Curator transparency questions to settle before a curated buy
Part of Curated deals and PMPs
The short answer
Before buying a curated deal, ask the curator to name who sells and who packages it, list the sites it includes and say whether that list can change, describe any data applied, state the fee type and amount, explain whether it appears in the SupplyChain object, and commit to delivery reporting by site. Get each answer in writing.
Key takeaways
- Three documents name the parties: the Deals API record, each exchange's sellers.json and the SupplyChain object in the bid request.
- A deal's site list is visible only if the curator shares it or the deal is static; an empty domain list means the deal may run on unspecified sites.
- The Deals API fee field says how a curator is paid, not how much, so the amount is a separate written question.
- In SupplyChain version 1.0 only companies in the payment flow appear as nodes, so a curator that handles no payment leaves no trace there.
What fields help distinguish the seller from a deal curator?
A curated deal can involve a publisher, an exchange, a company that sold the deal and a company that packaged it. Each is named in a different place, and no single file names them all. These are the fields a buyer can ask a curator to fill in, or read directly, to tell the roles apart, as defined in the IAB Tech Lab documents that set them.
| Field | Document | What it identifies |
|---|---|---|
| seller | Deals API, Deal object | The canonical domain of the business entity who sold the deal |
| curator | Deals API, Curation object | The canonical domain of the entity that packaged the inventory, technology or data |
| cdealid | Deals API, Curation object | The deal's identifier in the curator's own namespace |
| origin | Deals API, Deal object | The advertising system domain of the entity that will receive bid responses for the deal |
| name and domain | sellers.json, Seller object | The legal entity paid for inventory sold under a seller_id, and its business domain |
| seller_type | sellers.json, Seller object | Whether the account is PUBLISHER, INTERMEDIARY or BOTH |
| asi, sid and hp | SupplyChain object, each node | The selling system's domain, the seller account inside it, and whether the node handles payment |
Which questions should a buyer ask a curator?
The questions fall into six areas: identity, composition, data, fees, supply path and reporting. Ask them in one written request before the deal ID is accepted. A complete answer names a company, a domain, a number or a document; a vague answer, such as premium supply, is recorded as not answered.
| Area | Question | Evidence that answers it |
|---|---|---|
| Identity | Who sold, packaged and hosts this deal, by domain? | Deals API seller, curator and origin values, or the same domains in the confirmation |
| Composition | Which domains and apps can the deal deliver on today? | A dated domain and app list, or the Inventory object of a static deal |
| Change control | Can sites change after launch, and who approves it? | The dinventory value and a written notice period |
| Data | Is non-publisher data applied, and from which source? | The auxdata value and the provider's disclosure label |
| Fees | How is the curator paid, how much, and on what base? | The fee type plus the amount in the agreement |
| Supply path | Will the curator appear as a SupplyChain node? | A sample bid request with its schain |
| Reporting | Is delivery reported by site, with the external deal ID? | A sample report with site, exchange and deal ID columns |
Curator answers to have in hand before accepting the deal ID
- The seller, curator and origin are each named by domain, and the buyer knows which company signs the agreement.
- A dated list of included domains and apps has been received, or the curator has stated in writing that the deal is dynamic.
- The notice the buyer receives before sites are added or removed is written down, in days.
- The fee type, the fee amount and whether the fee comes out of the media price or is added to it are all stated.
- The buyer knows whether the curator appears in the SupplyChain object and, if so, under which seller account.
- Each answer of undisclosed is logged as undisclosed, with the date it was given.
How can a buyer see which sites a curated deal includes?
There are two views of a deal's sites: the planned list before launch and the delivered list after. The Deals API covers the first only for a static deal. Its Inventory object carries an array of site domains, and the specification says that "An empty list implies the deal may run across many unspecified site domain(s)." The dinventory field says whether inventory is fixed once the deal goes live or updated dynamically; a dynamic deal leaves the buyer relying on delivery reporting.
Delivery reporting has gaps too. Display & Video 360's inventory transparency guide (opens in a new tab) says inventory is anonymous when the bid request "includes the publisher's name, but not the URL," and semi-transparent when it "includes the channel and publisher's name." It advises excluding the Non-Reportable Sites and Apps channel in Apps and URLs targeting.
Four steps to see a curated deal's sites
- Ask for the planned list with a date. Request each domain and app the deal can deliver on, in a file the buyer can compare line by line.
- Check how the deal is marked. Ask for the dinventory value, so the buyer knows whether the list is fixed or can move during the flight.
- Exclude unnamed inventory where the platform allows it. In Display & Video 360, exclude the Non-Reportable Sites and Apps channel on the line items that buy the deal.
- Compare delivery with the plan. Run a report by App/URL for the deal and list each delivered site that is missing from the planned list.
What should a curator disclose about fees?
The Deals API gives a curator one fee field, and it describes the kind of fee, not its size. The values are 0 for undisclosed, 1 for a percentage of spend, 2 for a flat fee, 3 for CPM, and 4 when no fee is paid for curation services. A 3 tells the buyer the curator charges per thousand impressions, but not the rate, its base or who pays it.
| Fee type value | Meaning in the Deals API | Follow up question |
|---|---|---|
| 0 | Undisclosed | Will the agreement state the fee anyway? |
| 1 | Percentage of spend | A percentage of the bid, the clearing price or the publisher's payout? |
| 2 | Flat fee | For what period, and billed separately or inside the media price? |
| 3 | CPM | What rate, and added to the bid or taken from the publisher's share? |
| 4 | No fee is paid for curation services | Is the curator paid another way, such as a data fee? |
How does a curator appear in the supply chain?
The published SupplyChain object (opens in a new tab) says the chain of nodes "represents all entities who are involved in the direct flow of payment for inventory," and that for version 1.0 the hp property "should always be 1." So a curator that packages a deal but is not paid through the bid stream has no node of its own. A curator that resells the inventory is in the payment flow, and the specification says a reseller should copy the existing object, keep its complete value and add its own node to the end of the nodes array.
Draft guidance for version 1.1 on the development branch of IAB Tech Lab's Supply Chain Validation repository (opens in a new tab) adds nodes with hp set to 0 for entities that handle the request but not the payment, and says buyers' validation logic "should skip hp=0 nodes." It is development guidance, so ask the curator which version its requests carry.
Use sellers.json (opens in a new tab) to put a name to each node. Its name field is "the name of the company (the legal entity) that is paid for inventory that is transacted under the given seller_id." Our SupplyChain object guide covers reading each node.
What should a curator say about audience data?
When a curated deal adds audience segments, IAB Tech Lab's Data Transparency Standard 1.1 (opens in a new tab) names the questions. Its disclosure fields include Data Source(s), Data Inclusion Methodology (observed or known, declared, inferred, derived or modeled), Audience Expansion, Audience Refresh Cadence, Source Lookback Window and Geography. Ask the curator for that label for each segment in the deal.
For Canadian buys, the Office of the Privacy Commissioner's guidelines on online behavioural advertising (opens in a new tab), modified August 11, 2025, say people must be told about the various parties involved, and that an opt-out "takes effect immediately and is persistent." A curator that adds behavioral data is one of those parties. A deal built only from a reviewed site list raises none of these questions.
What do curator questions look like on a real brief?
Fictional example
An Alaska motorcycle dealer questions a curated deal
An unnamed motorcycle dealership with stores in Anchorage, Fairbanks and Juneau wants display beside motorcycle news, commuting and local news content in Alaska, in English, priced in USD. A curator offers a curated private auction built around motor vehicle content.
The agency sends the six area questions. The curator names itself as curator, a sales partner as seller and an exchange as origin, shares a dated list of 41 domains, marks the deal static and applies no outside data. It gives the fee type as CPM and, when asked again, the rate. Its sample request shows the exchange as the only payment node.
The planner removes three domains that are not on the client's approved list. The trader excludes non-reportable inventory and books a report by App/URL for week one. Each answer is filed with the deal ID.
How does PlacementGraph help check a curator's site list?
Frequently asked questions
Is a curator the same as a reseller?
Not always. A curator packages inventory, technology or data into a deal. It becomes a reseller in the supply chain only if it is paid for the inventory and passes it on, in which case SupplyChain version 1.0 expects it to append its own node. A curator paid by a separate fee outside the bid stream holds no node.
What should a buyer do when a curator answers undisclosed?
Record it as given, with the date, and decide whether the buy can go ahead without that fact. An undisclosed site list can be offset by delivery reporting by site; an undisclosed fee cannot be checked from the bid stream at all.
Does a curator need its own sellers.json entry?
sellers.json lists the seller accounts of one advertising system, and its name field is the legal entity paid for inventory under each seller ID. A curator that is never paid through that system may have no entry there. Draft SupplyChain 1.1 guidance strongly recommends sellers.json entries for entities that handle requests without handling payment.
Are curator questions different for a Canadian buy?
The identity, fee, site and supply path questions are the same. Canadian buys add two: prices and fees stated in CAD or USD explicitly, and, where the deal uses behavioral data, how the curator meets the privacy commissioner's guidance on informing people about the parties involved and honoring opt-outs.
Sources
- Deals API Specification v1.0 (opens in a new tab)IAB Tech Lab, February 6, 2026
- sellers.json specification (opens in a new tab)IAB Tech Lab, Supply Chain Validation repository
- SupplyChain object (opens in a new tab)IAB Tech Lab, OpenRTB repository
- Implementation Guidance (development branch, SupplyChain 1.1) (opens in a new tab)IAB Tech Lab, Supply Chain Validation repository
- Inventory transparency (opens in a new tab)Google, Display & Video 360 Help
- Data Transparency Standard 1.1 (opens in a new tab)IAB Tech Lab
- Guidelines on privacy and online behavioural advertising (opens in a new tab)Office of the Privacy Commissioner of Canada, modified August 11, 2025
Researched and written by PlacementGraph Research. Read how we research, source and update these pages. Corrections: diana@placementgraph.com.