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  • Team Name: OxyDev
  • Payment Address: 0x7a72002A872010924a4093D24712B49E5B89452c

Project Overview 📄

SubsCrypt is a BaaS(Blockchain as a service) for developers to facilitate the integration of their subscription methods on the PolkaDot blockchain using a smart contract. A dashboard panel for admins to gather useful business data of their subscribed users(by protecting users' privacy) and a dashboard panel for users to manage all their subscriptions in one place.


SubsCrypt focuses on solving a traditional problem on both the user and the developer side. Developers will no more be worried about the privacy of and maintaining the customers' database and payment mechanism. Using SubsCrypt, they can integrate Web3 in their service to benefit from blockchain in a developer-friendly way(minimum time and expertise resource). Users will also enjoy the privacy that they can preserve and the all-in-one platform to manage their subscriptions in different services. By making all these procedures easy, we can help small online businesses to enjoy the benefits of Web3 and to only focus on their service, which will hopefully lead to mass-adoption of Web3

We have been developing on different web3 technologies, but none could satisfy our customization requirements. By using Substrate, we can customize our parachain so it can fit our needs(we are also willing to continue our project to be a PolkaDot parachain)

Assume a scenario that Alice is a user of a service that provides monthly subscription for milk delivery(called Milkryption). Milkryption has a monthly and yearly subscryption method and they use SubsCrypt on their website (first they submit their method on our contract in our website, then they can use our API), so if Alice ever has used our service so far, she will only need to connect his wallet and subscript to the Milkryption using a trigger contract method(she will send some encrypted data that is encrypted with her key and also service provider key and then she will share that key with the service provider to have access to her data in the contract) but if that's her first time to ever use SubsCrypt, she has to also sign-up in the contract. Alice now can anytime request for a refund of remaining days of her service directly from the contract. Alice will hopefully use our service in several websites and now she can go to our website and manage his subscriptions(refunding or renewing) in one place.

In our country, we have a lot of restrictions and censorship. We are suffering from Iran's government's Strict policies and getting banned from universal communities and worldwide payment (e.g., PayPal and visa card) all because we are Iranian. Two months ago, our team started this idea to resolve these limits and connect our people worldwide. We will now announce our project as a service on blockchain to spread this type of freedom to the world. Besides, this, we have experience in developing different backend services and Dapps, and we came to the conclusion that our platform can help developers to migrate from web2 to web3 and also help users by enhancing their user experience to use web3 websites(they only need to use a wallet for registration, and our login procedure can be handled without wallet)

Project Details

  • Mockups/designs of any UI components One of the most important aspects of our service is UI/UX, and we are all aware of the difficulties of web3 usage for the majority of people, so we will provide a UI component that can be integrated into the websites and also a webpage that has an invoice to pay( developers can choose whichever method that suits them better). We are also planning to design a user/developer dashboard that will retrieve necessary data from the blockchain

  • An overview of the technology stack to be used
    As we explained, we want to provide a service that will fit into different stacks with minimum effort so that we will implement our side of this service with the following stack:

  • User/developer Dashboard (Front) => Vue.js and RPC API to contract
  • Smart Contract => Rust and Ink on edgeware
  • UI integration components => ES6 and purejs library
  • Backend high-level API to connect to smart contract => Django, node.js for this milestone

Ecosystem Fit

As we have been searching for similar ideas in the blockchain ecosystem, we found EIP1337 that has a similar idea, but the implementation is low level, and it does not help either developers or users have a smooth subscription platform.

Team 👥

Team members

  • Name of team leader Saber Zafarpoor (Product manager & Blockchain Designer) Hadi Esna (CTO & Blockchain Designer)
  • Names of team members Ahmad Salimi(Software Engineer) Alireza Ilami(Data Analyst) Sepehr Kianian(Front-End developer & Blockchain developer) Amir Sadra Abdolahi(Front-End developer & Blockchain developer) Yasaman Shad(Graphic Designer & UX) ...(we will hire blockchain researchers and UI developers to enhance the quality)


Team's experience

OxyDev consists of young enthusiast students/developers who graduated or undergraduates at #1 university of Iran (Sharif University of Technology) trying to make web3 easier to use and integrate into real-world services. We have developed several Defi projects in Tron and Ethereum Ecosystem and expanded our team to make venturous leaps to play our roles in making a more user-friendly world in the next generation of Web(Web3). We have done several projects of web2 that make our team aware of the pros and cons of web2.

Team Code Repos

Team LinkedIn Profiles

Development Roadmap 🔩

We will divide our project into four milestones. For the first milestone, we will implement our smart contract can be deployed to a substrate chain using ink! Which is a smart contract substrate pallet. The second and third milestones will be implemented in parallel. The last milestone will be connecting the components to work seamlessly together.

There will be three ways to connect to our smart contract:

  1. Using a Polkadot{.js} wallet to interact with the contract(state of the contract can be modified in this scenario)
  2. Using our RestAPI backend or third party library to retrieve data from the contract (state of the contract can not be modified in this scenario)
  3. Using any customized client to interact with the contract

Auth mechanism : We have designed a secure and user-friendly auth mechanism that users and providers can easily use it.

Users have to choose a pair of token and passphrase, which we recommend having a common token(more than 16 chars) in every provider that they subscribe but have a different passphrase(can be small). Users will submit sha256(token+passphrase) to the contract, and whenever they want to authenticate themselves, they have to provide these token and passphrase in a view function( which is not a transaction, so it's not on-chain and free). They also have to once set their sha256(token+passphrase) for using the SubsCrypt dashboard without a wallet. The authentication with a wallet is checked by the blockchain address sender.

First milestone: we will design(it is almost done right now) and implement our smart contract, and we will also design XD files of UI, and we will write our white-paper in this milestone(including the test unit).

The main functions that will be deployed on the chain in this milestone are as follow:

FunctionDescriptionParamsReturnsState mutability
addPlanThis function is for providers to add their plans; each plan has duration, price, max refund percent that they are willing to lock in contract and withdraw after that the subscription period has finished.list of durations, list of prices, list of max refund percentNonechange state
editPlanThis function is for providers to edit their plan. (Old subscriptions are not affected by this change)index of their plan, new duration, new max refund percent, new priceNonechange state
changeDisableThis function is for providers to edit their plan that changes the active or deactivate status of their plan(so people can or can't subscribe in that plan)plan indexNonechange state
subscribeThis payable function is for users to subscribe to their desired service and plan; they have to provide a hash of their password (the auth mechanism will be explained thoroughly in Auth Section) and provider address and plan index and some metadata that is encrypted by the public key of the provider(users can trust providers to share their data with but nobody else can know that data)provider address, plan index, the hash of pass, An optional encrypted metadataNonechange state(payable)
refundThis function is for users to refund their subscribe anytime they want and instantly withdraw the rest of their money(maximum amount of refund is indicated by max refund percent that provider had set for that plan)provider address, plan indexNonechange state
withdrawThis function is for providers to withdraw the amount that is now ready to withdraw(this is the money that we lock in the contract when a user subscribes to a plan according to max refund percent, and when their plan is finished, that money can be withdrawn). We used an optimized LinkedList solution, which is really cheap to execute and fast.Noneamount of money you are paidchange state
checkSubscriptionThis function is for users or anyone to check that if a user has an active subscription in a specific plan of a provideraddress of the user, address of provider, plan indexreturn booleanview
checkAuthThis function is used to check if the given combination of token and passphrase can authenticate a specific user for a provider(the auth mechanism will be explained thoroughly in Auth Section)address of the user, address of provider, token, passphrasereturn booleanview
retrieveWholeDataWithPasswordThis function is used to get every subscription record of a user with their token and passphrase, which first have to be set in setSubsCryptPass function(this token and passphrase is only worked to login in SubsCrypt website to have a whole review of your account)address of the user, token, passphrasereturn whole records of a userview
retrieveWholeDataWithWalletThis function is the same as the above function with a slight difference that it is used with user wallet to trigger the contract directlyNonereturn whole records of a userview
retrieveDataWithPasswordThis function is used to get every subscription record of a user only related to a specific provider with their token and passphrase is set once they subscribe to their chosen plan of that provideraddress of the user, address of provider, token, passphrasereturn whole records of a userview
retrieveDataWithWalletThis function is the same as the above function with a slight difference that it is used with user wallet to directly trigger the contractaddress of providerreturn whole records of a user-related to that providerview

Second milestone: we will implement the UI Dashboard(Vue.js) and UI modules(ES6 and pure js) regarding our XD design in the previous milestone.

Third milestone: Implementing our RestAPI backend in Node.js to provide an API layer to interact with our contract(it is optional to use this API), we will also implement our third-party libraries for Django and node.js to interact with our backend and implement the required functionality to make the integration for developers easier(including test unit).


  • Total Estimated Duration: 9 weeks
  • Full-time equivalent (FTE): 5
  • Total Costs: 30K Dai

Milestone 1 — Smart Contract

  • Estimated Duration: 3 weeks
  • FTE: 3
  • Costs: 8K Dai
0a.LicenseApache 2.0
1.Contract Implementationwe will implement the contract and deploy it to a test net.
1.1Contract codeimplementation of contract
1.2High-level APIwe will provide an API of contract
1.3Documentationfull documentation of API that explains how to connect to and use it.
1.4Testing GuideThe code will have unit-test coverage (100%) to ensure functionality and robustness. In the guide, we will describe how to run these tests
2.ArticleWe will write an article or tutorial that explains the work done in this milestone as part of the grant.
3.Design Front-End componentdesign UI and UX of front-end component with adobe xd.
4.white-paperfull description of roadmap and technical specification of this project
5.Polkadot Standards Proposals (PSPs)we will pull request a PSP in this milestone containing our implementations

Milestone 2 — UI

  • Estimated Duration: 5 weeks
  • FTE: 2
  • Costs: 10K Dai
1.UI DashboardA dashboard to manage user's subscriptions and also refund them
1.1UI Dashboard for usersA dashboard to manage user's subscriptions and also refund them
1.2UI Dashboard for adminsA dashboard to manage user's customers and create a coupon or see related charts, etc.
2.ES6 Module for developersDevelopers can use this module to integrate our service into their websites
2.1Implementation of ES6 Module for developerswe will write an ES6 Standard module
2.2Documentation of ES6 ModuleWe will provide both inline documentation of the code and a basic tutorial that explains how a developer can integrate our module into their projects
3.Unit TestWe will provide unit tests to cover our ES6 Module

Milestone 3 — Back-end libraries

  • Estimated Duration: 6 weeks(parallel with milestone 2)
  • FTE: 3
  • Costs: 12K Dai
1.Backend RestAPIwe will provide a RestAPI to facilitate the connection to blockchain. it will be used to check the subscription or retrieve any data from the contract.
1.1Backend RestAPI Implementationwe will provide a RestAPI to facilitate the connection to blockchain. it will be used to check the subscription or retrieve any data from the contract.
1.2Backend RestAPI DocumntaionA fully comprehensive documentation to use our RestAPI
1.3Backend RestAPI Unit testThe code will have unit-test coverage (100%) to ensure functionality and robustness.
2.Third Party librariesWe will provide some library to make integration of our service easier in different backend stacks by connecting to our Backend RestAPI
2.1Node.js LibraryA high-level library to use our service in Node.js
2.2Node.js Library documentationA fully comprehensive documentation to use our library
2.3Node.js Library Unit testThe code will have unit-test coverage (100%) to ensure functionality and robustness

Future Plans

when we finish this project successfully, then we will try to make our substrate pallet to become a standalone blockchain, and if everything goes well, we will try to be a PolkaDot parachain.

Works currently Done

  • Design and implementation of smart contract in solidity(Repo Link)
  • Mockup design of our Website DashBoard and Pop-Up Component
Modal Component UI dashboard