Prebid Server

Prebid Server is the open-source server-side header bidding application maintained by Prebid.org that receives an auction request from a web page, app, AMP page or CTV player, fans it out to bid adapters over OpenRTB, and returns the bids to the caller.

It exists in two implementations, Go and Java, and can be run by the publisher ("Do-It-Yourself") or by a Prebid.org member company as a hosted service; Prebid.org warns that self-hosting "is much harder than setting up Prebid.js" (Prebid.org, Prebid Server overview). All code and documentation on the Prebid site are released under the Apache License. Over 230 server-side bid adapters are available (Prebid.org).

For a publisher, running Prebid Server means owning the auction log, the timeouts, the consent handling and the cookie-sync behavior, and paying for the servers. It also means being the host of record for the schain node that SupplyChain v1.1 will require of wrappers and ad servers (IAB Tech Lab, 23 June 2026). AdCP's reference sell-side implementation is also maintained by the Prebid community (adcontextprotocol/adcp on GitHub), which is why Prebid Server operators will be among the first to see agentic demand.

Example of a stored request fragment (Prebid Server JSON):

{ "id": "req-1", "imp": [{ "id": "1", "banner": { "format": [{ "w": 300, "h": 250 }] },
  "ext": { "prebid": { "bidder": { "sspA": { "placementId": 123 } } } } }],
  "tmax": 800, "regs": { "gdpr": 1 }, "user": { "consent": "CP..." } }

Related: header bidding, OpenRTB, timeout, SupplyChain object.

Source: Prebid.org, Prebid Server documentation.

1. Prebid.org
2. IAB Tech Lab, 23 June 2026
3. adcontextprotocol/adcp on GitHub