Relayer Report #15—Harbor Launch, Building an NFT Marketplace on 0x

The latest updates from the 0x ecosystem: December 4th, 2018

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Happy December folks. My birthday is at the end of the month, so please feel free to give the gift of relayer updates to any unsuspecting family members on my behalf.

Last week 0x Tracker, a project that analyzes trades in the 0x ecosystem, was open sourced by its creator Craig Bovis, a longtime community member. (Prediction market relayer Veil also open sourced its code).  We also hired another engineer to the 0x Core Team, Xianny Ng who comes from Mapbox. Welcome Xianny!

Finally, we have decided to move our external communications with the community from Rocket Chat to Discord. While it’s more catered to developers, anyone from the 0x ecosystem can join our Discord here.

Harbor Launches

Harbor recently launched their security token platform, with the first investable project coming from the real estate arm of DRW, a trading firm based in Chicago. Minimum investments in “The Hub,” a student property near the University of South Carolina, start at $21,000, with 955 tokenized shares in total on the market.

What stood out to me in the announcement was the number of related cryptocurrency firms that are involved in the Harbor launch. Custody experts BitGo (who incidentally are venture-backed by DRW and David Sacks, advisor to 0x and Harbor) deal with custody, 0x relayer The Ocean among others will list these assets so they can be traded peer-to-peer and over-the-counter, and finally, the possibilities with other protocols are endless, as shown in Harbor’s tweet storm about their launch:

ERC20-compatible #securitytokens unlock exciting new possibilities. Real estate examples: create levered longs and shorts w/ @dydxprotocol, create baskets/ETFs w/ @Setprotocol, create margin loans w/ @makerdao #defi

This ability to leverage multiple protocols to build a new financial instrument is something that has really been picking up traction recently, like the ETHSF project Primotif that I talked about in RR 12:

Primotif lets users buy sets of Augur and dYdX short tokens to get balanced exposure to synthetic assets like the S&P500. Synthetic assets are “a mixture of assets that, when combined, have the same effect and value as another asset” (Source). In this case, Augur tokens track the underlying asset (S&P500) while the dYdX short tokens provide a hedge on the ETH/USD price. The bundling of these assets is made possible by Set Protocol, and finally the exchange of this set for Ether is done using 0x.

While this interoperability is really cool, why create security tokens in the first place? Immutability, cheaper fees, transparent settlement, less regulatory overhead, and global access all combining to increase liquidity and efficiency seems to be the value proposition of security tokens as well as the DeFi movement.

Further reading:

Harbor White Paper

Security Token Ecosystem Infographic (The Block)

The Tokenization of Real Estate (Sina Habibian)

On Developing With 0x

NFT relayer Emoon published this post about building with 0x, giving some guidance on how to get started with the protocol. I particularly liked the “Gotchas” section at the end that listed tricky mistakes they encountered:

While the Emoon experience of integrating with 0x was positive, there were some gotchas for our particular use case that are worth calling out:

  1. @0x/subproviders Doesn’t Work With Angular 6 When Doing Production Builds For Client or Server. Read more here.

  2. Old Version of bignumber.js. Read more here.

  3. If using the forwarding contract, remember that the taker (aka the buyer) pays any forwarding fees, not the maker (seller). As such, one has to factor that fee into the amount of ETH sent to the forwarding contract. This works differently than many other smart contracts that do atomic swaps, like Crypto Kitties for example, which take the fee from the seller.

  4. Also, if using the forwarding contract, remember that the maker (the seller) gets paid in WETH. The buyer is nicely abstracted from WETH but the seller is not, which is important to communicate to sellers who may be surprised when their order is filled but their ETH balance remains unchanged.

  5. Reading the 0x contracts is quite tricky, because of all the includes and nested files. Best bet is to actually print them out so you can bounce around between includes.

As 0x has grown, there are more options and abilities for relayers, meaning more education needed for any new dev or community member. Posts like this do a lot for the ecosystem, so thanks to the Emoon team.


STAR BIT (James):

  • Started adding Kyberswap function for one-click-buy function on the exchange

  • Released STAR Wallet 1.0.3 with new featuring of STAR BIT EX-connect, accelerating trade transactions, trading pair customize support

  • Developing an interesting Dapp on the exchange for Christmas - stay tuned

LedgerDex (Matt):

  • We did a number of bug fixes and UI improvements

  • LedgerDex attended the BlockShow Asia conference in Singapore

  • The LedgerDex team will be in Singapore in the coming days. If you are also in Singapore and interested in getting connected, please feel free to email us at

Ambo (Jai):

  • Ambo is a project that aims to simplify the difficulties presented in decentralized financial applications through a simple wallet

  • Read Ambo’s announcement here where we discuss the creation of Ambo

  • If you have any questions you can reach out to Jack (our head of partnerships) directly at

Bamboo Relay (Josh):

  • Completed Trezor integration

  • Work on improving UX for signing and transactions

Radar Relay (Joe):

OpenRelay (Greg):

  • New Screenside Chat (Ep.15): How OpenRelay does 0xv2 Order Types

  • Nearly complete: OpenRelay Order Pools

  • Signature-required Terms of Use for Makers also ready soon

Lake Trade (Rishabh):

  • Lake Trade SRA now live, optimizations in the works

  • Interview with Mathew @ LakeProject

  • Article addressing centralized exchanges published on Hackernoon

Hut34 (Tim):

  • Pushed improvements to our Google powered Ethereum wallet, now allowing users to trade 'cross pairs' - direct ZRX to REP

  • Data relay is close to a release with diaglog flow bots now sharing data objects along with exchange objects - releasing data portal soon

  • Big thanks to Jacob, 0x's aussie dev, who's helped us lay the groundwork for integrating the Google powered wallet as a provider to allow our user base to access all relays - we're super excited about this one, and expect to hear more very soon

Veil (Paul):

  • Revamped the Veil home page to show-off popular markets and highlight a new concept called channels, which are collections of similar markets like Memes or REP

  • Added a public Augur Open Interest graph to help track macro trends on Augur

DDEX (Diane):

  • DDEX will upgrade with the new features of Market Order Capability, flexible Maker-Taker fee, Price Improvement, HOT token incentive reward, and new UI


ETH Locked in DeFi (Mike McDonald):

A visualization of the amount of ETH locked up in dYdX, Augur, Maker, Compound, and Uniswap. Spoiler: Maker dwarfs everything else.

Meet Bitski, The Single Sign-On Wallet Crypto Desperately Needs (TechCrunch):

The Bitski developer beta has been released for its single sign-on cryptocurrency wallet platform. The vision is to make dApp onboarding as simple as possible, with a sample video of the Bitski experience here. In other wallet news, Gnosis Safe will be releasing its mobile wallet in Q1 of 2019.

UX of DEXs (Jacob Evans and Clay Robbins):

Videos are out for the DeFi Summit in Prague, with Jacob and Clay from the 0x team giving a presentation on the UX of decentralized exchange.

USDC Ecosystem Spotlight (Circle Blog):

Five new projects, including OpenSea and AirSwap, have started listing USDC.

Fun Stuff

A NY Times profile on Vinod Khosla and his beach battle, a stubborn, principled man. Another profile on the career bromance of the two MapReduce creators, who are the only Level 11 Google engineers (funny convention, but hey it’s Google). One last profile on the triple jeopardy of a hedge fund quant.

The Space Jam website looks exactly the same as it did in 1996, an archive of the old Internet.

“Don't waste your time on jealousy; sometimes you're ahead, sometimes you're behind...the race is long, and in the end, it's only with yourself.” - Everybody Wears Sunscreen

A MasterMind game that can be implemented with zk-SNARKS.

Much love,


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