
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


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


## 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 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


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

Free resources to learn about Zero Knowledge Proofs (ZKPs) and Cryptography

Road to ZK


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


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

### Objective:
Currently, the Iroha Client CLI supports the registration of assets that can be minted multiple times. However, for specific use cases like creating unique, one-of-a-kind tokens or non-fungible assets, there's a need for assets that can only be minted once.

### Requirements:
   - Suggested command format: 
     ```
     ./iroha_client_cli asset register --id="unique_asset#domain" --value-type=Quantity --mintable-once
     ```
   - The `--mintable-once` flag should be an optional flag that, when included, sets the asset to be mintable only once.

good first issue

iroha2

Iroha - A simple, enterprise-grade decentralized ledger

iroha

Implement Single-Mintable Asset Registration in Iroha Client CLI

Implement Multi-Signature Transactions via Client CLI

### Objective:
We need to extend the functionality of our iroha_client_cli to allow users to add new signatories to existing accounts.

### Requirements:
   - Suggested command format:
     ```
     ./iroha_client_cli account add-signatory \
         --account_id="<account_id>" \
         --public_key="<new_public_key>"
     ```
   - Where `account_id` is the ID of the account to which the signatory is being added, and `public_key` is the public key of the new signatory.


Implement Feature for Adding New Signatories via Client CLI

Right now we can't resume unziping and checksum verification because we try to download zero bytes from server and fail with IOException. Before starting download we should check if snapshot was downloaded.  

A robust execution client for Ethereum node operators.

nethermind

Resume snapshot unziping and checksum verification

This issue outlines how external contributors could really help out the starknet.go package by helping to increase the test coverage for starknet.go's rpc package. See the readme for the list of starknet methods.  I would also recommend looking at existing test cases for help.

A good approach would be to start with the read methods (those that don't require gas/fee tokens, eg, getTransactionByHash, starknet_getBlockWithTxs, etc), and with mock environments (doesn't require starknet endpoint). Only once you are very comfortable working with these would I recommend starting to work on devnet environments, and then testnet/mainnet environments.

If you are interested in starting a new issue please:
1. Create a new issue outlining which (method,environment) you would like to work on. Eg "Increase test coverage of (starknet_getNonce, mock)". Adding comments in the issue can help reviews.
2. Fork the repo, or create a new branch
3. Implement test cases for that method
4. When all github tests pass on your branch, create a PR, linking to the original issue you created.
5. Request a review

Ideally we should test successful requests (eg   getTransactionByHash with a valid hash), and failing requests (eg getTransactionByHash with an invalid hash). And if a method can work with multiple argument types (eg AddInvokeTranscation accepts BroadcastInvokev0Txn, and BroadcastInvokev1Txn, so we should test both of these etc.), we should also add a test case for that.

To run the tests in the rpc package:
1. Enter the directory 
2. run "go test . -env mock -v". Currently we test mock, devnet, testnet and mainnet environments (although a lot of these are empty tests)

starknet.go

Increase test coverage

transform logging statements from using formating in strings to structured logging, for example:
```diff
- debug!("Node set to disconnected: {}", node_id)
+ debug!(%node_id, "Node set to disconnected")
```
This would make it easier to make sense of emitted logs

help wanted

discv5

Rust

move discv5 to structured logging

# What is the bug? 
We miss auto install qpdf for command `yarn gen-pdf` in pcd packkage

# How can it be reproduced? (optional) 
Run `yarn gen-pdf` in pcd package.




Anon Aadhaar is a zero-knowledge protocol that allows Aadhaar ID owners to prove their identity in a privacy preserving way.

anon-aadhaar

JavaScript

Miss depenency qpdf 

Right now in the `iroha_cli` we are using a hand-written parser which already handles a bunch of arguments. We should rewrite it to use a more declarative approach with clap

              At some point we might consider to rewrite this using `clap`.

_Originally posted by @Erigara in https://github.com/hyperledger/iroha/pull/4100#discussion_r1410165928_
            

Refactor

[suggestion] Rewrite the iroha_cli entrypoint using clap

## Description

We are currently involved in some substantial network upgrades and in the process of making decisions about default values for lighthouse and the general limits we can push the software. 

One aspect of this is to collect a few metrics as a function of peer count. 

In particular we would like to measure the bandwidth, over both tcp and quic, and the total, average number of mesh peers and average number of nodes subscribed on subnets all as a function of peer-count. 

The metrics (at least the non-aggregated versions of them) already exist on the network dashboard, which can be found (and installed here: https://github.com/sigp/lighthouse-metrics/blob/master/dashboards/Network.json (this repo explains how to run the metrics also). 

What is left to do in this issue, is to run lighthouse with a specific --target-peers value for a few minutes (10-20, until we reach the target peer count (+- 10%)). Record the metrics or an average version of them and then repeat with a different --target--peers value. 
We probably want to do this for values [80,90,100,110,120,150,180,200,250,300] to get a relationship between these metrics and the peer count. 

We can run lighthouse with syncing and without an execution client to obtain these values. I write up of how to do this is here: https://github.com/sigp/lighthouse/pull/4961

We want to test these values on mainnet. There are a few upgrades coming this week (or next) which we probably want to get in first which should give improved numbers for these and improved metrics. 

Happy to help answer questions and provide guidance for anyone wishing to take this on. 


t Networking

lighthouse

Simple network analysis

per title. `bound=` is only allowed in the single arg form of `range()`, but it should be possible for this one too

ex.
```vyper
for i in range(1, N_COINS, bound=MAX_COINS):
  ...
```

Easy Pickings

Pythonic Smart Contract Language for the EVM

vyper

Python

allow `range(x, y, bound=N)`

enhancement

weggli-native

Embed a usage example in the README

**Is your feature request related to a problem? Please describe.**
Currently we only support uploading das data to aws s3 or locally, we would like to support more cloud providers for storage so that we can decentralize the risk of centralized failures and reduce maintenance costs.

**Describe the solution you'd like**
Add google cloud storage(GcsStorageService) 


nitro

Feature: Adding google cloud storage support to DAS

### Objective:
Develop and integrate a new command into the iroha_client_cli tool for burning (permanently deleting) public keys from an account in the Iroha blockchain network.

### Requirements:
The command should follow the existing syntax pattern of `iroha_client_cli`. It could be formatted as `key burn --account=[account_id] --key=[public_key]`, where `[account_id]` and `[public_key]` are placeholders for the user's account ID and the public key to be burned, respectively.


 Implement a Command for Burning Keys in iroha_client_cli

### Feature request

Return `BatchedResponse<Vec<SignedTransaction>>` instead of `Vec<SignedTransaction>`

### Motivation

It's hard to decode on our side without BatchedResponse

### Who can help?

@mversic

Enhancement

api-changes

Return pending transactions in batches

atm when building workspace we require "nightly" rust toolchain. This is only because wasm blobs in client are being built for testing purposes. This can be bypassed with `IROHA_SKIP_WASM_CHECKS=true cargo build`.

Iroha should build on stable toolchain by default to ease user experience. If "nightly" is required it should be opt-in, not opt-out. Also, in CI we must make sure that all wasm tests keep running

build

Enable Iroha build on stable

### Component

Anvil

### Describe the feature you would like

currently the Hardfork to specid conversion is only handled properly for mainnet
https://github.com/foundry-rs/foundry/blob/64320313edd81795751b8ec61d3cdcb35e419ce9/crates/anvil/src/config.rs#L805-L805

if no hardfork argument is provided:

https://github.com/foundry-rs/foundry/blob/64320313edd81795751b8ec61d3cdcb35e419ce9/crates/anvil/src/config.rs#L940-L941

we can make this smarter if we have hardfork/specid heights for L2s

## TODO
gather hardfork to evm specid blockheights for commonly used L2s/networks
* polygon
* OP
* Arbitrum
* ...

### Additional context

_No response_

T-feature

C-anvil

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

foundry

Better Hardfork -> evm SpecId handling for L2s

**Is your feature request related to a problem? Please describe.**
The following examples need good UI and docs:
- https://github.com/NethermindEth/dotnet-libp2p/tree/main/src/samples/chat
- https://github.com/NethermindEth/dotnet-libp2p/tree/main/src/samples/pubsub-chat 

**Describe the solution you'd like**
- Add good console UI for the chats
- Add usage docs and cli help

**Additional context**
- the apps are analogous to https://github.com/libp2p/go-libp2p/tree/master/examples/chat and https://github.com/libp2p/go-libp2p/tree/master/examples/chat-with-mdns

dotnet-libp2p

Improve samples UI

Introduced in #191 `Xor` filter currently hashes incoming keys. This is not needed as the keys are hashes on their own. If this is addressed, at least 3% gain should be observed. To make it work:

1. remove the `Hash` method from the Xor
2. make it use `ulong` keys
3. make Blockchain provide hashes as `ulong`
4. pass hashes around properly (int->ulong)


![Image](https://github.com/NethermindEth/Paprika/assets/519707/4ab15a79-31fe-4aaa-aa14-a5c280b73422)



🐌 performance

An experimental storage for Nethermind, removing the whole Trie abstraction and acting as a Trie and a database at once

Paprika

Xor8 should accept already precomputed hashes

In the following part of the documentation, in the comment, z is said to be used before declaration. Whereas the `x` is used pre-declaration.  
[Link to the part of documentation concerning this issue](https://github.com/crytic/slither/wiki/Detector-Documentation#description-47)

```Solidity
contract C {
    function f(uint z) public returns (uint) {
        uint y = x + 9 + z; // 'z' is used pre-declaration
        uint x = 7;

        if (z % 2 == 0) {
            uint max = 5;
            // ...
        }

        // 'max' was intended to be 5, but it was mistakenly declared in a scope and not assigned (so it is zero).
        for (uint i = 0; i < max; i++) {
            x += 1;
        }

        return x;
    }
}
```

slither

Small issue in documenting "variable-scope" detector

#191 introduced great performance gains but added a bit of allocs. It can be removed and pool can be leveraged more.

Contribute to open-source Web3 projects

✨ Ethereum.org

✨ Privacy & Scaling Explorations

✨ Solidity