Create Peggy Subgraph

[albertchon]

The current bridge UI is rather simple and does not provide users any visual indication of the progress of one's transfers.

We can use The Graph as a general purpose backend API for use by client-facing services as well as internal monitoring/alerting.

injective-station

The station (and possibly also DEX) can use this API to show historical cross-chain deposits/withdrawals as well as real-time estimates for pending deposits.

• obtaining historical ERC-20 deposits from Ethereum -> Injective (by scanning SendToCosmosEvent)
• obtaining a historical ERC-20 withdrawals from Injective -> Ethereum (by using CallHandlers on the submitBatch)

internal monitoring

Although this won't be used by any mission critical services, having this nice GraphQL API can easily allow us to make sure Peggy is functioning properly. With this API, we can create monitoring bots or even a future analytics site which uses this API as well.

• tracking the last updated Validator set & powers (also by using CallHandlers on the updateValset function)
• tracking all of the Deployed ERC-20's (by scanning ERC20DeployedEvent)
• tracking the up-to-date state variables for convenience

Implementation Checklist

• Define GraphQL Schema
• Implement event and call handler mappings
• Deploy on The Graph's hosted Ethereum Subgraph service