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· 4 min read
Dora Noda

Blockchain technology has emerged as a leading force in the digital world, offering revolutionary solutions that extend beyond cryptocurrency. Programming languages dedicated to blockchain technology are carving a unique space for themselves. Among these languages, Move has secured a significant spot, thanks to its robustness and inherent security features. Today, we will introduce an innovative tutorial called "Sui Move," designed to teach developers the Move programming language using a learn-by-example approach.

Dive into Blockchain Programming with Sui Move

Understanding Move: The Programming Language

Before we jump into the tutorial, let's briefly recap what Move is. Created by Facebook's subsidiary, Diem Association (formerly Libra), Move is a statically-typed, resource-oriented programming language. Its design is centered around enforcing safety and security, making it the ideal language for coding blockchain and cryptocurrency projects. The Sui Move is a variant of the Move programming language.

Resources in Move are a key construct that makes it stand out from other blockchain programming languages. These are special types that can't be copied or discarded, only moved between storage locations. This feature allows for precise control over digital assets and significantly mitigates the risk of common security issues, such as double-spending.

Sui Move: A Learn-by-Example Tutorial

Located at, "Sui Move" is a comprehensive, learn-by-example tutorial designed to teach developers how to code using the Move programming language.

"Sui Move" is constructed on the philosophy that hands-on learning accelerates comprehension and proficiency. The tutorial is divided into small, manageable chunks, each focusing on a specific aspect of Move. This allows learners to not only understand the technicalities of the language but also gain insights into how and where they can be implemented.

"Sui Move" stands out in its approach to teaching. Instead of overwhelming the learner with dense theory, it offers an array of examples for every concept. The learner can directly interact with these examples, providing a dynamic learning environment that encourages exploration and understanding at a deep level.

The tutorial is designed to be accessible for various experience levels. Whether you are a seasoned developer looking to dive into blockchain development or a beginner who's just starting, "Sui Move" is tailored to ensure you grasp and master the concepts effectively.

What You'll Learn

"Sui Move" covers a broad range of topics that form the core of Move programming language. Here's a snapshot of what you can expect:

  • Understanding the syntax and structure of Move.
  • Deep dive into Move's unique resource-oriented model.
  • Manipulating data using Move's functions and methods.
  • Learning to create and implement Modules and Scripts.
  • Handling exceptions and ensuring security in your Move programs.
  • Learning how to create a custom coin and NFT.

Why Choose Sui Move?

"Sui Move" is not just a tutorial; it's a well-structured learning journey. It offers:

  1. Real-world Examples: Every concept is paired with a practical example that demonstrates how to use it effectively.
  2. Comprehensive Coverage: It provides a thorough understanding of Move, from basic syntax to advanced constructs.
  3. Step-by-Step Guidance: Every module is designed to gradually build your understanding, reducing the learning curve and making complex concepts easier to grasp.
  4. Flexibility: It caters to a wide range of learners, from beginners to experienced developers.

Blockchain technology is shaping the future of numerous industries, and mastering a language like Move can open new avenues for developers. With "Sui Move," you have a resource that can guide you effectively through your learning journey. So, dive in, start coding, and explore the exciting opportunities that Move and blockchain technology hold for you.

Get started now at

· 3 min read
Dora Noda

There is a constant buzz in the world of cryptocurrency, with new narratives cropping up at regular intervals. While a lot of attention has been given to Shanghai upgrades, BRC20, meme coins, and halving phenomena, the "DeFi Summer" of 2020, a milestone in the rotation of narratives in the crypto world, has been mostly forgotten. However, three years later, there have been some noteworthy developments in the DeFi space worth highlighting.

A Fresh Perspective on the Changing Landscape of DeFi Market

The Declining Attention on DeFi

Post the "DeFi Summer" of 2020, the Decentralized Finance (DeFi) ecosystem has evolved and grown significantly, introducing innovations like decentralized exchanges, lending platforms, derivatives, fixed income tools, algorithmic stablecoins, asset synthetics, and aggregators.

However, after peaking in May 2021, traditional DeFi blue chips like UNI, LINK, SUSHI, and SNX have been seeing a decreasing trend. Leading DeFi projects such as Uniswap and Synthetix and new entries like OHM under "DeFi 2.0" seem to be gradually fading away from the market spotlight. The DeFi narrative, once the darling of the crypto world, has been overshadowed by other emerging narratives like NFTs, DAOs, Metaverse, and Web3.

Fundamentally, the services offered by most DeFi products are similar, with only a few leading products standing out due to their brand and user stickiness. Many platforms rely heavily on their native tokens to incentivize user participation. However, these liquidity rewards can inflate Total Value Locked (TVL) figures temporarily but are not sustainable in the long run, leading to volatility and quick capital movement when new higher yield opportunities arise. This dynamic has led to an overall downtrend in the price of DeFi tokens since 2020.

Innovations in the DeFi Space

Ignoring the declining performance of DeFi tokens in secondary markets, some interesting changes are happening within the DeFi landscape. Notably, leading projects like Curve and MakerDAO have been diversifying their product range, blurring the boundaries between different DeFi protocols.

MakerDAO, traditionally known for its DAI stablecoin, has started venturing into the lending space with the launch of Spark Protocol. This protocol, built on Aave V3 smart contracts, allows users to borrow assets like ETH, stETH, DAI, and sDAI. This is a remarkable shift in strategy and points towards a significant overlap of stablecoin and lending functionalities.

In a similar vein, Aave, primarily known for its lending services, is planning to launch its native decentralized stablecoin, GHO, backed by collateral and pegged to the dollar. Both MakerDAO and Aave's lending mechanisms are based on Aave V3 smart contracts, and it will be fascinating to see who emerges successful in this foray outside their traditional domains.

Curve, which is known for its large-scale asset exchange services, has also recently introduced its stablecoin, crvUSD. With Curve's inherent liquidity advantages, crvUSD seems to have a headstart in the stablecoin race.

Among all these DeFi blue chips, Frax Finance has made significant strides in liquidity collateralization. Its product frxETH has shown exceptional growth since its launch in October 2022, reaching almost 220,000 tokens valued at around $400 million within just 200 days.


The sustainability of DeFi projects that relied heavily on liquidity incentives was always questionable. This reality has prompted leading DeFi protocols to innovate and diversify their product ranges, breaching the traditional boundaries that separated them.

· 3 min read
Dora Noda

Ethereum, the world's most adopted blockchain platform for smart contracts, is known for its regular upgrades, each bringing forth new features, parameter adjustments, or enhanced security. These upgrades, driven by both proactive innovation and the need to mitigate potential security threats, have punctuated Ethereum's evolution over the years.

A Major Leap Towards a Faster, More Economical Network

Before the Ethereum merge last September, the platform had seen 14 upgrades. Notably, a reactive upgrade occurred in 2016 after the DAO Fork incident when Ethereum Classic (ETC) emerged following a cyber-attack that jeopardized the DAO project's ETH funding.

Over the past few years, significant upgrades have taken place. The London upgrade in August 2020 introduced EIP-1599, introducing ETH burning and dynamic adjustment of the Base Fee for every transaction. In September 2022, the Paris upgrade transitioned Ethereum's consensus mechanism from Proof of Work (POW) to Proof of Stake (POS), signaling the end of the machine mining era.

After the Shanghai upgrade, Ethereum's core development team announced that the most important update this year would be the Cancun upgrade, expected to occur later this year.

Cancun Upgrade: What Is It and Why Does It Matter?

Named after the city that hosted the Ethereum Developer Conference (Devcon), the upcoming Cancun upgrade will implement crucial improvements to the Ethereum network.

The star of the upgrade, EIP-4844, aims to allow Ethereum nodes to temporarily store and retrieve off-chain data, fulfilling the data and storage needs of blockchain applications. If successfully implemented, EIP-4844 is expected to reduce the costs of Layer 2 (L2) rollup solutions. Reportedly, EIP-4844 has already been tested on four development networks, with a fifth testing network about to launch.

Originally intended for completion during the Shanghai upgrade, EIP-4844 was postponed to the Cancun upgrade. Developers have also agreed to include EIP-6780 (preparing for future application of Verkle Trees), EIP-6475 (providing improved readability and compact serialization), and EIP-1153 (introducing transient storage opcode) in the upgrade.

The Principle Behind the Upgrade

The essence of Ethereum's scalability efforts lies in increasing data processing volume and speed. Two directions are pursued concurrently – Layer 2 rollups and sharding on the mainnet. The implementation of EIP-4844 is the first step towards complete sharding.

Prior to the Cancun upgrade, L2 information was stored in the Calldata of L1 information. This method was costly and limited due to Calldata's limited space.

With the Cancun upgrade, L1 will be stored in a new location called "Blob". Blob storage is more affordable and offers more space, allowing Ethereum to host more data, increase its transactions per second (TPS), and reduce costs. As Blob is a temporary data package cleaned up every 30 days, nodes only need to download a fixed amount of data per month, decreasing node burden.

In essence, the Cancun upgrade will make L2 cheaper and faster. This will not only benefit L2 protocols but will also foster rapid development for ecosystems built on L2.

In conclusion, the upcoming Ethereum Cancun upgrade promises to be an important milestone, heralding a new era of efficient, affordable, and scalable blockchain applications. Stay tuned for further updates as the Ethereum community continues its pioneering work in advancing decentralized technologies.

· 3 min read
Dora Noda

In recent times, discussions in the Bitcoin realm have seemingly transitioned towards the Bitcoin network itself, with BRC20 tokens emerging as a hot topic. People are contemplating whether the arrival of Bitcoin's Layer 2 (L2) expansion solutions and the BRC20 standard could introduce enhanced functionality and scalability to Bitcoin. However, it's important to tread carefully, as these discussions currently seem to lean more towards market speculation. Let's delve into Bitcoin's L2 architecture, BRC20, and potential security concerns.

BRC20 Tokens: A Promising Contender or a Mere Flash in the Pan?

Understanding Bitcoin’s L2 Architecture

The blockchain ecosystem grapples with a so-called 'impossible triangle'—security, decentralization, and scalability—of which only two can be achieved at the cost of the third. Bitcoin, for example, has prioritized security and decentralization, sacrificing scalability in the process. Bitcoin’s block generation time is approximately 10 minutes, a significant lag compared to other popular blockchains like Ethereum 2.0 or Solana that boast block times on the scale of seconds or even milliseconds. This limitation has spurred demand for Bitcoin scalability solutions, leading to the emergence of Bitcoin's L2 expansion, exemplified by systems such as Stacks.

Stacks is a decentralized application and smart contract network built on top of Bitcoin. This network connects to the Bitcoin blockchain through a cross-chain consensus mechanism, achieving the goal of preserving Bitcoin's security while also offering a rich application scenario for smart contracts. Stacks operates in a layered fashion, where the base settlement layer (Bitcoin) is supplemented by the addition of smart contracts and programmability (Stacks), which further incorporates a scalability and speed layer (Hiro's subnet). This layered approach not only offers functionality akin to blockchains like Ethereum but also avoids many shortcomings of complex public chains.

Explaining BRC20

To understand BRC20, we first need to familiarize ourselves with Ordinals. Ordinals is a protocol that assigns unique identifiers to Bitcoin's smallest unit, satoshis (sats), essentially transforming each sat into a unique non-fungible token (NFT), akin to Ethereum NFTs. Additionally, Ordinals allow for the inclusion of text, images, audio, and video within sats, further accentuating their uniqueness.

The creator of BRC20, leveraging the Ordinals protocol, introduced the concept of fungible tokens on Bitcoin by assigning a unified "format" and "attributes" to sats. BRC20, through Ordinals, inscribes JSON formatted text data into sats, acting as a ledger for BRC20 tokens and tracking token holdings and transfers.

Risks Associated with BRC20

Despite the attention BRC20 tokens have garnered, they currently exist as mere JSON files without practical value or business use-case, and their popularity largely hinges on Bitcoin's popularity and traffic. Further, managing BRC20 tokens is not as straightforward as handling Bitcoin and requires a dedicated wallet. Moreover, participation in BRC20 investment requires third-party tools which often carry an entry barrier.

Several risks surround BRC20 tokens. Firstly, market speculation and hype may create a bubble, overvaluing the tokens. Secondly, similar to other blockchain technologies, BRC20 tokens are susceptible to hacking attempts. Lastly, the lack of regulatory oversight in the blockchain and cryptocurrency markets could lead to fraudulent or illegal activities involving BRC20 tokens.

A common misconception among users is that BRC20 tokens, created using Bitcoin's security, are as secure and stable as Bitcoin. However, the two are fundamentally different. Bitcoin's security is underpinned by cryptographic and consensus algorithms, and it has been running relatively stably for a considerable duration. Conversely, BRC20 relies on the Ordinals

· 3 min read
Dora Noda

We are thrilled to announce that Sui, the highly anticipated blockchain platform, has successfully launched its mainnet. At, we are committed to providing our customers with the most innovative and cutting-edge solutions in the blockchain industry. As a result, we are excited to integrate Sui into our robust API suite, offering developers an even greater range of tools to create groundbreaking applications.

Sui Mainnet Launch: Expands API Suite to Include Next-Generation

Why Sui Matters

Sui is a next-generation blockchain platform designed to address the challenges faced by existing solutions in scalability, interoperability, and energy efficiency. It brings together the best features from various blockchain technologies, offering a more efficient and flexible platform for developers to build decentralized applications (dApps) and smart contracts. Some key aspects of Sui include:

  1. Scalability: Sui employs a unique consensus algorithm, which allows it to process 297k transactions per second, thus ensuring high throughput and minimal latency. This makes it an ideal choice for building dApps that require fast and secure transactions.
  2. Energy Efficiency: Sui's consensus algorithm also addresses the energy consumption concerns associated with traditional Proof-of-Work (PoW) mechanisms. By utilizing a more environmentally friendly approach, Sui contributes to a greener and more sustainable blockchain industry.

What This Means for Users:

As Sui joins our API suite, developers can look forward to:

  1. Access to Sui's Blockchain: Our API will enable developers to easily interact with the Sui blockchain, allowing them to build and deploy smart contracts, create tokens, and develop dApps on this revolutionary platform.
  2. Continued Support: remains committed to providing exceptional customer support, offering guidance and assistance in implementing Sui's technology within your projects.
  3. Stake with and Earn Rewards: By staking your tokens with, you can participate in the Sui ecosystem and earn rewards for contributing to the platform's growth and security.

Getting Started with's Sui RPC Key

If you're ready to start developing on the Sui blockchain using's API suite, follow these simple steps to get your Sui RPC key and kickstart your project:

Step 1: Obtain a Connection String

Visit our API Marketplace at to obtain a connection string. This string will enable you to access the Sui blockchain through our API and begin developing your decentralized application.

Step 2: Develop Your First Sui DApp

To build your first DApp on the Sui platform, follow our comprehensive guide available at This tutorial provides step-by-step instructions for setting up your development environment, implementing Sui's TypeScript SDK, and creating a fully functional DApp using the Sui blockchain.

By following these steps, you'll be well on your way to harnessing the power of the Sui blockchain and's API suite to develop innovative and groundbreaking decentralized applications. If you need any assistance, our dedicated support team is always ready to help guide you through the process.

Conclusion is proud to welcome Sui into our growing family of blockchain technologies. By adding Sui to our API suite, we are further expanding the possibilities for developers to create groundbreaking solutions in the blockchain space. As always, we remain dedicated to providing our users with the most innovative and reliable tools to empower their projects and drive the future of decentralized technology.

· 3 min read
Dora Noda

The Sui Foundation recently conducted a series of tests to determine the current peak throughput and time to finality for various workloads on the Sui network. A year after its announcement, the Sui network has made significant strides in performance, becoming a promising decentralized protocol for the future.

Key Findings

  • The Sui network, consisting of 100 globally distributed validators, achieved peak throughput ranging from 10,871 TPS to 297,000 TPS on different workloads.
  • Sui's time to finality is approximately 480 milliseconds, providing rapid transaction confirmations.

Performance Evaluation

To measure the performance of the Sui protocol, the foundation used a globally-distributed setup that closely mirrors the mainnet in terms of hardware configurations, number of validators, geographic distribution, and voting power distribution. The tests were conducted using 100 validators, 24-core AMD hardware, 256GB memory, and 25Gbps NIC.

Measuring Throughput with Programmable Transaction Blocks (PTB)

Sui's core developer primitive, PTB, allows for a complex and composable sequence of transactions. Chained transactions in a PTB can execute and fail atomically, providing increased efficiency and expressivity. Each PTB can support up to 1024 transactions, enabling Sui to handle large workloads and reduce transaction fees for users.

The Challenge of Measuring Throughput

Transactions Per Second (TPS) is a commonly used metric to measure a blockchain protocol's capacity. However, measuring the number of PTBs executed per second doesn't accurately reflect Sui's computational capacity. As the average PTB size increases, Sui's throughput increases, but the PTB/second metric would remain unchanged. Therefore, the foundation has chosen to measure the number of individual transactions within a PTB executed per second as a more consistent and practical metric.

Time to Finality

Finality in blockchain refers to the point where a transaction is considered irrevocable and cannot be modified or reverted. For this performance update, the Time to Finality measures the point in the transaction lifecycle where both the transaction itself and its effects are final and can be used in subsequent transactions. Sui's Time to Finality is approximately 480 milliseconds, with a 95th percentile latency of around 550 milliseconds.

Future Optimization and Scalability

The Sui protocol has made significant progress in its performance, but there are still many opportunities for optimization and scalability. In the near future, the Sui Foundation plans to refine the following aspects:

  • Scalability and coverage of benchmark tooling
  • Horizontal scalability to support intra-validator scaling across multiple machines
  • Resilience to under-performance of individual validators

As the Sui protocol evolves and its performance improves, the Sui Foundation will continue to share updates with the community for feedback and consideration. With its impressive throughput and time to finality, the Sui network is poised to make a significant impact in the world of decentralized systems.

· 3 min read
Dora Noda

We are glad to announce that, a leading provider of Blockchain API solutions, is expanding its offerings by adding Solana to our API suite. This move aims to provide our customers with a broader range of options to build and deploy innovative decentralized applications (dApps) on the Solana network.

In this blog post, we will discuss the reasons why Solana matters, and how integrating its APIs into our suite can benefit developers and businesses alike. Adds Solana to Our API Suite – Expanding Blockchain Opportunities for Developers

Why Solana Matters

Solana is an open-source, high-performance blockchain network designed to support a wide variety of applications, from decentralized finance (DeFi) and gaming to supply chain management and beyond. Some of the key features that make Solana stand out among other blockchain platforms include:

  1. High Performance: Solana is built to scale and can process up to 65,000 transactions per second (TPS) at sub-second confirmation times, which is significantly higher than many other blockchain platforms. This scalability allows developers to create and deploy dApps with minimal latency, ensuring a smooth user experience.
  2. Low Transaction Fees: Solana's innovative architecture allows for low transaction fees, which makes it cost-effective for developers and users alike. This feature not only helps lower the barriers to entry for new dApps but also enables existing applications to operate more efficiently.
  3. Proof of History (PoH): Solana's unique consensus algorithm, Proof of History, provides an energy-efficient and secure way to validate transactions on the network. By using verifiable delay functions (VDFs) to create a historical record of events, PoH eliminates the need for high-energy-consuming consensus mechanisms like Proof of Work.
  4. Developer-friendly: Solana offers a wide range of developer resources, including comprehensive documentation, a robust SDK, and easy-to-use APIs. This makes it easier for developers to build and deploy dApps on the Solana network, regardless of their prior experience with blockchain technology.

Integrating Solana APIs into's API Suite

By adding Solana to our API suite, we aim to provide developers with a comprehensive set of tools to build and deploy dApps on the Solana network. Our Solana API offerings will include:

  1. Transaction and Account Management: Easily create, sign, and submit transactions, as well as manage accounts on the Solana network.
  2. Smart Contract Deployment: Seamlessly deploy and interact with smart contracts on the Solana blockchain, simplifying the development process.
  3. Data and Analytics: Access real-time and historical data from the Solana blockchain, including transaction details, token balances, and more, for insightful analytics and reporting.
  4. Integration and Interoperability: Connect your dApps with other blockchain networks and applications using our robust set of APIs and SDKs, ensuring seamless integration and interoperability.


The addition of Solana to's API suite demonstrates our commitment to providing our customers with cutting-edge blockchain technology solutions. We believe that Solana's high-performance, low-cost, and developer-friendly features make it an ideal platform for building and deploying dApps across various industries. We look forward to helping developers leverage the power of Solana through our comprehensive API offerings.

If you have any questions about our Solana APIs or need assistance in getting started, please feel free to reach out to our support team. We're always here to help you harness the potential of blockchain technology for your projects.

· 3 min read
Dora Noda

The SUI Network is a high-performance public blockchain developed by former Meta engineers. Built with the Move programming language, it prioritizes security, scalability, and upgradability.

What is POAP?

POAP, or Proof-Of-Attendance Protocol, is a mechanism for distributing encrypted badges to record and commemorate specific events. POAP tokens can serve as proof that a user attended an event or as collectible items, similar to concert tickets or commemorative badges.

Event organizers typically use POAP to distribute tokens to participants, who can then collect unique POAP tokens (NFT badges) to remember their attendance at an event.

Introducing SUIA: The First POAP Application on the SUI Network is the first POAP application on the SUI blockchain, currently launched on SUI's devnet. In the future, Suia will have multiple purposes, such as event tickets, contribution awards, and gaming, providing a new immersive, gamified interaction method between web3 brands and users.

What are the features of SUIA?

Anyone can create POAP events on Suia, with all creation and distribution occurring transparently on the SUI blockchain. Users own their Suia assets, and the unique architecture and parallel performance of the SUI blockchain allow Suia to combine and create more gameplay possibilities, accommodating large-scale user participation, low latency, and low fees, facilitating connections with the web2 application market.

How to use SUIA?

  1. Visit the Suia website at, click "connect wallet" to link a wallet, currently supporting Sui wallet and Suiet Wallet.

  2. After connecting the wallet, click "create Suia" to experience creating a POAP NFT distribution event on the SUI blockchain. Follow the prompts to upload the NFT's type, name, description, amount, and whitelist restrictions if needed. Click "create" to complete the process, which requires a small amount of SUI tokens in the devnet environment.

  3. After creating the event, it will appear on the homepage, allowing other users to discover and claim your POAP.


Suia, developed by the Mynft team (creators of the first vote-to-earn web3 platform on the Flow blockchain), has a mature market and development experience, as well as a solid community foundation. Developing Suia on the SUI blockchain leverages the team's NFT expertise while filling the gap in POAP applications.

With a well-developed product and clear roadmap, strong project collaboration, and community management capabilities, Suia has attracted over 6,000 participants on its first day of testing. SUI World DAO will continue to monitor Suia's future collaborations and user growth as the SUI mainnet launches.

· 2 min read
Dora Noda

Sui Blockchain is a promising Layer-1 (L1) project that employs a unique set of technical innovations and tokenomics to deliver a scalable and efficient platform. This article will explore Sui's core innovations and evaluate its potential as a solution for mass adoption of Web 3.0 applications.

Key Innovations

  • Sui Move: A custom version of the Move language optimized for parallel execution, enabling frictionless mass asset creation and a smoother programming experience.
  • Single-Writer Transactions: A novel approach to handling simple transactions without consensus, using Byzantine Consistent Broadcast for security and efficiency.
  • Narwhal-Tusk Consensus Engine: A cutting-edge consensus mechanism using directed acyclic graph (DAG) data structures for high throughput and low latency.
  • Unique Tokenomics: Sui's tokenomics model addresses storage costs on the network by implementing a storage fund, which helps maintain relatively constant gas prices throughout the blockchain's lifetime. This design incentivizes validators and ensures ample storage space is available.


Sui Blockchain stands out with its innovative solutions to scalability, particularly the unlimited upper bound for single-write transactions. This makes it suitable for applications that rely heavily on single-writer transactions, like social media apps and mass NFT distribution.

Sui's scalability solutions unlock the potential for NFTs with low intrinsic value but high social purpose, such as on-chain coupons, decentralized IDs, and credit cards. Furthermore, Sui Move's language features can enable structurally storing objects on a blockchain with the security and permanence guarantees of the blockchain.


Sui Blockchain provides a viable blueprint for an L1 blockchain that can handle Web 2.0 level scalability. It symbolizes Web 3.0's growing maturity and the potential for a billion-user scale. Regardless of its long-term success, Sui's innovative approach to blockchain technology already represents a significant achievement.

· 4 min read
Tian Pan

Optimism is an EVM equivalent, optimistic rollup protocol designed to scale Ethereum. Scaling Ethereum means increasing the number of useful transactions the Ethereum network can process. Optimistic rollup is a layer 2 scalability technique which increases the computation & storage capacity of Ethereum without sacrificing security or decentralization. EVM Equivalence is complete compliance with the state transition function described in the Ethereum yellow paper, the formal definition of the protocol.

Optimistic rollup works by bundling multiple transactions into a single transaction, which is then verified by a smart contract on the Ethereum network. This process is called “rolling up” because the individual transactions are combined into a larger transaction that is submitted to the Ethereum network. The term “optimistic” refers to the fact that the system assumes that transactions are valid unless proven otherwise, which allows for faster and more efficient processing of transactions.

Overall Architecture

Optimism Architecture

op-node + op-geth

The rollup node can run either in validator or sequencer mode:

  1. validator (aka verifier): Similar to running an Ethereum node, it simulates L2 transactions locally, without rate limiting. It also lets the validator verify the work of the sequencer, by re-deriving output roots and comparing them against those submitted by the sequencer. In case of a mismatch, the validator can perform a fault proof.
  2. sequencer: The sequencer is a priviledged actor, which receives L2 transactions from L2 users, creates L2 blocks using them, which it then submits to data availability provider (via a batcher). It also submits output roots to L1. There is only one sequencer in the entire stack for now, and it's where people critisize that OP stack is not decenralized.


The batch submitter, also referred to as the batcher, is the entity submitting the L2 sequencer data to L1, to make it available for verifiers.


Proposer generates and submitting L2 Output checkpoints to the L2 output oracle contract on Ethereum. After finalization period has passed, this data enables withdrawals.

Both batcher and proposer submit states to L1. Why are they separated?

Batcher collect and submit tx data into L1 with a batch, while proposer submits the commitments (output roots) to the L2's state, which finalizes the view of L2 account states. They are decoupled so that they can work in parallel for efficiency.


Various contracts for L2 to interact with the L1:

  • OptimismPortal: A feed of L2 transactions which originated as smart contract calls in the L1 state.
  • Batch inbox: An L1 address to which the Batch Submitter submits transaction batches.
  • L2 output oracle: A smart contract that stores L2 output roots for use with withdrawals and fault proofs.

Optimism components

How to deposit?

How to withdraw?

Feedback to Optimism's Documentation

Understanding the OP stack can be challenging due to a number of factors. One such factor is the numerous components that are referred to multiple times with slightly different names in code and documentation. For example, the terms "op-batcher" and "batch-submitter" / "verifiers" and "validators" may be used interchangeably, leading to confusion and difficulty in understanding the exact function of each component.

Another challenge in understanding the OP stack is the evolving architecture, which may result in some design elements becoming deprecated over time. Unfortunately, the documentation may not always be updated to reflect these changes. This can lead to further confusion and difficulty in understanding the system, as users may be working with outdated or inaccurate information.

To overcome these challenges, it is important to carefully review all available documentation, to keep concepts consistently across places, and to stay up-to-date with any changes or updates to the OP stack. This may require additional research and collaboration with other users or developers, but it is essential in order to fully understand and effectively utilize this complex system.