
Ethereum represents the gateway to a worldwide, decentralized computing paradigm. This platform enables you to run decentralized applications (DApps) and smart contracts that have no central points of failure or control, integrate with a payment network, and operate on an open blockchain. With this practical guide, Andreas M. Antonopoulos and Gavin Wood provide everything you need to know about building smart contracts and DApps on Ethereum and other virtual-machine blockchains.

Discover why IBM, Microsoft, NASDAQ, and hundreds of other organizations are experimenting with Ethereum. This essential guide shows you how to develop the skills necessary to be an innovator in this growing and exciting new industry.

A guide to the operation and use of Ethereum and other EVM-compatible blockchains.

Mastering Ethereum


The story of the idealists, technologists, and opportunists fighting to bring cryptocurrency to the masses.

In their short history, Bitcoin and other cryptocurrencies have gone through booms, busts, and internecine wars, recently reaching a market valuation of more than $2 trillion. The central promise of crypto endures—vast fortunes made from decentralized networks not controlled by any single entity and not yet regulated by many governments.

The recent growth of crypto would have been all but impossible if not for a brilliant young man named Vitalik Buterin and his creation: Ethereum. In this book, Laura Shin takes readers inside the founding of this novel cryptocurrency network, which enabled users to launch their own new coins, thus creating a new crypto fever. She introduces readers to larger-than-life characters like Buterin, the Web3 wunderkind; his short-lived CEO, Charles Hoskinson; and Joe Lubin, a former Goldman Sachs VP who became one of crypto’s most well-known billionaires. Sparks fly as these outsized personalities fight for their piece of a seemingly limitless new business opportunity.

This fascinating book shows the crypto market for what it really is: a deeply personal struggle to influence the coming revolution in money, culture, and power.

Idealism, Greed, Lies, and the Making of the First Big Cryptocurrency Craze

The Cryptopians


Tokens - often referred to as cryptocurrencies - can represent anything from an asset to an access right, such as gold, diamonds, a fraction of a Picasso painting or an entry ticket to a concert. Tokens could also be used to reward social media contributions, incentivize the reduction of CO2 emissions, or even ones attention for watching an ad. While it has become easy to create a token, which is collectively managed by a public Web3 infrastructure like a blockchain network, the understanding of how to apply these tokens is still vague.

The industry keeps referring to “Blockchain” as different from “Bitcoin,” creating an artificial divide that is often misleading. There seems to be too little understanding about the fact that Bitcoin is a blockchain network, which is (a) globally managed by people who mostly do not know each other, and (b) enabled by the consensus protocol that (c) incentivizes all network actors for their contributions with a native token. The governance rules are tied to the minting of a native blockchain token. The Bitcoin token can, therefore, be seen as the currency of a distributed Internet tribe, called the Bitcoin network, where network actors are rewarded with Bitcoins, just as the Ether is the currency of the distributed Internet tribe Ethereum network, or Sia is the native currency of the Sia network. The Bitcoin network and other distributed ledgers all represent a collectively maintained public infrastructure and are the backbone of the next generation Internet, what the crypto community refers to as the Web3.

This book attempts to summarize existing knowledge about blockchain networks and other distributed ledgers as the backbone of the Web3, and contextualize the socio-economic implications of the Web3 applications such as smart contracts, tokens, and DAOs to the concepts of money, economics, governance and decentralized finance (DeFi).

Token Economy


Learn to Code Blockchain DApps By Building Simple Games

CryptoZombies is an interactive school that teaches you all things technical about blockchains. Learn to make smart contracts in Solidity or Libra by making your own crypto-collectibles game.

#1 Solidity Tutorial & Ethereum Blockchain Programming Course

CryptoZombies


Node Guardians is a gamified educational platform that creates lore-rich programming challenges for experienced Solidity, Huff, Cairo and Noir developers. Think of it as a skill-based RPG where developers can become familiar with specific stack components and a place where they can showcase their abilities. 

### Skills Upgrade

We have created a series of coding challenges called “quests” to engage smart contract developers, providing them with the knowledge to build safe and gas efficient applications. In addition to practical skills, we also provide theoretical knowledge about crypto history, technology and economics through building a library of articles that break down complex concepts of distributed systems & decentralized finance.


### Public Good

Node Guardians is a public good for developers and will always remain so. 
In addition to supporting the growth of cool ecosystems, we plan to make the platform sustainable by managing [infrastructure](https://infra.nodeguardians.io/) across various networks.

Rewarding non-contributing operators wastes funds, we prefer community-building and education.


Node Guardians is a gamified educational platform that creates lore-rich programming challenges for experienced Solidity, Cairo, Huff and Noir developers.

Node Guardians


Speed Run Ethereum aims to provide a structured learning path for onboarding developers to Ethereum.

Ethereum Dev Speed Run with a framework for submitting challenges, get feedback from ethereum builders, and in the process unlocking new challenges and proof of completion.

Speedrun Ethereum

Teaching the next generation of smart contract developers and auditors. Learn from industry-leading experts how to build the next generation of web3 applications and level up your career.


Level up your web3 career through industry leading comprehensive courses

Cyfrin Updraft


This is an initiative for the early solidity developers by those who were early developers sometime.

In this approach, we are looking to categorize the smart contract according to the difficulty level in multiple standards. For now, we are keeping the standard 0 to 5(can be discussed).

This initiative needs great support from Blockchain enthusiast, developer and researchers to build this school in a way which can attract learners and provide them ease for development.

First place for early developers to learn Solidity 

solidity-school


## Introductory Modules

- What is a SNARK?
- Building a SNARK (part 1)
- Building a SNARK (part 2)

## Whiteboard Sessions with ZK Projects​

- SNARKs vs. STARKS with Brendan and Bobbin
- PLONK and Custom Gates with Adrian Hamelink
- Lookup Arguments for Performance Optimisation with Mary Maller
- Zero Knowledge Virtual Machine (zkVM) with grjte
- Achieving Decentralised Private Computation with Pratyush Mishra
- Introduction to zkRollups with Barry Whitehat
- zkEVM with Jordi Baylina
- ZK Swaps with Henry de Valence
- zkID with Oleksandr Brezhniev
- Fast Recursion with Plonky2 with William Borgeaud

ZK Whiteboard Sessions is an educational series on all things zero knowledge

ZK Whiteboard Sessions


## What is a smart contract?

Smart contracts are the backbone of decentralized applications (DApps) and Web3. A smart contract is a simple program that lives on a blockchain network (such as Ethereum). They're actually not that smart. And nothing like a (legal) contract. They’re more like an executable piece of code that requires input or an trigger from an external source. They can validate those input conditions and if correct, execute their own logic to update the state on a blockchain.

## Benefits

They often serve the following purposes:
- Store and maintain data
- Manage relationships with users, or other contracts

Benefits of smart contracts are
- Immutable - once deployed none can change them
- Composable - they’re public and anyone can interact with them, or build on top of them. Much like public APIs

## Resources

The following resources have been the most popular resources on the site for a long time. These are all highly recommend to start learning about Solidity


### 1. Official Solidity website
The most obvious resources is ofcourse the official website and documentation of the Solidity team itself. The Solidity team covers all the core concepts and fundamentals of Solidity and smart contracts in general. Highly recommended

https://soliditylang.org/


### 2. Solidity by Example
The second one on the list is Solidity by Example. A great collection of more practical examples, incl. source code and supporting videos.

https://solidity-by-example.org/


### 3. CryptoZombies 
CryptoZombies is an interactive school that teaches you all things technical about blockchains. A fun and interactive way to write smart contracts in Solidity by making your own crypto-collectibles game.

https://cryptozombies.io/


### 4. Speedrun Ethereum

Speedrun Ethereum helps you get to the next level. It teaches you how to build on Ethereum; the superpowers and the gotchas while you build up your Web3 portfolio. If you like this, also make sure to check out the other work of the amazing [Austin Griffith](https://twitter.com/austingriffith) such as [ETH-build](https://eth.build/) and [Scaffold-eth](https://scaffoldeth.io/).

https://speedrunethereum.com/


### 5. Smart Contract Best Practices 

Smart contracts are complex instruments that have the authority to allocate high-value resources between complex systems. Often working autonomously. With huge financial loss at risk. This makes them critical components in these systems. Development of such components requires thoughtful design, solid engineering practices, rigorous testing and a strong security mindset. This document provides a baseline knowledge of security considerations.

https://consensys.github.io/smart-contract-best-practices/


## Other resources

If you'd like to read more, make sure to checkout all the other [Solidity](/tags/smart%20contracts) resources on the site.

Solidity is a programming language designed for developing smart contracts that run on Ethereum. It's the most in demand skill in the Web3 space. These are the best resources to help you learn more about it.

Best resources to learn Solidity


Navigating conversations and understanding key concepts in web3 sometimes requires its own terminology. In this regard, web3 is not just a technological shift, but also a cultural one.

This guide will provide you with the **most essential terms** to decode the language and become a web3 citizen. It is tailored to provide you with clear and concise definitions for the unique terms that define this industry.

Dive in, discover, and enhance your fluency in the unique lexicon of the web3 industry. (-:

If you want to contribute to the glossary, [have a look on Github](https://github.com/wslyvh/useWeb3/tree/main).

## Glossary a-z

- **Airdrop**  
  Distribution of free tokens, usually to promote a product or incentivise early users

- **Altcoin**  
  Alternative coin, any cryptocurrency other than Bitcoin

- **AMM**  
  Automated Market Maker, popular mechanism among decentralized exchanges (DEXes) involving liquidity pools instead of an orderbook-based system

- **Anon**  
  Anonymous, entity that wishes to remain anonymous or pseudonymous

- **Beacon Chain**  
  Ethereum’s proof-of-stake (PoS) consensus layer

- **Bridge**  
  Service that transfers tokens between multiple blockchains (cross-chain)

- **BUIDL**  
  Term to describe the web3 building ethos, even despite a bear market, inspired by HODL

- **CeFi**  
  Centralized finance, the “traditional” finance sector, in contrast to DeFi (decentralized finance)

- **CEX**  
  Centralized Exchange, app for swapping tokens run by a company, often used for fiat exchange; in contrast to DEX (Decentralized Exchange)

- **Cypherpunks**  
  Cypher + punks, movement originating in the early 90s, emphasizing the need for privacy in the digital age, enforced by cryptography

- **DAO**  
  Decentralized Autonomous Organization, blockchain-based organizations that are owned and governed by their members via tokens

- **DApp**  
  Decentralized Application, blockchain-based services that use smart contracts in their backend and thus have a distributed nature, without the need for intermediaries

- **DeFi**  
  Decentralized Finance, general term for decentralized services in the financial sector, that are permissionless and globally available, e.g., DEXes (decentralized exchanges) or lending protocols

- **Degen**  
  Degenerate, term for a person that is deeply involved in crypto or a specific sector, e.g., DeFi Degens

- **DEX**  
  Decentralized Exchange, blockchain-based app for swapping tokens that use smart contracts to be permissionless

- **Diamond Hands**  
  Holding a digital asset through very volatile times

- **DYOR**  
  Do Your Own Research, principle of self-verification instead of trusting others

- **EIP**  
  Ethereum Improvement Proposal, a process to describe standards for the Ethereum platform

- **ERC**  
  Ethereum Request for Comments, form of EIP to specify application layer standards; the most popular ones are ERC20 for fungible tokens and ERC721 for non-fungible tokens

- **EVM**  
  Ethereum Virtual Machine, the environment in which all Ethereum accounts and smart contracts live, the EVM defines the rules for computing a new valid state from block to block

- **Exchange**  
  An application that allows users to buy and sell crypto assets

- **Exit Scam**  
  Scenario in which a project or a part of a team steals the investors’ money and leaves

- **Explorer**  
  Webpage that displays information about the transaction history of a blockchain

- **Faucet**  
  Service that dispenses free tokens, usually for test networks

- **Flippening**  
  Term to describe a pivotal change in price or perception, e.g., when the market cap of a token exceeds the one of another token

- **FOMO**  
  Fear Of Missing Out, term to describe the feeling of not being included in something, e.g., a crypto investment or news

- **Fork**  
  Split of a blockchain or project due to technical issues or a dispute

- **FUD**  
  Fear, Uncertainty and Doubt, the opposite of FOMO

- **Gas**  
  Term for the fee that Ethereum transactions cost; it is used to reward validators and prevents malicious use of the blockchain

- **Genesis Block**  
  The first block recorded in a blockchain

- **Gm**  
  Good morning, form of greetings in crypto communities; due to the global nature of web3 it can be used at any time of the day

- **Hash**  
  Function that can be used to map data of arbitrary size to fixed-size values, e.g., for encryption, cryptographic hash functions are used in many parts of the web3 industry

- **HODL**  
  A frequent term referring to a strict buy-and-hold strategy, became famous after a misspelling in the bitcointalk forum in 2013

- **ICO**  
  Initial coin offering, the process of selling tokens when launching a new crypto project, inspired by the initial public offering (IPO) for stocks.

- **JOMO**  
  Joy Of Missing Out, converting FOMO into a positive feeling

- **KYC**  
  Know Your Customer, a process to verify the identity of customers; often used by centralized exchanges or entities

- **Layer 1**  
  Base blockchain architecture that serves as the foundation for other layers, also called mainnet, e.g., Ethereum

- **Layer 2**  
  Built on top of layer 1, usually for scaling purposes, e.g., Optimism

- **Minting**  
  Process of creating new token(s)

- **Mixer**  
  Decentralized Application that “mixes” tokens to cover their transaction history, used for private transactions

- **NFT**  
  Non-Fungible Token, a type of token that is not interchangeable or divisible, in contrast to fungible tokens; often used for digital collectibles

- **Node**  
  An instance holding a copy of the blockchain, it is connected to other nodes, synchronizing the blockchain and thus forming the network

- **OG**  
  Original Gangster, a person who was very early involved in crypto or a specific project

- **Oracle**  
  Data bridge to bring real-world information onto the blockchain

- **P2P**  
  Peer-to-peer, referring to a transaction between two people without other (central) parties involved

- **Rollups**  
  Popular type of layer 2, scaling solution that uses transaction bundling (“rolling up”) transactions before publishing them to the main chain

- **Rug Pull**  
  Scenario in which a team abandons a project and/or removes its liquidity, similar to exit scams

- **SBTs**  
  Soul-Bound-token, type of NFT that is non-transferrable

- **Smart contract**  
  Programs that run on the blockchain that follow the "if this then that" logic, they execute themselves when certain conditions are met

- **Snapshot**  
  Record of a blockchain at a particular block height, also the name of a popular DAO voting tool

- **Solidity**  
  Smart Contract Programming Language, created for the Ethereum blockchain but popular for other chains as well

- **Stablecoin**  
  A cryptocurrency that is pegged to another asset, mostly USD

- **Staking**  
  Process of locking tokens to contribute to validation in a proof of stake blockchain

- **Token**  
  Representation of a digital asset on a blockchain

- **TVL**  
  Total Value Locked, equivalent of USD locked in a blockchain or protocol, often used as an indicator in DeFi, e.g. in lending protocols

- **Validator**  
  Virtual entity participating in the consensus of a proof of stake blockchain, they participate in producing blocks and validating transactions

- **WAGMI**  
  Acronym for “We're All Gonna Make It”, expression used to show an optimistic attitude about the future of web3

- **Whale**  
  An entity holding a large amount of cryptocurrency, sometimes even a significant part of a project

- **Whitepaper**  
  Document that is released with new crypto projects to explain the details of the project.

- **ZKP**  
  Zero-Knowledge-Proof, cryptographic mechanism to verify an information without revealing it, often used for scaling solutions of privacy applications


The glossary provides you with definitions for the most important terms to navigate the web3 landscape.

Crypto glossary – important terms to navigate web3


This handbook is for people who are interested in exploring the vision behind “Web3”, and who wish to acquire in-demand skills that are essential to realizing that vision.  

A Handbook for Smart Contract Development

Learn Solidity


Create Eth App supports multiple frontend frameworks. It comes with a host of decentralized finance templates pre-filled with contract ABIs, addresses and subgraphs. Everything you need to build a modern Ethereum-powered single-page app.

- Learning how to write Ethereum-powered apps in a comfortable and feature-rich development environment.
- Starting new Ethereum-powered single-page React applications without wasting time on copy-pasting boilerplates
- Creating examples with React for your Ethereum-related libraries and components.

Create Ethereum-powered apps with one command

Create Eth App


**Features**
- Next.js
- Ethereum
- Typescript
- Chakra UI
- Wagmi
- Connectkit
- Ethers.js

An open-source Next.js + Ethereum starter kit to quickly ship Web3 Apps

Nexth Starter kit


Everything you need to build on Ethereum!

Quickly experiment with Solidity using a frontend that adapts to your smart contract

Forkable Ethereum dev stack focused on fast product iterations

Scaffold-ETH


Becoming a blockchain engineer is the most fun, rewarding, and exhilarating choice I’ve and my colleagues have ever made. And we’ve already blazed the trail for you to get started! In this article, we will show you exactly how to learn to become a blockchain engineer, from beginner to professional.

Spoiler alert, here is the exact blueprint we are going to cover to get you to a successful blockchain engineer:

1. Understand why you should become a blockchain engineer
2. Take a Blockchain Course
3. Join a Hackathon, the Community, & Build
4. Start your own protocol, Take a job, Freelance & Contribute

If you make it this far, you’ve done it! Although, I’ll add a bonus step 5 that we will talk about soon.

5. You’ve made it! Keep learning!

That’s it! These are the exact steps you need to take to become a blockchain engineer!

Become a blockchain, solidity, and smart contract engineer by following these steps

Become a Blockchain Engineer


Odds are you’ve heard about the Ethereum blockchain, whether or not you know what it is. It’s been in the news a lot lately, including the cover of some major magazines, but reading those articles can be like gibberish if you don’t have a foundation for what exactly Ethereum is. So what is it? In essence, a public database that keeps a permanent record of digital transactions. Importantly, this database doesn’t require any central authority to maintain and secure it. Instead it operates as a “trustless” transactional system — a framework in which individuals can make peer-to-peer transactions without needing to trust a third party OR one another.

Still confused? That’s where this post comes in. My aim is to explain how Ethereum functions at a technical level, without complex math or scary-looking formulas. Even if you’re not a programmer, I hope you’ll walk away with at least better grasp of the tech. If some parts are too technical and difficult to grok, that’s totally fine! There’s really no need to understand every little detail. I recommend just focusing on understanding things at a broad level.

Many of the topics covered in this post are a breakdown of the concepts discussed in the yellow paper. I’ve added my own explanations and diagrams to make understanding Ethereum easier. Those brave enough to take on the technical challenge can also read the Ethereum yellow paper.

Many of the topics covered in this post are a breakdown of the concepts discussed in the yellow paper. I’ve added my own explanations and diagrams to make it easier.

How does Ethereum work, anyway?


I recently joined Edge & Node as a Developer Relations Engineer and have been diving deeper into smart contract development with Ethereum. I have settled upon what I think is the best stack for building full stack dApps with Solidity:

▶︎ Client Framework - React
▶︎ Ethereum development environment - Hardhat
▶︎ Ethereum Web Client Library - Ethers.js
▶︎ API layer - The Graph Protocol

Building Full Stack dApps with React, Ethers.js, Solidity, and Hardhat

The Complete Guide to Full Stack Ethereum Development


Educational sandbox for building on web3. Visually understand how Ethereum works by doing.

ETH.Build


https://www.youtube.com/watch?v=gyMwXuJrbJQ

This course will give you a full introduction into all of the core concepts in blockchain, smart contracts, solidity, NFTs/ERC721s, ERC20s, Coding Decentralized Finance (DeFi), javascript and solidity, Chainlink, Ethereum, upgradable smart contracts, and full stack blockchain development.   

Some of the technologies covered are:
- The Graph
- Chainlink
- Metamask
- Alchemy
- Remix
- Hardhat
- Solidity
- Openzeppelin
- Trail of Bits
- Ganache
- Ethers
- Etherscan
- Coinmarketcap
- Aave
- IPFS
- Fleek.hq
- Filecoin
- NextJS
- Moralis
- Web3uikit
- Opensea
- Pinata
- Nft.storage

 And more!

Follow along with the videos and you'll be a blockchain wizard in no time!  💻 The repository with helpful links to all code, resources, and support forums is located here: https://github.com/smartcontractkit/full-blockchain-solidity-course-js.

This course will give you a full introduction into all of the core concepts related to blockchain, smart contracts, Solidity, ERC20s, full-stack Web3 dapps, decentralized finance (DeFi), JavaScript, TypeScript, Chainlink, Ethereum, upgradable smart contracts, DAOs, the graph, moralis, aave, IPFS, and more. Follow along with the videos and you'll be a blockchain wizard in no time!

Learn Blockchain, Solidity, and Full Stack Web3 Development with JavaScript – 32-Hour Course


Learning Solidity with a collection of YouTube videos and example code.

Learning Solidity


Here we collect and discuss the best DeFi & Blockchain researches and tools 

DeFi Developer roadmap


ETH Gas Tracker helps you discover how gas works, why it matters and help you set optimal gas fees to use the Ethereum network more efficiently. Get real-time gas prices, historical data, and average fees to time your transactions and save money. Ethereum Gas Tracker is the best way to track gas prices and provides an API for developers to integrate gas data into their applications.

Monitor and track the Ethereum, and L2 gas prices to reduce transaction fees and save money

ETH Gas Tracker


This document provides a baseline knowledge of security considerations for intermediate Solidity programmers. It is maintained by ConsenSys Diligence, with contributions from our friends in the broader Ethereum community.

A guide to Ethereum smart contract security best practices

Smart Contract Best Practices

good first issue

Rust full node implementation of the Fuel v2 protocol.

fuel-core

Rust

Have parity between pre confirmation statuses and `Success` and `Failed` statuses

We don't support pre merge forks. Currently it seems we only print a warning but don't exit.

`Invalid fork, only post-merge networks are supported`

Here is an example: https://hive.ethpandaops.io/#/logs/generic/1764481225-6e5dd5867999a36740f06977ee28b03c/ethrex_default%2Fclient-320dac750650b5f445748ce2efcc8b1e5b04a303457f4156fe412af2180361a3.log

Instead, we should print an error and exit the node.

Also, this logic is quite fragile and should be improved: https://github.com/lambdaclass/ethrex/blob/9feefd2e3fd2e8bb2097e5e39e0d20f7315c5880/crates/common/types/genesis.rs#L77-L83

Minimalist, fast and modular implementation of the Ethereum protocol in Rust. L1 and L2 execution client.

ethrex

Exit the client if on a pre merge fork

https://github.com/lambdaclass/ethrex/pull/5453#discussion_r2572335977

> Geth uses https://github.com/ethereum/go-ethereum/blob/5e6f7374deaae104e243703f5aea25c68f4d6df6/eth/protocols/eth/discovery.go#L41 which would update ENR record updated with each new block head

We should have a periodic task that checks the current fork ID and updates it in case it's stale.

Periodically update local ENR

We haven’t measured the server’s most expensive code paths yet. Once traffic ramps up, we’ll need data to decide where to optimize. Scope for later:

- Benchmark `MidenNetworkClient::apply_delta` and `merge_deltas` with realistic payload sizes to gauge serialization and replay-protection overhead under the global network-client mutex.
- Stress `FilesystemService::pull_deltas_after` with many delta files to see when directory scans/deserialization bottleneck `get_delta` APIs.
- Load test the canonicalization worker (mocked storage/network) to measure how many candidates/sec it can retire and whether the shared network-client lock becomes the bottleneck

enhancement

cla: allowlist

Cloud backup and syncronization layer for Miden private accounts

private-state-manager

Benchmark server hot paths

Currently, the gas tip estimator performs about 40 queries to
the DB for every updates. While it caches the latest value, it
could be made much more efficient with little effort.

The general flow of gas estimation as it is now is as follows:
- From the latest 20 canonical blocks, get the base fee and the
  three cheapest transactions (in terms of gas tip);
- Of those (at most) 60 values, take the median.

Now, for that number of values all we really need is to keep a
window of those ordered by block number, with a safety margin
for reorgs, in memory, which amounts to at most a few kiB.
If we update this array on every canonical block, we avoid
accessing the DB entirely to estimate gas tips.


perf(l1,l2): gas tip estimator design

See #5354

We currently announce the same local IP address we listen on to our peers. However, this doesn't work when our node is behind a NAT. In those cases, we need to allow the user to set their externally reachable address (or automatically resolve our address by using an external service...).


Decouple local interface address from externally announced address

See #5354

Some users might want to use an IPv6 socket for receiving inbound RLPx connections. For this, we need to support having different addresses for both protocols. We also need different flags to set both addresses independently.

Support different addresses for discv4 and RLPx

We are computing jump targets when we initialize a new code. We should avoid doing so for delegation indicators. Especially since we're storing them in the DB.

levm

Avoid computing jump targets for delegation indicators

With #5297, we have a way for the user to set a specific address for the P2P layer. This works fine for IPv4; however, using an IPv6 address has the additional problem that most nodes use IPv4 addresses (specifically, bootnodes). We should find a way to translate between the two, or even have a dual stack of IPv4+IPv6.

Add support for IPv6 addresses

When we get an element, be it trie node, storage slot or account state, we look for it in the Difflayers first. However, Difflyaers hold their data encoded as Vec<u8>. This means that if we have a high hit rate among the difflayers we will need to re-decode elements each time. Also, before entering them into the difflayer, we have them decoded as accounts or storage slots, so effectively we are encoding them to save them and decoding them again to get them.

Ideally, we want to hold the items decoded and encode them when we want to save them to disk. This way each get that hits the difflayers doesn't decode anything, the cost is purely traversal.

There's a catch: we will encode elements to calculate the trie hash. We might want to save the encoded version in the struct so when it's time to save this to disk we just get that field instead of encoding it again.

Some changes this may involve:
- Changing the trie/triedb interfaces so they hold accounts and storages. Instead of having a single trie struct for everything, it will be either generic or enum. Encoding and decoding will now be done internally, not externally. 
- Having separate fields in difflayers for accounts, storages, and trie nodes.

performance

Have the elements decoded in the difflayers

Since Rust 1.80 LazyLock and LazyCell were stabilized and can replace the use of the external crate lazy_static and its macro.

Refactor the use of lazy_static to std LazyLock/LazyCell

(Transaction) Nonce: UInt256->ulong
(Transaction) GasLimit long->ulong
(Transaction) SpentGas long->ulong

(Receipt) GasUsed long->ulong
(Receipt) GasUsedTotal long->ulong

(BlockHeader) GasLimit long->ulong
(BlockHeader) GasUsed long->ulong

Could use discussion:
(BlockHeader) Number long->ulong/UInt256: Geth uses big.Int so UInt256, but IMO there is no point and ulong would suffice. It will also speed up any lookups in hashmaps ect and save some memory space.
(Receipt) BlockNumber - as above 

A robust execution client for Ethereum node operators.

nethermind

Unify types with Geth

We currently have unit tests for fork-id computation on all testnets (Holesky, Sepolia, Hoodi), but we lack unit tests for mainnet. We want to add something similar to this:

https://github.com/lambdaclass/ethrex/blob/353d5894c9e0e151a866d2c39dbdf693b2c1e46e/crates/common/types/fork_id.rs#L251

but for mainnet. The values need to be double-checked with other clients.

testing

Test fork-id computation for mainnet chain configuration


[packages/sdk-platforms/rust/zksync-sso-erc4337/crates/zksync-sso-erc4337-ffi-web/src/lib.rs](https://github.com/matter-labs/zksync-sso/pull/210/files/0bcfd3533bfd7038374c785218d84f645cd75610#diff-0cc3a6504964d0097a9bf2249ae1119992b6f5f75073b4020aaef99ebd166750)

Using unwrap() after validating array lengths on lines 1470-1481 is redundant and could panic if the try_into conversion fails for other reasons. Replace unwrap() with a proper error return since this is a public API function. Use .map_err(|_| JsValue::from_str(\"Failed to convert r to fixed array\"))? pattern instead.

The userVerification is set to 'required' during authentication but 'discouraged' during registration (line 177 in webauthn.ts). This inconsistency may cause authentication failures on some authenticators. These values should match unless there's a specific security reason for the difference.

These hardcoded gas fee values (matching lines 1920-1921 in test) should be extracted as named constants or configurable parameters. Magic numbers like 0x77359400 make the code harder to maintain and understand. Consider defining constants like DEFAULT_MAX_PRIORITY_FEE and DEFAULT_MAX_FEE at module level.

zksync-sso

Web-SDK cleanup

this issues reported after #1084 

after #1084, we need to differentiate opcode circuit/table circuit in another way.
It's better to refactor https://github.com/scroll-tech/ceno/blob/master/ceno_zkvm/src/bin/riscv_stats.rs for retrieve circuit information in more robust way

Accelerated Zero-knowledge Virtual Machine by Non-uniform Prover Based on GKR Protocol

ceno

make circuit stats shows `ShardRAMCircuit`

Allow usage of the auth token in the URL in playground or via a separate field allowing using external data provider like Quicknode, Ankr, eth.

Adjust the playground to support the auth token

We clone the `Store` extensively throughout the codebase, since we mostly expect this to be a handle. This changed in #5071, since now the chain config (624 bytes) is copied on each clone. We should check if this affects performance.

We should also check if it makes sense to cache the chain config at this level, or if it makes more sense to cache it inside the `Blockchain` struct, for example.

[PERF] Avoid copying a `ChainConfig` on each `Store::clone`

Creating histograms of data is quite useful for visualizing blockchain data, especially transactions and events. 

In FireFly Core, we have been using histograms to drive the [FireFly UI ](https://github.com/hyperledger/firefly-ui?tab=readme-ov-file)

<img width="3806" height="1870" alt="Image" src="https://github.com/user-attachments/assets/17e85b2e-cde7-41a0-8786-ddc8d8505932" />

<img width="3742" height="1858" alt="Image" src="https://github.com/user-attachments/assets/e77d0bc7-50ad-4704-9fe2-9c609d53cc46" />

These APIs built on top of the SQL Database package in FireFly Common and would be an awesome addition to this common library to be re-used across other FireFly components such as transaction managers, data exchange, etc... to give an API to view data in a histogram.

Within FireFly Core, exists most of the code for this:
- The type definition [ChartHistogram](https://github.com/hyperledger/firefly/blob/f67a468378abc7f512231ccda7db626845e0f1ec/pkg/core/charthistogram.go#L28)
- The code in the SQL layer to execute the right SELECT query and build the histogram result [GetChartHistogram](https://github.com/hyperledger/firefly/blob/f67a468378abc7f512231ccda7db626845e0f1ec/internal/database/sqlcommon/chart_sql.go#L105)
- We should have an interface for the database plugin such as [iChartCollection](https://github.com/hyperledger/firefly/blob/f67a468378abc7f512231ccda7db626845e0f1ec/pkg/database/plugin.go#L569)


The task would be to port that code over so it can be re-used 

firefly-common

Port ChartHistogram from FireFly Core

the why developers run tests is that all test files are usually included in final top lvl file. compiling and running this file will runs all tests in project.

now what often happens is that developers forget to include test file in top lvl file. it can happen when developers are adding new features (https://github.com/vacp2p/nim-libp2p/pull/1825), or even refactoring (reorganizing) test files.

it would be possible to create some utility that would be run in top lvl file, some function `checkDanglingTest` that would if there are dangling files. this would prevent this from happening.

`checkDanglingTest` pseudocode:
- list all test files in current dir and sub dirs (test files have match some regexp, eg test file has name `test**.nim`
  - user can provide path to root dir, and regexp that matches files
- list all test files that are included in this file
  - function should collect all files listed in `import ...`, also fetching all imports of those imports
- finally if there is difference between these two lists, show output 
  - user may configure with argument `--fail-on-dangling` if check should abort text execution (or just do it by default always)



Beautiful and efficient unit testing for Nim evolved from the standard library `unittest` module

nim-unittest2

feat: add dangling test files check

Currently we have two separate structures to deal with Ethereum Node Records, a "generic" one, named `NodeRecord`, that allocates to keep the pairs, and a specific one with the ones we understand, named `NodeRecordPairs`. I think we should move to using only the latter. Our own `local_node_record` currently uses the former, cloning a vector for every message. We should always use `NodeRecordPairs`, ignoring fields we don't know, like Geth does, and rejecting peers with invalid values in the ones we do know.

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