Testing 88mph v3

Getting started on the Rinkeby testnet

McFly 🛹| 88mph
Published in
4 min readJul 5, 2021


Today, we’re proud to announce the deployment of 88mph v3 on Ethereum testnet Rinkeby— the protocol is now available for you to experiment with, and develop on top of.

Get Rinkeby ETH on MyCrypto and Rinkeby DAI on Compound App > DAI > Supply > Faucet.

v3— Key Upgrades

  • Withdraw partially, roll over, top up your existing deposits.
  • A more generous fixed-interest rate for deposits with a short duration, and a more conservative rate for the long duration.
  • MPH rewards are vested linearly over the deposit duration and are transferrable NFT.
  • Stake MPH for xMPH, earn protocol’s revenues via our bi-weekly buy-back mechanism, and voting rights.
  • No more MPH payback mechanism.
  • Introducing a 0.5% early withdrawal fee; distributed to the MPH stakers.
  • Floating rate bonds are now called Yield Tokens (YT), a new per-deposit system, where a user can choose to fund a fraction of the debt of any individual deposit, regardless of order.
  • YT are fungible ERC-20/ERC-1155 tokens.
  • YT interest payout is triggered whenever a portion of the deposit funded is withdrawn, or when someone manually triggers a payout using DInterest.payInterestToFunders().
  • As a developer; interacting with the protocol is easier than ever. There are tons of accountancy burdens removed, help functions, and simple improvements to make an integration with 88mph as easy as building with Compound or Aave.
  • The solvency of each pool can now be managed dynamically by harvesting a % of a pool’s surplus and be redirected to another pool; future release will allow xMPH holders to govern the pool’s parameters.
  • One last thing, you can add artistic value to a deposit by attaching whatever metadata you want (88mph deposits are ERC-721 tokens).


The 88mph Protocol and the smart contract architecture have had some significant improvements and changes; Check our documentation and Github repo.

Web Interface

So, we’re changing our brand look!

Visit https://88mph.app/rinkeby/

We’ve entirely rebuilt the web application so that you can test the basic functionality of the v3. This is a work in progress and is missing core functionality — over the coming days, it will be updated in significant ways; please excuse any glaring bugs. If you don’t like our boring Fintech UI, switch to our 80s theme in the top right corner of your screen.
— Team of PhDs at the 88mph Design and Research center.


Developers can easily access 88mph v3’s data and pull it straight into their applications using GraphQL. You can use the new 88mph subgraph to query information about the protocol, pools, and users.

Testing 88mph v3

88mph v3 has been audited by PeckShield and Code 423n4, and no significant security issues were found. However, as with any smart contract, there may be undiscovered bugs — if you report a critical flaw in the Rinkeby version, we can offer a significant bug bounty via Immunefi (actually, up to $100,420.69 USD to be precise during the next 3 weeks).

Trail of Bits will conduct an audit between July 19 and August 9, in parallel with our guarded launch on Ethereum mainnet.

Help us improve

As you are interested in our app, we’d like to speak to you to help us improve our user experience.

Would you be interested in a 30-minute call? We’ll be asking a few questions about your experience using our 88mph v3. Everything we talk about will remain confidential. You’ll receive $100 worth of MPH as a token of our appreciation.

If you’re interested and have time over the next few weeks, please click the link below to set up a call that fits well in your calendar.
Book a call with McFly, cofounder 88mph: https://calendly.com/mcfly-88mph/88mph-user-interview/

You can also discuss the changes, or make feature requests, by joining our Discord or by tweeting at us — we’d love to hear from you!