
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

Encoding and Decoding ABI allocates a lot, rewrite it to a version that will allocate a lot less (stream-like or spans?) and update usages.

help wanted

performance

low priority

A robust execution client for Ethereum node operators.

nethermind

Optimize ABI API to have less allocation

## Component the issue is related to
Data Transformer

## Issue
`CairoU256::from_bytes` accepts an unbound `u8` slice, panicking if it's shorter than 32 bytes and ignoring the extra bytes if it's longer.
The argument should be a fixed-sized slice - `&[u8; 32]`.
Usage in `cheatnet::runtime_extensions::forge_runtime_extension` should be adjusted to the new method.

sncast

maintenance

Blazing fast toolkit for developing Starknet contracts.

starknet-foundry

Rust

Improve the `data-transformer::cairo-types::CairoU256` creation logic

## Component the issue is related to
Data Transformer

## Issue
At the moment, representations of Cairo numeric types provided by `data-transformer` are not fully tested.
A proper unit tests need to be added in `bytes31`, `u96` and `u384`. Also, utility functions from the [`helpers`](https://github.com/foundry-rs/starknet-foundry/blob/master/crates/data-transformer/src/cairo_types/helpers.rs) modules should be tested.

Below is an example test which you can refer to:
https://github.com/foundry-rs/starknet-foundry/blob/master/crates/conversions/tests/e2e/non_zero_u128.rs

ODBoost

odboost: Easy

Add unit tests for data transformer types

There is no easy way to create new tasks. Add a command `just new-task` to the root `justfile` that takes the following arguments:

1. L1 network short name. Allowed network names are currently `eth`, `oeth`, `opsep`, `sep`, and `sep-dev-0`. Unrecognized network names should error
2. L2 network short name. Allowed network names are all short names from the superchain registry. Unrecognized network names should error
3. Task name. This must be a hyphenated string such as `fjord-gas-config` or `guardian-upgrade`
4. Task kind. Single or nested are the only allowed values for now. In the future we can expand this to other tasks, like presigned pauses, or the fault proof recovery template tasks.

The command should:
- Create a folder called `tasks/{arg1}/{arg2}-{x}-{arg3}`, where `arg1` and `arg3` match the above arguments. `arg2` matches the above argument but is omitted if the L2 network is OP Mainnet (this is the current convention). Lastly, `x` is the next incrementing number for that L2's task sequence. For example if `mode-002-*` is the most recent task for mode, the next task would have `x` as `003`.
- Create `README.md` and `VALIDATION.md` templates with placeholders for the user to fill out
- Create a template `input.json` file
- Create the appropriate `SignFromJson.s.sol` or `NestedSignFromJson.s.sol` with the appropriate imports, functions that need to be implemented, etc
- A `.env` file (or equivalent if #336 is done first)

good first issue

superchain-ops

Solidity

Command to scaffold a new task directory with required files

**As a** blockchain administrator
**I want** the chaincode QueryApproved function to support Fabric v3 features
**So that** I can query all chaincode approvals for a channel

Fabric v3 allows the QueryApprovedChaincodeDefinition lifecycle transaction function to:

1. Omit a sequence ID to query the latest sequence number of a given chaincode definition.
2. Specify only the channel name to query all approved chaincode definitions on the channel.

These capabilities should be tested in the end-to-end tests when using Fabric v3. If they add value, additional unit tests should be added for these scenarios. This behaviour should be documented in the Godoc for the chaincode.Gateway.QueryApproved function.

See the [Fabric CLI examples](https://hyperledger-fabric.readthedocs.io/en/latest/commands/peerlifecycle.html#peer-lifecycle-chaincode-queryapproved-example) for further information.

fabric-admin-sdk

New chaincode.QueryApproved capability in Fabric v3

One of the largest bottlenecks during syncing post [eip-1108](https://eips.ethereum.org/EIPS/eip-1108) are the bncurve precompiles - nim-bncurve can no longer keep up.

As an alternative, we could switch to `mcl` which is a classic battletested option that is [fast](https://hackmd.io/@gnark/eccbench). Getting to this point requires first creating an `mcl` wrapper similar to `nim-secp256k1` and then adding a selection layer similar to how nim-ssz-serialization can switch between multiple sha256 instances.

Worth exploring is also [constantine](https://github.com/mratsim/constantine), though this should be added only once we have an mcl backend, so that we can run comparative analysis.

`nim-bncurve` should be kept as a pure-nim fallback option.


optimization

Nimbus: an Ethereum Execution Client for Resource-Restricted Devices

nimbus-eth1

Add `mcl` (and possibly `constantine`) backends for alt_bn128 precompiles

### Which components does the task require to be changed? (think hard pls)

sncast

### Description

There are currently two similar `AccountType` enums. We should consider refactoring to keep only one to avoid redundancy.

Refs:
https://github.com/foundry-rs/starknet-foundry/blob/526e415cce71789f4839c5b9aa85d872f75d59b6/crates/sncast/src/lib.rs#L45

https://github.com/foundry-rs/starknet-foundry/blob/526e415cce71789f4839c5b9aa85d872f75d59b6/crates/sncast/src/starknet_commands/account/mod.rs#L42

refactor

Remove redundancy in `AccountType` enums

https://github.com/privacy-scaling-explorations/zk-kit.circom/blob/326cef9fdb9a2f845b890cffea0594975768be1f/packages/poseidon-cipher/src/poseidon-cipher.circom#L110C1-L116C18

this can be replaced with 
```
Num2Bits(128)(nonce);
```

refactoring :recycle:

audit 🔍

zk-kit.circom

Circom

better nonce constraint

https://github.com/privacy-scaling-explorations/zk-kit.circom/blob/326cef9fdb9a2f845b890cffea0594975768be1f/packages/utils/src/safe-comparators.circom#L16

the inputs are not constrained to be in the range of n. A counter example is 
```
Found SafeLessThan counter example:
n: 8
in: [1000, 512]
Expected: 0 Got: 1
```

A suggested change:
```
template SafeLessThan(n) {
    assert(n <= 252);
    signal input in[2];
    signal output out;

    // Constrain inputs to n bits
    component range_check[2];
    for (var i = 0; i < 2; i++) {
        range_check[i] = Num2Bits(n);
        range_check[i].in <== in[i];
    }

    component n2b = Num2Bits();
    n2b.in <== in[0] + (1<<n) - in[1];

    out <== 1 - n2b.out[n];
}
```

bug 🐛

SafeLessThan is unsafe

The variables lta and ltb are no-oping [here](https://github.com/privacy-scaling-explorations/zk-kit.circom/blob/326cef9fdb9a2f845b890cffea0594975768be1f/packages/utils/src/float.circom#L56) and may be removed. There are no constraints applied to either variable, the assert statement is a witness computation time operation, not a proving operation.

The only case where they do an operation is if the value of either a or b is attempting to be constrained to the constant 252 bits. If this is the case it should be implemented with Num2Bits directly as LessThan does not apply this constraint.

There is another no-op occurence [here](https://github.com/privacy-scaling-explorations/zk-kit.circom/blob/326cef9fdb9a2f845b890cffea0594975768be1f/packages/utils/src/float.circom#L70). This value should instead be constrained with isz === 0

noop variable assert

https://github.com/privacy-scaling-explorations/zk-kit.solidity/blob/a4e7136d6771456d0118729f3f5fe3dc9f7a4148/packages/imt/contracts/QuinaryIMT.sol#L9
https://github.com/privacy-scaling-explorations/zk-kit.solidity/blob/a4e7136d6771456d0118729f3f5fe3dc9f7a4148/packages/imt/contracts/BinaryIMT.sol#L13
https://github.com/privacy-scaling-explorations/zk-kit.solidity/blob/a4e7136d6771456d0118729f3f5fe3dc9f7a4148/packages/lazy-imt/contracts/LazyIMT.sol#L9

Should we put in place a mechanism to always call init once and only once?

A monorepo of reusable contracts for zero-knowledge technologies. 

zk-kit.solidity

init function in IMT trees can be called multiple times

https://github.com/privacy-scaling-explorations/zk-kit/blob/253277c91c8ffee33bfb4bc5abd8a0db0251df61/packages/smt/src/smt.ts#L237

not sure if it is as designed, but verifyProof return True for any key with an empty tree. It makes better sense if false is returned:
```
verifyProof(merkleProof: MerkleProof): boolean {
    if (this.root === this.zeroNode) {
        // Empty tree case
        return merkleProof.root === this.zeroNode && 
               merkleProof.siblings.length === 0 &&
               merkleProof.matchingEntry === undefined &&
               merkleProof.membership === false;
    }
    // ... rest of the method ...
}```

A monorepo of reusable libraries for zero-knowledge technologies.

zk-kit

TypeScript

verifyProof probably should return false for any key if the tree is empty

https://github.com/privacy-scaling-explorations/zk-kit/blob/de43718b9a400f46b3b89a288d01b9d32e9b17d3/packages/smt/src/smt.ts#L292

here childNodes could be a leaf node of Entry type ([Key, Value, EntryMark]). However, the type system is defined as:
private nodes: Map<Node, ChildNodes>
export type ChildNodes = Node[]
export type Node = string | bigint

A more accurate system would be:
export type Node = string | bigint
export type InternalChildNodes = [Node, Node]
export type LeafChildNodes = [Key, Value, EntryMark]
export type ChildNodes = InternalChildNodes | LeafChildNodes
private nodes: Map<Node, ChildNodes>

the type of childNodes is not comprehensive

https://github.com/privacy-scaling-explorations/zk-kit/blob/c912111c134b6bbefe223bb61ba22f864036e9ba/packages/poseidon-cipher/src/poseidonCipher.ts#L19

implementation that uses the javascript BigInt is vulnerable to timing attacks ([more info](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/BigInt#cryptography)). 
If constant-time operation is a requirement, this needs changes to use constant time modular math libraries.
Otherwise, dependent packages/applications should be made aware.

documentation  📖

use of BigInt is vulnerable to timing attacks

Feature Request: Use Git Submodule for Legal Documents Comparison

## Summary:
We should introduce a CI step that compares local legal documents in the `status-mobile` and `status-desktop` repositories with the source legal documents in the `status-software-legal-documents` repository. This can be achieved by adding `status-software-legal-documents` as a Git submodule and using it as the basis for comparison.

## Motivation:
To ensure that platform-specific legal documents (such as privacy policies) are always in sync with the canonical versions from the `status-software-legal-documents` repository, we can automate the comparison process using Git submodules and git diff. This ensures there are no discrepancies and minimises the risk of legal document inconsistencies.

## Proposed Solution:
1. Add the `status-software-legal-documents` repository as a Git submodule:
To ensure the legal documents are up-to-date across platforms, we can add the `status-software-legal-documents` repository as a submodule to the platform-specific repositories.

```bash
# Navigate to the target repository (e.g., status-mobile)
cd status-mobile

# Add the legal documents repository as a submodule
git submodule add https://github.com/status-im/status-software-legal-documents.git path/to/legal-docs

# Initialise and update the submodule
git submodule update --init
```

2. Compare Local Files with the Submodule:
Once the submodule is added, we can compare the local legal documents with the submodule files using `git diff --no-index`. This allows us to verify if any differences exist between the two versions.

Example:
```bash
git diff --no-index path/to/local-file.md path/to/legal-docs/privacy-policy.md
```

3. Automate Comparison in CI:
To automate this process, we can create a script that performs the following:

- Ensures the submodule is updated to the latest version.
- Uses `git diff --no-index` to compare the local and submodule files.
- Fails the CI job if any differences are found.

Example CI Script:
```bash
#!/bin/bash

# Ensure the submodule is updated to the latest version
git submodule update --remote

# Compare the local file with the submodule file
if ! git diff --no-index path/to/local-file.md path/to/legal-docs/privacy-policy.md; then
  echo "Differences found between the local file and the submodule file."
  exit 1
else
  echo "No differences found. Files are in sync."
fi
```

This script could be added to the CI pipeline to ensure that PRs involving legal documents are automatically checked for consistency.

## Why Do This?:
- Automatic Synchronisation: Ensures platform-specific legal documents are always up-to-date with the source legal documents in `status-software-legal-documents`.
- Reduced Risk of Inconsistencies: Using a Git submodule and git diff ensures that discrepancies between the documents are caught early.
- Simplified CI Process: Instead of manually checking or downloading files for comparison, we can rely on the Git submodule to manage updates and synchronisation.

## Next Steps:
See the Sub-issues section

<details>
<summary>Old issue proposal</summary>

## Summary:
We should introduce some kind of CI process to ensure that the platform documents (across `status-mobile`, `status-desktop`, etc.) have no differences from the official legal documents hosted in `status-software-legal-documents`. This would help maintain consistency and avoid potential legal discrepancies across platforms.

## Motivation:
As the legal documents (e.g., privacy policy, terms of use) may be duplicated across different repositories and projects (`status-mobile`, `status-desktop`, etc), it's crucial to ensure that no accidental changes or discrepancies are introduced in those platform-specific versions. A CI check will automatically verify that the copies of the legal documents used in these repositories are always up-to-date with the canonical versions from the `status-software-legal-documents` repository.

## Proposed Solution:
1. Download the raw versions of the files from GitHub and compare them:
We can use a CI tool to download the raw files from the relevant repositories, and then compare them using git diff (or another diff tool). Here's an example of how it could be done:

```bash
wget -O legal-original.md https://raw.githubusercontent.com/status-im/status-software-legal-documents/master/privacy-policy.md
wget -O mobile-copy.md https://raw.githubusercontent.com/status-im/status-mobile/develop/path/to/privacy-policy.md
wget -O desktop-copy.md https://raw.githubusercontent.com/status-im/status-desktop/develop/path/to/privacy-policy.md
```
2. Use git diff to compare the downloaded files:
Once the files are downloaded, we can use git diff to compare the legal document against the platform-specific copies:

```bash
git diff legal-original.md mobile-copy.md
git diff legal-original.md desktop-copy.md
```

3. Automating in CI:
This can be integrated into the CI pipeline by writing a small script that performs the following steps:

- Fetch the legal document from the `status-software-legal-documents` repository.
- Fetch the corresponding documents from the platform repositories (e.g., `status-mobile`, `status-desktop`).
- Compare the documents using a diff tool.
- Fail the CI job if any differences are found.
We can add this CI step to repositories like `status-mobile` and `status-desktop` so that every PR that modifies these documents will automatically check for discrepancies.

Example CI Script:
```bash
#!/bin/bash

# Fetch legal document
wget -O legal-original.md https://raw.githubusercontent.com/status-im/status-software-legal-documents/master/privacy-policy.md

# Fetch platform-specific copies
wget -O mobile-copy.md https://raw.githubusercontent.com/status-im/status-mobile/develop/path/to/privacy-policy.md
wget -O desktop-copy.md https://raw.githubusercontent.com/status-im/status-desktop/develop/path/to/privacy-policy.md

# Perform diff checks
if ! git diff --quiet legal-original.md mobile-copy.md; then
  echo "Diff found between legal document and mobile version"
  exit 1
fi

if ! git diff --quiet legal-original.md desktop-copy.md; then
  echo "Diff found between legal document and desktop version"
  exit 1
fi

echo "No diff found, all platform documents are up to date"
```

## Next Steps:
- Integrate this script (or a variation of it) into the CI for relevant repositories.
- Ensure that any PRs affecting legal documents trigger this check.

## Benefits:
- Prevents accidental modification or out-of-sync issues with legal documents across platforms.
- Ensures users of all platforms are presented with the same legal information.
- Adds an extra layer of compliance and peace of mind for the team.
</details>

The single source of truth for all Status Software privacy policy references. If it isn't in this repo it probably isn't legitimate, unless Legal say different.

status-software-legal-documents

Feature Request: Use Git Submodule for Legal Documents Comparison

## Component the issue is related to
Cast - data transformer

## Issue
Data transformer should throw an error in case of passing an *ambiguous* struct or enum name.
We test this behaviour for structs but tests for enums are lacking.
One need to create a new contract which uses an external enum and defines its own with identical name at the same time.

There is already an existing test for structs that can be seen here

https://github.com/foundry-rs/starknet-foundry/blob/5306b4375c5b01653d295fef8d4d0f58ea071da8/crates/data-transformer/tests/integration.rs#L578

Create a new test that tests ambigous enums, in similar manner as the test linked above.

## Example and explanation:
Suppose we use Alexandria's `BitArray` type in our contract. We define our own struct with the same name and use it to.
```rs
#[starknet::contract]
mod Contract {
    /* ... */

    use alexandria_data_structures;

    pub struct BitArray { };

    fn method(
        self: @ContractState,
        external_type_array: alexandria_data_structures::bit_array::BitArray,
        our_own_type_array: BitArray
    ) { }
}
```

When calling `method` from CLI, we need to refer to these structures using paths:
```shell
sncast [...] --calldata "alexandria_data_structures::bit_array::BitArray { ... }" "data_transformer_contract::BitArray{ ... }"
```

When called without paths, Cast will throw an error:
```
Error while processing Cairo-like calldata:

Caused by:
    Found more than one struct "BitArray" in ABI, please specify a full path to the item
```

Add tests with ambiguous enum to data transformer

In `script/utils/check-task-statuses.sh` we define the following allowed task status:

https://github.com/ethereum-optimism/superchain-ops/blob/4a7d0f398555c9d17c83f84586db29d6743c7a96/script/utils/check-task-statuses.sh#L4

Of these, the SIGNED (for presigned pauses only), EXECUTED. and CANCELLED statuses are terminal, meaning once a task's status is changed to this value it should never change again.

When we add new tasks, the task author must manually remember to add them to CI (see `just_simulate_sc_rehearsal_1` as an example), but this is easy to forget. Instead, we should have CI do the following:
- Loop over all tasks in all `tasks/*` directories.
- Extract all tasks that have a status that is not a terminal status
- Determine if they are single safe or nested safe tasks (this can be done based on the name of the Solidity file—if it's `NestedSignFromJson` it's a nested safe task, otherwise it's a standard single safe)
- Simulate the task in CI (simulation commands differ for nested vs. standard). For nested safes, we should also simulate the approve calls, which provides an additional mitigation for https://github.com/ethereum-optimism/superchain-ops/issues/268
- The CI job should fail if any approval or simuation fails

The reason we filter tasks by "tasks in a non-terminal status" instead of "statues that precede execution" is to be more robust: If a new task status is added, by default CI will try executing tasks with those status, and we can add that task status to the terminal status list if needed


Automatically run tasks in CI if task is in a non-terminal state

# Summary

[Reference](https://docs.fuel.network/docs/fuels-ts/types/bits512/) 

- We could rename these to `B512` from `Bits512` to better align with the wider ecosystem.
- We're missing documentation on how to form a B512, from two B256.
- I think the [example](https://docs.fuel.network/docs/fuels-ts/types/bits512/#b512-in-the-sdk) of just using the wallet public key could be changed to show how to form this with two b256.
- We could also improve the Sway example with a more complex use-case, rather than just echoing out the response.
- The Rust SDK are using the B512::from function ([here](https://github.com/FuelLabs/fuels-rs/blob/84266d27a9640b1f6c7b2d2c81186ff6b024b8ff/e2e/sway/types/contracts/b512/src/main.sw)) and I was unclear how to imitate this with the TS SDK. (this could be a feature request)

docs

fuels-ts

Documentation for `B512`

### Summary

[Reference docs](https://docs.fuel.network/docs/fuels-ts/types/bits256/)
- We could rename these to B256 from [Bits256](https://docs.fuel.network/docs/fuels-ts/types/bits256/#bits256)to better align with the wider ecosystem.
- Currently we display how use `getRandomB256` however I believe we should use actual addresses for a better showcase of their use cases.
- We're missing how to use these addresses with an actual contract.
- We're also missing how these can be used in Sway programs.

Documentation for `B256`

Closes: https://github.com/foundry-rs/foundry/issues/4497

BTT is picking up steam, and it would be worth mentioning it in the Foundry Book.

References:

- [Bulloak landing page](https://bulloak.dev/)
- [Bulloak GitHub](https://github.com/alexfertel/bulloak)
- [BTT at Solidity Summit 2023](https://prberg.com/presentations/solidity-summit-2023/)
- [BTT on Twitter #1](https://x.com/PaulRBerg/status/1682346315806539776)

cc @alexfertel

T-enhancement

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