Prebid Integration

Integrates Yaleo placements into Prebid.js using the yaleo bidder adapter from the official Prebid.js repository (v10+).

See Yaleo Bid Adapter for bidder params and integration details.

Server

js/apps/yaleo-bidder/server is an Express server that handles OpenRTB requests from Prebid.js. It fetches placement configuration and ads from Xandr, then serializes the result as pre-rendered HTML returned as a Prebid bid.

Client

js/apps/yaleo-bidder/client is injected into the pre-rendered HTML and hydrates the placement once it is rendered in the publisher page. It handles dynamic behavior: dispatching analytics events, adjusting the host iframe size, and applying parent page media queries to the iframe.

Dark Theme

Dark theme can be forced when the server renders the placement HTML:

1. Per ad unit — set forceDarkTheme: true in the yaleo bidder params.
2. Request-wide — set device.ext.darkmode: 1 on the OpenRTB request (via Prebid ortb2). The server maps this to dark theme for every placement that does not set forceDarkTheme.

Per-ad-unit forceDarkTheme takes precedence over device.ext.darkmode.

When neither is set, the hydrated client may still enable dark theme via publisher-specific detectors, and via prefers-color-scheme on known dark-theme sites.

See Yaleo Bid Adapter → Dark Theme for configuration examples.

Legacy

A Prebid.js adapter that runs all placement and ad fetching logic client-side, with rendering provided by https://cdn.adnz.co/yaleo/prebid.js (part of js/apps/yaleo).

Note

The bidder code is yaleo_legacy. Some publishers still use this adapter under the yaleo bidder code.

See Yaleo Legacy Bid Adapter for params.

See Migration from Legacy Adapter for migration steps.

Reasons for Creating a New Adapter

• Multi-ad placements were not supported. Prebid.js does not allow sequential requests within a single auction. For multi-ad placements, the placement configuration (which includes the number of ads) must be fetched first, followed by a separate ad request — a flow the legacy adapter could not support.
• Could not be published in the official Prebid.js repository. The adapter explicitly loaded an external JS script, which violates Prebid.js required adapter rules.
• Required redundant parameters. Publishers had to specify the Xandr tag ID explicitly, even though it is already part of the Yaleo placement configuration.