Please describe your proposed solution.

Answer:

By deploying an open API for multisig wallets and transactions we, as an ecosystem, gain 2 things.

1) Developers can integrate the API when they are creating a new multisig wallet

2) Users can cooperate and participate by using their own multisig software solution. This will allow users to pick the software that best fits them and seamlessly cooperate with everyone else.

The sinc accepts wallet descriptors, and it accepts transaction + signature bundles as inputs freely, this way transactions created by anyone that is not a member of the multisig are rejected instantly safeguarding users from fishing spam attacks.

For fetching transactions the API will request the connecting member sign a message proving they own the corresponding key, after verification is completed, an access token is given for future logins and all new transactions relevant to this key are promoted to him.

Please define the positive impact your project will have on the wider Cardano community.

By having robust multisig infrastructure ,we will open the doors to larger and more serious investors.

By making the underline rails of the multisig wallet space open for all, we allow easier international cooperation since members can use software tailored to their own needs, including but not limited to language , accessibility, Hardware wallet support, cold storage, local data provider etc.

What is your capability to deliver your project with high levels of trust and accountability? How do you intend to validate if your approach is feasible?

I have developed a Multisig Wallet for Cardano that is already operational.

This functionality has been implemented and tested.

I have over 10 years experience in Linux operation and experience operating a high performance pool since the first days fd Cardano, deploying and maintain a high reliability service is trivial to me.

Additionally I have 2 years of JavaScript/Nodejs/MongoDB experience and given that the MVP of the product is already completed.

And I am now completing Catalyst proposal 100928 that will bring Defi capabilities to Multisig wallets

What are the key milestones you need to achieve in order to complete your project successfully?

Separate out the Sync service from the BroClan software and deploy it

Key Activities: setup new gitHub project, split the sync logic code of BroClan to the new project, deploy on a test environment, test using BroClan and direct calls

Timeline: 2 weeks

<u>Deliverable</u> : A running API service accessible to all and a corresponding GitHub project with its code.

>Implement long polling for developers that do not want to use web sockets

Key Activities: Implement alternative fetch and authentication stream using RestAPI endpoints instead of websockets, test and verify, deploy to production

Timeline: 1 weeks

<u>Deliverable </u>: The existing API service with the added capability of being able to login and fetch using only https requests (no websockets)

>Implement transaction sign-in for HD-Wallets

Key Activities: Setup alternative proses flow where a transaction is signed to authenticate a client, setup an indexer for the backend to find utxos and to submit the signed transactions.

Timeline: 1 week

<u>Deliverable</u>: the ability's to login to the service using a hardware wallet, or a software wallet that does not support message sighing, add multitenancy support to avoid having users pay repeatedly every time they switch devices.

>Create a JavaScript library for the client side integration

Key Activities: Create new github repo, implement all the functionality required to use the API (Submit, authentication, polling, web sockets), create npm package, test with BroClan and manual usage, create Documentation page with full functionality overview.

Timeline: 2 weeks

<u>Deliverable</u>: an npm package that you are able to easily install into your JavaScript project and the corresponding GitHub repository.

>N/A

>When The project is wrapped up the Cardano ecosystem should have a operational API live with a sync service that anyone can connect to.

Additionally you should be able to deploy your own instance easily with instructions on the corresponding GitHub repo, and any developer should be able to easily use the service in their own project with our NPM library.

Who is in the project team and what are their roles?

Leandros Holleman- Project manager, Developer and SysAdmin

I am a 1 man team and given the limited scope of the project I can handle it on my own.

Please provide a cost breakdown of the proposed work and resources.

Given that we are working with very light data packages, and the multisig space is in its very early stage on Cardano, the following computational resources should be enough for the first 2 years of operation. Hopefully transaction sighed login should bring enough revenue to expand and maintain the service after the 2 years are completed.

MongoDB Atlas instance:

€9/month * 24 Months = €216

API Host node €20/month * 24 = €480

1)Separate out the Sync service from the BroClan software and deploy it

EE: 40 hours

2)Implement long polling for developers that do not want to use web sockets

EE: 40hours

3)Implement transaction sign-in for HD-Wallets

EE: 40 hours

4)Create a JavaScript library for the client side integration

EE: 60hours

180Hours * €50/Hour = €9000

Total : €9,696 ~ 28000 ADA

How does the cost of the project represent value for money for the Cardano ecosystem?

Given that a lot of the grunt work is already done the Cardano solution can get this up an running for a bit cheaper that it would be if it was to be build on demand.

By implementing this we allow cross play around multisig wallets.

And by having this available it means teams that are building multisig wallets from this point foreword will not need to build it by them self.