that contracts and applications can reach as an off-chain data layer. Builders deploy onto it when application data and compute should not sit with a single hosting provider.

eth.limo is a gateway that serves ENS-named, IPFS-hosted frontends over ordinary HTTPS, such as yourname.eth.limo. Teams shipping an IPFS frontend point users at their eth.limo address so a normal browser can load it.

Irys, formerly Bundlr, is a JavaScript SDK for permanent and programmable data storage built on Arweave. Applications install it when data should be paid for once and kept indefinitely.

Pinata is an IPFS pinning and file upload service used to host NFT metadata and images for contract projects. Teams upload assets there so token metadata stays available after mint.

1inch AI is the official distribution point for the 1inch hosted MCP server and its agent skills, covering token swaps, limit orders, and SDK documentation search. Agent builders point Claude, Cursor, or Copilot at it so an agent can quote and place swaps.

The Alchemy MCP Server gives AI clients access to Alchemy's blockchain data and RPC APIs across more than 100 chains. The hosted server at mcp.alchemy.com is the maintained route, while the open source repository holds the legacy local version.

Base MCP is a Model Context Protocol server that connects AI agents to wallet and onchain tools on Base, with pre-built prompts and workflows for wallet operations, token transfers, and DeFi interactions. Nothing happens onchain without explicit approval since the server never holds or accesses private keys, instead constructing pending requests that a Base Account reviews and signs, and it ships with skill plugins covering Morpho, Moonwell, Aerodrome, Bankr, Avantis, Virtuals, and Uniswap.

Wraps Blockscout APIs and exposes blockchain data (balances, tokens, NFTs, contract metadata) via MCP for use in AI agents and IDEs.

The Coinbase Payments MCP, now documented as the Agentic Wallet MCP, gives an AI agent tools to move and accept crypto payments through Coinbase's payment APIs. Builders add it when an agent needs to send or receive payments.

CoinGecko MCP is a remote Model Context Protocol server that gives AI agents access to CoinGecko's market data, including live prices and market caps, historical charts, DeFi and onchain pool data, and NFT collection analytics. It connects to Claude, Cursor, VS Code, and other MCP clients with minimal setup and is backed by CoinGecko's existing API.

Morpho Agents is a beta interface built for AI agents to read, simulate, and write to Morpho's lending protocols. The User Agent product is a CLI and MCP server giving agents full read, simulate, and write access on Ethereum and Base with any wallet infrastructure, running every write through a simulation first, while the Builder Agent is an AGENTS.md knowledge base that turns a code agent into a Morpho integration expert.

Pendle AI is a set of AI plugins for Pendle Finance, packaged as MCP servers, that let agents trade yield tokens, manage LP positions, place limit orders, and query DeFi market data across seven EVM chains. It includes a Pendle V2 plugin for the core yield-trading protocol and a Boros plugin for interest-rate derivatives on Arbitrum, and is compatible with Claude Code and other MCP-based tools.

QuickNode MCP Server brings the power of QuickNode's blockchain infrastructure directly to your AI assistant.

MCP server that wraps Slither static analysis for Solidity smart contracts. Query contract metadata, functions, inheritance, call graphs, and run security detectors. Works with Foundry and Hardhat projects. Includes typed Python client for programmatic use.

Tenderly MCP is a Model Context Protocol server that brings Tenderly's blockchain development tools into AI assistants like Claude, exposing around 59 tools for transaction simulation, virtual testing environments, call trace and event inspection, and project management. It authenticates via OAuth and lets an agent set an active project, then run simulations and debug transactions without leaving the chat.

WalletChan MCP is a local MCP adapter that connects AI agents to WalletChan wallet accounts through popup approvals, portfolio reads, swaps, and bridges, with optional delegated execution via ERC-7710 permissions. It lets local MCP clients like Claude Desktop, Cursor, and Codex interact with a WalletChan wallet across Base, Ethereum, Polygon, and Unichain.

A simple, lightweight and fast MCP (Model Context Protocol) server that provides Solidity development capabilities using the Foundry toolchain (Forge, Cast, and Anvil).

A Claude Code plugin marketplace from Trail of Bits providing skills to enhance AI-assisted security analysis, testing, and development workflows.

Claude Code skills for Solidity security and development. solidity-auditor provides fast (typically under 5 min) security feedback on Solidity changes while you develop. Works with Claude Code CLI, VS Code Claude extension, and Cursor.

Agent skills for secure smart contract development with OpenZeppelin Contracts libraries, including setup and upgrade workflows for Solidity and other ecosystems.

Across Skills is a knowledge base and MCP endpoint for building crosschain applications on Across, covering the Across swap API, suggested fees, deposit tracking, and embedded crosschain actions that execute contract calls across different chains in a single transaction. It is aimed at both AI agents and developers building production crosschain apps, and is available under an MIT license.

Bankr Skills is a catalog of plug-and-play agent skills built around Bankr's wallet, trading, and security infrastructure, letting builders add natural-language crypto trading, portfolio management, token launching, and DeFi operations to an agent without standing up wallet plumbing themselves. Specialized skills in the catalog cover things like deploying ERC-20 tokens with Uniswap V4 pools, cross-chain swaps across 50-plus chains via Symbiosis, and prediction-market intelligence, all routable from natural language across Base, Ethereum, Polygon, Solana, and Unichain.

Bitrefill Skill is an agent skill that routes an AI assistant through buying gift cards, mobile top-ups, and eSIMs from Bitrefill across 180-plus countries and 1,500-plus brands, paid for with crypto, Lightning, USDC, or a prefunded Bitrefill balance. It detects the execution environment and available wallet integrations to pick the lowest-friction checkout path, supports guest checkout via Base wallet sign-in, and keeps user-facing messaging free of technical jargon like x402, MCP, or JWT.

DefiLlama Skills is a collection of MCP skills exposing roughly 23 DeFi analytics tools built on DefiLlama data, covering full market snapshots of TVL, categories, chains, events, and stablecoins alongside guided workflows for protocol analysis, token research, chain ecosystem comparisons, yield strategy discovery, and risk assessment. It is aimed specifically at wiring DefiLlama's analytics into AI agents, distinct from the main DefiLlama analytics site.

Structured Ethereum knowledge for AI agents - end-to-end guides from dApp idea to production. Skills cover wallets, L2s, standards, tools, DeFi, security, testing, indexing, and frontend UX. Fetch via URL, curl, or Claude plugin. No install required.

OpenSea Skills is a collection of agent skills for interacting with the OpenSea NFT marketplace, bundled under a router skill that directs an agent to the right sub-skill for its task. It covers querying NFT and collection data, buying and selling items through the Seaport protocol, swapping ERC20 tokens, configuring wallet signers, and registering gated AI tools, and installs via the Agent Skills spec with npx skills add.

Sign In With Agent - lets servers authenticate AI agents and filter out humans. Built on ERC-8004 and ERC-8128, with SDK support for Next.js, Express, Hono, and Fastify.

AI tools for building on Uniswap, including reusable skills, plugins, and agents for coding assistants integrating Uniswap workflows.

AI agent skills for smart contract security auditing. Ten plugins covering reentrancy, oracle/flash loan, proxy/upgrade, state invariants, semantic guards, and more. QuillShield methodology for vulnerabilities traditional static analysis misses. Works with Claude and Cursor.

Claude plugin with Solidity development standards for production-grade code. More thorough on testing, code quality, and smart contract sensitivity. Install via Cyfrin marketplace. By Patrick Collins and the Cyfrin team.

Smart contract security auditor for Claude Code and Codex CLI. Integrates Slither, Aderyn, Cyfrin checklist, and Solodit findings. Map-Hunt-Attack methodology with four MCP tools for static analysis and findings search.

Claude Code skill that scans Solidity codebases for security vulnerabilities using 36 unique vulnerability types. Four-phase audit: load cheatsheet, syntactic and semantic codebase sweep, deep validation with reference files, and report. References from smart-contract-vulnerabilities.

request-wallet-sign is a standalone npm CLI utility that lets AI agents request wallet signatures from a human through a browser interface without ever holding private keys. The agent passes transaction details as command-line arguments and the tool spins up a local server that displays a decoded, plain-English summary of the request, where the user connects a wallet, reviews the details, and approves the signing. It runs local-only by default for instant use, supports standard transactions, typed data, and personal signatures, and can use Cloudflare tunnels for cross-device signing, with a built-in timeout that auto-closes tabs once a request is handled.

Speedrun Ethereum is a hands-on series of challenges designed to help you learn by building. Each challenge delivers one key "aha" moment, a mental unlock about how Ethereum really works. At the same time, you'll be building your Ethereum portfolio.

The Ethernaut is OpenZeppelin's browser capture-the-flag: each level is a broken contract you exploit to learn common Solidity vulnerabilities hands-on.

Updraft is Cyfrin's free, hands-on curriculum for Solidity, security, Foundry, and DeFi: use it when you want structured exercises and certifications before shipping high-risk contracts.

Solidity Testing Handbook is a comprehensive guide to testing smart contracts in the Solidity programming language. It covers the basics of testing, the different types of tests, and the tools available for testing.

Alchemy University offers tutorials and guided learning content for Ethereum developers, including smart contract and web3 app development.

BuidlGuidl CTF is a Solidity challenge platform where developers solve practical Ethereum security and smart contract puzzles.

Building Secure Contracts is Trail of Bits' collection of guidelines, checklists, and training material for writing and reviewing Solidity contracts. Solidity developers work through its exercises and program analysis tutorials while building and reviewing code.

Damn Vulnerable DeFi is a hands-on Ethereum security training environment featuring realistic Solidity and DeFi exploitation challenges.

RareSkills is an Ethereum and smart contract education platform with structured courses, bootcamps, and in-depth developer learning content.

Solidity by Example is a collection of short annotated Solidity snippets organized by language feature and pattern. Builders look things up there while writing contracts.

WTF Solidity is a free open-source Solidity course running from basics to advanced topics, with runnable code examples in Chinese and English. Beginners work through it to learn Solidity by editing and running each example.

Training, incubation, and acceleration programs for non-tech people and devs to start in the web3 privacy ecosystem.

OpenRPC is JSON-RPC schema tooling and generators in the spirit of OpenAPI: you describe RPC surfaces once, then ship typed clients, docs, and tests for Ethereum and L2 JSON-RPC stacks.

evm.codes is an interactive reference for EVM opcodes where each instruction can be inspected and run. Builders use it to learn what an opcode does and to experiment with short sequences of instructions.

EIP.Tools is a browser explorer for EIPs, ERCs, RIPs, and CAIPs with search, summaries, trending views, and a relationship graph when you need to skim how standards connect.