Wallet Activity

This recipe will show an example application that indexes wallet activity from a ERC-20 Token Contract. The activity we are interested in is when a wallet transfers tokens.

Prerequisites

A Convect account
A Convect project & function
An ERC-20 Token Contract Address

Drizzle Schema

This example will use Drizzle to manage database operations. Feel free to use a different ORM or database.

src/db/schema.ts

import {integer, pgTable, serial, text, unique} from 'drizzle-orm/pg-core';

export const activity = pgTable(
  'activity',
  {
    id: serial('id').primaryKey(),
    from: text('from').notNull(),
    to: text('to').notNull(),
    value: integer('token_id').notNull(),
    transactionHash: text('transaction_hash').notNull(),
    type: text('type', {enum: ['TRANSFER']}).notNull(),
  },
  t => [unique().on(t.transactionHash, t.type)],
);

Convect Function

Export the Convect Function from the file.

src/[project-name]/[function-name].ts

import {convect, ethSepolia, log, transaction} from 'convect-xyz';
import {db} from '../db';
import {activity} from '../db/schema';

const transferHandler = transaction({
  name: 'transfer',
  chains: [ethSepolia],
  logs: [
    log({
      origin: '0x0000000000000000000000000000000000000000',
      signature:
        'event Transfer(address indexed from, address indexed to, uint256 value)',
    }),
  ],
  handler: async transactions => {
    const records = transactions.flatMap(tx => tx.logs);

    await db
      .insert(activity)
      .values(
        records.map(log => ({
          from: log.args.from,
          to: log.args.to,
          value: Number(log.args.value),
          transactionHash: log.transactionHash,
          type: 'TRANSFER' as const,
        })),
      )
      .onConflictDoNothing();
  },
});

export default convect({
  handlers: [transferHandler],
});

Deploy the Function

Deploy the function to Convect. It will output a deployment URL for you to make some final configuration changes if needed and approve the deployment.

npx convect deploy -s [project-name]/[function-name]

Wallet Activity

Prerequisites

Drizzle Schema

Convect Function

Deploy the Function

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