Logonity - decentralized logo marketplace

Proof of Concept of Aeternity blockchain based decentralized application (DAPP)

Logonity - decentralised logo marketplace

Proof of Concept of Aeternity blockchain based decentralized application (DAPP)

Platform overview

Logonity is POC and MVP dapp (decentralised application) based on Aeternity Blockchain. The goal was to develop the marketplace for logo commissions. Basically everyone can submit the logo creation – providing the description of desired logo and the reward for the work (in Ae tokens). Also everyone can submit their logo proposals for the commissions. Principal (of the logo) choosing the won logo – can download the full version of the file. The won logo author gets the reward for the logo commission.

Application is based on smart contract. The logic of creating commission, submitting the proposals, locking the reward and finally choosing the winner and sending the reward to the winner – it’s all based on the smart contract working in Blockchain. Centralised server used by Logonity is dedicated to store picture files (since it’s not appropriate data for the blockchain).

Complete backlog of the Aeternity based dapp development lifecycle

I’ve documented the process of developing this application in 6 in-depth articles:

Day 1: 1 Week Aepp Challange – Idea and concept
Day 2: Aeternity dapp architecture and technologies
Day 3: Sophia smart contract
Day 4: aepp-sdk-js and communication with the blockchain
Day 5: Dapp client, contract use and security
Day 6: Logonity 1.0 Alpha overview and features


Problem to solve

Blockchain resolves the problem of trust.

Smart contracts based on Blockchain gives the possibility of immutable, transparent software logic flow. Including to this the possibility of sending value – in form of tokens, it can be used in many different scenarios. In Logonity example Blockchain ensures that commissions for the work (logo creation) are all valuable – there is reward locked in the smart contract. Every logo author can be sure that if his logo will be chosen as the winner – he will for sure get the reward.

There are no technical possibilities of changing smart contract logic. It means that there is no possibility to cheat the smart contract rules (that’s why it’s smart).

Since the Blockchain cryptocurrencies (tokens) have value – Blockchain in that sense is used also as the currency and reward source.


Aeternity Blockchain



Technical overview

Smart contract is written in Sophia – functional language dedicated for Aeternity.

The frontend is developed in Vue.js and is based on Quasar Framework. Material Design based UI (integrated in Quasar) was used to design UI.

Backend is Node.js application integrated with PostgreSQL database.

Client integrates the Aeternity Javascript SDK. It gives the possibility to interact with smart contracts and with blockchain in general.

Every commission creation is simply smart contract deployment and it’s initialization. Commissions are also saved in PostgreSQL in order to be saved – there is no possibility to get information about the deployed smart contract if the smart contract address will not be saved. This is why there is neccessity to store somewhere at least contract address in order to have possibility to interact with it. Every commissions locks in the smart contract the provided by the logo principal amount of tokens. The neccessity is ofcourse that commission author has the given amount of token – which will be taken and locked in contract.

Logo proposals are saved in the smart contract and in the database. The information about logo proposal author is saved in the blockchain. The logo file is saved in centralised backend.

Everyone can see submitted logo proposals. Centralised backend server provides the preview of submitted logo picture files (with watermark).

The chosen won logo by the commission author automatically receives the reward locked in the smart contract. Commission author has the possibility to download full version file from the Logonity backend server.


The project is already suspended. It's no longer online.