reMarkable to Notion Sync

remarkableNotionSync.gs

const GMAIL_LABEL_NAME = 'NotionToSync';
const SYNCED_LABEL = 'SyncedToNotion';

// if you set this, the attachments will be copied over to google drive and the links added to the notion page
const GDRIVE_FOLDER_ID = '';

const gmailToNotion = () => {
  const label = GmailApp.getUserLabelByName(GMAIL_LABEL_NAME);
  const successLabel = GmailApp.getUserLabelByName(SYNCED_LABEL);
  label.getThreads(0, 20).forEach((thread) => {
    const [message] = thread.getMessages().reverse();
    postToNotion(message);
    thread.removeLabel(label);
    thread.addLabel(successLabel)
  });
};

function getRichTextChunks(messageBody) {
  let remainingString = messageBody;
  const content = [];
  while (remainingString.length > 0) {
    // https://developers.notion.com/reference/request-limits#limits-for-property-values
    if (remainingString.length <= 2000) {
      content.push(getRichTextObjectForChunk(remainingString));
      remainingString = '';
    } else {
      const maximalChunk = remainingString.substring(0, 2000);
      const lastLineBreakInChunk = maximalChunk.lastIndexOf('\n');
      const actualChunk = remainingString.substring(0, lastLineBreakInChunk);
      content.push(getRichTextObjectForChunk(actualChunk));
      remainingString = remainingString.substring(lastLineBreakInChunk + 1);
    }
  }
  return content;
}

function getRichTextObjectForChunk(messageChunk) {
  return {
    type: 'text',
    text: {
      content: messageChunk
    },
  }
}

function getPdfBlocksForAttachments(message) {
  var attachments = message.getAttachments();
  var pdfBlocks = [];
  for (var k = 0; k < attachments.length; k++) {
    Logger.log('Message contains the attachment "%s" (%s bytes)', attachments[k].getName(), attachments[k].getSize());
    var folder = DriveApp.getFolderById(GDRIVE_FOLDER_ID);
    var ts = Utilities.formatDate(new Date(), Session.getScriptTimeZone(), "yyMMddHHmmss");
    var createdFile = folder.createFile(attachments[k].copyBlob()).setName(attachments[k].getName() + ts);
    pdfBlocks.push({
      "object": "block",
      "type": "paragraph",
      "paragraph": {
        "rich_text": [
          {
            "type": "text",
            "text": {
              "content": attachments[k].getName(),
              "link": {
                "url": createdFile.getUrl()
              }
            },
            "annotations": {
              "bold": false,
              "italic": false,
              "strikethrough": false,
              "underline": false,
              "code": false,
              "color": "default"
            },
            "plain_text": attachments[k].getName(),
            "href": createdFile.getUrl()
          }
        ],
        "color": "default"
      }
    })
  }
}

function postToNotion(message) {
  const richTextChunks = getRichTextChunks(message.getPlainBody());
  const pdfBlocks = GDRIVE_FOLDER_ID ? getPdfBlocksForAttachments(message) : [];
  const url = 'https://api.notion.com/v1/pages';
  const body = {
    parent: {
      type: "database_id",
      database_id: "<Your Target Notion Database Id>",
    },
    icon: {
      type: "emoji",
      emoji: "📝"
    },
    children: [
      ...pdfBlocks,
      {
        object: 'block',
        type: 'paragraph',
        paragraph: {
          rich_text: richTextChunks,
        },
      }
    ],
    properties: {
      Name: {
        title: [
          {
            text: {
              content: message.getSubject(),
            },
          },
        ],
      }
    }
  }

  UrlFetchApp.fetch(url, {
    method: 'post',
    contentType: "application/json",
    muteHttpExceptions: false,
    headers: {
      Authorization: `Bearer <Your Notion Secret>`,
      'Notion-Version': '2022-02-22'
    },
    payload: JSON.stringify(body)
  });
}

I've created an updated fork that is working with pdfs, pngs and svgs uploaded directly into Notion
https://gist.github.com/powmod/f248ab6147d0664a96da5e448e0622eb