Nebulas Weekly Report #17

Welcome to the #17 of Nebulas Weekly Report! Delivering developments of Nebulas project. Nebulas Weekly Report is maintained by the Nebulas team. Please send feedback to, or @nebulasio on Twitter.

LAST WEEK’S News and Reports

Nebulas Blockchain Writing Contest officially kicked off on February 1st. Nebulas team have already got lots of feedback till now and we are very thrilled to hear more from the community.

Sincere gratitude to all community members who have participated in our event. Nebulas team will contact the winner via Twitter to send out gifts and prizes after the contest ended on February 19th at 8:00 a.m. (UTC-8), so please follow us on twitter @nebulasio and behold for the feedback.

Nebulas comes from the community and serves in the community. There are so much talents in the community and this writing contest is our first step toward a full series of activities interacting with the community.

We wholeheartedly call for more believers to join us, giving suggestions and contributing the community. Together we build the Nebulas ecosystem.

LAST WEEK’S Top Commits

Last week, we focus on concurrent transactions packing & verification. Concurrent transactions verification is a big challenge for us. We cannot make sure two transactions can be executed independently before executing them. Thus, we have to find a way to record their dependent relationship into a DAG(Directed Acyclic Graph), and verify them concurrently according to the DAG. We have to be very carefully to manage the DAG because a lot of states in block will be changed during the execution of transactions. Moreover, we wrote more test cases to test smart contracts in our testnet last week and we’re glad the testnet seems stable.

Summary this week is as following,


  • Extracted all states in block into a world state: it’ll be easier to manage the changes of states
  • Partially implemented concurrent transactions packing & verification.


  • Added more test cases for smart contracts.

Learn more about Nebulas:

Official website:

Twitter: @nebulasio