ERC20 Watcher

Overview

• Create developer facing GQL schema (erc20.graphql) for ERC20 contracts
  • GQL queries that return useful information
    • Individual token data corresponding to the ERC20 ABI
    • Aggregate data like running 1-day, 7-day & 30-day transfer counts and volumes
  • GQL mutation to add a new ERC20 contract to watch
• Create a server (erc20-info-server) to expose the above GQL API
  • Initally, the GQL resolvers will return mock data
• Create a basic React app (erc20-dashboard) that consumes the GQL API from erc20-info-server.
• Create a new watcher (erc20-watcher-ts) that is capable of watching multiple ERC20 tokens, capturing their events and state
  • Update the erc20-info-server GQL resolver to return data by querying the lower-layer erc20-watcher-ts GQL API
  • For GQL result data, at a minimum, return the request and list of CIDs/mhKeys required to generate that result.
    • Note: This implies, for example, performing aggregation in code instead of at the SQL layer.
• Create an ERC20 watcher factory (erc20-watcher-factory-ts) that auto-detects ERC20 tokens created on-chain and calls erc20-info-server to request watching them.

Setup

This project uses yarn workspaces.

Install packages (Node.JS v15.11.0):

yarn

Create a postgres12 database and provide connection settings in environments/local.toml.

For example:

sudo su - postgres
createdb erc20-watcher

Run the watcher:

cd packages/watcher
yarn run server

GQL console: http://localhost:3001/graphql

To run tests (GQL queries) against the mock server:

cd packages/watcher
yarn run server:mock

cd packages/watcher
yarn test

Example GQL Queries

{
  name(blockHash: "0x5ef95c9847f15179b64fa57994355623f899aca097ad779421b8dff866a8b9c3", token: "0x1ca7c995f8eF0A2989BbcE08D5B7Efe50A584aa1") {
    value
    proof {
      data
    }
  }

  symbol(blockHash: "0x5ef95c9847f15179b64fa57994355623f899aca097ad779421b8dff866a8b9c3", token: "0x1ca7c995f8eF0A2989BbcE08D5B7Efe50A584aa1") {
    value
    proof {
      data
    }
  }

  totalSupply(blockHash: "0x5ef95c9847f15179b64fa57994355623f899aca097ad779421b8dff866a8b9c3", token: "0x1ca7c995f8eF0A2989BbcE08D5B7Efe50A584aa1") {
    value
    proof {
      data
    }
  }

  balanceOf(blockHash: "0x5ef95c9847f15179b64fa57994355623f899aca097ad779421b8dff866a8b9c3", token: "0x1ca7c995f8eF0A2989BbcE08D5B7Efe50A584aa1", owner: "0xDC7d7A8920C8Eecc098da5B7522a5F31509b5Bfc") {
    value
    proof {
      data
    }
  }

  allowance(blockHash: "0x81ed2b04af35b1b276281c37243212731202d5a191a27d07b22a605fd442998d", token: "0x1ca7c995f8eF0A2989BbcE08D5B7Efe50A584aa1", owner: "0xDC7d7A8920C8Eecc098da5B7522a5F31509b5Bfc", spender: "0xCA6D29232D1435D8198E3E5302495417dD073d61") {
    value
    proof {
      data
    }
  }

  events(blockHash: "0x3441ba476dff95c58528afe754ceec659e0ef8ff1b59244ec4545f4f9784a51c", token: "0x1ca7c995f8eF0A2989BbcE08D5B7Efe50A584aa1") {
    event {
      __typename
      ... on TransferEvent {
        from
        to
        value
      }
      ... on ApprovalEvent {
        owner
        spender
        value
      }
    }
    proof {
      data
    }
  }
}