Programmatic Video Header Bidding Test Environment
Tick the SSPs to include in this auction. Each ticked bidder gets a synthetic bid request in phase 3; the highest mock CPM wins phases 4–7. Limelight is on by default.
| Field | Value |
|---|---|
| Bid Source Simulated = mock CPM. Real = live SSP auction. | |
| Content URL * | |
| GAM Base Tag * | |
| Prebid Timeout | |
| Prebid Cache URL * | |
| Mock Bid CPM | |
| Strategic Bias | On (+$0.05) |
| Floor Min ($) Reject bids below | Off |
| Floor Max ($) Cap bids above | Off |
Configure the auction, then generate a copy-paste embed tag for the publisher.
The ad tag, placement type, and pricing controls that drive the auction.
Tick the SSPs that should compete — the highest CPM wins the impression.
Limelight is on by default. Add others as your inventory expands.
All hb_* targeting keys emitted by the Bidding Player engine
| Key | Example Value | Source | GAM Line Item Use |
|---|---|---|---|
hb_pb |
2.50 |
Winning CPM, bucketed + biased | Target price-bucket line items. One line item per $0.10 step ($0.10–$30.00). |
hb_bidder |
appnexus |
Winning bidder code | Bidder-level reporting. Can target bidder-specific creatives. |
hb_uuid |
3b25cafe… |
Prebid Cache UUID | Required in VAST creative: …?uuid=%%PATTERN:hb_uuid%% |
hb_adid |
abc123ef |
Creative ID from bid response | Attribution and creative-level reporting in GAM. |
hb_size |
640x360 |
Measured player dimensions | Size-based line item targeting. |
hb_format |
video |
Always "video" for instream | Filter video-only line items from display line items. |
enableSendAllBids: true, Prebid emits a copy of five standard keys for every bidder that returned a bid — not just the winner. This lets you build per-bidder GAM line items (e.g. target hb_pb_appnexus = 2.50) and get bidder-level revenue attribution in GAM reports without custom scripting.
| Key Pattern | Example (AppNexus) | Description |
|---|---|---|
hb_pb_<bidder_code> |
hb_pb_appnexus = 2.50 |
Price bucket for this specific bidder |
hb_bidder_<bidder_code> |
hb_bidder_appnexus = appnexus |
Bidder code — useful for per-bidder creative targeting |
hb_adid_<bidder_code> |
hb_adid_appnexus = abc123 |
Creative ID for this bidder's ad |
hb_size_<bidder_code> |
hb_size_appnexus = 640x360 |
Player size from this bidder's response |
hb_uuid_<bidder_code> |
hb_uuid_appnexus = 3b25… |
Prebid cache UUID for this bidder's creative |
Your GAM header-bidding line items need a VAST wrapper creative that resolves the winning bid's cached ad. Paste this URL into the VAST tag URL field of your GAM creative:
https://prebid.adnxs.com/pbc/v1/cache?uuid=%%PATTERN:hb_uuid%%
%%PATTERN:hb_uuid%% is a GAM macro replaced at ad-serve time with the value of the hb_uuid key-value. If you override the Prebid cache URL in Hosting & CDN, update this creative URL to match.
Admin → Key-values → New. Type: Predefined. Create each key below:
Create one line item per $0.10 price step:
Prebid HB — $0.50Price Priority$0.50 CPM12 (above house, below direct)hb_pb = 0.50Repeat for $0.10 → $30.00 (300 line items). Use GAM's duplication feature or a setup script.
The VAST creative must include %%PATTERN:hb_uuid%%. Without the cache UUID macro, GAM cannot resolve the winning bidder's ad and the slot will be empty. One creative can be shared across all 300 line items.
Run a test in the Sandbox tab. Phase 5 shows the exact hb_pb value sent to GAM — verify it matches a line item you've set up. Phase 6 shows the full stitched ad tag URL with all key-values appended to cust_params.