Polymarket Commission Email Filter - Google Apps Script

/*
Polymarket Commission Email Filter - Google Apps Script

Archives matching commission emails strictly below LIMIT_DOLLARS.
The default threshold is $10; change it to your preferred amount.
Messages remain available in Gmail's All Mail.

SETUP
1. Create a project at https://script.google.com/ and paste this code into Code.gs.
2. Set LIMIT_DOLLARS to your preferred threshold.
3. In the editor, go to Services > + > Gmail API > Add.
4. Run archiveSmallCommissions once and authorize Gmail access.
5. Go to Triggers > Add Trigger, select archiveSmallCommissions,
   choose Time-driven, and set your preferred schedule.
6. If you use a standard Google Cloud project, also enable the Gmail API
   in that project's Google Cloud console.
*/

const LIMIT_DOLLARS = 10;
const DUB_SENDER = '[email protected]';

function archiveSmallCommissions() {
  const lock = LockService.getScriptLock();
  if (!lock.tryLock(1000)) return;

  try {
    // Collect messages first, then archive them:
    // this prevents inbox changes from affecting pagination.
    const messageIds = [];
    let pageToken;

    do {
      const options = {
        q: `in:inbox from:${DUB_SENDER} subject:commission subject:Polymarket`,
        maxResults: 500
      };
      if (pageToken) options.pageToken = pageToken;

      const page = Gmail.Users.Messages.list('me', options);
      for (const message of page.messages || []) {
        messageIds.push(message.id);
      }
      pageToken = page.nextPageToken;
    } while (pageToken);

    let archived = 0;

    for (const id of messageIds) {
      const message = Gmail.Users.Messages.get('me', id, {
        format: 'metadata',
        metadataHeaders: ['Subject', 'From']
      });

      if (!(message.labelIds || []).includes('INBOX')) continue;

      const headers = message.payload.headers || [];
      const getHeader = name =>
        (headers.find(h => h.name.toLowerCase() === name) || {}).value || '';

      // Double-check the sender's exact email address.
      const from = getHeader('from').trim();
      const address = (from.match(/<([^<>]+)>/) || [null, from])[1];
      if (address.trim().toLowerCase() !== DUB_SENDER) continue;

      // Read only the commission amount from the subject,
      // not the purchase amount from the message body.
      const subject = getHeader('subject').trim();
      const match = subject.match(
        /^You['’]ve made a \$([0-9]+(?:,[0-9]{3})*)(?:\.([0-9]{2}))? commission from Polymarket$/i
      );

      // Leave messages with unrecognized subjects unchanged.
      if (!match) continue;

      const cents =
        Number(match[1].replace(/,/g, '')) * 100 +
        Number(match[2] || '0');

      if (!Number.isSafeInteger(cents)) continue;

      if (cents < LIMIT_DOLLARS * 100) {
        // Removing the INBOX label archives the message.
        Gmail.Users.Messages.modify(
          { removeLabelIds: ['INBOX'] },
          'me',
          id
        );
        archived++;
      }
    }

    console.log(`Messages archived: ${archived}`);
  } finally {
    lock.releaseLock();
  }
}