opnAssist

The ad operations toolkit for publishers. Manage ads.txt, compare SSP coverage, and inspect Prebid.js header bidding — all in one extension.

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Two tools, one extension

Built for publishers, ad ops teams, and programmatic professionals who need to keep ads.txt files in check and debug Prebid.js integrations.

ads.txt Manager

  • Create and manage SSP groups organized by exchange — Google, Index Exchange, PubMatic, Magnite, and 30+ others
  • Import ads.txt from local files with automatic grouping by exchange domain
  • Import directly from a Google Drive shared link — maintain one master file and sync with a single click
  • Drive files use # comment lines as group separators, keeping your file human-readable and structured
  • Fetch any site's live ads.txt by domain and instantly compare against your saved groups
  • Per-group match percentages and an overall coverage meter show exactly what's missing

Prebid.js Inspector

  • Auto-detects all Prebid.js instances including custom namespaces (pbjs, tv_pbjs, owpbjs, and more)
  • Works across all frames: top-level, same-origin iframes, SafeFrames, and about:blank frames
  • Real-time auction monitoring — see every auction, bid, no-bid, winner, and render as they happen
  • Sortable bid table with CPM, response time, size, and status (bid / no-bid / won)
  • Ad unit listing with sizes (banner, video, native) and configured bidders
  • Historical event replay — opens after auctions? No problem, past events are replayed automatically

Google Drive Sync

  • Link a public Google Drive text file containing your master ads.txt
  • Re-sync with one click to pull the latest version
  • Drive-imported groups are tagged and replaced on sync — manual groups stay untouched
  • Unlink at any time to go back to manual management
  • No OAuth required — works with any publicly shared Drive file

Built for Ad Ops

  • Manifest V3 — modern, secure, no persistent background pages
  • All code runs locally — no external servers, no data collection, no analytics
  • Works with any Prebid.js version (1.x through 9.x+)
  • Popup for quick access, plus a DevTools panel for always-on monitoring
  • Lightweight — does not modify page content or inject ads

Permissions explained

Every permission has a specific purpose. opnAssist requests only what it needs.

Permission Why it's needed
activeTab Read the current page URL to auto-fill the domain field for ads.txt comparison
storage Save your SSP groups and Drive sync settings locally on your device
tabs Detect the active tab and communicate with content scripts for Prebid detection
scripting Inject Prebid.js detection scripts into page frames
webNavigation Detect dynamically-created iframes so Prebid scanning covers late-loaded frames
Host: ads.txt URLs Fetch live ads.txt files from any domain you enter for comparison
Host: Google ad domains Inject detection scripts into GAM SafeFrame and ad-serving iframes
Host: drive.google.com Fetch your shared ads.txt file from Google Drive for import and sync