opnAssist

About

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