The Best Exchange is a Decentralized Exchange

CKB Weekly #5

Hello, welcome to issue #5 of the CKB Weekly, a newsletter about the Nervos Common Knowledge Base blockchain and related technology. We’ve got a few articles and videos to share this week, and some exciting developments around the topic of decentralized exchange, hope you enjoy!


Decentralized Exchanges (or DEXs) are top of mind in the Nervos community this week.

Explained: Best DEX Design & UDTswap for Nervos” outlines a Nervos DEX being produced through the Grants program by the Growfi team and we are seeing another very exciting development:

Why should interaction with a DEX have to be done through a web page or app? With the flexibility of open transactions on CKB, we see the possibility for a Telegram bot to aggregate DEX orders and submit them to CKB, while remaining completely trustless.

What is an open transaction?

Open transactions give users the ability to collaboratively generate a single transaction. In the case of a DEX, one user would sign a portion of the transaction, authorizing use of a certain amount of their funds (as long as they receive a certain amount of something else). 

A second user would then also sign a portion of the transaction authorizing use of a certain amount of their funds (as long as they receive a certain amount of something else). If the terms of these two transactions match, CKB would validate the transaction successfully and the funds would be moved between the users.

You can start to see how all of this could be managed through something like a Telegram bot, and still be a trustless decentralized exchange. More information about open transactions can be found on Nervos Talk.

CKB core dev Xuejie Xiao aka 学姐 (as shown above) - gave a live coding seminar on Bilibili (most popular online streaming site in China), during which he shared the open transaction demo and several useful tools:

  • Standalone-debugger- tests contracts directly without running them on CKB testnet, supports debug, printf, can see number of contract cycle runs and full contract run path, etc.

  • Perkins' tent- creating a CKB server directly from a docker image package, contains not only ckb but also graphql-server, a more powerful ckb-indexer, flow control features and more!

  • Felix - a lumos-based implementation of a DApp that sends red packets within Telegram, on which more new features will be developed later.


  • Daniel, Co-founder of #Nervos delivered the keynote speech at the Global Mining Forum in Chengdu.

  • Jordan and Matt shared a deep dive into Nervos at the Saxony Blockchain meetup (video).

  • Meet the CKB core researchers” short video by the Nervos Foundation.

Technical Updates


  • CKB

    • (#2093) bump libc from 0.2.70 to 0.2.71

    • (#2043) upgrade tokio for tx-pool

    • If you are curious about why a design in CKB is what it is now, please post your questions in this repository.

  • Dev Tools (new!)

    • Lumos (JavaScript/TypeScript based dapp development framework) released v0.2.4

    • Capsule (Rust based smart contract development framework) released v0.0.1-pre2

    • Keyper - Nervos allows developers flexibility with the cryptography used by their applications, Keyper provides a standard which makes it easy for users to interact with diverse cryptography across different applications, through wallets or browser extensions. Check out Introducing Keyper for cell management on Nervos by Matt Quinn.

  • Neuron

  • CKB Explorer

Layer 2

  • Muta [layer2 framework on CKB]

    • Muta released v0.1.2-beta1

    • (#280) upgrade overlord version with tracing

    • (#294) supported new metrics

    • (#298) supported mempool monitor

  • SECBIT Labs [Zero knowledge proof toolkit for CKB]

    • Sorting out the code and will put it on the Github soon


  • Supporting wallets - MathWallet, ABC Wallet, imToken, HyperPay, Bitpie, Cobo, Hoo, Renrenbit

  • Supporting mining pools - 13 [source:miningpoolstats]

  • Exchanges - 29 market pairs [source: coingecko

  • Lay2 [build dApp on CKB and run them everywhere] 

    • Try different precomp methods to optimize the performance of secp256r1

    • Start to implement a basic API of pw-core like signing, sending transactions, etc.

  • Obsidian Labs[developer IDE]

    • Prepare for open source and release Linux version of  CKB Studio

  • Synapse [browser wallet and keyper agency]

    • Synapse Extension v0.0.2 released

Lina is stepping into her seventh month and the hashrate has grown about 168 times to 11.93PH/S from 75.47TH/S when she was born in November. 

“Lina” by Di Fang

*CKB Weekly is curated by a group of people who witnessed Lina’s birth and started this to record her growth. Any views expressed are personal and do not represent an official position of the Nervos project. Got updates or articles you would like to include? Any feedback or other suggestions? Let us know by replying to the email.