Generate erc721-watcher using codegen

packages/erc721-watcher/.eslintignore

@@ -0,0 +1,2 @@
+# Don't lint build output.
+dist

packages/erc721-watcher/.eslintrc.json

@@ -0,0 +1,27 @@
+{
+    "env": {
+        "browser": true,
+        "es2021": true
+    },
+    "extends": [
+        "semistandard",
+        "plugin:@typescript-eslint/recommended"
+    ],
+    "parser": "@typescript-eslint/parser",
+    "parserOptions": {
+        "ecmaVersion": 12,
+        "sourceType": "module"
+    },
+    "plugins": [
+        "@typescript-eslint"
+    ],
+    "rules": {
+        "@typescript-eslint/no-explicit-any": "off",
+        "@typescript-eslint/explicit-module-boundary-types": [
+            "warn",
+            {
+                "allowArgumentsExplicitlyTypedAsAny": true
+            }
+        ]
+    }
+}

packages/erc721-watcher/README.md

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+# erc721-watcher
+
+## Setup
+
+* Run the following command to install required packages:
+
+  ```bash
+  yarn
+  ```
+
+* Run the IPFS (go-ipfs version 0.12.2) daemon:
+
+  ```bash
+  ipfs daemon
+  ```
+
+* Create a postgres12 database for the watcher:
+
+  ```bash
+  sudo su - postgres
+  createdb erc721-watcher
+  ```
+
+* If the watcher is an `active` watcher:
+
+  Create database for the job queue and enable the `pgcrypto` extension on them (https://github.com/timgit/pg-boss/blob/master/docs/usage.md#intro):
+
+  ```
+  createdb erc721-watcher-job-queue
+  ```
+
+  ```
+  postgres@tesla:~$ psql -U postgres -h localhost erc721-watcher-job-queue
+  Password for user postgres:
+  psql (12.7 (Ubuntu 12.7-1.pgdg18.04+1))
+  SSL connection (protocol: TLSv1.3, cipher: TLS_AES_256_GCM_SHA384, bits: 256, compression: off)
+  Type "help" for help.
+
+  erc721-watcher-job-queue=# CREATE EXTENSION pgcrypto;
+  CREATE EXTENSION
+  erc721-watcher-job-queue=# exit
+  ```
+
+* In the [config file](./environments/local.toml):
+
+  * Update the database connection settings.
+
+  * Update the `upstream` config and provide the `ipld-eth-server` GQL API endpoint.
+
+  * Update the `server` config with state checkpoint settings and provide the IPFS API address.
+
+## Customize
+
+* Indexing on an event:
+
+  * Edit the custom hook function `handleEvent` (triggered on an event) in [hooks.ts](./src/hooks.ts) to perform corresponding indexing using the `Indexer` object.
+
+  * While using the indexer storage methods for indexing, pass `diff` as true if default state is desired to be generated using the state variables being indexed.
+
+* Generating state:
+
+  * Edit the custom hook function `createInitialState` (triggered if the watcher passes the start block, checkpoint: `true`) in [hooks.ts](./src/hooks.ts) to save an initial state `IPLDBlock` using the `Indexer` object.
+
+  * Edit the custom hook function `createStateDiff` (triggered on a block) in [hooks.ts](./src/hooks.ts) to save the state in a `diff` `IPLDBlock` using the `Indexer` object. The default state (if exists) is updated.
+
+  * Edit the custom hook function `createStateCheckpoint` (triggered just before default and CLI checkpoint) in [hooks.ts](./src/hooks.ts) to save the state in a `checkpoint` `IPLDBlock` using the `Indexer` object.
+
+## Run
+
+* Run the watcher:
+
+  ```bash
+  yarn server
+  ```
+
+GQL console: http://localhost:3006/graphql
+
+* If the watcher is an `active` watcher:
+
+  * Run the job-runner:
+
+    ```bash
+    yarn job-runner
+    ```
+
+  * To watch a contract:
+
+    ```bash
+    yarn watch:contract --address <contract-address> --kind <contract-kind> --checkpoint <true | false> --starting-block [block-number]
+    ```
+
+    * `address`: Address or identifier of the contract to be watched.
+    * `kind`: Kind of the contract.
+    * `checkpoint`: Turn checkpointing on (`true` | `false`).
+    * `starting-block`: Starting block for the contract (default: `1`).
+
+    Examples:
+
+    Watch a contract with its address and checkpointing on:
+
+    ```bash
+    yarn watch:contract --address 0x1F78641644feB8b64642e833cE4AFE93DD6e7833 --kind ERC20 --checkpoint true
+    ```
+
+    Watch a contract with its identifier and checkpointing on:
+
+    ```bash
+    yarn watch:contract --address MyProtocol --kind protocol --checkpoint true
+    ```
+
+  * To fill a block range:
+
+    ```bash
+    yarn fill --start-block <from-block> --end-block <to-block>
+    ```
+
+    * `start-block`: Block number to start filling from.
+    * `end-block`: Block number till which to fill.
+
+  * To create a checkpoint for a contract:
+
+    ```bash
+    yarn checkpoint --address <contract-address> --block-hash [block-hash]
+    ```
+
+    * `address`: Address or identifier of the contract for which to create a checkpoint.
+    * `block-hash`: Hash of a block (in the pruned region) at which to create the checkpoint (default: latest canonical block hash).
+
+  * To reset the watcher to a previous block number:
+
+    * Reset state:
+
+      ```bash
+      yarn reset state --block-number <previous-block-number>
+      ```
+
+    * Reset job-queue:
+
+      ```bash
+      yarn reset job-queue --block-number <previous-block-number>
+      ```
+
+    * `block-number`: Block number to which to reset the watcher.
+
+  * To export and import the watcher state:
+
+    * In source watcher, export watcher state:
+
+      ```bash
+      yarn export-state --export-file [export-file-path]
+      ```
+
+      * `export-file`: Path of JSON file to which to export the watcher data.
+
+    * In target watcher, run job-runner:
+
+      ```bash
+      yarn job-runner
+      ```
+
+    * Import watcher state:
+
+      ```bash
+      yarn import-state --import-file <import-file-path>
+      ```
+
+      * `import-file`: Path of JSON file from which to import the watcher data.
+
+    * Run fill:
+
+      ```bash
+      yarn fill --start-block <snapshot-block> --end-block <to-block>
+      ```
+
+      * `snapshot-block`: Block number at which the watcher state was exported.
+
+    * Run server:
+
+      ```bash
+      yarn server
+      ```
+
+  * To inspect a CID:
+
+    ```bash
+    yarn inspect-cid --cid <cid>
+    ```
+
+    * `cid`: CID to be inspected.

packages/erc721-watcher/environments/local.toml

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+[server]
+  host = "127.0.0.1"
+  port = 3006
+  kind = "active"
+
+  # Checkpointing state.
+  checkpointing = true
+
+  # Checkpoint interval in number of blocks.
+  checkpointInterval = 2000
+
+  # IPFS API address (can be taken from the output on running the IPFS daemon).
+  # ipfsApiAddr = "/ip4/127.0.0.1/tcp/5001"
+
+
+[database]
+  type = "postgres"
+  host = "localhost"
+  port = 5432
+  database = "erc721-watcher"
+  username = "postgres"
+  password = "postgres"
+  synchronize = true
+  logging = false
+
+[upstream]
+  [upstream.ethServer]
+    gqlApiEndpoint = "http://127.0.0.1:8082/graphql"
+    rpcProviderEndpoint = "http://127.0.0.1:8081"
+    blockDelayInMilliSecs = 2000
+
+  [upstream.cache]
+    name = "requests"
+    enabled = false
+    deleteOnStart = false
+
+[jobQueue]
+  dbConnectionString = "postgres://postgres:postgres@localhost/erc721-watcher-job-queue"
+  maxCompletionLagInSecs = 300
+  jobDelayInMilliSecs = 100
+  eventsInBatch = 50

packages/erc721-watcher/package.json

@@ -0,0 +1,67 @@
+{
+  "name": "@vulcanize/erc721-watcher",
+  "version": "0.1.0",
+  "description": "erc721-watcher",
+  "private": true,
+  "main": "dist/index.js",
+  "scripts": {
+    "lint": "eslint .",
+    "build": "tsc",
+    "server": "DEBUG=vulcanize:* ts-node src/server.ts",
+    "job-runner": "DEBUG=vulcanize:* ts-node src/job-runner.ts",
+    "watch:contract": "DEBUG=vulcanize:* ts-node src/cli/watch-contract.ts",
+    "fill": "DEBUG=vulcanize:* ts-node src/fill.ts",
+    "reset": "DEBUG=vulcanize:* ts-node src/cli/reset.ts",
+    "checkpoint": "DEBUG=vulcanize:* ts-node src/cli/checkpoint.ts",
+    "export-state": "DEBUG=vulcanize:* ts-node src/cli/export-state.ts",
+    "import-state": "DEBUG=vulcanize:* ts-node src/cli/import-state.ts",
+    "inspect-cid": "DEBUG=vulcanize:* ts-node src/cli/inspect-cid.ts"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/vulcanize/watcher-ts.git"
+  },
+  "author": "",
+  "license": "AGPL-3.0",
+  "bugs": {
+    "url": "https://github.com/vulcanize/watcher-ts/issues"
+  },
+  "homepage": "https://github.com/vulcanize/watcher-ts#readme",
+  "dependencies": {
+    "@apollo/client": "^3.3.19",
+    "@ethersproject/providers": "5.3.0",
+    "@ipld/dag-cbor": "^6.0.12",
+    "@vulcanize/ipld-eth-client": "^0.1.0",
+    "@vulcanize/solidity-mapper": "^0.1.0",
+    "@vulcanize/util": "^0.1.0",
+    "@vulcanize/graph-node": "^0.1.0",
+    "apollo-server-express": "^2.25.0",
+    "apollo-type-bigint": "^0.1.3",
+    "debug": "^4.3.1",
+    "ethers": "^5.2.0",
+    "express": "^4.17.1",
+    "graphql": "^15.5.0",
+    "graphql-import-node": "^0.0.4",
+    "json-bigint": "^1.0.0",
+    "reflect-metadata": "^0.1.13",
+    "typeorm": "^0.2.32",
+    "yargs": "^17.0.1",
+    "decimal.js": "^10.3.1"
+  },
+  "devDependencies": {
+    "@ethersproject/abi": "^5.3.0",
+    "@types/express": "^4.17.11",
+    "@types/yargs": "^17.0.0",
+    "@typescript-eslint/eslint-plugin": "^4.25.0",
+    "@typescript-eslint/parser": "^4.25.0",
+    "eslint": "^7.27.0",
+    "eslint-config-semistandard": "^15.0.1",
+    "eslint-config-standard": "^16.0.3",
+    "eslint-plugin-import": "^2.23.3",
+    "eslint-plugin-node": "^11.1.0",
+    "eslint-plugin-promise": "^5.1.0",
+    "eslint-plugin-standard": "^5.0.0",
+    "ts-node": "^10.0.0",
+    "typescript": "^4.3.2"
+  }
+}

packages/erc721-watcher/src/artifacts/ERC721.json

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+{
+  "abi": [
+    {
+      "inputs": [
+        {
+          "internalType": "string",
+          "name": "name_",
+          "type": "string"
+        },
+        {
+          "internalType": "string",
+          "name": "symbol_",
+          "type": "string"
+        }
+      ],
+      "stateMutability": "nonpayable",
+      "type": "constructor"
+    },
+    {
+      "anonymous": false,
+      "inputs": [
+        {
+          "indexed": true,
+          "internalType": "address",
+          "name": "owner",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "internalType": "address",
+          "name": "approved",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "internalType": "uint256",
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "Approval",
+      "type": "event"
+    },
+    {
+      "anonymous": false,
+      "inputs": [
+        {
+          "indexed": true,
+          "internalType": "address",
+          "name": "owner",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "internalType": "address",
+          "name": "operator",
+          "type": "address"
+        },
+        {
+          "indexed": false,
+          "internalType": "bool",
+          "name": "approved",
+          "type": "bool"
+        }
+      ],
+      "name": "ApprovalForAll",
+      "type": "event"
+    },
+    {
+      "anonymous": false,
+      "inputs": [
+        {
+          "indexed": true,
+          "internalType": "address",
+          "name": "from",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "internalType": "address",
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "indexed": true,
+          "internalType": "uint256",
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "Transfer",
+      "type": "event"
+    },
+    {
+      "inputs": [
+        {
+          "internalType": "address",
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "internalType": "uint256",
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "approve",
+      "outputs": [],
+      "stateMutability": "nonpayable",
+      "type": "function"
+    },
+    {
+      "inputs": [
+        {
+          "internalType": "address",
+          "name": "owner",
+          "type": "address"
+        }
+      ],
+      "name": "balanceOf",
+      "outputs": [
+        {
+          "internalType": "uint256",
+          "name": "",
+          "type": "uint256"
+        }
+      ],
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "inputs": [
+        {
+          "internalType": "uint256",
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "getApproved",
+      "outputs": [
+        {
+          "internalType": "address",
+          "name": "",
+          "type": "address"
+        }
+      ],
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "inputs": [
+        {
+          "internalType": "address",
+          "name": "owner",
+          "type": "address"
+        },
+        {
+          "internalType": "address",
+          "name": "operator",
+          "type": "address"
+        }
+      ],
+      "name": "isApprovedForAll",
+      "outputs": [
+        {
+          "internalType": "bool",
+          "name": "",
+          "type": "bool"
+        }
+      ],
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "inputs": [],
+      "name": "name",
+      "outputs": [
+        {
+          "internalType": "string",
+          "name": "",
+          "type": "string"
+        }
+      ],
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "inputs": [
+        {
+          "internalType": "uint256",
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "ownerOf",
+      "outputs": [
+        {
+          "internalType": "address",
+          "name": "",
+          "type": "address"
+        }
+      ],
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "inputs": [
+        {
+          "internalType": "address",
+          "name": "from",
+          "type": "address"
+        },
+        {
+          "internalType": "address",
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "internalType": "uint256",
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "safeTransferFrom",
+      "outputs": [],
+      "stateMutability": "nonpayable",
+      "type": "function"
+    },
+    {
+      "inputs": [
+        {
+          "internalType": "address",
+          "name": "from",
+          "type": "address"
+        },
+        {
+          "internalType": "address",
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "internalType": "uint256",
+          "name": "tokenId",
+          "type": "uint256"
+        },
+        {
+          "internalType": "bytes",
+          "name": "_data",
+          "type": "bytes"
+        }
+      ],
+      "name": "safeTransferFrom",
+      "outputs": [],
+      "stateMutability": "nonpayable",
+      "type": "function"
+    },
+    {
+      "inputs": [
+        {
+          "internalType": "address",
+          "name": "operator",
+          "type": "address"
+        },
+        {
+          "internalType": "bool",
+          "name": "approved",
+          "type": "bool"
+        }
+      ],
+      "name": "setApprovalForAll",
+      "outputs": [],
+      "stateMutability": "nonpayable",
+      "type": "function"
+    },
+    {
+      "inputs": [
+        {
+          "internalType": "bytes4",
+          "name": "interfaceId",
+          "type": "bytes4"
+        }
+      ],
+      "name": "supportsInterface",
+      "outputs": [
+        {
+          "internalType": "bool",
+          "name": "",
+          "type": "bool"
+        }
+      ],
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "inputs": [],
+      "name": "symbol",
+      "outputs": [
+        {
+          "internalType": "string",
+          "name": "",
+          "type": "string"
+        }
+      ],
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "inputs": [
+        {
+          "internalType": "uint256",
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "tokenURI",
+      "outputs": [
+        {
+          "internalType": "string",
+          "name": "",
+          "type": "string"
+        }
+      ],
+      "stateMutability": "view",
+      "type": "function"
+    },
+    {
+      "inputs": [
+        {
+          "internalType": "address",
+          "name": "from",
+          "type": "address"
+        },
+        {
+          "internalType": "address",
+          "name": "to",
+          "type": "address"
+        },
+        {
+          "internalType": "uint256",
+          "name": "tokenId",
+          "type": "uint256"
+        }
+      ],
+      "name": "transferFrom",
+      "outputs": [],
+      "stateMutability": "nonpayable",
+      "type": "function"
+    }
+  ],
+  "storageLayout": {
+    "storage": [
+      {
+        "astId": 718,
+        "contract": "ERC721.sol:ERC721",
+        "label": "_name",
+        "offset": 0,
+        "slot": "0",
+        "type": "t_string_storage"
+      },
+      {
+        "astId": 720,
+        "contract": "ERC721.sol:ERC721",
+        "label": "_symbol",
+        "offset": 0,
+        "slot": "1",
+        "type": "t_string_storage"
+      },
+      {
+        "astId": 724,
+        "contract": "ERC721.sol:ERC721",
+        "label": "_owners",
+        "offset": 0,
+        "slot": "2",
+        "type": "t_mapping(t_uint256,t_address)"
+      },
+      {
+        "astId": 728,
+        "contract": "ERC721.sol:ERC721",
+        "label": "_balances",
+        "offset": 0,
+        "slot": "3",
+        "type": "t_mapping(t_address,t_uint256)"
+      },
+      {
+        "astId": 732,
+        "contract": "ERC721.sol:ERC721",
+        "label": "_tokenApprovals",
+        "offset": 0,
+        "slot": "4",
+        "type": "t_mapping(t_uint256,t_address)"
+      },
+      {
+        "astId": 738,
+        "contract": "ERC721.sol:ERC721",
+        "label": "_operatorApprovals",
+        "offset": 0,
+        "slot": "5",
+        "type": "t_mapping(t_address,t_mapping(t_address,t_bool))"
+      }
+    ],
+    "types": {
+      "t_address": {
+        "encoding": "inplace",
+        "label": "address",
+        "numberOfBytes": "20"
+      },
+      "t_bool": {
+        "encoding": "inplace",
+        "label": "bool",
+        "numberOfBytes": "1"
+      },
+      "t_mapping(t_address,t_bool)": {
+        "encoding": "mapping",
+        "key": "t_address",
+        "label": "mapping(address => bool)",
+        "numberOfBytes": "32",
+        "value": "t_bool"
+      },
+      "t_mapping(t_address,t_mapping(t_address,t_bool))": {
+        "encoding": "mapping",
+        "key": "t_address",
+        "label": "mapping(address => mapping(address => bool))",
+        "numberOfBytes": "32",
+        "value": "t_mapping(t_address,t_bool)"
+      },
+      "t_mapping(t_address,t_uint256)": {
+        "encoding": "mapping",
+        "key": "t_address",
+        "label": "mapping(address => uint256)",
+        "numberOfBytes": "32",
+        "value": "t_uint256"
+      },
+      "t_mapping(t_uint256,t_address)": {
+        "encoding": "mapping",
+        "key": "t_uint256",
+        "label": "mapping(uint256 => address)",
+        "numberOfBytes": "32",
+        "value": "t_address"
+      },
+      "t_string_storage": {
+        "encoding": "bytes",
+        "label": "string",
+        "numberOfBytes": "32"
+      },
+      "t_uint256": {
+        "encoding": "inplace",
+        "label": "uint256",
+        "numberOfBytes": "32"
+      }
+    }
+  }
+}

packages/erc721-watcher/src/cli/checkpoint.ts

@@ -0,0 +1,79 @@
+//
+// Copyright 2021 Vulcanize, Inc.
+//
+
+import path from 'path';
+import yargs from 'yargs';
+import 'reflect-metadata';
+import debug from 'debug';
+import assert from 'assert';
+
+import { Config, DEFAULT_CONFIG_PATH, getConfig, initClients, JobQueue } from '@vulcanize/util';
+import { GraphWatcher, Database as GraphDatabase } from '@vulcanize/graph-node';
+
+import { Database } from '../database';
+import { Indexer } from '../indexer';
+
+const log = debug('vulcanize:checkpoint');
+
+const main = async (): Promise<void> => {
+  const argv = await yargs.parserConfiguration({
+    'parse-numbers': false
+  }).options({
+    configFile: {
+      alias: 'f',
+      type: 'string',
+      require: true,
+      demandOption: true,
+      describe: 'Configuration file path (toml)',
+      default: DEFAULT_CONFIG_PATH
+    },
+    address: {
+      type: 'string',
+      require: true,
+      demandOption: true,
+      describe: 'Contract address to create the checkpoint for.'
+    },
+    blockHash: {
+      type: 'string',
+      describe: 'Blockhash at which to create the checkpoint.'
+    }
+  }).argv;
+
+  const config: Config = await getConfig(argv.configFile);
+  const { ethClient, ethProvider } = await initClients(config);
+
+  const db = new Database(config.database);
+  await db.init();
+
+  const graphDb = new GraphDatabase(config.database, path.resolve(__dirname, 'entity/*'));
+  await graphDb.init();
+
+  const graphWatcher = new GraphWatcher(graphDb, ethClient, ethProvider, config.server);
+
+  const jobQueueConfig = config.jobQueue;
+  assert(jobQueueConfig, 'Missing job queue config');
+
+  const { dbConnectionString, maxCompletionLagInSecs } = jobQueueConfig;
+  assert(dbConnectionString, 'Missing job queue db connection string');
+
+  const jobQueue = new JobQueue({ dbConnectionString, maxCompletionLag: maxCompletionLagInSecs });
+  await jobQueue.start();
+
+  const indexer = new Indexer(config.server, db, ethClient, ethProvider, jobQueue, graphWatcher);
+  await indexer.init();
+
+  graphWatcher.setIndexer(indexer);
+
+  const blockHash = await indexer.processCLICheckpoint(argv.address, argv.blockHash);
+
+  log(`Created a checkpoint for contract ${argv.address} at block-hash ${blockHash}`);
+
+  await db.close();
+};
+
+main().catch(err => {
+  log(err);
+}).finally(() => {
+  process.exit(0);
+});

packages/erc721-watcher/src/cli/export-state.ts

@@ -0,0 +1,132 @@
+//
+// Copyright 2021 Vulcanize, Inc.
+//
+
+import assert from 'assert';
+import yargs from 'yargs';
+import 'reflect-metadata';
+import debug from 'debug';
+import fs from 'fs';
+import path from 'path';
+
+import { Config, DEFAULT_CONFIG_PATH, getConfig, initClients, JobQueue, StateKind } from '@vulcanize/util';
+import { GraphWatcher, Database as GraphDatabase } from '@vulcanize/graph-node';
+import * as codec from '@ipld/dag-cbor';
+
+import { Database } from '../database';
+import { Indexer } from '../indexer';
+
+const log = debug('vulcanize:export-state');
+
+const main = async (): Promise<void> => {
+  const argv = await yargs.parserConfiguration({
+    'parse-numbers': false
+  }).options({
+    configFile: {
+      alias: 'f',
+      type: 'string',
+      require: true,
+      demandOption: true,
+      describe: 'Configuration file path (toml)',
+      default: DEFAULT_CONFIG_PATH
+    },
+    exportFile: {
+      alias: 'o',
+      type: 'string',
+      describe: 'Export file path'
+    }
+  }).argv;
+
+  const config: Config = await getConfig(argv.configFile);
+  const { ethClient, ethProvider } = await initClients(config);
+
+  const db = new Database(config.database);
+  await db.init();
+
+  const graphDb = new GraphDatabase(config.database, path.resolve(__dirname, 'entity/*'));
+  await graphDb.init();
+
+  const graphWatcher = new GraphWatcher(graphDb, ethClient, ethProvider, config.server);
+
+  const jobQueueConfig = config.jobQueue;
+  assert(jobQueueConfig, 'Missing job queue config');
+
+  const { dbConnectionString, maxCompletionLagInSecs } = jobQueueConfig;
+  assert(dbConnectionString, 'Missing job queue db connection string');
+
+  const jobQueue = new JobQueue({ dbConnectionString, maxCompletionLag: maxCompletionLagInSecs });
+  await jobQueue.start();
+
+  const indexer = new Indexer(config.server, db, ethClient, ethProvider, jobQueue, graphWatcher);
+  await indexer.init();
+
+  graphWatcher.setIndexer(indexer);
+
+  const exportData: any = {
+    snapshotBlock: {},
+    contracts: [],
+    ipldCheckpoints: []
+  };
+
+  const contracts = await db.getContracts();
+
+  // Get latest block with hooks processed.
+  const block = await indexer.getLatestHooksProcessedBlock();
+  assert(block);
+
+  // Export snapshot block.
+  exportData.snapshotBlock = {
+    blockNumber: block.blockNumber,
+    blockHash: block.blockHash
+  };
+
+  // Export contracts and checkpoints.
+  for (const contract of contracts) {
+    exportData.contracts.push({
+      address: contract.address,
+      kind: contract.kind,
+      checkpoint: contract.checkpoint,
+      startingBlock: block.blockNumber
+    });
+
+    // Create and export checkpoint if checkpointing is on for the contract.
+    if (contract.checkpoint) {
+      await indexer.createCheckpoint(contract.address, block.blockHash);
+
+      const ipldBlock = await indexer.getLatestIPLDBlock(contract.address, StateKind.Checkpoint, block.blockNumber);
+      assert(ipldBlock);
+
+      const data = indexer.getIPLDData(ipldBlock);
+
+      if (indexer.isIPFSConfigured()) {
+        await indexer.pushToIPFS(data);
+      }
+
+      exportData.ipldCheckpoints.push({
+        contractAddress: ipldBlock.contractAddress,
+        cid: ipldBlock.cid,
+        kind: ipldBlock.kind,
+        data
+      });
+    }
+  }
+
+  if (argv.exportFile) {
+    const encodedExportData = codec.encode(exportData);
+
+    const filePath = path.resolve(argv.exportFile);
+    const fileDir = path.dirname(filePath);
+
+    if (!fs.existsSync(fileDir)) fs.mkdirSync(fileDir, { recursive: true });
+
+    fs.writeFileSync(filePath, encodedExportData);
+  } else {
+    log(exportData);
+  }
+};
+
+main().catch(err => {
+  log(err);
+}).finally(() => {
+  process.exit(0);
+});

packages/erc721-watcher/src/cli/import-state.ts

@@ -0,0 +1,122 @@
+//
+// Copyright 2021 Vulcanize, Inc.
+//
+
+import assert from 'assert';
+import 'reflect-metadata';
+import yargs from 'yargs';
+import { hideBin } from 'yargs/helpers';
+import debug from 'debug';
+import { PubSub } from 'apollo-server-express';
+import fs from 'fs';
+import path from 'path';
+
+import { getConfig, fillBlocks, JobQueue, DEFAULT_CONFIG_PATH, Config, initClients, StateKind } from '@vulcanize/util';
+import { GraphWatcher, Database as GraphDatabase } from '@vulcanize/graph-node';
+import * as codec from '@ipld/dag-cbor';
+
+import { Database } from '../database';
+import { Indexer } from '../indexer';
+import { EventWatcher } from '../events';
+import { IPLDBlock } from '../entity/IPLDBlock';
+
+const log = debug('vulcanize:import-state');
+
+export const main = async (): Promise<any> => {
+  const argv = await yargs(hideBin(process.argv)).parserConfiguration({
+    'parse-numbers': false
+  }).options({
+    configFile: {
+      alias: 'f',
+      type: 'string',
+      demandOption: true,
+      describe: 'configuration file path (toml)',
+      default: DEFAULT_CONFIG_PATH
+    },
+    importFile: {
+      alias: 'i',
+      type: 'string',
+      demandOption: true,
+      describe: 'Import file path (JSON)'
+    }
+  }).argv;
+
+  const config: Config = await getConfig(argv.configFile);
+  const { ethClient, ethProvider } = await initClients(config);
+
+  const db = new Database(config.database);
+  await db.init();
+
+  const graphDb = new GraphDatabase(config.database, path.resolve(__dirname, 'entity/*'));
+  await graphDb.init();
+
+  const graphWatcher = new GraphWatcher(graphDb, ethClient, ethProvider, config.server);
+
+  // Note: In-memory pubsub works fine for now, as each watcher is a single process anyway.
+  // Later: https://www.apollographql.com/docs/apollo-server/data/subscriptions/#production-pubsub-libraries
+  const pubsub = new PubSub();
+
+  const jobQueueConfig = config.jobQueue;
+  assert(jobQueueConfig, 'Missing job queue config');
+
+  const { dbConnectionString, maxCompletionLagInSecs } = jobQueueConfig;
+  assert(dbConnectionString, 'Missing job queue db connection string');
+
+  const jobQueue = new JobQueue({ dbConnectionString, maxCompletionLag: maxCompletionLagInSecs });
+  await jobQueue.start();
+
+  const indexer = new Indexer(config.server, db, ethClient, ethProvider, jobQueue, graphWatcher);
+  await indexer.init();
+
+  graphWatcher.setIndexer(indexer);
+
+  const eventWatcher = new EventWatcher(config.upstream, ethClient, indexer, pubsub, jobQueue);
+
+  // Import data.
+  const importFilePath = path.resolve(argv.importFile);
+  const encodedImportData = fs.readFileSync(importFilePath);
+  const importData = codec.decode(Buffer.from(encodedImportData)) as any;
+
+  // Fill the snapshot block.
+  await fillBlocks(
+    jobQueue,
+    indexer,
+    eventWatcher,
+    config.upstream.ethServer.blockDelayInMilliSecs,
+    {
+      startBlock: importData.snapshotBlock.blockNumber,
+      endBlock: importData.snapshotBlock.blockNumber
+    }
+  );
+
+  // Fill the Contracts.
+  for (const contract of importData.contracts) {
+    await indexer.watchContract(contract.address, contract.kind, contract.checkpoint, contract.startingBlock);
+  }
+
+  // Get the snapshot block.
+  const block = await indexer.getBlockProgress(importData.snapshotBlock.blockHash);
+  assert(block);
+
+  // Fill the IPLDBlocks.
+  for (const checkpoint of importData.ipldCheckpoints) {
+    let ipldBlock = new IPLDBlock();
+
+    ipldBlock = Object.assign(ipldBlock, checkpoint);
+    ipldBlock.block = block;
+
+    ipldBlock.data = Buffer.from(codec.encode(ipldBlock.data));
+
+    await indexer.saveOrUpdateIPLDBlock(ipldBlock);
+  }
+
+  // The 'diff_staged' and 'init' IPLD blocks are unnecessary as checkpoints have been already created for the snapshot block.
+  await indexer.removeIPLDBlocks(block.blockNumber, StateKind.Init);
+  await indexer.removeIPLDBlocks(block.blockNumber, StateKind.DiffStaged);
+};
+
+main().catch(err => {
+  log(err);
+}).finally(() => {
+  process.exit(0);
+});

packages/erc721-watcher/src/cli/inspect-cid.ts

@@ -0,0 +1,77 @@
+//
+// Copyright 2021 Vulcanize, Inc.
+//
+
+import path from 'path';
+import assert from 'assert';
+import yargs from 'yargs';
+import 'reflect-metadata';
+import debug from 'debug';
+import util from 'util';
+
+import { Config, DEFAULT_CONFIG_PATH, getConfig, initClients, JobQueue } from '@vulcanize/util';
+import { GraphWatcher, Database as GraphDatabase } from '@vulcanize/graph-node';
+
+import { Database } from '../database';
+import { Indexer } from '../indexer';
+
+const log = debug('vulcanize:inspect-cid');
+
+const main = async (): Promise<void> => {
+  const argv = await yargs.parserConfiguration({
+    'parse-numbers': false
+  }).options({
+    configFile: {
+      alias: 'f',
+      type: 'string',
+      require: true,
+      demandOption: true,
+      describe: 'Configuration file path (toml)',
+      default: DEFAULT_CONFIG_PATH
+    },
+    cid: {
+      alias: 'c',
+      type: 'string',
+      demandOption: true,
+      describe: 'CID to be inspected'
+    }
+  }).argv;
+
+  const config: Config = await getConfig(argv.configFile);
+  const { ethClient, ethProvider } = await initClients(config);
+
+  const db = new Database(config.database);
+  await db.init();
+
+  const graphDb = new GraphDatabase(config.database, path.resolve(__dirname, 'entity/*'));
+  await graphDb.init();
+
+  const graphWatcher = new GraphWatcher(graphDb, ethClient, ethProvider, config.server);
+
+  const jobQueueConfig = config.jobQueue;
+  assert(jobQueueConfig, 'Missing job queue config');
+
+  const { dbConnectionString, maxCompletionLagInSecs } = jobQueueConfig;
+  assert(dbConnectionString, 'Missing job queue db connection string');
+
+  const jobQueue = new JobQueue({ dbConnectionString, maxCompletionLag: maxCompletionLagInSecs });
+  await jobQueue.start();
+
+  const indexer = new Indexer(config.server, db, ethClient, ethProvider, jobQueue, graphWatcher);
+  await indexer.init();
+
+  graphWatcher.setIndexer(indexer);
+
+  const ipldBlock = await indexer.getIPLDBlockByCid(argv.cid);
+  assert(ipldBlock, 'IPLDBlock for the provided CID doesn\'t exist.');
+
+  const ipldData = await indexer.getIPLDData(ipldBlock);
+
+  log(util.inspect(ipldData, false, null));
+};
+
+main().catch(err => {
+  log(err);
+}).finally(() => {
+  process.exit(0);
+});

packages/erc721-watcher/src/cli/reset-cmds/job-queue.ts

@@ -0,0 +1,22 @@
+//
+// Copyright 2021 Vulcanize, Inc.
+//
+
+import debug from 'debug';
+
+import { getConfig, resetJobs } from '@vulcanize/util';
+
+const log = debug('vulcanize:reset-job-queue');
+
+export const command = 'job-queue';
+
+export const desc = 'Reset job queue';
+
+export const builder = {};
+
+export const handler = async (argv: any): Promise<void> => {
+  const config = await getConfig(argv.configFile);
+  await resetJobs(config);
+
+  log('Job queue reset successfully');
+};

packages/erc721-watcher/src/cli/reset-cmds/state.ts

@@ -0,0 +1,126 @@
+//
+// Copyright 2021 Vulcanize, Inc.
+//
+
+import path from 'path';
+import debug from 'debug';
+import { MoreThan } from 'typeorm';
+import assert from 'assert';
+
+import { getConfig, initClients, resetJobs, JobQueue } from '@vulcanize/util';
+import { GraphWatcher, Database as GraphDatabase } from '@vulcanize/graph-node';
+
+import { Database } from '../../database';
+import { Indexer } from '../../indexer';
+import { BlockProgress } from '../../entity/BlockProgress';
+
+import { SupportsInterface } from '../../entity/SupportsInterface';
+import { BalanceOf } from '../../entity/BalanceOf';
+import { OwnerOf } from '../../entity/OwnerOf';
+import { GetApproved } from '../../entity/GetApproved';
+import { IsApprovedForAll } from '../../entity/IsApprovedForAll';
+import { Name } from '../../entity/Name';
+import { Symbol } from '../../entity/Symbol';
+import { TokenURI } from '../../entity/TokenURI';
+import { _Name } from '../../entity/_Name';
+import { _Symbol } from '../../entity/_Symbol';
+import { _Owners } from '../../entity/_Owners';
+import { _Balances } from '../../entity/_Balances';
+import { _TokenApprovals } from '../../entity/_TokenApprovals';
+import { _OperatorApprovals } from '../../entity/_OperatorApprovals';
+
+const log = debug('vulcanize:reset-state');
+
+export const command = 'state';
+
+export const desc = 'Reset state to block number';
+
+export const builder = {
+  blockNumber: {
+    type: 'number'
+  }
+};
+
+export const handler = async (argv: any): Promise<void> => {
+  const config = await getConfig(argv.configFile);
+  await resetJobs(config);
+  const { ethClient, ethProvider } = await initClients(config);
+
+  // Initialize database.
+  const db = new Database(config.database);
+  await db.init();
+
+  const graphDb = new GraphDatabase(config.database, path.resolve(__dirname, 'entity/*'));
+  await graphDb.init();
+
+  const graphWatcher = new GraphWatcher(graphDb, ethClient, ethProvider, config.server);
+
+  const jobQueueConfig = config.jobQueue;
+  assert(jobQueueConfig, 'Missing job queue config');
+
+  const { dbConnectionString, maxCompletionLagInSecs } = jobQueueConfig;
+  assert(dbConnectionString, 'Missing job queue db connection string');
+
+  const jobQueue = new JobQueue({ dbConnectionString, maxCompletionLag: maxCompletionLagInSecs });
+  await jobQueue.start();
+
+  const indexer = new Indexer(config.server, db, ethClient, ethProvider, jobQueue, graphWatcher);
+  await indexer.init();
+
+  graphWatcher.setIndexer(indexer);
+
+  const blockProgresses = await indexer.getBlocksAtHeight(argv.blockNumber, false);
+  assert(blockProgresses.length, `No blocks at specified block number ${argv.blockNumber}`);
+  assert(!blockProgresses.some(block => !block.isComplete), `Incomplete block at block number ${argv.blockNumber} with unprocessed events`);
+  const [blockProgress] = blockProgresses;
+
+  const dbTx = await db.createTransactionRunner();
+
+  try {
+    const entities = [BlockProgress, SupportsInterface, BalanceOf, OwnerOf, GetApproved, IsApprovedForAll, Name, Symbol, TokenURI, _Name, _Symbol, _Owners, _Balances, _TokenApprovals, _OperatorApprovals];
+
+    const removeEntitiesPromise = entities.map(async entityClass => {
+      return db.removeEntities<any>(dbTx, entityClass, { blockNumber: MoreThan(argv.blockNumber) });
+    });
+
+    await Promise.all(removeEntitiesPromise);
+
+    const syncStatus = await indexer.getSyncStatus();
+    assert(syncStatus, 'Missing syncStatus');
+
+    if (syncStatus.latestIndexedBlockNumber > blockProgress.blockNumber) {
+      await indexer.updateSyncStatusIndexedBlock(blockProgress.blockHash, blockProgress.blockNumber, true);
+    }
+
+    if (syncStatus.latestCanonicalBlockNumber > blockProgress.blockNumber) {
+      await indexer.updateSyncStatusCanonicalBlock(blockProgress.blockHash, blockProgress.blockNumber, true);
+    }
+
+    const ipldStatus = await indexer.getIPLDStatus();
+
+    if (ipldStatus) {
+      if (ipldStatus.latestHooksBlockNumber > blockProgress.blockNumber) {
+        await indexer.updateIPLDStatusHooksBlock(blockProgress.blockNumber, true);
+      }
+
+      if (ipldStatus.latestCheckpointBlockNumber > blockProgress.blockNumber) {
+        await indexer.updateIPLDStatusCheckpointBlock(blockProgress.blockNumber, true);
+      }
+
+      if (ipldStatus.latestIPFSBlockNumber > blockProgress.blockNumber) {
+        await indexer.updateIPLDStatusIPFSBlock(blockProgress.blockNumber, true);
+      }
+    }
+
+    await indexer.updateSyncStatusChainHead(blockProgress.blockHash, blockProgress.blockNumber, true);
+
+    dbTx.commitTransaction();
+  } catch (error) {
+    await dbTx.rollbackTransaction();
+    throw error;
+  } finally {
+    await dbTx.release();
+  }
+
+  log('Reset state successfully');
+};

packages/erc721-watcher/src/cli/reset.ts

@@ -0,0 +1,24 @@
+//
+// Copyright 2021 Vulcanize, Inc.
+//
+
+import 'reflect-metadata';
+import debug from 'debug';
+
+import { getResetYargs } from '@vulcanize/util';
+
+const log = debug('vulcanize:reset');
+
+const main = async () => {
+  return getResetYargs()
+    .commandDir('reset-cmds', { extensions: ['ts', 'js'], exclude: /([a-zA-Z0-9\s_\\.\-:])+(.d.ts)$/ })
+    .demandCommand(1)
+    .help()
+    .argv;
+};
+
+main().then(() => {
+  process.exit();
+}).catch(err => {
+  log(err);
+});

packages/erc721-watcher/src/cli/watch-contract.ts

@@ -0,0 +1,91 @@
+//
+// Copyright 2021 Vulcanize, Inc.
+//
+
+import path from 'path';
+import yargs from 'yargs';
+import 'reflect-metadata';
+import debug from 'debug';
+import assert from 'assert';
+
+import { Config, DEFAULT_CONFIG_PATH, getConfig, initClients, JobQueue } from '@vulcanize/util';
+import { GraphWatcher, Database as GraphDatabase } from '@vulcanize/graph-node';
+
+import { Database } from '../database';
+import { Indexer } from '../indexer';
+
+const log = debug('vulcanize:watch-contract');
+
+const main = async (): Promise<void> => {
+  const argv = await yargs.parserConfiguration({
+    'parse-numbers': false
+  }).options({
+    configFile: {
+      alias: 'f',
+      type: 'string',
+      require: true,
+      demandOption: true,
+      describe: 'Configuration file path (toml)',
+      default: DEFAULT_CONFIG_PATH
+    },
+    address: {
+      type: 'string',
+      require: true,
+      demandOption: true,
+      describe: 'Address of the deployed contract'
+    },
+    kind: {
+      type: 'string',
+      require: true,
+      demandOption: true,
+      describe: 'Kind of contract'
+    },
+    checkpoint: {
+      type: 'boolean',
+      require: true,
+      demandOption: true,
+      describe: 'Turn checkpointing on'
+    },
+    startingBlock: {
+      type: 'number',
+      default: 1,
+      describe: 'Starting block'
+    }
+  }).argv;
+
+  const config: Config = await getConfig(argv.configFile);
+  const { ethClient, ethProvider } = await initClients(config);
+
+  const db = new Database(config.database);
+  await db.init();
+
+  const graphDb = new GraphDatabase(config.database, path.resolve(__dirname, 'entity/*'));
+  await graphDb.init();
+
+  const graphWatcher = new GraphWatcher(graphDb, ethClient, ethProvider, config.server);
+
+  const jobQueueConfig = config.jobQueue;
+  assert(jobQueueConfig, 'Missing job queue config');
+
+  const { dbConnectionString, maxCompletionLagInSecs } = jobQueueConfig;
+  assert(dbConnectionString, 'Missing job queue db connection string');
+
+  const jobQueue = new JobQueue({ dbConnectionString, maxCompletionLag: maxCompletionLagInSecs });
+  await jobQueue.start();
+
+  const indexer = new Indexer(config.server, db, ethClient, ethProvider, jobQueue, graphWatcher);
+  await indexer.init();
+
+  graphWatcher.setIndexer(indexer);
+
+  await indexer.watchContract(argv.address, argv.kind, argv.checkpoint, argv.startingBlock);
+
+  await db.close();
+  await jobQueue.stop();
+};
+
+main().catch(err => {
+  log(err);
+}).finally(() => {
+  process.exit(0);
+});

packages/erc721-watcher/src/client.ts

@@ -0,0 +1,181 @@
+//
+// Copyright 2021 Vulcanize, Inc.
+//
+
+import { gql } from '@apollo/client/core';
+import { GraphQLClient, GraphQLConfig } from '@vulcanize/ipld-eth-client';
+
+import { queries, mutations, subscriptions } from './gql';
+
+export class Client {
+  _config: GraphQLConfig;
+  _client: GraphQLClient;
+
+  constructor (config: GraphQLConfig) {
+    this._config = config;
+
+    this._client = new GraphQLClient(config);
+  }
+
+  async getSupportsInterface (blockHash: string, contractAddress: string, interfaceId: string): Promise<any> {
+    const { supportsInterface } = await this._client.query(
+      gql(queries.supportsInterface),
+      { blockHash, contractAddress, interfaceId }
+    );
+
+    return supportsInterface;
+  }
+
+  async getBalanceOf (blockHash: string, contractAddress: string, owner: string): Promise<any> {
+    const { balanceOf } = await this._client.query(
+      gql(queries.balanceOf),
+      { blockHash, contractAddress, owner }
+    );
+
+    return balanceOf;
+  }
+
+  async getOwnerOf (blockHash: string, contractAddress: string, tokenId: bigint): Promise<any> {
+    const { ownerOf } = await this._client.query(
+      gql(queries.ownerOf),
+      { blockHash, contractAddress, tokenId }
+    );
+
+    return ownerOf;
+  }
+
+  async getGetApproved (blockHash: string, contractAddress: string, tokenId: bigint): Promise<any> {
+    const { getApproved } = await this._client.query(
+      gql(queries.getApproved),
+      { blockHash, contractAddress, tokenId }
+    );
+
+    return getApproved;
+  }
+
+  async getIsApprovedForAll (blockHash: string, contractAddress: string, owner: string, operator: string): Promise<any> {
+    const { isApprovedForAll } = await this._client.query(
+      gql(queries.isApprovedForAll),
+      { blockHash, contractAddress, owner, operator }
+    );
+
+    return isApprovedForAll;
+  }
+
+  async getName (blockHash: string, contractAddress: string): Promise<any> {
+    const { name } = await this._client.query(
+      gql(queries.name),
+      { blockHash, contractAddress }
+    );
+
+    return name;
+  }
+
+  async getSymbol (blockHash: string, contractAddress: string): Promise<any> {
+    const { symbol } = await this._client.query(
+      gql(queries.symbol),
+      { blockHash, contractAddress }
+    );
+
+    return symbol;
+  }
+
+  async getTokenURI (blockHash: string, contractAddress: string, tokenId: bigint): Promise<any> {
+    const { tokenURI } = await this._client.query(
+      gql(queries.tokenURI),
+      { blockHash, contractAddress, tokenId }
+    );
+
+    return tokenURI;
+  }
+
+  async _getName (blockHash: string, contractAddress: string): Promise<any> {
+    const { _name } = await this._client.query(
+      gql(queries._name),
+      { blockHash, contractAddress }
+    );
+
+    return _name;
+  }
+
+  async _getSymbol (blockHash: string, contractAddress: string): Promise<any> {
+    const { _symbol } = await this._client.query(
+      gql(queries._symbol),
+      { blockHash, contractAddress }
+    );
+
+    return _symbol;
+  }
+
+  async _getOwners (blockHash: string, contractAddress: string, key0: bigint): Promise<any> {
+    const { _owners } = await this._client.query(
+      gql(queries._owners),
+      { blockHash, contractAddress, key0 }
+    );
+
+    return _owners;
+  }
+
+  async _getBalances (blockHash: string, contractAddress: string, key0: string): Promise<any> {
+    const { _balances } = await this._client.query(
+      gql(queries._balances),
+      { blockHash, contractAddress, key0 }
+    );
+
+    return _balances;
+  }
+
+  async _getTokenApprovals (blockHash: string, contractAddress: string, key0: bigint): Promise<any> {
+    const { _tokenApprovals } = await this._client.query(
+      gql(queries._tokenApprovals),
+      { blockHash, contractAddress, key0 }
+    );
+
+    return _tokenApprovals;
+  }
+
+  async _getOperatorApprovals (blockHash: string, contractAddress: string, key0: string, key1: string): Promise<any> {
+    const { _operatorApprovals } = await this._client.query(
+      gql(queries._operatorApprovals),
+      { blockHash, contractAddress, key0, key1 }
+    );
+
+    return _operatorApprovals;
+  }
+
+  async getEvents (blockHash: string, contractAddress: string, name: string): Promise<any> {
+    const { events } = await this._client.query(
+      gql(queries.events),
+      { blockHash, contractAddress, name }
+    );
+
+    return events;
+  }
+
+  async getEventsInRange (fromBlockNumber: number, toBlockNumber: number): Promise<any> {
+    const { eventsInRange } = await this._client.query(
+      gql(queries.eventsInRange),
+      { fromBlockNumber, toBlockNumber }
+    );
+
+    return eventsInRange;
+  }
+
+  async watchContract (contractAddress: string, startingBlock?: number): Promise<any> {
+    const { watchContract } = await this._client.mutate(
+      gql(mutations.watchContract),
+      { contractAddress, startingBlock }
+    );
+
+    return watchContract;
+  }
+
+  async watchEvents (onNext: (value: any) => void): Promise<ZenObservable.Subscription> {
+    return this._client.subscribe(
+      gql(subscriptions.onEvent),
+      ({ data }) => {
+        onNext(data.onEvent);
+      }
+    );
+  }
+}

packages/erc721-watcher/src/database.ts

@@ -0,0 +1,469 @@
+//
+// Copyright 2021 Vulcanize, Inc.
+//
+
+import assert from 'assert';
+import { Connection, ConnectionOptions, DeepPartial, FindConditions, QueryRunner, FindManyOptions } from 'typeorm';
+import path from 'path';
+
+import { IPLDDatabase as BaseDatabase, IPLDDatabaseInterface, QueryOptions, StateKind, Where } from '@vulcanize/util';
+
+import { Contract } from './entity/Contract';
+import { Event } from './entity/Event';
+import { SyncStatus } from './entity/SyncStatus';
+import { IpldStatus } from './entity/IpldStatus';
+import { BlockProgress } from './entity/BlockProgress';
+import { IPLDBlock } from './entity/IPLDBlock';
+import { SupportsInterface } from './entity/SupportsInterface';
+import { BalanceOf } from './entity/BalanceOf';
+import { OwnerOf } from './entity/OwnerOf';
+import { GetApproved } from './entity/GetApproved';
+import { IsApprovedForAll } from './entity/IsApprovedForAll';
+import { Name } from './entity/Name';
+import { Symbol } from './entity/Symbol';
+import { TokenURI } from './entity/TokenURI';
+import { _Name } from './entity/_Name';
+import { _Symbol } from './entity/_Symbol';
+import { _Owners } from './entity/_Owners';
+import { _Balances } from './entity/_Balances';
+import { _TokenApprovals } from './entity/_TokenApprovals';
+import { _OperatorApprovals } from './entity/_OperatorApprovals';
+
+export class Database implements IPLDDatabaseInterface {
+  _config: ConnectionOptions;
+  _conn!: Connection;
+  _baseDatabase: BaseDatabase;
+  _propColMaps: { [key: string]: Map<string, string>; }
+
+  constructor (config: ConnectionOptions) {
+    assert(config);
+
+    this._config = {
+      ...config,
+      entities: [path.join(__dirname, 'entity/*')]
+    };
+
+    this._baseDatabase = new BaseDatabase(this._config);
+    this._propColMaps = {};
+  }
+
+  async init (): Promise<void> {
+    this._conn = await this._baseDatabase.init();
+    this._setPropColMaps();
+  }
+
+  async close (): Promise<void> {
+    return this._baseDatabase.close();
+  }
+
+  async getSupportsInterface ({ blockHash, contractAddress, interfaceId }: { blockHash: string, contractAddress: string, interfaceId: string }): Promise<SupportsInterface | undefined> {
+    return this._conn.getRepository(SupportsInterface)
+      .findOne({
+        blockHash,
+        contractAddress,
+        interfaceId
+      });
+  }
+
+  async getBalanceOf ({ blockHash, contractAddress, owner }: { blockHash: string, contractAddress: string, owner: string }): Promise<BalanceOf | undefined> {
+    return this._conn.getRepository(BalanceOf)
+      .findOne({
+        blockHash,
+        contractAddress,
+        owner
+      });
+  }
+
+  async getOwnerOf ({ blockHash, contractAddress, tokenId }: { blockHash: string, contractAddress: string, tokenId: bigint }): Promise<OwnerOf | undefined> {
+    return this._conn.getRepository(OwnerOf)
+      .findOne({
+        blockHash,
+        contractAddress,
+        tokenId
+      });
+  }
+
+  async getGetApproved ({ blockHash, contractAddress, tokenId }: { blockHash: string, contractAddress: string, tokenId: bigint }): Promise<GetApproved | undefined> {
+    return this._conn.getRepository(GetApproved)
+      .findOne({
+        blockHash,
+        contractAddress,
+        tokenId
+      });
+  }
+
+  async getIsApprovedForAll ({ blockHash, contractAddress, owner, operator }: { blockHash: string, contractAddress: string, owner: string, operator: string }): Promise<IsApprovedForAll | undefined> {
+    return this._conn.getRepository(IsApprovedForAll)
+      .findOne({
+        blockHash,
+        contractAddress,
+        owner,
+        operator
+      });
+  }
+
+  async getName ({ blockHash, contractAddress }: { blockHash: string, contractAddress: string }): Promise<Name | undefined> {
+    return this._conn.getRepository(Name)
+      .findOne({
+        blockHash,
+        contractAddress
+      });
+  }
+
+  // eslint-disable-next-line @typescript-eslint/ban-types
+  async getSymbol ({ blockHash, contractAddress }: { blockHash: string, contractAddress: string }): Promise<Symbol | undefined> {
+    return this._conn.getRepository(Symbol)
+      .findOne({
+        blockHash,
+        contractAddress
+      });
+  }
+
+  async getTokenURI ({ blockHash, contractAddress, tokenId }: { blockHash: string, contractAddress: string, tokenId: bigint }): Promise<TokenURI | undefined> {
+    return this._conn.getRepository(TokenURI)
+      .findOne({
+        blockHash,
+        contractAddress,
+        tokenId
+      });
+  }
+
+  async _getName ({ blockHash, contractAddress }: { blockHash: string, contractAddress: string }): Promise<_Name | undefined> {
+    return this._conn.getRepository(_Name)
+      .findOne({
+        blockHash,
+        contractAddress
+      });
+  }
+
+  async _getSymbol ({ blockHash, contractAddress }: { blockHash: string, contractAddress: string }): Promise<_Symbol | undefined> {
+    return this._conn.getRepository(_Symbol)
+      .findOne({
+        blockHash,
+        contractAddress
+      });
+  }
+
+  async _getOwners ({ blockHash, contractAddress, key0 }: { blockHash: string, contractAddress: string, key0: bigint }): Promise<_Owners | undefined> {
+    return this._conn.getRepository(_Owners)
+      .findOne({
+        blockHash,
+        contractAddress,
+        key0
+      });
+  }
+
+  async _getBalances ({ blockHash, contractAddress, key0 }: { blockHash: string, contractAddress: string, key0: string }): Promise<_Balances | undefined> {
+    return this._conn.getRepository(_Balances)
+      .findOne({
+        blockHash,
+        contractAddress,
+        key0
+      });
+  }
+
+  async _getTokenApprovals ({ blockHash, contractAddress, key0 }: { blockHash: string, contractAddress: string, key0: bigint }): Promise<_TokenApprovals | undefined> {
+    return this._conn.getRepository(_TokenApprovals)
+      .findOne({
+        blockHash,
+        contractAddress,
+        key0
+      });
+  }
+
+  async _getOperatorApprovals ({ blockHash, contractAddress, key0, key1 }: { blockHash: string, contractAddress: string, key0: string, key1: string }): Promise<_OperatorApprovals | undefined> {
+    return this._conn.getRepository(_OperatorApprovals)
+      .findOne({
+        blockHash,
+        contractAddress,
+        key0,
+        key1
+      });
+  }
+
+  async saveSupportsInterface ({ blockHash, blockNumber, contractAddress, interfaceId, value, proof }: DeepPartial<SupportsInterface>): Promise<SupportsInterface> {
+    const repo = this._conn.getRepository(SupportsInterface);
+    const entity = repo.create({ blockHash, blockNumber, contractAddress, interfaceId, value, proof });
+    return repo.save(entity);
+  }
+
+  async saveBalanceOf ({ blockHash, blockNumber, contractAddress, owner, value, proof }: DeepPartial<BalanceOf>): Promise<BalanceOf> {
+    const repo = this._conn.getRepository(BalanceOf);
+    const entity = repo.create({ blockHash, blockNumber, contractAddress, owner, value, proof });
+    return repo.save(entity);
+  }
+
+  async saveOwnerOf ({ blockHash, blockNumber, contractAddress, tokenId, value, proof }: DeepPartial<OwnerOf>): Promise<OwnerOf> {
+    const repo = this._conn.getRepository(OwnerOf);
+    const entity = repo.create({ blockHash, blockNumber, contractAddress, tokenId, value, proof });
+    return repo.save(entity);
+  }
+
+  async saveGetApproved ({ blockHash, blockNumber, contractAddress, tokenId, value, proof }: DeepPartial<GetApproved>): Promise<GetApproved> {
+    const repo = this._conn.getRepository(GetApproved);
+    const entity = repo.create({ blockHash, blockNumber, contractAddress, tokenId, value, proof });
+    return repo.save(entity);
+  }
+
+  async saveIsApprovedForAll ({ blockHash, blockNumber, contractAddress, owner, operator, value, proof }: DeepPartial<IsApprovedForAll>): Promise<IsApprovedForAll> {
+    const repo = this._conn.getRepository(IsApprovedForAll);
+    const entity = repo.create({ blockHash, blockNumber, contractAddress, owner, operator, value, proof });
+    return repo.save(entity);
+  }
+
+  async saveName ({ blockHash, blockNumber, contractAddress, value, proof }: DeepPartial<Name>): Promise<Name> {
+    const repo = this._conn.getRepository(Name);
+    const entity = repo.create({ blockHash, blockNumber, contractAddress, value, proof });
+    return repo.save(entity);
+  }
+
+  // eslint-disable-next-line @typescript-eslint/ban-types
+  async saveSymbol ({ blockHash, blockNumber, contractAddress, value, proof }: DeepPartial<Symbol>): Promise<Symbol> {
+    const repo = this._conn.getRepository(Symbol);
+    const entity = repo.create({ blockHash, blockNumber, contractAddress, value, proof });
+    return repo.save(entity);
+  }
+
+  async saveTokenURI ({ blockHash, blockNumber, contractAddress, tokenId, value, proof }: DeepPartial<TokenURI>): Promise<TokenURI> {
+    const repo = this._conn.getRepository(TokenURI);
+    const entity = repo.create({ blockHash, blockNumber, contractAddress, tokenId, value, proof });
+    return repo.save(entity);
+  }
+
+  async _saveName ({ blockHash, blockNumber, contractAddress, value, proof }: DeepPartial<_Name>): Promise<_Name> {
+    const repo = this._conn.getRepository(_Name);
+    const entity = repo.create({ blockHash, blockNumber, contractAddress, value, proof });
+    return repo.save(entity);
+  }
+
+  async _saveSymbol ({ blockHash, blockNumber, contractAddress, value, proof }: DeepPartial<_Symbol>): Promise<_Symbol> {
+    const repo = this._conn.getRepository(_Symbol);
+    const entity = repo.create({ blockHash, blockNumber, contractAddress, value, proof });
+    return repo.save(entity);
+  }
+
+  async _saveOwners ({ blockHash, blockNumber, contractAddress, key0, value, proof }: DeepPartial<_Owners>): Promise<_Owners> {
+    const repo = this._conn.getRepository(_Owners);
+    const entity = repo.create({ blockHash, blockNumber, contractAddress, key0, value, proof });
+    return repo.save(entity);
+  }
+
+  async _saveBalances ({ blockHash, blockNumber, contractAddress, key0, value, proof }: DeepPartial<_Balances>): Promise<_Balances> {
+    const repo = this._conn.getRepository(_Balances);
+    const entity = repo.create({ blockHash, blockNumber, contractAddress, key0, value, proof });
+    return repo.save(entity);
+  }
+
+  async _saveTokenApprovals ({ blockHash, blockNumber, contractAddress, key0, value, proof }: DeepPartial<_TokenApprovals>): Promise<_TokenApprovals> {
+    const repo = this._conn.getRepository(_TokenApprovals);
+    const entity = repo.create({ blockHash, blockNumber, contractAddress, key0, value, proof });
+    return repo.save(entity);
+  }
+
+  async _saveOperatorApprovals ({ blockHash, blockNumber, contractAddress, key0, key1, value, proof }: DeepPartial<_OperatorApprovals>): Promise<_OperatorApprovals> {
+    const repo = this._conn.getRepository(_OperatorApprovals);
+    const entity = repo.create({ blockHash, blockNumber, contractAddress, key0, key1, value, proof });
+    return repo.save(entity);
+  }
+
+  getNewIPLDBlock (): IPLDBlock {
+    return new IPLDBlock();
+  }
+
+  async getIPLDBlocks (where: FindConditions<IPLDBlock>): Promise<IPLDBlock[]> {
+    const repo = this._conn.getRepository(IPLDBlock);
+
+    return this._baseDatabase.getIPLDBlocks(repo, where);
+  }
+
+  async getLatestIPLDBlock (contractAddress: string, kind: StateKind | null, blockNumber?: number): Promise<IPLDBlock | undefined> {
+    const repo = this._conn.getRepository(IPLDBlock);
+
+    return this._baseDatabase.getLatestIPLDBlock(repo, contractAddress, kind, blockNumber);
+  }
+
+  async getPrevIPLDBlock (blockHash: string, contractAddress: string, kind?: string): Promise<IPLDBlock | undefined> {
+    const repo = this._conn.getRepository(IPLDBlock);
+
+    return this._baseDatabase.getPrevIPLDBlock(repo, blockHash, contractAddress, kind);
+  }
+
+  // Fetch all diff IPLDBlocks after the specified block number.
+  async getDiffIPLDBlocksByBlocknumber (contractAddress: string, blockNumber: number): Promise<IPLDBlock[]> {
+    const repo = this._conn.getRepository(IPLDBlock);
+
+    return this._baseDatabase.getDiffIPLDBlocksByBlocknumber(repo, contractAddress, blockNumber);
+  }
+
+  async saveOrUpdateIPLDBlock (dbTx: QueryRunner, ipldBlock: IPLDBlock): Promise<IPLDBlock> {
+    const repo = dbTx.manager.getRepository(IPLDBlock);
+
+    return this._baseDatabase.saveOrUpdateIPLDBlock(repo, ipldBlock);
+  }
+
+  async removeIPLDBlocks (dbTx: QueryRunner, blockNumber: number, kind: string): Promise<void> {
+    const repo = dbTx.manager.getRepository(IPLDBlock);
+
+    await this._baseDatabase.removeIPLDBlocks(repo, blockNumber, kind);
+  }
+
+  async getIPLDStatus (): Promise<IpldStatus | undefined> {
+    const repo = this._conn.getRepository(IpldStatus);
+
+    return this._baseDatabase.getIPLDStatus(repo);
+  }
+
+  async updateIPLDStatusHooksBlock (queryRunner: QueryRunner, blockNumber: number, force?: boolean): Promise<IpldStatus> {
+    const repo = queryRunner.manager.getRepository(IpldStatus);
+
+    return this._baseDatabase.updateIPLDStatusHooksBlock(repo, blockNumber, force);
+  }
+
+  async updateIPLDStatusCheckpointBlock (queryRunner: QueryRunner, blockNumber: number, force?: boolean): Promise<IpldStatus> {
+    const repo = queryRunner.manager.getRepository(IpldStatus);
+
+    return this._baseDatabase.updateIPLDStatusCheckpointBlock(repo, blockNumber, force);
+  }
+
+  async updateIPLDStatusIPFSBlock (queryRunner: QueryRunner, blockNumber: number, force?: boolean): Promise<IpldStatus> {
+    const repo = queryRunner.manager.getRepository(IpldStatus);
+
+    return this._baseDatabase.updateIPLDStatusIPFSBlock(repo, blockNumber, force);
+  }
+
+  async getContracts (): Promise<Contract[]> {
+    const repo = this._conn.getRepository(Contract);
+
+    return this._baseDatabase.getContracts(repo);
+  }
+
+  async createTransactionRunner (): Promise<QueryRunner> {
+    return this._baseDatabase.createTransactionRunner();
+  }
+
+  async getProcessedBlockCountForRange (fromBlockNumber: number, toBlockNumber: number): Promise<{ expected: number, actual: number }> {
+    const repo = this._conn.getRepository(BlockProgress);
+
+    return this._baseDatabase.getProcessedBlockCountForRange(repo, fromBlockNumber, toBlockNumber);
+  }
+
+  async getEventsInRange (fromBlockNumber: number, toBlockNumber: number): Promise<Array<Event>> {
+    const repo = this._conn.getRepository(Event);
+
+    return this._baseDatabase.getEventsInRange(repo, fromBlockNumber, toBlockNumber);
+  }
+
+  async saveEventEntity (queryRunner: QueryRunner, entity: Event): Promise<Event> {
+    const repo = queryRunner.manager.getRepository(Event);
+    return this._baseDatabase.saveEventEntity(repo, entity);
+  }
+
+  async getBlockEvents (blockHash: string, where: Where, queryOptions: QueryOptions): Promise<Event[]> {
+    const repo = this._conn.getRepository(Event);
+
+    return this._baseDatabase.getBlockEvents(repo, blockHash, where, queryOptions);
+  }
+
+  async saveEvents (queryRunner: QueryRunner, block: DeepPartial<BlockProgress>, events: DeepPartial<Event>[]): Promise<BlockProgress> {
+    const blockRepo = queryRunner.manager.getRepository(BlockProgress);
+    const eventRepo = queryRunner.manager.getRepository(Event);
+
+    return this._baseDatabase.saveEvents(blockRepo, eventRepo, block, events);
+  }
+
+  async saveContract (queryRunner: QueryRunner, address: string, kind: string, checkpoint: boolean, startingBlock: number): Promise<Contract> {
+    const repo = queryRunner.manager.getRepository(Contract);
+
+    return this._baseDatabase.saveContract(repo, address, kind, checkpoint, startingBlock);
+  }
+
+  async updateSyncStatusIndexedBlock (queryRunner: QueryRunner, blockHash: string, blockNumber: number, force = false): Promise<SyncStatus> {
+    const repo = queryRunner.manager.getRepository(SyncStatus);
+
+    return this._baseDatabase.updateSyncStatusIndexedBlock(repo, blockHash, blockNumber, force);
+  }
+
+  async updateSyncStatusCanonicalBlock (queryRunner: QueryRunner, blockHash: string, blockNumber: number, force = false): Promise<SyncStatus> {
+    const repo = queryRunner.manager.getRepository(SyncStatus);
+
+    return this._baseDatabase.updateSyncStatusCanonicalBlock(repo, blockHash, blockNumber, force);
+  }
+
+  async updateSyncStatusChainHead (queryRunner: QueryRunner, blockHash: string, blockNumber: number, force = false): Promise<SyncStatus> {
+    const repo = queryRunner.manager.getRepository(SyncStatus);
+
+    return this._baseDatabase.updateSyncStatusChainHead(repo, blockHash, blockNumber, force);
+  }
+
+  async getSyncStatus (queryRunner: QueryRunner): Promise<SyncStatus | undefined> {
+    const repo = queryRunner.manager.getRepository(SyncStatus);
+
+    return this._baseDatabase.getSyncStatus(repo);
+  }
+
+  async getEvent (id: string): Promise<Event | undefined> {
+    const repo = this._conn.getRepository(Event);
+
+    return this._baseDatabase.getEvent(repo, id);
+  }
+
+  async getBlocksAtHeight (height: number, isPruned: boolean): Promise<BlockProgress[]> {
+    const repo = this._conn.getRepository(BlockProgress);
+
+    return this._baseDatabase.getBlocksAtHeight(repo, height, isPruned);
+  }
+
+  async markBlocksAsPruned (queryRunner: QueryRunner, blocks: BlockProgress[]): Promise<void> {
+    const repo = queryRunner.manager.getRepository(BlockProgress);
+
+    return this._baseDatabase.markBlocksAsPruned(repo, blocks);
+  }
+
+  async getBlockProgress (blockHash: string): Promise<BlockProgress | undefined> {
+    const repo = this._conn.getRepository(BlockProgress);
+    return this._baseDatabase.getBlockProgress(repo, blockHash);
+  }
+
+  async getBlockProgressEntities (where: FindConditions<BlockProgress>, options: FindManyOptions<BlockProgress>): Promise<BlockProgress[]> {
+    const repo = this._conn.getRepository(BlockProgress);
+
+    return this._baseDatabase.getBlockProgressEntities(repo, where, options);
+  }
+
+  async updateBlockProgress (queryRunner: QueryRunner, block: BlockProgress, lastProcessedEventIndex: number): Promise<BlockProgress> {
+    const repo = queryRunner.manager.getRepository(BlockProgress);
+
+    return this._baseDatabase.updateBlockProgress(repo, block, lastProcessedEventIndex);
+  }
+
+  async removeEntities<Entity> (queryRunner: QueryRunner, entity: new () => Entity, findConditions?: FindManyOptions<Entity> | FindConditions<Entity>): Promise<void> {
+    return this._baseDatabase.removeEntities(queryRunner, entity, findConditions);
+  }
+
+  async getAncestorAtDepth (blockHash: string, depth: number): Promise<string> {
+    return this._baseDatabase.getAncestorAtDepth(blockHash, depth);
+  }
+
+  _getPropertyColumnMapForEntity (entityName: string): Map<string, string> {
+    return this._conn.getMetadata(entityName).ownColumns.reduce((acc, curr) => {
+      return acc.set(curr.propertyName, curr.databaseName);
+    }, new Map<string, string>());
+  }
+
+  _setPropColMaps (): void {
+    this._propColMaps.SupportsInterface = this._getPropertyColumnMapForEntity('SupportsInterface');
+    this._propColMaps.BalanceOf = this._getPropertyColumnMapForEntity('BalanceOf');
+    this._propColMaps.OwnerOf = this._getPropertyColumnMapForEntity('OwnerOf');
+    this._propColMaps.GetApproved = this._getPropertyColumnMapForEntity('GetApproved');
+    this._propColMaps.IsApprovedForAll = this._getPropertyColumnMapForEntity('IsApprovedForAll');
+    this._propColMaps.Name = this._getPropertyColumnMapForEntity('Name');
+    this._propColMaps.Symbol = this._getPropertyColumnMapForEntity('Symbol');
+    this._propColMaps.TokenURI = this._getPropertyColumnMapForEntity('TokenURI');
+    this._propColMaps._Name = this._getPropertyColumnMapForEntity('_Name');
+    this._propColMaps._Symbol = this._getPropertyColumnMapForEntity('_Symbol');
+    this._propColMaps._Owners = this._getPropertyColumnMapForEntity('_Owners');
+    this._propColMaps._Balances = this._getPropertyColumnMapForEntity('_Balances');
+    this._propColMaps._TokenApprovals = this._getPropertyColumnMapForEntity('_TokenApprovals');
+    this._propColMaps._OperatorApprovals = this._getPropertyColumnMapForEntity('_OperatorApprovals');
+  }
+}

packages/erc721-watcher/src/entity/BalanceOf.ts

@@ -0,0 +1,31 @@
+//
+// Copyright 2021 Vulcanize, Inc.
+//
+
+import { Entity, PrimaryGeneratedColumn, Column, Index } from 'typeorm';
+import { bigintTransformer } from '@vulcanize/util';
+
+@Entity()
+@Index(['blockHash', 'contractAddress', 'owner'], { unique: true })
+export class BalanceOf {
+  @PrimaryGeneratedColumn()
+  id!: number;
+
+  @Column('varchar', { length: 66 })
+  blockHash!: string;
+
+  @Column('integer')
+  blockNumber!: number;
+
+  @Column('varchar', { length: 42 })
+  contractAddress!: string;
+
+  @Column('varchar', { length: 42 })
+  owner!: string;
+
+  @Column('numeric', { transformer: bigintTransformer })
+  value!: bigint;
+
+  @Column('text', { nullable: true })
+  proof!: string;
+}

packages/erc721-watcher/src/entity/BlockProgress.ts

@@ -0,0 +1,48 @@
+//
+// Copyright 2021 Vulcanize, Inc.
+//
+
+import { Entity, PrimaryGeneratedColumn, Column, Index, CreateDateColumn } from 'typeorm';
+import { BlockProgressInterface } from '@vulcanize/util';
+
+@Entity()
+@Index(['blockHash'], { unique: true })
+@Index(['blockNumber'])
+@Index(['parentHash'])
+export class BlockProgress implements BlockProgressInterface {
+  @PrimaryGeneratedColumn()
+  id!: number;
+
+  @Column('varchar')
+  cid!: string;
+
+  @Column('varchar', { length: 66 })
+  blockHash!: string;
+
+  @Column('varchar', { length: 66 })
+  parentHash!: string;
+
+  @Column('integer')
+  blockNumber!: number;
+
+  @Column('integer')
+  blockTimestamp!: number;
+
+  @Column('integer')
+  numEvents!: number;
+
+  @Column('integer')
+  numProcessedEvents!: number;
+
+  @Column('integer')
+  lastProcessedEventIndex!: number;
+
+  @Column('boolean')
+  isComplete!: boolean;
+
+  @Column('boolean', { default: false })
+  isPruned!: boolean;
+
+  @CreateDateColumn()
+  createdAt!: Date;
+}

packages/erc721-watcher/src/entity/Contract.ts

@@ -0,0 +1,24 @@
+//
+// Copyright 2021 Vulcanize, Inc.
+//
+
+import { Entity, PrimaryGeneratedColumn, Column, Index } from 'typeorm';
+
+@Entity()
+@Index(['address'], { unique: true })
+export class Contract {
+  @PrimaryGeneratedColumn()
+  id!: number;
+
+  @Column('varchar', { length: 42 })
+  address!: string;
+
+  @Column('varchar')
+  kind!: string;
+
+  @Column('boolean')
+  checkpoint!: boolean;
+
+  @Column('integer')
+  startingBlock!: number;
+}

packages/erc721-watcher/src/entity/Event.ts

@@ -0,0 +1,38 @@
+//
+// Copyright 2021 Vulcanize, Inc.
+//
+
+import { Entity, PrimaryGeneratedColumn, Column, Index, ManyToOne } from 'typeorm';
+import { BlockProgress } from './BlockProgress';
+
+@Entity()
+@Index(['block', 'contract'])
+@Index(['block', 'contract', 'eventName'])
+export class Event {
+  @PrimaryGeneratedColumn()
+  id!: number;
+
+  @ManyToOne(() => BlockProgress, { onDelete: 'CASCADE' })
+  block!: BlockProgress;
+
+  @Column('varchar', { length: 66 })
+  txHash!: string;
+
+  @Column('integer')
+  index!: number;
+
+  @Column('varchar', { length: 42 })
+  contract!: string;
+
+  @Column('varchar', { length: 256 })
+  eventName!: string;
+
+  @Column('text')
+  eventInfo!: string;
+
+  @Column('text')
+  extraInfo!: string;
+
+  @Column('text')
+  proof!: string;
+}

packages/erc721-watcher/src/entity/GetApproved.ts

@@ -0,0 +1,31 @@
+//
+// Copyright 2021 Vulcanize, Inc.
+//
+
+import { Entity, PrimaryGeneratedColumn, Column, Index } from 'typeorm';
+import { bigintTransformer } from '@vulcanize/util';
+
+@Entity()
+@Index(['blockHash', 'contractAddress', 'tokenId'], { unique: true })
+export class GetApproved {
+  @PrimaryGeneratedColumn()
+  id!: number;
+
+  @Column('varchar', { length: 66 })
+  blockHash!: string;
+
+  @Column('integer')
+  blockNumber!: number;
+
+  @Column('varchar', { length: 42 })
+  contractAddress!: string;
+
+  @Column('numeric', { transformer: bigintTransformer })
+  tokenId!: bigint;
+
+  @Column('varchar')
+  value!: string;
+
+  @Column('text', { nullable: true })
+  proof!: string;
+}

packages/erc721-watcher/src/entity/IPLDBlock.ts

@@ -0,0 +1,31 @@
+//
+// Copyright 2021 Vulcanize, Inc.
+//
+
+import { Entity, PrimaryGeneratedColumn, Column, Index, ManyToOne } from 'typeorm';
+import { StateKind } from '@vulcanize/util';
+import { BlockProgress } from './BlockProgress';
+
+@Entity()
+@Index(['cid'], { unique: true })
+@Index(['block', 'contractAddress'])
+@Index(['block', 'contractAddress', 'kind'], { unique: true })
+export class IPLDBlock {
+  @PrimaryGeneratedColumn()
+  id!: number;
+
+  @ManyToOne(() => BlockProgress, { onDelete: 'CASCADE' })
+  block!: BlockProgress;
+
+  @Column('varchar', { length: 42 })
+  contractAddress!: string;
+
+  @Column('varchar')
+  cid!: string;
+
+  @Column({ type: 'enum', enum: StateKind })
+  kind!: StateKind;
+
+  @Column('bytea')
+  data!: Buffer;
+}

packages/erc721-watcher/src/entity/IpldStatus.ts

@@ -0,0 +1,20 @@
+//
+// Copyright 2021 Vulcanize, Inc.
+//
+
+import { Entity, PrimaryGeneratedColumn, Column } from 'typeorm';
+
+@Entity()
+export class IpldStatus {
+  @PrimaryGeneratedColumn()
+  id!: number;
+
+  @Column('integer')
+  latestHooksBlockNumber!: number;
+
+  @Column('integer')
+  latestCheckpointBlockNumber!: number;
+
+  @Column('integer')
+  latestIPFSBlockNumber!: number;
+}

packages/erc721-watcher/src/entity/IsApprovedForAll.ts

@@ -0,0 +1,33 @@
+//
+// Copyright 2021 Vulcanize, Inc.
+//
+
+import { Entity, PrimaryGeneratedColumn, Column, Index } from 'typeorm';
+
+@Entity()
+@Index(['blockHash', 'contractAddress', 'owner', 'operator'], { unique: true })
+export class IsApprovedForAll {
+  @PrimaryGeneratedColumn()
+  id!: number;
+
+  @Column('varchar', { length: 66 })
+  blockHash!: string;
+
+  @Column('integer')
+  blockNumber!: number;
+
+  @Column('varchar', { length: 42 })
+  contractAddress!: string;
+
+  @Column('varchar', { length: 42 })
+  owner!: string;
+
+  @Column('varchar', { length: 42 })
+  operator!: string;
+
+  @Column('boolean')
+  value!: boolean;
+
+  @Column('text', { nullable: true })
+  proof!: string;
+}

packages/erc721-watcher/src/entity/Name.ts

@@ -0,0 +1,27 @@
+//
+// Copyright 2021 Vulcanize, Inc.
+//
+
+import { Entity, PrimaryGeneratedColumn, Column, Index } from 'typeorm';
+
+@Entity()
+@Index(['blockHash', 'contractAddress'], { unique: true })
+export class Name {
+  @PrimaryGeneratedColumn()
+  id!: number;
+
+  @Column('varchar', { length: 66 })
+  blockHash!: string;
+
+  @Column('integer')
+  blockNumber!: number;
+
+  @Column('varchar', { length: 42 })
+  contractAddress!: string;
+
+  @Column('varchar')
+  value!: string;
+
+  @Column('text', { nullable: true })
+  proof!: string;
+}

packages/erc721-watcher/src/entity/OwnerOf.ts

@@ -0,0 +1,31 @@
+//
+// Copyright 2021 Vulcanize, Inc.
+//
+
+import { Entity, PrimaryGeneratedColumn, Column, Index } from 'typeorm';
+import { bigintTransformer } from '@vulcanize/util';
+
+@Entity()
+@Index(['blockHash', 'contractAddress', 'tokenId'], { unique: true })
+export class OwnerOf {
+  @PrimaryGeneratedColumn()
+  id!: number;
+
+  @Column('varchar', { length: 66 })
+  blockHash!: string;
+
+  @Column('integer')
+  blockNumber!: number;
+
+  @Column('varchar', { length: 42 })
+  contractAddress!: string;
+
+  @Column('numeric', { transformer: bigintTransformer })
+  tokenId!: bigint;
+
+  @Column('varchar')
+  value!: string;
+
+  @Column('text', { nullable: true })
+  proof!: string;
+}

packages/erc721-watcher/src/entity/SupportsInterface.ts

@@ -0,0 +1,30 @@
+//
+// Copyright 2021 Vulcanize, Inc.
+//
+
+import { Entity, PrimaryGeneratedColumn, Column, Index } from 'typeorm';
+
+@Entity()
+@Index(['blockHash', 'contractAddress', 'interfaceId'], { unique: true })
+export class SupportsInterface {
+  @PrimaryGeneratedColumn()
+  id!: number;
+
+  @Column('varchar', { length: 66 })
+  blockHash!: string;
+
+  @Column('integer')
+  blockNumber!: number;
+
+  @Column('varchar', { length: 42 })
+  contractAddress!: string;
+
+  @Column('varchar')
+  interfaceId!: string;
+
+  @Column('boolean')
+  value!: boolean;
+
+  @Column('text', { nullable: true })
+  proof!: string;
+}

packages/erc721-watcher/src/entity/Symbol.ts

@@ -0,0 +1,27 @@
+//
+// Copyright 2021 Vulcanize, Inc.
+//
+
+import { Entity, PrimaryGeneratedColumn, Column, Index } from 'typeorm';
+
+@Entity()
+@Index(['blockHash', 'contractAddress'], { unique: true })
+export class Symbol {
+  @PrimaryGeneratedColumn()
+  id!: number;
+
+  @Column('varchar', { length: 66 })
+  blockHash!: string;
+
+  @Column('integer')
+  blockNumber!: number;
+
+  @Column('varchar', { length: 42 })
+  contractAddress!: string;
+
+  @Column('varchar')
+  value!: string;
+
+  @Column('text', { nullable: true })
+  proof!: string;
+}

packages/erc721-watcher/src/entity/SyncStatus.ts

@@ -0,0 +1,30 @@
+//
+// Copyright 2021 Vulcanize, Inc.
+//
+
+import { Entity, PrimaryGeneratedColumn, Column } from 'typeorm';
+import { SyncStatusInterface } from '@vulcanize/util';
+
+@Entity()
+export class SyncStatus implements SyncStatusInterface {
+  @PrimaryGeneratedColumn()
+  id!: number;
+
+  @Column('varchar', { length: 66 })
+  chainHeadBlockHash!: string;
+
+  @Column('integer')
+  chainHeadBlockNumber!: number;
+
+  @Column('varchar', { length: 66 })
+  latestIndexedBlockHash!: string;
+
+  @Column('integer')
+  latestIndexedBlockNumber!: number;
+
+  @Column('varchar', { length: 66 })
+  latestCanonicalBlockHash!: string;
+
+  @Column('integer')
+  latestCanonicalBlockNumber!: number;
+}

packages/erc721-watcher/src/entity/TokenURI.ts

@@ -0,0 +1,31 @@
+//
+// Copyright 2021 Vulcanize, Inc.
+//
+
+import { Entity, PrimaryGeneratedColumn, Column, Index } from 'typeorm';
+import { bigintTransformer } from '@vulcanize/util';
+
+@Entity()
+@Index(['blockHash', 'contractAddress', 'tokenId'], { unique: true })
+export class TokenURI {
+  @PrimaryGeneratedColumn()
+  id!: number;
+
+  @Column('varchar', { length: 66 })
+  blockHash!: string;
+
+  @Column('integer')
+  blockNumber!: number;
+
+  @Column('varchar', { length: 42 })
+  contractAddress!: string;
+
+  @Column('numeric', { transformer: bigintTransformer })
+  tokenId!: bigint;
+
+  @Column('varchar')
+  value!: string;
+
+  @Column('text', { nullable: true })
+  proof!: string;
+}

packages/erc721-watcher/src/entity/_Balances.ts

@@ -0,0 +1,31 @@
+//
+// Copyright 2021 Vulcanize, Inc.
+//
+
+import { Entity, PrimaryGeneratedColumn, Column, Index } from 'typeorm';
+import { bigintTransformer } from '@vulcanize/util';
+
+@Entity()
+@Index(['blockHash', 'contractAddress', 'key0'], { unique: true })
+export class _Balances {
+  @PrimaryGeneratedColumn()
+  id!: number;
+
+  @Column('varchar', { length: 66 })
+  blockHash!: string;
+
+  @Column('integer')
+  blockNumber!: number;
+
+  @Column('varchar', { length: 42 })
+  contractAddress!: string;
+
+  @Column('varchar', { length: 42 })
+  key0!: string;
+
+  @Column('numeric', { transformer: bigintTransformer })
+  value!: bigint;
+
+  @Column('text', { nullable: true })
+  proof!: string;
+}

packages/erc721-watcher/src/entity/_Name.ts

@@ -0,0 +1,27 @@
+//
+// Copyright 2021 Vulcanize, Inc.
+//
+
+import { Entity, PrimaryGeneratedColumn, Column, Index } from 'typeorm';
+
+@Entity()
+@Index(['blockHash', 'contractAddress'], { unique: true })
+export class _Name {
+  @PrimaryGeneratedColumn()
+  id!: number;
+
+  @Column('varchar', { length: 66 })
+  blockHash!: string;
+
+  @Column('integer')
+  blockNumber!: number;
+
+  @Column('varchar', { length: 42 })
+  contractAddress!: string;
+
+  @Column('varchar')
+  value!: string;
+
+  @Column('text', { nullable: true })
+  proof!: string;
+}

packages/erc721-watcher/src/entity/_OperatorApprovals.ts

@@ -0,0 +1,33 @@
+//
+// Copyright 2021 Vulcanize, Inc.
+//
+
+import { Entity, PrimaryGeneratedColumn, Column, Index } from 'typeorm';
+
+@Entity()
+@Index(['blockHash', 'contractAddress', 'key0', 'key1'], { unique: true })
+export class _OperatorApprovals {
+  @PrimaryGeneratedColumn()
+  id!: number;
+
+  @Column('varchar', { length: 66 })
+  blockHash!: string;
+
+  @Column('integer')
+  blockNumber!: number;
+
+  @Column('varchar', { length: 42 })
+  contractAddress!: string;
+
+  @Column('varchar', { length: 42 })
+  key0!: string;
+
+  @Column('varchar', { length: 42 })
+  key1!: string;
+
+  @Column('boolean')
+  value!: boolean;
+
+  @Column('text', { nullable: true })
+  proof!: string;
+}

packages/erc721-watcher/src/entity/_Owners.ts

@@ -0,0 +1,31 @@
+//
+// Copyright 2021 Vulcanize, Inc.
+//
+
+import { Entity, PrimaryGeneratedColumn, Column, Index } from 'typeorm';
+import { bigintTransformer } from '@vulcanize/util';
+
+@Entity()
+@Index(['blockHash', 'contractAddress', 'key0'], { unique: true })
+export class _Owners {
+  @PrimaryGeneratedColumn()
+  id!: number;
+
+  @Column('varchar', { length: 66 })
+  blockHash!: string;
+
+  @Column('integer')
+  blockNumber!: number;
+
+  @Column('varchar', { length: 42 })
+  contractAddress!: string;
+
+  @Column('numeric', { transformer: bigintTransformer })
+  key0!: bigint;
+
+  @Column('varchar')
+  value!: string;
+
+  @Column('text', { nullable: true })
+  proof!: string;
+}

packages/erc721-watcher/src/entity/_Symbol.ts

@@ -0,0 +1,27 @@
+//
+// Copyright 2021 Vulcanize, Inc.
+//
+
+import { Entity, PrimaryGeneratedColumn, Column, Index } from 'typeorm';
+
+@Entity()
+@Index(['blockHash', 'contractAddress'], { unique: true })
+export class _Symbol {
+  @PrimaryGeneratedColumn()
+  id!: number;
+
+  @Column('varchar', { length: 66 })
+  blockHash!: string;
+
+  @Column('integer')
+  blockNumber!: number;
+
+  @Column('varchar', { length: 42 })
+  contractAddress!: string;
+
+  @Column('varchar')
+  value!: string;
+
+  @Column('text', { nullable: true })
+  proof!: string;
+}

packages/erc721-watcher/src/entity/_TokenApprovals.ts

@@ -0,0 +1,31 @@
+//
+// Copyright 2021 Vulcanize, Inc.
+//
+
+import { Entity, PrimaryGeneratedColumn, Column, Index } from 'typeorm';
+import { bigintTransformer } from '@vulcanize/util';
+
+@Entity()
+@Index(['blockHash', 'contractAddress', 'key0'], { unique: true })
+export class _TokenApprovals {
+  @PrimaryGeneratedColumn()
+  id!: number;
+
+  @Column('varchar', { length: 66 })
+  blockHash!: string;
+
+  @Column('integer')
+  blockNumber!: number;
+
+  @Column('varchar', { length: 42 })
+  contractAddress!: string;
+
+  @Column('numeric', { transformer: bigintTransformer })
+  key0!: bigint;
+
+  @Column('varchar')
+  value!: string;
+
+  @Column('text', { nullable: true })
+  proof!: string;
+}

packages/erc721-watcher/src/events.ts

@@ -0,0 +1,121 @@
+//
+// Copyright 2021 Vulcanize, Inc.
+//
+
+import assert from 'assert';
+import debug from 'debug';
+import { PubSub } from 'apollo-server-express';
+
+import { EthClient } from '@vulcanize/ipld-eth-client';
+import {
+  JobQueue,
+  EventWatcher as BaseEventWatcher,
+  EventWatcherInterface,
+  QUEUE_BLOCK_PROCESSING,
+  QUEUE_EVENT_PROCESSING,
+  UNKNOWN_EVENT_NAME,
+  UpstreamConfig
+} from '@vulcanize/util';
+
+import { Indexer } from './indexer';
+import { Event } from './entity/Event';
+
+const EVENT = 'event';
+
+const log = debug('vulcanize:events');
+
+export class EventWatcher implements EventWatcherInterface {
+  _ethClient: EthClient
+  _indexer: Indexer
+  _subscription: ZenObservable.Subscription | undefined
+  _baseEventWatcher: BaseEventWatcher
+  _pubsub: PubSub
+  _jobQueue: JobQueue
+
+  constructor (upstreamConfig: UpstreamConfig, ethClient: EthClient, indexer: Indexer, pubsub: PubSub, jobQueue: JobQueue) {
+    assert(ethClient);
+    assert(indexer);
+
+    this._ethClient = ethClient;
+    this._indexer = indexer;
+    this._pubsub = pubsub;
+    this._jobQueue = jobQueue;
+    this._baseEventWatcher = new BaseEventWatcher(upstreamConfig, this._ethClient, this._indexer, this._pubsub, this._jobQueue);
+  }
+
+  getEventIterator (): AsyncIterator<any> {
+    return this._pubsub.asyncIterator([EVENT]);
+  }
+
+  getBlockProgressEventIterator (): AsyncIterator<any> {
+    return this._baseEventWatcher.getBlockProgressEventIterator();
+  }
+
+  async start (): Promise<void> {
+    assert(!this._subscription, 'subscription already started');
+
+    await this.initBlockProcessingOnCompleteHandler();
+    await this.initEventProcessingOnCompleteHandler();
+    this._baseEventWatcher.startBlockProcessing();
+  }
+
+  async stop (): Promise<void> {
+    this._baseEventWatcher.stop();
+  }
+
+  async initBlockProcessingOnCompleteHandler (): Promise<void> {
+    this._jobQueue.onComplete(QUEUE_BLOCK_PROCESSING, async (job) => {
+      const { id, data: { failed } } = job;
+
+      if (failed) {
+        log(`Job ${id} for queue ${QUEUE_BLOCK_PROCESSING} failed`);
+        return;
+      }
+
+      await this._baseEventWatcher.blockProcessingCompleteHandler(job);
+    });
+  }
+
+  async initEventProcessingOnCompleteHandler (): Promise<void> {
+    await this._jobQueue.onComplete(QUEUE_EVENT_PROCESSING, async (job) => {
+      const { id, data: { request, failed, state, createdOn } } = job;
+
+      if (failed) {
+        log(`Job ${id} for queue ${QUEUE_EVENT_PROCESSING} failed`);
+        return;
+      }
+
+      const dbEvents = await this._baseEventWatcher.eventProcessingCompleteHandler(job);
+      const timeElapsedInSeconds = (Date.now() - Date.parse(createdOn)) / 1000;
+
+      // Cannot publish individual event as they are processed together in a single job.
+      // TODO: Use a different pubsub to publish event from job-runner.
+      // https://www.apollographql.com/docs/apollo-server/data/subscriptions/#production-pubsub-libraries
+      for (const dbEvent of dbEvents) {
+        log(`Job onComplete event ${dbEvent.id} publish ${!!request.data.publish}`);
+
+        if (!failed && state === 'completed' && request.data.publish) {
+          // Check for max acceptable lag time between request and sending results to live subscribers.
+          if (timeElapsedInSeconds <= this._jobQueue.maxCompletionLag) {
+            await this.publishEventToSubscribers(dbEvent, timeElapsedInSeconds);
+          } else {
+            log(`event ${dbEvent.id} is too old (${timeElapsedInSeconds}s), not broadcasting to live subscribers`);
+          }
+        }
+      }
+    });
+  }
+
+  async publishEventToSubscribers (dbEvent: Event, timeElapsedInSeconds: number): Promise<void> {
+    if (dbEvent && dbEvent.eventName !== UNKNOWN_EVENT_NAME) {
+      const resultEvent = this._indexer.getResultEvent(dbEvent);
+
+      log(`pushing event to GQL subscribers (${timeElapsedInSeconds}s elapsed): ${resultEvent.event.__typename}`);
+
+      // Publishing the event here will result in pushing the payload to GQL subscribers for `onEvent`.
+      await this._pubsub.publish(EVENT, {
+        onEvent: resultEvent
+      });
+    }
+  }
+}

packages/erc721-watcher/src/fill.ts

@@ -0,0 +1,98 @@
+//
+// Copyright 2021 Vulcanize, Inc.
+//
+
+import path from 'path';
+import assert from 'assert';
+import 'reflect-metadata';
+import yargs from 'yargs';
+import { hideBin } from 'yargs/helpers';
+import debug from 'debug';
+import { PubSub } from 'apollo-server-express';
+
+import { Config, getConfig, fillBlocks, JobQueue, DEFAULT_CONFIG_PATH, initClients } from '@vulcanize/util';
+import { GraphWatcher, Database as GraphDatabase } from '@vulcanize/graph-node';
+
+import { Database } from './database';
+import { Indexer } from './indexer';
+import { EventWatcher } from './events';
+
+const log = debug('vulcanize:server');
+
+export const main = async (): Promise<any> => {
+  const argv = await yargs(hideBin(process.argv)).parserConfiguration({
+    'parse-numbers': false
+  }).options({
+    configFile: {
+      alias: 'f',
+      type: 'string',
+      demandOption: true,
+      describe: 'configuration file path (toml)',
+      default: DEFAULT_CONFIG_PATH
+    },
+    startBlock: {
+      type: 'number',
+      demandOption: true,
+      describe: 'Block number to start processing at'
+    },
+    endBlock: {
+      type: 'number',
+      demandOption: true,
+      describe: 'Block number to stop processing at'
+    },
+    prefetch: {
+      type: 'boolean',
+      default: false,
+      describe: 'Block and events prefetch mode'
+    },
+    batchBlocks: {
+      type: 'number',
+      default: 10,
+      describe: 'Number of blocks prefetched in batch'
+    }
+  }).argv;
+
+  const config: Config = await getConfig(argv.configFile);
+  const { ethClient, ethProvider } = await initClients(config);
+
+  const db = new Database(config.database);
+  await db.init();
+
+  const graphDb = new GraphDatabase(config.database, path.resolve(__dirname, 'entity/*'));
+  await graphDb.init();
+
+  const graphWatcher = new GraphWatcher(graphDb, ethClient, ethProvider, config.server);
+
+  const jobQueueConfig = config.jobQueue;
+  assert(jobQueueConfig, 'Missing job queue config');
+
+  const { dbConnectionString, maxCompletionLagInSecs } = jobQueueConfig;
+  assert(dbConnectionString, 'Missing job queue db connection string');
+
+  const jobQueue = new JobQueue({ dbConnectionString, maxCompletionLag: maxCompletionLagInSecs });
+  await jobQueue.start();
+
+  const indexer = new Indexer(config.server, db, ethClient, ethProvider, jobQueue, graphWatcher);
+  await indexer.init();
+
+  graphWatcher.setIndexer(indexer);
+
+  // Note: In-memory pubsub works fine for now, as each watcher is a single process anyway.
+  // Later: https://www.apollographql.com/docs/apollo-server/data/subscriptions/#production-pubsub-libraries
+  const pubsub = new PubSub();
+
+  const eventWatcher = new EventWatcher(config.upstream, ethClient, indexer, pubsub, jobQueue);
+
+  await fillBlocks(jobQueue, indexer, eventWatcher, config.upstream.ethServer.blockDelayInMilliSecs, argv);
+};
+
+main().catch(err => {
+  log(err);
+}).finally(() => {
+  process.exit();
+});
+
+process.on('SIGINT', () => {
+  log(`Exiting process ${process.pid} with code 0`);
+  process.exit(0);
+});

packages/erc721-watcher/src/gql/index.ts

@@ -0,0 +1,3 @@
+export * as mutations from './mutations';
+export * as queries from './queries';
+export * as subscriptions from './subscriptions';

packages/erc721-watcher/src/gql/mutations/index.ts

@@ -0,0 +1,4 @@
+import fs from 'fs';
+import path from 'path';
+
+export const watchContract = fs.readFileSync(path.join(__dirname, 'watchContract.gql'), 'utf8');

packages/erc721-watcher/src/gql/mutations/watchContract.gql

@@ -0,0 +1,3 @@
+mutation watchContract($address: String!, $kind: String!, $checkpoint: Boolean!, $startingBlock: Int){
+    watchContract(address: $address, kind: $kind, checkpoint: $checkpoint, startingBlock: $startingBlock)
+}

packages/erc721-watcher/src/gql/queries/_balances.gql

@@ -0,0 +1,8 @@
+query _balances($blockHash: String!, $contractAddress: String!, $key0: String!){
+    _balances(blockHash: $blockHash, contractAddress: $contractAddress, key0: $key0){
+        value
+        proof{
+            data
+        }
+    }
+}

packages/erc721-watcher/src/gql/queries/_name.gql

@@ -0,0 +1,8 @@
+query _name($blockHash: String!, $contractAddress: String!){
+    _name(blockHash: $blockHash, contractAddress: $contractAddress){
+        value
+        proof{
+            data
+        }
+    }
+}

packages/erc721-watcher/src/gql/queries/_operatorApprovals.gql

@@ -0,0 +1,8 @@
+query _operatorApprovals($blockHash: String!, $contractAddress: String!, $key0: String!, $key1: String!){
+    _operatorApprovals(blockHash: $blockHash, contractAddress: $contractAddress, key0: $key0, key1: $key1){
+        value
+        proof{
+            data
+        }
+    }
+}

packages/erc721-watcher/src/gql/queries/_owners.gql

@@ -0,0 +1,8 @@
+query _owners($blockHash: String!, $contractAddress: String!, $key0: BigInt!){
+    _owners(blockHash: $blockHash, contractAddress: $contractAddress, key0: $key0){
+        value
+        proof{
+            data
+        }
+    }
+}

packages/erc721-watcher/src/gql/queries/_symbol.gql

@@ -0,0 +1,8 @@
+query _symbol($blockHash: String!, $contractAddress: String!){
+    _symbol(blockHash: $blockHash, contractAddress: $contractAddress){
+        value
+        proof{
+            data
+        }
+    }
+}

packages/erc721-watcher/src/gql/queries/_tokenApprovals.gql

@@ -0,0 +1,8 @@
+query _tokenApprovals($blockHash: String!, $contractAddress: String!, $key0: BigInt!){
+    _tokenApprovals(blockHash: $blockHash, contractAddress: $contractAddress, key0: $key0){
+        value
+        proof{
+            data
+        }
+    }
+}

packages/erc721-watcher/src/gql/queries/balanceOf.gql

@@ -0,0 +1,8 @@
+query balanceOf($blockHash: String!, $contractAddress: String!, $owner: String!){
+    balanceOf(blockHash: $blockHash, contractAddress: $contractAddress, owner: $owner){
+        value
+        proof{
+            data
+        }
+    }
+}

packages/erc721-watcher/src/gql/queries/events.gql

@@ -0,0 +1,39 @@
+query events($blockHash: String!, $contractAddress: String!, $name: String){
+    events(blockHash: $blockHash, contractAddress: $contractAddress, name: $name){
+        block{
+            cid
+            hash
+            number
+            timestamp
+            parentHash
+        }
+        tx{
+            hash
+            index
+            from
+            to
+        }
+        contract
+        eventIndex
+        event{
+            ... on ApprovalEvent {
+                owner
+                approved
+                tokenId
+            }
+            ... on ApprovalForAllEvent {
+                owner
+                operator
+                approved
+            }
+            ... on TransferEvent {
+                from
+                to
+                tokenId
+            }
+        }
+        proof{
+            data
+        }
+    }
+}

packages/erc721-watcher/src/gql/queries/eventsInRange.gql

@@ -0,0 +1,39 @@
+query eventsInRange($fromBlockNumber: Int!, $toBlockNumber: Int!){
+    eventsInRange(fromBlockNumber: $fromBlockNumber, toBlockNumber: $toBlockNumber){
+        block{
+            cid
+            hash
+            number
+            timestamp
+            parentHash
+        }
+        tx{
+            hash
+            index
+            from
+            to
+        }
+        contract
+        eventIndex
+        event{
+            ... on ApprovalEvent {
+                owner
+                approved
+                tokenId
+            }
+            ... on ApprovalForAllEvent {
+                owner
+                operator
+                approved
+            }
+            ... on TransferEvent {
+                from
+                to
+                tokenId
+            }
+        }
+        proof{
+            data
+        }
+    }
+}

packages/erc721-watcher/src/gql/queries/getApproved.gql

@@ -0,0 +1,8 @@
+query getApproved($blockHash: String!, $contractAddress: String!, $tokenId: BigInt!){
+    getApproved(blockHash: $blockHash, contractAddress: $contractAddress, tokenId: $tokenId){
+        value
+        proof{
+            data
+        }
+    }
+}

packages/erc721-watcher/src/gql/queries/getState.gql

@@ -0,0 +1,15 @@
+query getState($blockHash: String!, $contractAddress: String!, $kind: String){
+    getState(blockHash: $blockHash, contractAddress: $contractAddress, kind: $kind){
+        block{
+            cid
+            hash
+            number
+            timestamp
+            parentHash
+        }
+        contractAddress
+        cid
+        kind
+        data
+    }
+}

packages/erc721-watcher/src/gql/queries/getStateByCID.gql

@@ -0,0 +1,15 @@
+query getStateByCID($cid: String!){
+    getStateByCID(cid: $cid){
+        block{
+            cid
+            hash
+            number
+            timestamp
+            parentHash
+        }
+        contractAddress
+        cid
+        kind
+        data
+    }
+}

packages/erc721-watcher/src/gql/queries/index.ts

@@ -0,0 +1,21 @@
+import fs from 'fs';
+import path from 'path';
+
+export const events = fs.readFileSync(path.join(__dirname, 'events.gql'), 'utf8');
+export const eventsInRange = fs.readFileSync(path.join(__dirname, 'eventsInRange.gql'), 'utf8');
+export const supportsInterface = fs.readFileSync(path.join(__dirname, 'supportsInterface.gql'), 'utf8');
+export const balanceOf = fs.readFileSync(path.join(__dirname, 'balanceOf.gql'), 'utf8');
+export const ownerOf = fs.readFileSync(path.join(__dirname, 'ownerOf.gql'), 'utf8');
+export const getApproved = fs.readFileSync(path.join(__dirname, 'getApproved.gql'), 'utf8');
+export const isApprovedForAll = fs.readFileSync(path.join(__dirname, 'isApprovedForAll.gql'), 'utf8');
+export const name = fs.readFileSync(path.join(__dirname, 'name.gql'), 'utf8');
+export const symbol = fs.readFileSync(path.join(__dirname, 'symbol.gql'), 'utf8');
+export const tokenURI = fs.readFileSync(path.join(__dirname, 'tokenURI.gql'), 'utf8');
+export const _name = fs.readFileSync(path.join(__dirname, '_name.gql'), 'utf8');
+export const _symbol = fs.readFileSync(path.join(__dirname, '_symbol.gql'), 'utf8');
+export const _owners = fs.readFileSync(path.join(__dirname, '_owners.gql'), 'utf8');
+export const _balances = fs.readFileSync(path.join(__dirname, '_balances.gql'), 'utf8');
+export const _tokenApprovals = fs.readFileSync(path.join(__dirname, '_tokenApprovals.gql'), 'utf8');
+export const _operatorApprovals = fs.readFileSync(path.join(__dirname, '_operatorApprovals.gql'), 'utf8');
+export const getStateByCID = fs.readFileSync(path.join(__dirname, 'getStateByCID.gql'), 'utf8');
+export const getState = fs.readFileSync(path.join(__dirname, 'getState.gql'), 'utf8');

packages/erc721-watcher/src/gql/queries/isApprovedForAll.gql

@@ -0,0 +1,8 @@
+query isApprovedForAll($blockHash: String!, $contractAddress: String!, $owner: String!, $operator: String!){
+    isApprovedForAll(blockHash: $blockHash, contractAddress: $contractAddress, owner: $owner, operator: $operator){
+        value
+        proof{
+            data
+        }
+    }
+}

packages/erc721-watcher/src/gql/queries/name.gql

@@ -0,0 +1,8 @@
+query name($blockHash: String!, $contractAddress: String!){
+    name(blockHash: $blockHash, contractAddress: $contractAddress){
+        value
+        proof{
+            data
+        }
+    }
+}

packages/erc721-watcher/src/gql/queries/ownerOf.gql

@@ -0,0 +1,8 @@
+query ownerOf($blockHash: String!, $contractAddress: String!, $tokenId: BigInt!){
+    ownerOf(blockHash: $blockHash, contractAddress: $contractAddress, tokenId: $tokenId){
+        value
+        proof{
+            data
+        }
+    }
+}

packages/erc721-watcher/src/gql/queries/supportsInterface.gql

@@ -0,0 +1,8 @@
+query supportsInterface($blockHash: String!, $contractAddress: String!, $interfaceId: String!){
+    supportsInterface(blockHash: $blockHash, contractAddress: $contractAddress, interfaceId: $interfaceId){
+        value
+        proof{
+            data
+        }
+    }
+}

packages/erc721-watcher/src/gql/queries/symbol.gql

@@ -0,0 +1,8 @@
+query symbol($blockHash: String!, $contractAddress: String!){
+    symbol(blockHash: $blockHash, contractAddress: $contractAddress){
+        value
+        proof{
+            data
+        }
+    }
+}

packages/erc721-watcher/src/gql/queries/tokenURI.gql

@@ -0,0 +1,8 @@
+query tokenURI($blockHash: String!, $contractAddress: String!, $tokenId: BigInt!){
+    tokenURI(blockHash: $blockHash, contractAddress: $contractAddress, tokenId: $tokenId){
+        value
+        proof{
+            data
+        }
+    }
+}

packages/erc721-watcher/src/gql/subscriptions/index.ts

@@ -0,0 +1,4 @@
+import fs from 'fs';
+import path from 'path';
+
+export const onEvent = fs.readFileSync(path.join(__dirname, 'onEvent.gql'), 'utf8');

packages/erc721-watcher/src/gql/subscriptions/onEvent.gql

@@ -0,0 +1,39 @@
+subscription onEvent{
+    onEvent{
+        block{
+            cid
+            hash
+            number
+            timestamp
+            parentHash
+        }
+        tx{
+            hash
+            index
+            from
+            to
+        }
+        contract
+        eventIndex
+        event{
+            ... on ApprovalEvent {
+                owner
+                approved
+                tokenId
+            }
+            ... on ApprovalForAllEvent {
+                owner
+                operator
+                approved
+            }
+            ... on TransferEvent {
+                from
+                to
+                tokenId
+            }
+        }
+        proof{
+            data
+        }
+    }
+}

packages/erc721-watcher/src/hooks.ts

@@ -0,0 +1,80 @@
+//
+// Copyright 2021 Vulcanize, Inc.
+//
+
+import assert from 'assert';
+
+// import { updateStateForMappingType, updateStateForElementaryType } from '@vulcanize/util';
+
+import { Indexer, ResultEvent } from './indexer';
+
+/**
+ * Hook function to store an initial state.
+ * @param indexer Indexer instance.
+ * @param blockHash Hash of the concerned block.
+ * @param contractAddress Address of the concerned contract.
+ * @returns Data block to be stored.
+ */
+export async function createInitialState (indexer: Indexer, contractAddress: string, blockHash: string): Promise<any> {
+  assert(indexer);
+  assert(blockHash);
+  assert(contractAddress);
+
+  // Store the desired initial state in an IPLDBlock.
+  const ipldBlockData: any = {
+    state: {}
+  };
+
+  // Use updateStateForElementaryType to update initial state with an elementary property.
+  // Eg. const ipldBlockData = updateStateForElementaryType(ipldBlockData, '_totalBalance', result.value.toString());
+
+  // Use updateStateForMappingType to update initial state with a nested property.
+  // Eg. const ipldBlockData = updateStateForMappingType(ipldBlockData, '_allowances', [owner, spender], allowance.value.toString());
+
+  // Return initial state data to be saved.
+  return ipldBlockData;
+}
+
+/**
+ * Hook function to create state diff.
+ * @param indexer Indexer instance that contains methods to fetch the contract varaiable values.
+ * @param blockHash Block hash of the concerned block.
+ */
+export async function createStateDiff (indexer: Indexer, blockHash: string): Promise<void> {
+  assert(indexer);
+  assert(blockHash);
+
+  // Use indexer.createStateDiff() method to save custom state diff(s).
+}
+
+/**
+ * Hook function to create state checkpoint
+ * @param indexer Indexer instance.
+ * @param contractAddress Address of the concerned contract.
+ * @param blockHash Block hash of the concerned block.
+ * @returns Whether to disable default checkpoint. If false, the state from this hook is updated with that from default checkpoint.
+ */
+export async function createStateCheckpoint (indexer: Indexer, contractAddress: string, blockHash: string): Promise<boolean> {
+  assert(indexer);
+  assert(blockHash);
+  assert(contractAddress);
+
+  // Use indexer.createStateCheckpoint() method to create a custom checkpoint.
+
+  // Return false to update the state created by this hook by auto-generated checkpoint state.
+  // Return true to disable update of the state created by this hook by auto-generated checkpoint state.
+  return false;
+}
+
+/**
+ * Event hook function.
+ * @param indexer Indexer instance that contains methods to fetch and update the contract values in the database.
+ * @param eventData ResultEvent object containing event information.
+ */
+export async function handleEvent (indexer: Indexer, eventData: ResultEvent): Promise<void> {
+  assert(indexer);
+  assert(eventData);
+
+  // Use indexer methods to index data.
+  // Pass `diff` parameter to indexer methods as true to save an auto-generated state from the indexed data.
+}

packages/erc721-watcher/src/job-runner.ts

@@ -0,0 +1,287 @@
+//
+// Copyright 2021 Vulcanize, Inc.
+//
+
+import path from 'path';
+import assert from 'assert';
+import 'reflect-metadata';
+import yargs from 'yargs';
+import { hideBin } from 'yargs/helpers';
+import debug from 'debug';
+
+import {
+  getConfig,
+  Config,
+  JobQueue,
+  JobRunner as BaseJobRunner,
+  QUEUE_BLOCK_PROCESSING,
+  QUEUE_EVENT_PROCESSING,
+  QUEUE_BLOCK_CHECKPOINT,
+  QUEUE_HOOKS,
+  QUEUE_IPFS,
+  JOB_KIND_PRUNE,
+  JobQueueConfig,
+  DEFAULT_CONFIG_PATH,
+  initClients
+} from '@vulcanize/util';
+import { GraphWatcher, Database as GraphDatabase } from '@vulcanize/graph-node';
+
+import { Indexer } from './indexer';
+import { Database } from './database';
+
+const log = debug('vulcanize:job-runner');
+
+export class JobRunner {
+  _indexer: Indexer
+  _jobQueue: JobQueue
+  _baseJobRunner: BaseJobRunner
+  _jobQueueConfig: JobQueueConfig
+
+  constructor (jobQueueConfig: JobQueueConfig, indexer: Indexer, jobQueue: JobQueue) {
+    this._jobQueueConfig = jobQueueConfig;
+    this._indexer = indexer;
+    this._jobQueue = jobQueue;
+    this._baseJobRunner = new BaseJobRunner(this._jobQueueConfig, this._indexer, this._jobQueue);
+  }
+
+  async start (): Promise<void> {
+    await this.subscribeBlockProcessingQueue();
+    await this.subscribeEventProcessingQueue();
+    await this.subscribeBlockCheckpointQueue();
+    await this.subscribeHooksQueue();
+    await this.subscribeIPFSQueue();
+  }
+
+  async subscribeBlockProcessingQueue (): Promise<void> {
+    await this._jobQueue.subscribe(QUEUE_BLOCK_PROCESSING, async (job) => {
+      await this._baseJobRunner.processBlock(job);
+
+      const { data: { kind } } = job;
+
+      // If it's a pruning job: Create a hooks job.
+      if (kind === JOB_KIND_PRUNE) {
+        await this.createHooksJob();
+      }
+
+      await this._jobQueue.markComplete(job);
+    });
+  }
+
+  async subscribeEventProcessingQueue (): Promise<void> {
+    await this._jobQueue.subscribe(QUEUE_EVENT_PROCESSING, async (job) => {
+      await this._baseJobRunner.processEvent(job);
+    });
+  }
+
+  async subscribeHooksQueue (): Promise<void> {
+    await this._jobQueue.subscribe(QUEUE_HOOKS, async (job) => {
+      const { data: { blockHash, blockNumber } } = job;
+
+      // Get the current IPLD Status.
+      const ipldStatus = await this._indexer.getIPLDStatus();
+
+      if (ipldStatus) {
+        if (ipldStatus.latestHooksBlockNumber < (blockNumber - 1)) {
+          // Create hooks job for parent block.
+          const [parentBlock] = await this._indexer.getBlocksAtHeight(blockNumber - 1, false);
+          await this.createHooksJob(parentBlock.blockHash, parentBlock.blockNumber);
+
+          const message = `Hooks for blockNumber ${blockNumber - 1} not processed yet, aborting`;
+          log(message);
+
+          throw new Error(message);
+        }
+
+        if (ipldStatus.latestHooksBlockNumber > (blockNumber - 1)) {
+          log(`Hooks for blockNumber ${blockNumber} already processed`);
+
+          return;
+        }
+      }
+
+      // Process the hooks for the given block number.
+      await this._indexer.processCanonicalBlock(blockHash);
+
+      // Update the IPLD status.
+      await this._indexer.updateIPLDStatusHooksBlock(blockNumber);
+
+      // Create a checkpoint job after completion of a hook job.
+      await this.createCheckpointJob(blockHash, blockNumber);
+
+      await this._jobQueue.markComplete(job);
+    });
+  }
+
+  async subscribeBlockCheckpointQueue (): Promise<void> {
+    await this._jobQueue.subscribe(QUEUE_BLOCK_CHECKPOINT, async (job) => {
+      const { data: { blockHash, blockNumber } } = job;
+
+      // Get the current IPLD Status.
+      const ipldStatus = await this._indexer.getIPLDStatus();
+      assert(ipldStatus);
+
+      if (ipldStatus.latestCheckpointBlockNumber >= 0) {
+        if (ipldStatus.latestCheckpointBlockNumber < (blockNumber - 1)) {
+          // Create a checkpoint job for parent block.
+          const [parentBlock] = await this._indexer.getBlocksAtHeight(blockNumber - 1, false);
+          await this.createCheckpointJob(parentBlock.blockHash, parentBlock.blockNumber);
+
+          const message = `Checkpoints for blockNumber ${blockNumber - 1} not processed yet, aborting`;
+          log(message);
+
+          throw new Error(message);
+        }
+
+        if (ipldStatus.latestCheckpointBlockNumber > (blockNumber - 1)) {
+          log(`Checkpoints for blockNumber ${blockNumber} already processed`);
+
+          return;
+        }
+      }
+
+      // Process checkpoints for the given block.
+      await this._indexer.processCheckpoint(blockHash);
+
+      // Update the IPLD status.
+      await this._indexer.updateIPLDStatusCheckpointBlock(blockNumber);
+
+      // Create an IPFS job after completion of a checkpoint job.
+      if (this._indexer.isIPFSConfigured()) {
+        await this.createIPFSPutJob(blockHash, blockNumber);
+      }
+
+      await this._jobQueue.markComplete(job);
+    });
+  }
+
+  async subscribeIPFSQueue (): Promise<void> {
+    await this._jobQueue.subscribe(QUEUE_IPFS, async (job) => {
+      const { data: { blockHash, blockNumber } } = job;
+
+      const ipldStatus = await this._indexer.getIPLDStatus();
+      assert(ipldStatus);
+
+      if (ipldStatus.latestIPFSBlockNumber >= 0) {
+        if (ipldStatus.latestIPFSBlockNumber < (blockNumber - 1)) {
+          // Create a IPFS job for parent block.
+          const [parentBlock] = await this._indexer.getBlocksAtHeight(blockNumber - 1, false);
+          await this.createIPFSPutJob(parentBlock.blockHash, parentBlock.blockNumber);
+
+          const message = `IPFS for blockNumber ${blockNumber - 1} not processed yet, aborting`;
+          log(message);
+
+          throw new Error(message);
+        }
+
+        if (ipldStatus.latestIPFSBlockNumber > (blockNumber - 1)) {
+          log(`IPFS for blockNumber ${blockNumber} already processed`);
+
+          return;
+        }
+      }
+
+      // Get IPLDBlocks for the given blocHash.
+      const ipldBlocks = await this._indexer.getIPLDBlocksByHash(blockHash);
+
+      // Push all the IPLDBlocks to IPFS.
+      for (const ipldBlock of ipldBlocks) {
+        const data = this._indexer.getIPLDData(ipldBlock);
+        await this._indexer.pushToIPFS(data);
+      }
+
+      // Update the IPLD status.
+      await this._indexer.updateIPLDStatusIPFSBlock(blockNumber);
+
+      await this._jobQueue.markComplete(job);
+    });
+  }
+
+  async createHooksJob (blockHash?: string, blockNumber?: number): Promise<void> {
+    if (!blockNumber || !blockHash) {
+      // Get the latest canonical block
+      const latestCanonicalBlock = await this._indexer.getLatestCanonicalBlock();
+
+      // Create a hooks job for parent block of latestCanonicalBlock because pruning for first block is skipped as it is assumed to be a canonical block.
+      blockHash = latestCanonicalBlock.parentHash;
+      blockNumber = latestCanonicalBlock.blockNumber - 1;
+    }
+
+    await this._jobQueue.pushJob(
+      QUEUE_HOOKS,
+      {
+        blockHash,
+        blockNumber
+      }
+    );
+  }
+
+  async createCheckpointJob (blockHash: string, blockNumber: number): Promise<void> {
+    await this._jobQueue.pushJob(
+      QUEUE_BLOCK_CHECKPOINT,
+      {
+        blockHash,
+        blockNumber
+      }
+    );
+  }
+
+  async createIPFSPutJob (blockHash: string, blockNumber: number): Promise<void> {
+    await this._jobQueue.pushJob(
+      QUEUE_IPFS,
+      {
+        blockHash,
+        blockNumber
+      }
+    );
+  }
+}
+
+export const main = async (): Promise<any> => {
+  const argv = await yargs(hideBin(process.argv))
+    .option('f', {
+      alias: 'config-file',
+      demandOption: true,
+      describe: 'configuration file path (toml)',
+      type: 'string',
+      default: DEFAULT_CONFIG_PATH
+    })
+    .argv;
+
+  const config: Config = await getConfig(argv.f);
+  const { ethClient, ethProvider } = await initClients(config);
+
+  const db = new Database(config.database);
+  await db.init();
+
+  const graphDb = new GraphDatabase(config.database, path.resolve(__dirname, 'entity/*'));
+  await graphDb.init();
+
+  const graphWatcher = new GraphWatcher(graphDb, ethClient, ethProvider, config.server);
+
+  const jobQueueConfig = config.jobQueue;
+  assert(jobQueueConfig, 'Missing job queue config');
+
+  const { dbConnectionString, maxCompletionLagInSecs } = jobQueueConfig;
+  assert(dbConnectionString, 'Missing job queue db connection string');
+
+  const jobQueue = new JobQueue({ dbConnectionString, maxCompletionLag: maxCompletionLagInSecs });
+  await jobQueue.start();
+
+  const indexer = new Indexer(config.server, db, ethClient, ethProvider, jobQueue, graphWatcher);
+  await indexer.init();
+
+  graphWatcher.setIndexer(indexer);
+
+  const jobRunner = new JobRunner(jobQueueConfig, indexer, jobQueue);
+  await jobRunner.start();
+};
+
+main().then(() => {
+  log('Starting job runner...');
+}).catch(err => {
+  log(err);
+});
+
+process.on('uncaughtException', err => {
+  log('uncaughtException', err);
+});

packages/erc721-watcher/src/resolvers.ts

@@ -0,0 +1,172 @@
+//
+// Copyright 2021 Vulcanize, Inc.
+//
+
+import assert from 'assert';
+import BigInt from 'apollo-type-bigint';
+import debug from 'debug';
+import Decimal from 'decimal.js';
+import { GraphQLScalarType } from 'graphql';
+
+import { ValueResult, BlockHeight, StateKind } from '@vulcanize/util';
+
+import { Indexer } from './indexer';
+import { EventWatcher } from './events';
+
+const log = debug('vulcanize:resolver');
+
+export const createResolvers = async (indexer: Indexer, eventWatcher: EventWatcher): Promise<any> => {
+  assert(indexer);
+
+  return {
+    BigInt: new BigInt('bigInt'),
+
+    BigDecimal: new GraphQLScalarType({
+      name: 'BigDecimal',
+      description: 'BigDecimal custom scalar type',
+      parseValue (value) {
+        // value from the client
+        return new Decimal(value);
+      },
+      serialize (value: Decimal) {
+        // value sent to the client
+        return value.toFixed();
+      }
+    }),
+
+    Event: {
+      __resolveType: (obj: any) => {
+        assert(obj.__typename);
+
+        return obj.__typename;
+      }
+    },
+
+    Subscription: {
+      onEvent: {
+        subscribe: () => eventWatcher.getEventIterator()
+      }
+    },
+
+    Mutation: {
+      watchContract: async (_: any, { address, kind, checkpoint, startingBlock = 1 }: { address: string, kind: string, checkpoint: boolean, startingBlock: number }): Promise<boolean> => {
+        log('watchContract', address, kind, checkpoint, startingBlock);
+        await indexer.watchContract(address, kind, checkpoint, startingBlock);
+
+        return true;
+      }
+    },
+
+    Query: {
+      supportsInterface: (_: any, { blockHash, contractAddress, interfaceId }: { blockHash: string, contractAddress: string, interfaceId: string }): Promise<ValueResult> => {
+        log('supportsInterface', blockHash, contractAddress, interfaceId);
+        return indexer.supportsInterface(blockHash, contractAddress, interfaceId);
+      },
+
+      balanceOf: (_: any, { blockHash, contractAddress, owner }: { blockHash: string, contractAddress: string, owner: string }): Promise<ValueResult> => {
+        log('balanceOf', blockHash, contractAddress, owner);
+        return indexer.balanceOf(blockHash, contractAddress, owner);
+      },
+
+      ownerOf: (_: any, { blockHash, contractAddress, tokenId }: { blockHash: string, contractAddress: string, tokenId: bigint }): Promise<ValueResult> => {
+        log('ownerOf', blockHash, contractAddress, tokenId);
+        return indexer.ownerOf(blockHash, contractAddress, tokenId);
+      },
+
+      getApproved: (_: any, { blockHash, contractAddress, tokenId }: { blockHash: string, contractAddress: string, tokenId: bigint }): Promise<ValueResult> => {
+        log('getApproved', blockHash, contractAddress, tokenId);
+        return indexer.getApproved(blockHash, contractAddress, tokenId);
+      },
+
+      isApprovedForAll: (_: any, { blockHash, contractAddress, owner, operator }: { blockHash: string, contractAddress: string, owner: string, operator: string }): Promise<ValueResult> => {
+        log('isApprovedForAll', blockHash, contractAddress, owner, operator);
+        return indexer.isApprovedForAll(blockHash, contractAddress, owner, operator);
+      },
+
+      name: (_: any, { blockHash, contractAddress }: { blockHash: string, contractAddress: string }): Promise<ValueResult> => {
+        log('name', blockHash, contractAddress);
+        return indexer.name(blockHash, contractAddress);
+      },
+
+      symbol: (_: any, { blockHash, contractAddress }: { blockHash: string, contractAddress: string }): Promise<ValueResult> => {
+        log('symbol', blockHash, contractAddress);
+        return indexer.symbol(blockHash, contractAddress);
+      },
+
+      tokenURI: (_: any, { blockHash, contractAddress, tokenId }: { blockHash: string, contractAddress: string, tokenId: bigint }): Promise<ValueResult> => {
+        log('tokenURI', blockHash, contractAddress, tokenId);
+        return indexer.tokenURI(blockHash, contractAddress, tokenId);
+      },
+
+      _name: (_: any, { blockHash, contractAddress }: { blockHash: string, contractAddress: string }): Promise<ValueResult> => {
+        log('_name', blockHash, contractAddress);
+        return indexer._name(blockHash, contractAddress);
+      },
+
+      _symbol: (_: any, { blockHash, contractAddress }: { blockHash: string, contractAddress: string }): Promise<ValueResult> => {
+        log('_symbol', blockHash, contractAddress);
+        return indexer._symbol(blockHash, contractAddress);
+      },
+
+      _owners: (_: any, { blockHash, contractAddress, key0 }: { blockHash: string, contractAddress: string, key0: bigint }): Promise<ValueResult> => {
+        log('_owners', blockHash, contractAddress, key0);
+        return indexer._owners(blockHash, contractAddress, key0);
+      },
+
+      _balances: (_: any, { blockHash, contractAddress, key0 }: { blockHash: string, contractAddress: string, key0: string }): Promise<ValueResult> => {
+        log('_balances', blockHash, contractAddress, key0);
+        return indexer._balances(blockHash, contractAddress, key0);
+      },
+
+      _tokenApprovals: (_: any, { blockHash, contractAddress, key0 }: { blockHash: string, contractAddress: string, key0: bigint }): Promise<ValueResult> => {
+        log('_tokenApprovals', blockHash, contractAddress, key0);
+        return indexer._tokenApprovals(blockHash, contractAddress, key0);
+      },
+
+      _operatorApprovals: (_: any, { blockHash, contractAddress, key0, key1 }: { blockHash: string, contractAddress: string, key0: string, key1: string }): Promise<ValueResult> => {
+        log('_operatorApprovals', blockHash, contractAddress, key0, key1);
+        return indexer._operatorApprovals(blockHash, contractAddress, key0, key1);
+      },
+
+      events: async (_: any, { blockHash, contractAddress, name }: { blockHash: string, contractAddress: string, name?: string }) => {
+        log('events', blockHash, contractAddress, name);
+
+        const block = await indexer.getBlockProgress(blockHash);
+        if (!block || !block.isComplete) {
+          throw new Error(`Block hash ${blockHash} number ${block?.blockNumber} not processed yet`);
+        }
+
+        const events = await indexer.getEventsByFilter(blockHash, contractAddress, name);
+        return events.map(event => indexer.getResultEvent(event));
+      },
+
+      eventsInRange: async (_: any, { fromBlockNumber, toBlockNumber }: { fromBlockNumber: number, toBlockNumber: number }) => {
+        log('eventsInRange', fromBlockNumber, toBlockNumber);
+
+        const { expected, actual } = await indexer.getProcessedBlockCountForRange(fromBlockNumber, toBlockNumber);
+        if (expected !== actual) {
+          throw new Error(`Range not available, expected ${expected}, got ${actual} blocks in range`);
+        }
+
+        const events = await indexer.getEventsInRange(fromBlockNumber, toBlockNumber);
+        return events.map(event => indexer.getResultEvent(event));
+      },
+
+      getStateByCID: async (_: any, { cid }: { cid: string }) => {
+        log('getStateByCID', cid);
+
+        const ipldBlock = await indexer.getIPLDBlockByCid(cid);
+
+        return ipldBlock && ipldBlock.block.isComplete ? indexer.getResultIPLDBlock(ipldBlock) : undefined;
+      },
+
+      getState: async (_: any, { blockHash, contractAddress, kind = StateKind.Diff }: { blockHash: string, contractAddress: string, kind: string }) => {
+        log('getState', blockHash, contractAddress, kind);
+
+        const ipldBlock = await indexer.getPrevIPLDBlock(blockHash, contractAddress, kind);
+
+        return ipldBlock && ipldBlock.block.isComplete ? indexer.getResultIPLDBlock(ipldBlock) : undefined;
+      }
+    }
+  };
+};

packages/erc721-watcher/src/schema.gql

@@ -0,0 +1,110 @@
+scalar BigInt
+
+scalar BigDecimal
+
+scalar Bytes
+
+type Proof {
+  data: String!
+}
+
+type ResultBoolean {
+  value: Boolean!
+  proof: Proof
+}
+
+type ResultString {
+  value: String!
+  proof: Proof
+}
+
+type ResultInt {
+  value: Int!
+  proof: Proof
+}
+
+type ResultBigInt {
+  value: BigInt!
+  proof: Proof
+}
+
+type _Block_ {
+  cid: String!
+  hash: String!
+  number: Int!
+  timestamp: Int!
+  parentHash: String!
+}
+
+type _Transaction_ {
+  hash: String!
+  index: Int!
+  from: String!
+  to: String!
+}
+
+type ResultEvent {
+  block: _Block_!
+  tx: _Transaction_!
+  contract: String!
+  eventIndex: Int!
+  event: Event!
+  proof: Proof
+}
+
+union Event = ApprovalEvent | ApprovalForAllEvent | TransferEvent
+
+type ApprovalEvent {
+  owner: String!
+  approved: String!
+  tokenId: BigInt!
+}
+
+type ApprovalForAllEvent {
+  owner: String!
+  operator: String!
+  approved: Boolean!
+}
+
+type TransferEvent {
+  from: String!
+  to: String!
+  tokenId: BigInt!
+}
+
+type ResultIPLDBlock {
+  block: _Block_!
+  contractAddress: String!
+  cid: String!
+  kind: String!
+  data: String!
+}
+
+type Query {
+  events(blockHash: String!, contractAddress: String!, name: String): [ResultEvent!]
+  eventsInRange(fromBlockNumber: Int!, toBlockNumber: Int!): [ResultEvent!]
+  supportsInterface(blockHash: String!, contractAddress: String!, interfaceId: String!): ResultBoolean!
+  balanceOf(blockHash: String!, contractAddress: String!, owner: String!): ResultBigInt!
+  ownerOf(blockHash: String!, contractAddress: String!, tokenId: BigInt!): ResultString!
+  getApproved(blockHash: String!, contractAddress: String!, tokenId: BigInt!): ResultString!
+  isApprovedForAll(blockHash: String!, contractAddress: String!, owner: String!, operator: String!): ResultBoolean!
+  name(blockHash: String!, contractAddress: String!): ResultString!
+  symbol(blockHash: String!, contractAddress: String!): ResultString!
+  tokenURI(blockHash: String!, contractAddress: String!, tokenId: BigInt!): ResultString!
+  _name(blockHash: String!, contractAddress: String!): ResultString!
+  _symbol(blockHash: String!, contractAddress: String!): ResultString!
+  _owners(blockHash: String!, contractAddress: String!, key0: BigInt!): ResultString!
+  _balances(blockHash: String!, contractAddress: String!, key0: String!): ResultBigInt!
+  _tokenApprovals(blockHash: String!, contractAddress: String!, key0: BigInt!): ResultString!
+  _operatorApprovals(blockHash: String!, contractAddress: String!, key0: String!, key1: String!): ResultBoolean!
+  getStateByCID(cid: String!): ResultIPLDBlock
+  getState(blockHash: String!, contractAddress: String!, kind: String): ResultIPLDBlock
+}
+
+type Mutation {
+  watchContract(address: String!, kind: String!, checkpoint: Boolean!, startingBlock: Int): Boolean!
+}
+
+type Subscription {
+  onEvent: ResultEvent!
+}

packages/erc721-watcher/src/server.ts

@@ -0,0 +1,106 @@
+//
+// Copyright 2021 Vulcanize, Inc.
+//
+
+import fs from 'fs';
+import path from 'path';
+import assert from 'assert';
+import 'reflect-metadata';
+import express, { Application } from 'express';
+import { ApolloServer, PubSub } from 'apollo-server-express';
+import yargs from 'yargs';
+import { hideBin } from 'yargs/helpers';
+import debug from 'debug';
+import 'graphql-import-node';
+import { createServer } from 'http';
+
+import { DEFAULT_CONFIG_PATH, getConfig, Config, JobQueue, KIND_ACTIVE, initClients } from '@vulcanize/util';
+import { GraphWatcher, Database as GraphDatabase } from '@vulcanize/graph-node';
+
+import { createResolvers } from './resolvers';
+import { Indexer } from './indexer';
+import { Database } from './database';
+import { EventWatcher } from './events';
+
+const log = debug('vulcanize:server');
+
+export const main = async (): Promise<any> => {
+  const argv = await yargs(hideBin(process.argv))
+    .option('f', {
+      alias: 'config-file',
+      demandOption: true,
+      describe: 'configuration file path (toml)',
+      type: 'string',
+      default: DEFAULT_CONFIG_PATH
+    })
+    .argv;
+
+  const config: Config = await getConfig(argv.f);
+  const { ethClient, ethProvider } = await initClients(config);
+
+  const { host, port, kind: watcherKind } = config.server;
+
+  const db = new Database(config.database);
+  await db.init();
+
+  const graphDb = new GraphDatabase(config.database, path.resolve(__dirname, 'entity/*'));
+  await graphDb.init();
+
+  const graphWatcher = new GraphWatcher(graphDb, ethClient, ethProvider, config.server);
+
+  // Note: In-memory pubsub works fine for now, as each watcher is a single process anyway.
+  // Later: https://www.apollographql.com/docs/apollo-server/data/subscriptions/#production-pubsub-libraries
+  const pubsub = new PubSub();
+
+  const jobQueueConfig = config.jobQueue;
+  assert(jobQueueConfig, 'Missing job queue config');
+
+  const { dbConnectionString, maxCompletionLagInSecs } = jobQueueConfig;
+  assert(dbConnectionString, 'Missing job queue db connection string');
+
+  const jobQueue = new JobQueue({ dbConnectionString, maxCompletionLag: maxCompletionLagInSecs });
+
+  const indexer = new Indexer(config.server, db, ethClient, ethProvider, jobQueue, graphWatcher);
+  await indexer.init();
+
+  graphWatcher.setIndexer(indexer);
+
+  const eventWatcher = new EventWatcher(config.upstream, ethClient, indexer, pubsub, jobQueue);
+
+  if (watcherKind === KIND_ACTIVE) {
+    await jobQueue.start();
+    await eventWatcher.start();
+  }
+
+  const resolvers = await createResolvers(indexer, eventWatcher);
+
+  const app: Application = express();
+  const typeDefs = fs.readFileSync(path.join(__dirname, 'schema.gql')).toString();
+  const server = new ApolloServer({
+    typeDefs,
+    resolvers
+  });
+
+  await server.start();
+  server.applyMiddleware({ app });
+
+  const httpServer = createServer(app);
+  server.installSubscriptionHandlers(httpServer);
+
+  httpServer.listen(port, host, () => {
+    log(`Server is listening on host ${host} port ${port}`);
+  });
+
+  return { app, server };
+};
+
+main().then(() => {
+  log('Starting server...');
+}).catch(err => {
+  log(err);
+});
+
+process.on('SIGINT', () => {
+  log(`Exiting process ${process.pid} with code 0`);
+  process.exit(0);
+});

packages/erc721-watcher/src/types.ts

@@ -0,0 +1,3 @@
+//
+// Copyright 2021 Vulcanize, Inc.
+//

packages/erc721-watcher/tsconfig.json

@@ -0,0 +1,74 @@
+{
+  "compilerOptions": {
+    /* Visit https://aka.ms/tsconfig.json to read more about this file */
+
+    /* Basic Options */
+    // "incremental": true,                         /* Enable incremental compilation */
+    "target": "es5",                                /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', 'ES2018', 'ES2019', 'ES2020', 'ES2021', or 'ESNEXT'. */
+    "module": "commonjs",                           /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', 'es2020', or 'ESNext'. */
+    // "lib": [],                                   /* Specify library files to be included in the compilation. */
+    // "allowJs": true,                             /* Allow javascript files to be compiled. */
+    // "checkJs": true,                             /* Report errors in .js files. */
+    // "jsx": "preserve",                           /* Specify JSX code generation: 'preserve', 'react-native', 'react', 'react-jsx' or 'react-jsxdev'. */
+    // "declaration": true,                         /* Generates corresponding '.d.ts' file. */
+    // "declarationMap": true,                      /* Generates a sourcemap for each corresponding '.d.ts' file. */
+    // "sourceMap": true,                           /* Generates corresponding '.map' file. */
+    // "outFile": "./",                             /* Concatenate and emit output to single file. */
+    "outDir": "dist",                            /* Redirect output structure to the directory. */
+    // "rootDir": "./",                             /* Specify the root directory of input files. Use to control the output directory structure with --outDir. */
+    // "composite": true,                           /* Enable project compilation */
+    // "tsBuildInfoFile": "./",                     /* Specify file to store incremental compilation information */
+    // "removeComments": true,                      /* Do not emit comments to output. */
+    // "noEmit": true,                              /* Do not emit outputs. */
+    // "importHelpers": true,                       /* Import emit helpers from 'tslib'. */
+    // "downlevelIteration": true,                  /* Provide full support for iterables in 'for-of', spread, and destructuring when targeting 'ES5' or 'ES3'. */
+    // "isolatedModules": true,                     /* Transpile each file as a separate module (similar to 'ts.transpileModule'). */
+
+    /* Strict Type-Checking Options */
+    "strict": true,                                 /* Enable all strict type-checking options. */
+    // "noImplicitAny": true,                       /* Raise error on expressions and declarations with an implied 'any' type. */
+    // "strictNullChecks": true,                    /* Enable strict null checks. */
+    // "strictFunctionTypes": true,                 /* Enable strict checking of function types. */
+    // "strictBindCallApply": true,                 /* Enable strict 'bind', 'call', and 'apply' methods on functions. */
+    // "strictPropertyInitialization": true,        /* Enable strict checking of property initialization in classes. */
+    // "noImplicitThis": true,                      /* Raise error on 'this' expressions with an implied 'any' type. */
+    // "alwaysStrict": true,                        /* Parse in strict mode and emit "use strict" for each source file. */
+
+    /* Additional Checks */
+    // "noUnusedLocals": true,                      /* Report errors on unused locals. */
+    // "noUnusedParameters": true,                  /* Report errors on unused parameters. */
+    // "noImplicitReturns": true,                   /* Report error when not all code paths in function return a value. */
+    // "noFallthroughCasesInSwitch": true,          /* Report errors for fallthrough cases in switch statement. */
+    // "noUncheckedIndexedAccess": true,            /* Include 'undefined' in index signature results */
+    // "noImplicitOverride": true,                  /* Ensure overriding members in derived classes are marked with an 'override' modifier. */
+    // "noPropertyAccessFromIndexSignature": true,  /* Require undeclared properties from index signatures to use element accesses. */
+
+    /* Module Resolution Options */
+    // "moduleResolution": "node",                  /* Specify module resolution strategy: 'node' (Node.js) or 'classic' (TypeScript pre-1.6). */
+    // "baseUrl": "./",                             /* Base directory to resolve non-absolute module names. */
+    // "paths": {},                                 /* A series of entries which re-map imports to lookup locations relative to the 'baseUrl'. */
+    // "rootDirs": [],                              /* List of root folders whose combined content represents the structure of the project at runtime. */
+    // "typeRoots": [],                             /* List of folders to include type definitions from. */
+    // "types": [],                                 /* Type declaration files to be included in compilation. */
+    // "allowSyntheticDefaultImports": true,        /* Allow default imports from modules with no default export. This does not affect code emit, just typechecking. */
+    "esModuleInterop": true,                        /* Enables emit interoperability between CommonJS and ES Modules via creation of namespace objects for all imports. Implies 'allowSyntheticDefaultImports'. */
+    // "preserveSymlinks": true,                    /* Do not resolve the real path of symlinks. */
+    // "allowUmdGlobalAccess": true,                /* Allow accessing UMD globals from modules. */
+
+    /* Source Map Options */
+    // "sourceRoot": "",                            /* Specify the location where debugger should locate TypeScript files instead of source locations. */
+    // "mapRoot": "",                               /* Specify the location where debugger should locate map files instead of generated locations. */
+    // "inlineSourceMap": true,                     /* Emit a single file with source maps instead of having a separate file. */
+    // "inlineSources": true,                       /* Emit the source alongside the sourcemaps within a single file; requires '--inlineSourceMap' or '--sourceMap' to be set. */
+
+    /* Experimental Options */
+    "experimentalDecorators": true,                 /* Enables experimental support for ES7 decorators. */
+    // "emitDecoratorMetadata": true,               /* Enables experimental support for emitting type metadata for decorators. */
+
+    /* Advanced Options */
+    "skipLibCheck": true,                           /* Skip type checking of declaration files. */
+    "forceConsistentCasingInFileNames": true,       /* Disallow inconsistently-cased references to the same file. */
+    "resolveJsonModule": true                       /* Enabling the option allows importing JSON, and validating the types in that JSON file. */
+  },
+  "include": ["src/**/*"]
+}