watcher-ts/README.md
Ashwin Phatak 7213a1dc6d
Lazy ERC20 watcher (#11)
* Storage mapping utils.

* Resolver factories.

* Get ERC20 balance from upstream ipld-eth-server slot.

* Get ERC20 allowance from storage slot.

* Parse ERC20 events from block events.

* Cache GQL requests in leveldb.

* Refactor fetch/cache from upstream into eth-loader class.

* Refactoring.

* Refactor eth-client, extract cache class.

* Cache config settings.

* Debug logs.

* Rename server to watcher.

* Start local server by default.

* Split into multiple packages.

* eth-client API methods.

* Update docs.
2021-05-28 16:56:40 +05:30

2.5 KiB

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

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

{
  balanceOf(blockHash: "0x671e693ec3dccc948606db8d7e65ac3e16baea80a0dd6d56a126e07ccf85231f", token: "0x1ca7c995f8eF0A2989BbcE08D5B7Efe50A584aa1", owner: "0xDC7d7A8920C8Eecc098da5B7522a5F31509b5Bfc") {
    value
    proof {
      data
    }
  }

  allowance(blockHash: "0x671e693ec3dccc948606db8d7e65ac3e16baea80a0dd6d56a126e07ccf85231f", token: "0x1ca7c995f8eF0A2989BbcE08D5B7Efe50A584aa1", owner: "0xDC7d7A8920C8Eecc098da5B7522a5F31509b5Bfc", spender: "0xCA6D29232D1435D8198E3E5302495417dD073d61") {
    value
    proof {
      data
    }
  }

  events(blockHash: "0x671e693ec3dccc948606db8d7e65ac3e16baea80a0dd6d56a126e07ccf85231f", token: "0x1ca7c995f8eF0A2989BbcE08D5B7Efe50A584aa1") {
    event {
      ... on TransferEvent {
        from
        to
        value
      }
      ... on ApprovalEvent {
        owner
        spender
        value
      }
    }
    proof {
      data
    }
  }
}