opnAssist

ads.txt Manager & Prebid Inspector

opnAssist is an ad operations toolkit built for publishers, ad ops teams, and programmatic advertising professionals. It combines two essential tools into one lightweight extension: an ads.txt Manager and a real-time Prebid.js Inspector. --- ads.txt Manager --- Keep your ads.txt file organized, up to date, and verified across all your properties. SSP Group Management - Create and manage SSP groups to organize your authorized sellers by exchange (Google, Index Exchange, PubMatic, Magnite, and 30+ others) - Import ads.txt entries from local files with automatic grouping by exchange domain - Import directly from a Google Drive shared link — maintain one master ads.txt file and sync it across your workflow with a single click - Google Drive files are parsed using # comment lines as group separators, so your file stays human-readable while being structured for the tool - Manually add, edit, or delete individual groups at any time ads.txt Compare & Diff - Fetch any site's live ads.txt by entering a domain name - Or upload a local ads.txt file for offline comparison - Instantly compare the live file against your saved SSP groups - See per-group match percentages — quickly spot which exchanges are missing entries - Overall coverage meter shows your total match rate at a glance - Each entry is marked as found or missing so you know exactly what to add 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 — your manually-added groups remain untouched - Unlink at any time to go back to manual management --- Prebid.js Inspector --- Monitor Prebid.js header bidding activity in real time, directly from the extension popup or DevTools panel. Namespace Detection - Automatically detects all Prebid.js instances on the page, including custom namespaces (pbjs, tv_pbjs, owpbjs, and more) - Works across all frames: top-level pages, same-origin iframes, SafeFrame containers, and dynamically-created about:blank frames - Scans _pbjsGlobals, well-known Prebid variable names, and window properties - Filter data by namespace when multiple Prebid instances are present Ad Units - Lists all registered Prebid ad units with their sizes (banner, video, native) and configured bidders - Shows bidder parameters for each ad unit - Filter by frame to see which ad units belong to which iframe Auctions - Real-time auction monitoring: see every auction as it happens - Auction cards show ad unit codes, timeout, bid count, no-bid count, unique bidders, top CPM, and winner - Expand any auction to see the full bidder-by-bidder breakdown - Duration tracking shows how long each auction took Bids - Sortable table of all bid responses across all auctions - Columns: bidder, ad unit, CPM, size, response time, and status (bid/nobid/won) - Won bids are highlighted and always sorted to the top - Sort by any column to find your highest CPMs, slowest bidders, or most active ad units Renders - Track when ads actually render on the page - See which bidder won, the winning CPM, creative size, and render timestamp - Confirms that winning bids are actually being displayed Frame Awareness - Every data point is tagged with its source frame - Filter by frame to isolate Prebid activity in specific iframes - Useful for sites with multiple Prebid instances in different frames (e.g., a page Prebid and a video player Prebid) Historical Replay - Opens the popup after auctions have already run? No problem — opnAssist replays historical events from Prebid's event log - Captures data from the moment the page loads, not just from when you opened the extension --- Technical Details --- - Manifest V3 extension — modern, secure, no background pages - All code runs locally — no external servers, no data collection, no analytics - Works on any website with Prebid.js, regardless of Prebid version (supports Prebid 1.x through 9.x+) - Lightweight: does not modify page content or inject ads - DevTools panel available for always-on monitoring alongside the popup --- Who is this for? --- - Publishers managing ads.txt across multiple domains - Ad ops teams verifying SSP configurations - Programmatic consultants auditing client setups - Header bidding engineers debugging Prebid.js integrations - Anyone who needs to quickly check if an ads.txt file is complete and which bidders are active on a page --- Permissions Explained --- - activeTab: Read the current page URL for domain detection - storage: Save your SSP groups and Drive sync settings locally - tabs: Detect the current page and communicate with content scripts - scripting: Inject Prebid detection scripts into page frames - webNavigation: Detect new iframes for Prebid scanning - Host permissions for doubleclick.net, googlesyndication.com, googleadservices.com: Inject detection scripts into GAM ad frames - Host permission for drive.google.com: Fetch your shared ads.txt file from Google Drive - Host permissions for ads.txt URLs: Fetch live ads.txt files for comparison