Can we use the a modified version of the existing Graph Protocol node?

[yourheropaul]

This is The Graph's version of the indexing node: https://github.com/graphprotocol/graph-cli. They also have a mapping-creator: https://github.com/graphprotocol/graph-ts and it seems like they have forked Substrate.

Advantages

The Graph nodes already feature scalable GraphQL APIs, self-hosted setups, and are continually maintained by a dedicated team.

Perhaps this is an off-the-shelf solution? It turns out this is only for Ethereum chains initially, and uses web3 as its interface.

Problems and solutions

The Graph's project goal is to support any blockchain, but it currently only supports Ethereum. There is a concept of multiple datasources and in theory any WASM runtime is supported.

In order to make this system compatible with a Substrate/Joystream node, we'd need to:

1. Fork the main graph node
2. Implement a Substrate data source
3. (optionally) create a runtime for non-Ethereum smart contracts (which should be possible)
4. Make sure that the graph node serves proofs via GraphQL

Questions

1. How tightly coupled is the Ethereum datasource?
2. Are there any other implications of changing the datasource?

[yourheropaul]

The main issues here would be:

1. Modifying a complex Rust application
2. Making sure proofs are provided for the web API (see Proposal in update handle validation method to limit to: ^[a-z0-9_]+$ joystream#17)

[yourheropaul]

This isn't really feasible.