Understanding the Prebid Reconciliation SDK Module: Enhanced Impression Transparency for Publishers

As advertising supply chains become more complex, publishers face mounting challenges in reconciling who saw an ad, where, and when. Fragmented log files between ad servers, SSPs, DSPs, and measurement vendors often lead to discrepancies, lost revenue, and time-consuming audits.

Prebid’s Reconciliation SDK Module addresses this problem by standardizing impression data collection and enabling cross-system match-ups. Understanding how this module works — and how to configure it — can help ensure your reporting is accurate and your monetization is optimized.

What Is the Prebid Reconciliation SDK Module?

The Reconciliation SDK Module is an extension for Prebid.js that collects detailed impression and supply chain data and reports it to a central Reconciliation Service. This data sharing enables log-level reconciliation across publishers, SSPs, DSPs, and advertisers, making it much easier to align revenue numbers and ad delivery stats across platforms.

The module was developed in response to industry demand for transparency and was piloted as part of a broader initiative using Distributed Ledger Technology (DLT), aimed at building trust in digital advertising.

How Does Reconciliation Work in Practice?

Once implemented, the module appends impression-specific identifiers and supply chain information to each ad slot. When an ad is served, these details are captured and shared, allowing you (and your partners) to compare log files on a per-impression basis. This greatly reduces the guesswork involved in resolving reporting mismatches between ad server logs and what demand partners claim to have served or paid for.

Configuring the Reconciliation SDK in Prebid.js

Integrating the Reconciliation SDK module requires both a build-time and run-time step. First, you must include the reconciliation module when building your Prebid.js package. Then, you configure the module in your Prebid setup via the realTimeData.dataProviders array.

Build and Configuration Example

To include the module in your build, use the following Gulp command:

gulp build –modules=reconciliationRtdProvider

At runtime, configure the module like so:

pbjs.setConfig({
realTimeData: {
dataProviders: [{
name: ‘reconciliation’,
params: {
publisherMemberId: ‘your_unique_publisher_id’,
allowAccess: true // Optional, defaults to false
}
}]
}
});

– Set publisherMemberId to your unique identifier (required).
– allowAccess should be enabled only if you want to allow advertisers’ Reconciliation Tags access to your ad unit IDs.

What Data Does the Module Output?

For each ad slot, the module generates custom targeting values that make each impression uniquely traceable throughout the supply chain. These values are then available for downstream reporting, debugging, and reconciliation — both on your end and for demand partners.

Real-World Output Example

Suppose you have two ad units, slotA and slotB. The module will output objects like:

{
‘slotA’: {
‘RSDK_AUID’: ‘/slotA-Unit’,
‘RSDK_ADID’: ‘b5bbc103-00e9-499d-9637-bdba05b65427’
},
‘slotB’: {
‘RSDK_AUID’: ‘/slotB-Unit’,
‘RSDK_ADID’: ‘325da95e-e37d-45fa-a46f-8ff91168b121’
}
}

Here, RSDK_AUID traces back to your ad slot, while RSDK_ADID is a unique impression ID. Matching on these allows cross-system reconciliation in complex header bidding environments, where multiple SSPs and partners are involved.

What this means for publishers

Enabling the Reconciliation SDK module arms your ad ops and tech teams with detailed, impression-level transparency. This not only streamlines partner audits and log-level troubleshooting but can help quickly resolve disputes around discrepancies. With supply chains under increasing regulatory and brand scrutiny, publishers who can prove alignment between their reporting and third parties’ logs will be in a stronger position during revenue negotiations and compliance checks.

Practical takeaway

For most publishers, the biggest pain point in header bidding is the lack of consistent, reconcilable data across partners and platforms. By enabling the Prebid Reconciliation SDK Module, you position your team to operate with greater clarity, speed, and efficiency.

Action steps:
– Ensure your Prebid.js build includes the reconciliation module
– Assign a unique publisherMemberId and carefully set allowAccess as needed
– Use the module output to check impression matching across your ad server, SSP, and partner logs

Implementing this module is a relatively small lift with potentially outsized gains in data transparency, troubleshooting, and revenue assurance.