Weld Scraper — Google Sheets Add-on

A Google Sheets add-on that lets users trigger Weld scrapers and write results directly into spreadsheets.

Setup

Prerequisites

• clasp installed globally: npm install -g @google/clasp
• A Google account with Apps Script access
• A Weld API key (from the Weld dashboard → Settings → API Keys)

Development

1. Login to clasp:

   clasp login
   

2. Create a new Apps Script project (bound to a test spreadsheet):

   cd packages/sheets-plugin
   clasp create --type sheets --title "Weld Scraper Dev"
   

   This updates .clasp.json with your script ID.

3. Push code to Google:

   clasp push
   

4. Open the script editor (to verify):

   clasp open
   

5. Test in a spreadsheet:

   • Open the spreadsheet bound to the script
   • Refresh the page — a "Weld" menu appears
   • Click Weld → Open Sidebar

Watch mode

clasp push --watch

Automatically pushes on file changes.

Architecture

src/
├── Code.gs           # Menu, onOpen, sidebar launchers
├── Auth.gs           # API key storage & validation
├── Api.gs            # Weld REST API client (UrlFetchApp)
├── SheetWriter.gs    # Write scrape results to sheet tabs
├── Sidebar.html      # Main sidebar UI (scrape form, progress, results)
└── Setup.html        # Settings/API key configuration screen

How it works

1. User opens the sidebar and enters their Weld API key
2. User selects a scraper, pastes URLs (or loads from selected cells)
3. Clicking "Start Scrape" calls POST /api/jobs/create via UrlFetchApp
4. The sidebar polls GET /api/jobs/get every 4 seconds (client-side polling avoids the 6-minute GAS execution limit)
5. On completion, SheetWriter.gs fetches results and writes them to a new sheet tab

API endpoints used

Method	Endpoint	Purpose
GET	/api/scrapers	List available scrapers
POST	/api/jobs/create	Create a scrape job
GET	/api/jobs/get	Poll job status
GET	/api/jobs/results	Fetch completed results
GET	/api/jobs	List job history
GET	/api/credits/balance	Show credit balance

Publishing

To publish to the Google Workspace Marketplace:

1. Create a standard GCP project
2. Switch the Apps Script project to use it
3. Enable the Marketplace SDK
4. Configure OAuth consent screen
5. Create a versioned deployment in Apps Script
6. Submit for Google review

See Google's publishing guide for details.

Scopes

The add-on requires these minimal OAuth scopes:

• spreadsheets.currentonly — Read/write only the current spreadsheet
• script.external_request — Make HTTP requests to the Weld API