NFT Indexer API - Microservice

Name of Project

[NFT Indexer API - Microservice]

Proposal overview

There are very limited ways to query on-chain data and NFT projects needed rich queries. So NFT projects either needed to create their own way to index on-chain data or use third-party services. This project is about creating a complete API as a service and also a dockerized open-source microservice to run the indexer locally by marketplaces.

Product Details

The indexer will iterate over events of a contract and add them to DB. Then they will add to the watcher system that will be notified whenever an event happens and update the DB state. The end product will be work for both HRC721-HRC1155 and will also process the common metadata standards.

Development Roadmap

The indexer will be implemented in 3 Phase:

Phase 1

The full opensource microservice for HRC-721 and HRC1155. Indexer and API. No Metadata. All owners and transfers history and data. Both REST API and Graphql.

  • Estimated Duration: 3 weeks
  • Cost : 15,000 USD

Phase 2

The metadata fetcher, parser and analysis ( rarity analysis )

  • Estimated Duration: 3 weeks
  • Cost : 15,000 USD

Phase 3

A proper deployement of the public API ( rate limit, API key, … ) system.

  • Estimated Duration: 3 weeks
  • Cost : 10,000 USD

Similar Experiences

I’m the lead developer of the which is on of the main marketplaces on Zilliqa Blockchain and I have created an indexer on that chain so I’m pretty familliar with needed APIs and the overall architecture of an NFT indexer.

I have created a rarity analysis tool for NFTs on BSC in this repository

I also have created part of the ERC721 indexer as part of this repository which was a harmony bounty that I gave up.

External links


Unfortunately, your proposal is not ready for a Launch grant. The idea is great but it needs to be a more full stack approach of building out a service. There are also open source repos available for this. The key here is servicing the community with a full desktop and mobile web experience.

We hope you continue to build on this concept and circle back when it is ready to be discussed further. Thank you for choosing Harmony.