
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


More and more DeFi projects on Ethereum are getting hacked. This is your chance to join the party.

Each challenge can be considered standalone. Depending on the challenge, you should either stop the system from working, steal as much funds as you can, or do some other unexpected things.

Put your black hat on, and break some DeFi projects on Ethereum!

Damn Vulnerable DeFi


This is an interactive tutorial website for learning Vyper while building games using smart contracts, similar to Cryptozombies.

VyperFun


If you're a dev that's curious about crypto but not sure where to start -- this is the spot for you. Get access to project-based courses you'll love.

Learn about crypto by building cool stuff.

_buildspace


Learn How to Build a Crypto Company

The course videos from a16z’s Crypto Startup School, held in the spring of 2020, are now available to all.

Use the hours of free videos and the reading materials, to navigate the idea maze and start building crypto projects.

Hours of videos, lectures, presentations, real-world insights and fireside chats from some of the best minds in the crypto space.

a16z Crypto Startup School


Blockchain is an exciting new discipline in Computer Science. It combines a wide array of skills from math and cryptography to social sciences and understanding organizations. Understanding blockchain decentralization and how/where to apply it is a brand new skill that very few have mastered.

You will build your skills from the ground up with strong fundamentals that will provide you with the ability to adapt in this rapidly evolving ecosystem.

Choose From Multiple Paths to Begin Your Ethereum Coding Journey.

Fast-track your Ethereum Developer career in an instructor-led and challenging bootcamp focused on discussion and application!

ChainShot


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


Blockchain has emerged from the once shadowy world of cryptocurrency to become [the most in-demand skill in 2020](https://business.linkedin.com/talent-solutions/blog/trends-and-research/2020/most-in-demand-hard-and-soft-skills), according to LinkedIn. The promise of blockchain is huge. And large companies are continuing to hire and expand their blockchain teams, incl. Facebook, Amazon, Microsft, EY, Deloitte, IBM, and Oracle, to name a few. So, it should be well worth the effort to become familiar with how blockchain works, what its perceived benefits are, and as a developer starting building on top of them. 

Over the past few years, I’ve been helping and on-boarding new team members and developers into the blockchain space. This helped me to collect blogs, links, materials, and resources and see which worked well for everyone’s learning journey. It’s time to share that with a broader audience. This guide provides a starting point for developers who’re keen to learn more about blockchain and development on top of Ethereum. It will be opinionated and not contain a full list of everything available. But rather, a concise list of highly recommended options, from my own experiences. 

1. Blockchain foundations
1. Ethereum 101
1. Ethereum Development, Smart contracts & DApps 

# 1. Blockchain foundations 

New to blockchain? Let's start with a bit of the history and its foundations that motivated the creation and development of blockchain.

- [A Cyberphunk's Manifesto](https://www.activism.net/cypherpunk/manifesto.html), Eric Hughes
- [Why decentralization matters](https://onezero.medium.com/why-decentralization-matters-5e3f79f7638e), Chris Dixon
- [The Promise of the Blockchain](https://vimeo.com/161183966) (VIDEO), Vinay Gupta
- [The shift from open platforms to digital commons](http://www.bollier.org/blog/shift-open-platforms-digital-commons), David Bollier
- [Deconfusing decentralization](https://youtu.be/7S1IqaSLrq8) (VIDEO), Greg Slepak


# 2. Ethereum 101 

Now that we have an understanding where we're coming from, let's dive in a little bit deeper into the fundamental components & building blocks.

- [Bitcoin Whitepaper](https://bitcoin.org/bitcoin.pdf), Satoshi Nakamoto - the original whitepaper that started the current trend in blockchain technology: Bitcoin: A Peer-to-Peer Electronic Cash System
- [Ethereum Whitepaper](https://ethereum.org/en/whitepaper/), Vitalik Buterin - a next-generation smart contract & decentralized application platform
- [Ethereum Yellowpaper](https://ethereum.github.io/yellowpaper/paper.pdf), Gavin Wood - a more technical version of the Ethereum whitepaper
- [Smart Contracts](https://www.fon.hum.uva.nl/rob/Courses/InformationInSpeech/CDROM/Literature/LOTwinterschool2006/szabo.best.vwh.net/smart.contracts.html), Nick Szabo
- [Ethereum in 25 mins](https://youtu.be/mCzyDLanA7s) (VIDEO), Vitalik Buterin
- [How does Ethereum work, anyway](https://www.preethikasireddy.com/post/how-does-ethereum-work-anyway), Preethi Kasireddy
- [Mastering Ethereum](https://amzn.to/2VZvfz8) (BOOK), Andreas M. Antonopoulos, Gavin Wood. Or view on [Github](https://github.com/ethereumbook/ethereumbook)


# 3. Ethereum Development 


Once you've gone through all (or at least most) of the above, you should have a solid grasp of all the concepts. So now we can finally move on to the fun part: actually building stuff! 

To get a full, comprehensive overview of the Ethereum development landscape, check out:
- [Ethereum Developers](https://ethereum.org/en/developers/)
- [The full ConsenSys developer tool list](https://github.com/ConsenSys/ethereum-developer-tools-list)

The Ethereum portal covers sections per programming language, to help you filter out what's relevant for you. Though JavaScript is most commonly used, I'd start with something that you're already familiar with, to flatten the learning curve. Use the above only for future reference. As mentioned previously, I'm trying to keep it simple and offer a few recommended options, from my own experiences. Feel free to discover, try, and learn everything from the developer portals, once you've covered these.

## Other resources

Explore this site to learn more from 

- [🎓 Courses](https://www.useweb3.xyz/courses)
- [📚 Books](https://www.useweb3.xyz/books)
- [💻 Tutorials](https://www.useweb3.xyz/tutorials)
- [🏗️ Starter kits](https://www.useweb3.xyz/starter-kits)
- And more..


This guide provides a starting point for developers who’re keen to learn more about Web3

Beginners Guide to Web3


## 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 pratical 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


Web3 is about the next evolution of the web. A web that is more open, transparent and permissionless and runs on decentralized infrastructure such as blockchains. Global and decentralized applications (DApps) that anyone can interact with. They often have native assets integrated (such as Ether) to transact value, but are not just about money or payments. These decentralized applications offer a range of digitial services, such as storage, bandwidth and computation without any risk of downtime, censorship, fraud, or 3rd-party interference.

## Benefits

- **Open** - in that they are built from open-source software, by an open and accessible community of developers and executed in full view of the world. 
- **Trustless** - in that the network itself allows participants to interact publicly, or privately without a trusted third party
- **Permissionless** - in that anyone, both users and suppliers, can participate without authorisation from a governing body


## Opportunities

- Financial Tools (payments, fund raising, lending, borrowing,..)
- Identity solutions (self-sovereign, decentralized identifiers,..) 
- More secure voting and governance mechanisms
- Efficient resources management (CO2 tracking, smart grid’s,..)
- Digital ownership registries (e.g. land, collectibles, NFT’s,..)
- Supply chain tracking


## Web3 Development

[useWeb3](https://www.useweb3.xyz/) is a learning platform for developers to explore and learn about Web3. Whether you’re a new dev getting your hands dirty for the first time, or a seasoned developer making the transition into the Web3 space. 

Explore the latest resources, tutorials, challenges, tools, courses and boilerplates and start learning. Once you’re ready, browse the job board to land a job at some of the leading companies that work on core, open-source infrastructure, products, tools, frameworks, DAO's, etc.


## Further reading

- [A Cyberphunk's Manifesto](https://www.activism.net/cypherpunk/manifesto.html), Eric Hughes
- [The Meaning of Decentralization](https://medium.com/@VitalikButerin/the-meaning-of-decentralization-a0c92b76a274), Vitalik Buterin
- [Why decentralization matters](https://onezero.medium.com/why-decentralization-matters-5e3f79f7638e), Chris Dixon
- [What Is Web 3.0 & Why It Matters](https://medium.com/fabric-ventures/what-is-web-3-0-why-it-matters-934eb07f3d2b), Max Mersch and Richard Muirhead
- [What exactly is Web3?](https://youtu.be/l44z35vabvA), Juan Benet (VIDEO)


Web3 is about the next evolution of the web. A web that is more open, transparent and decentralized.

What is Web3


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


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


Introduces great features:

- React hooks - Uses React hooks as your primary building ingredient
- Auto refresh - Refreshes on a new block, wallet change or network change
- Multicall - Combines multiple blockchain calls into a single multicall

Combines the best practices:
- Modern stack - Employs ethers.js, web3-react, multicall & waffle
- Extendability - Extends easily with custom hooks
- Testability - Simple integration tests for UI and blockchain

Framework for rapid Dapp development. Simple. Robust. Extendable. Testable

useDapp


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


Nowadays there are countless well-made resources on how to learn blockchain development of all kinds and with different specializations in mind, however, it is still very hard to get guidance and personalized suggestions based on your interests. I am writing this guide in order to provide an aggregator of all the resources that I’ve found over the years, plus give some opinionated commentary on how to approach them and how to use them in order to maximize learning and practical understanding in order to get building cool things in the space as soon as possible.

This guide will focus on the Ethereum ecosystem as that’s where most developers and applications are. If you are interested in other ecosystems that are non-EVM compatible and are not L2s on Ethereum, then check out their respective documentation or guides written by their developer communities. Examples of other non-EVM compatible blockchains that are popular are Solana (Rust/Anchor), Polkadot (Rust/Substrate), Cosmos, Terra, and others. Most of these blockchains do or will support the EVM stack through various initiatives like Neon EVM (Solana), Moonbeam/Moonriver (Polkadot/Kusama), EVMOS (Cosmos), etc.

I really want this guide to become a community-sourced public good that everyone will be able to take advantage of. I will do my best to present it to the wider blockchain developer community to get constructive feedback, proofreading help, and insight into how to make it the best available guide available.

devpill.me


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

Like the title says - there was an accident where we merged pr that passed tests into main with a wrong tool path. We should write a test that checks if the page doesn't throw a 404 at us. 

enhancement

good first issue

A handy toolset for every Ethereum developer ⚒️

dethtools

TypeScript

Add tests for the tool tree component

**Describe the bug**
We've introduced an unexpected breaking change in 1.13.4:
In case you do not use your own configuration file, _mainnet.cfg_ settings are used by default and since the update, SnapSync is enabled by default for the mainnet configuration, which means it's enabled for your node too.
It will cause a problem in networks without SnapSync supporting nodes.

**Expected behavior**
Nodes without a config file shouldn't use the _mainnet.cfg_ file as a default. 



Our flagship .NET Ethereum client for Linux, Windows, and macOS—full and actively developed

nethermind

Don't make mainnet.cfg the default

eipw

Rust

Markdown lint to ensure inline solidity with a `SPDX-License-Identifier` has a license of CC0.

For example:

```
Error: error[markdown-rel-links]: non-relative link or image
  --> EIPS/eip-5190.md
   |
17 | This EIP also extends account-bound token from [EIP-4973](https://eips.ethereum.org/EIPS/eip-4973), but the difference is that it can be transferred to other account for mobility between managing device.
   |
   = help: use `[EIP-4973](./eip-4973.md)` instead
```

Special case `markdown-rel-links` to help when linking to eips.ethereum.org

### Component

Cast

### Describe the feature you would like

The command cast send can be send transaction just by rpc and calldata subcommand.

### Additional context

MacBook-Pro ~ % cast send [calldata] -rpc 


T-feature

C-cast

Foundry is a blazing fast, portable and modular toolkit for Ethereum application development written in Rust.

foundry

Cast send tx by Calldata

See https://github.com/foundry-rs/foundry/pull/2299

A-forge

A-reference

T-new

A book on all things Foundry, available at https://book.getfoundry.sh.

book

Solidity

Document `vm.derive`

### Describe the desired feature

The description on https://pypi.org/project/slither-analyzer/ is not being rendered as markdown. Add the line `long_description_content_type="text/markdown",` to the `setup.py` for it to render correctly in future releases.

slither

Python

README is not correctly rendered on PyPi

I've seen this mistake more than a couple of times already, so I think it's worth doing this little extra check.

package:hardhat-etherscan

Hardhat is a development environment to compile, deploy, test, and debug your Ethereum software. Get Solidity stack traces & console.log.

hardhat

[hardhat-etherscan] Show an error if the etherscan config has an `apikey` property instead of `apiKey`

We have found that some webhook notifications to the controller (such as RFC 0160 Connections) do not have the `~thread` decorator from the protocol being executed.  This is at minimum useful and in some cases required for the controller to track requests across many protocol instances. For the initial message of a protocol, the `~thread` decorator is (often) not present in the message and so the `id` for the message must be included in the webhook data (the `id` of the first message becomes the `thid` of the protocol instance). The `id` could always be added to all of the webhooks as well.

The task is to review all webhooks related to protocol messages and add the `~thread` decorator or `id` (for first messages of a protocol only) to all webhooks.

help wanted

Hyperledger Aries Cloud Agent Python (ACA-Py) is a foundation for building decentralized identity applications and services running in non-mobile environments.

aries-cloudagent-python

Add ~thread decorator information to webhooks that don't have it

@chriseth reports that search hits in our docs look like this in Google:
![image](https://user-images.githubusercontent.com/137030/178474001-f26cf55c-76ca-4346-a7ef-ce3e407bd094.png)

Here's what Googles's help says about this: [No page information in search results](https://support.google.com/webmasters/answer/7489871).

I'm pretty sure this has something to do with the [`robots.txt`](https://docs.soliditylang.org/robots.txt) changes we did some time ago #10898. The search result seems to be from `develop`, which our `robots.txt` block. We only allow `latest`, `v0.7.6` and latest release. The question is - why is `develop` still getting indexed (and appears in results before those other allowed versions) if we blocked it?

bug :bug:

documentation :book:

Solidity, the Smart Contract Programming Language

solidity

No summary for our documentation pages in Google search results

Launched a fabric network using fabric cli with a total of 3 firefly nodes. Deployed asset-transfer-basic chaincode by following the steps mentioned in the documentation https://hyperledger.github.io/firefly/tutorials/custom_contracts/fabric.html.

Ran three blockchain transactions from org1 and then created an event listener from org2. After creating an event listener, org2 didn't receive any events. Ran fourth transaction from org1, now org2 received the fourth transaction but not the previous transactions.

Below is the payload used for creating event listener in org2
```
{
  "interface": {
    "id": "f1e5522c-59a5-4787-bbfd-89975e5b0954"
  },
  "location": {
    "channel": "firefly",
    "chaincode": "asset_transfer"
  },
  "event": {
    "name": "AssetCreated"
  },
  "options": {
    "firstEvent": "oldest"
  },
  "topic": "assets"
}
```
### Expected: 
Org2 should receive all the events emitted before creating an event listener
### Actual: 
Org2 didn't receive events emitted before creating an event listener

Hyperledger FireFly is the first open source Supernode: a complete stack for enterprises to build and scale secure Web3 applications. The FireFly API for digital assets, data flows, and blockchain transactions makes it radically faster to build production-ready apps on popular chains and protocols.

firefly

Unable to listen to events emitted before creating event listener

See https://github.com/foundry-rs/foundry/pull/2243

Should be explained and present in the Anvil reference

A-anvil

Document trailing block number syntax

**Why do you think it is important?**

People may be confused as it is not clear what it is used for and how to choose the right value. Groups are an abstraction of Merkle trees, but it is still necessary to explain how a Merkle tree works for those who want to go deeper.

documentation

website

Zero value

## Description

Solidity compiler publishes `license` property for `SPDX-License-Identifier` at the starting docstring of `SourceUnit`.

## Context

This feature is still missing support in the typed AST. We should also consider supporting `documentation` property for the `SourceUnit` in related processors, but also tweaking `StructuredDocumentationReconstructor` and `StructuredDocumentationReconstructingPostprocessor` to correctly detect it for legacy compiler versions.

## Tests

A sample with `license` is following:

```solidity
/// SPDX-License-Identifier: UNLICENSED
/// Other documentation on SourceUnit level.
pragma solidity ^0.8.15;

contract Test{}
```

The produced AST is following:

```js
{
    "sources": {
        "sample.sol": {
            "ast": {
                "absolutePath": "sample.sol",
                "exportedSymbols": {
                    "Test": [
                        2
                    ]
                },
                "id": 3,
                "license": "UNLICENSED",
                // The ^ "license" field.
                // Note that other docs are missing but we can probably extract it on our own.
                "nodeType": "SourceUnit",
                "nodes": [
                    {
                        "id": 1,
                        "literals": [
                            "solidity",
                            "^",
                            "0.8",
                            ".15"
                        ],
                        "nodeType": "PragmaDirective",
                        "src": "85:24:0"
                    },
                    {
                        "abstract": false,
                        "baseContracts": [],
                        "canonicalName": "Test",
                        "contractDependencies": [],
                        "contractKind": "contract",
                        "fullyImplemented": true,
                        "id": 2,
                        "linearizedBaseContracts": [
                            2
                        ],
                        "name": "Test",
                        "nameLocation": "120:4:0",
                        "nodeType": "ContractDefinition",
                        "nodes": [],
                        "scope": 3,
                        "src": "111:15:0",
                        "usedErrors": []
                    }
                ],
                "src": "85:42:0"
            },
            "id": 0
        }
    }
}
```

A TypeScript package providing a normalized typed Solidity AST along with the utilities necessary to generate the AST (from Solc) and traverse/manipulate it.

solc-typed-ast

Support `SourceUnit` documentation strings and `license` field

The `divMod` function in [points.go](https://github.com/NethermindEth/juno/blob/64ec93002abdc74e44bf6b20995a192bb07236fd/pkg/crypto/pedersen/points.go#L2050-L2058) is a major bottleneck when applying state diffs to the local database. Right now, we are using `big.Int`s, which are inefficient.

**Solution**

An implementation of [Lehmer's GCD algorithm](https://en.wikipedia.org/wiki/Lehmer%27s_GCD_algorithm) using the felt package. This is the same algorithm that the `big` package uses, but our `felt.Felt`s should vastly outperform `big.Int`s. 

Note that we don't want to use the modular arithmetic functions provided by the felt package when computing the GCD. Since our felts are just `[4]uint64` underneath, we can use the very fast [uint256](https://github.com/holiman/uint256) library instead.

**Alternatives Considered**

I have tried to implement this using [`gmp.Int`](https://github.com/ncw/gmp) as a drop-in replacement for `big.Int`, but it was slower than using `big.Int`s directly (probably due to the increase in allocations from felt -> big.Int -> gmp.Int -> big.Int -> felt). 

I also considered porting the [`igcdex`](https://github.com/sympy/sympy/blob/6ea48db2bd108a0c5b3c53aa2f1ef9e5d617bf3c/sympy/core/numbers.py#L445-L488) function from the Python [reference implementation](https://github.com/starkware-libs/cairo-lang/blob/2abd303e1808612b724bc1412b2b5babd04bb4e7/src/starkware/python/math_utils.py#L27), but it implements Euclid's GCD algorithm, which is slower than Lehmer's algorithm for big numbers.

crypto

juno

Optimize the DivMod function

## Description

After removing the fallback for engines in the execution_layer crate, we don't need the `secret_files` and `execution_endpoint` to be able to hold more than one in each field. Those could be changed to be options or even mandatory fields.

The relevant code is [here](https://github.com/sigp/lighthouse/blob/748475be1ded2c9a29cbd8b985f6ae2980720a36/beacon_node/execution_layer/src/lib.rs#L119-L123)


lighthouse

Remove redundancy in the ulrs in the execution layer' config

**Describe the bug**
When we are proceeding to install juno, I a fresh machine, according to the system, some dependencies are missing, for example on the ubuntu case, there isn't reference to install `gcc`.

**To Reproduce**
Steps to reproduce the behavior:
1. Try to install Juno on a Ubuntu empty machine

**Expected behavior**
Add more documentation for each of the different operative systems and orient the documentation to a more user friendly 

**Screenshots**
Juno command missing because the path doesn't include the bin folder of golang after `go install`
![image](https://user-images.githubusercontent.com/35319980/177059491-7628aec2-b181-459d-9b41-1db4f1dc5d54.png)

`gcc` missing
![image (1)](https://user-images.githubusercontent.com/35319980/177059493-01137c3b-2655-4554-b6b7-52d1b1fc564e.png)

**Desktop (please complete the following information):**
 - OS: Any


Add installation instructions for different OS

Since https://github.com/foundry-rs/foundry/pull/2151 we can parse more complex function calls. We should document how this works with `forge create` - see the existing docs here: https://github.com/foundry-rs/book/pull/406

T-enhancement

Document how to pass arrays and structs to constructors

### Component

Cast

### Describe the feature you would like

This [handy utility](https://emn178.github.io/solidity-optimize-name/) generates an optimized function name (i.e. a function selector with leading zero bytes) for a given Solidity function signature. For example, `transfer(address,uint256)` returns the optimized name `transfer_G8l(address,uint256)`, with the selector `0x0000c771`. 

This would be a nice helper utility to add to `cast`.

Seems like this might make sense as a flag or subcommand under `cast sig`. Maybe something like:

```bash
$ cast sig "transfer(address,uint256)"
0xa9059cbb
$ cast sig "transfer(address,uint256)" --optimize
transfer_G8l(address,uint256)
0x0000c771
```



### Additional context

(Inspired by a deleted tweet from @transmissions11)

feat(cast): add optimize selector command

**Describe the bug**

```sh
   ok 41 All WASM build files OK
    not ok 42 ReferenceError: memory is not defined
      ---
        operator: error
        at: bound (/home/runner/work/cactus/cactus/node_modules/tape-promise/node_modules/onetime/index.js:30:12)
        stack: |-
          /tmp/cactus-test-tooling-rustc-container-test2022530-13267-iz29ib.vbfdl/hello_world_bg.js:165
          cachedInt32Memory0 = new Int32Array(wasm.memory.buffer);
          ReferenceError: memory is not defined
              at Object.<anonymous> (/tmp/cactus-test-tooling-rustc-container-test2022530-13267-iz29ib.vbfdl/hello_world_bg.js:165:42)
              at Generator.next (<anonymous>)
              at Generator.next (<anonymous>)
              at Object.<anonymous> (/tmp/cactus-test-tooling-rustc-container-test2022530-13267-iz29ib.vbfdl/hello_world.js:1)
              at Generator.next (<anonymous>)
```

**To Reproduce**

Run `packages/cactus-test-tooling/src/test/typescript/integration/rustc-container/rustc-container-target-bundler.test.ts`

**Expected behavior**

Passes.


**Cloud provider or hardware configuration:**

Everywhere.

**Operating system name, version, build:**

Ubuntu-20.04

**Hyperledger Cactus release version or commit (git rev-parse --short HEAD):**

`main`


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