Last updated: 13 October 2026

OpenProposal is an IAB Tech Lab specification that standardises how publishers define advertising products and packages and represent them in RFP responses. It is part of AAMP 3.0, IAB Tech Lab's framework for agentic advertising. The problem it addresses is simple to state: a buyer agent cannot compare offers it cannot read, and today every publisher describes its inventory differently. A standard description lets a buyer agent compare responses from different sellers without translating each one.

TL;DR. OpenProposal is one component of AAMP, the Agentic Advertising Management Protocols, published by IAB Tech Lab as open source on GitHub. It gives publishers a standard way to describe products and packages and to respond to RFPs, so buyer agents can evaluate offers in one format. Whatever the exact schema, an offer an agent can evaluate has to state the inventory, the format, the audience, the pricing terms, the flight and the measurement basis. The field names and required properties are defined in the specification itself, which publishers should read before building to it. A clear product description is also the first line of defence in a dispute, because delivery is judged against what was described.

What is OpenProposal?

OpenProposal is the part of IAB Tech Lab's AAMP framework that deals with the sell-side description of what is for sale. According to IAB Tech Lab, it standardises how publishers define advertising products and packages and how they represent them in responses to requests for proposals. IAB Tech Lab describes it as part of AAMP 3.0.

AAMP itself is a set of separately versioned components announced in early 2026, covering agent communication and orchestration, reference buyer and seller agents, agent discovery, agent services inside host platforms and audiences. OpenProposal sits upstream of the deal. Before a buyer agent negotiates or executes anything through the Deals API, it needs to know what each publisher is offering, and OpenProposal is the component that gives that offer a common shape.

Why do publishers need a standard way to describe products to agents?

Publishers describe their inventory in many forms today: rate cards, media kits, spreadsheets, slide decks and RFP responses written to each agency's template. Each publisher names its products differently, groups them differently and states terms in a different order. A human planner translates all of that by reading it. A buyer agent working across dozens of sellers either has to guess at that translation or ask a person to do it, and both defeat the point of using an agent.

A standard description removes the translation step. If every publisher states its products and packages in the same structure, a buyer agent can line up responses side by side and compare like with like. The same structure helps the publisher: a seller agent can answer an RFP from a catalogue it already maintains rather than from a fresh document each time.

What is the difference between a product and a package?

In common industry usage, a product is a defined unit of inventory a publisher sells: a placement, a format in a particular environment, or a sponsorship. A package is a bundle of products sold together under combined terms, such as a homepage takeover combined with run-of-section display for the same flight.

The distinction matters to an agent because terms can attach at either level. A package price may only apply if every component is bought, and a package may carry delivery commitments that no single product carries on its own. OpenProposal's own definitions of products and packages are in the specification, and an implementer should take them from there rather than from this summary.

What does a product or package description need to state for an agent to evaluate it?

The six elements below are practical guidance on what any machine-readable offer needs to make clear. It is not the OpenProposal schema field list, which is published in the specification on GitHub.

Inventory. Where the ad will run: the site, app or channel, the section or placement, and whether the volume is guaranteed or offered on a non-guaranteed basis. An agent cannot weigh an offer against its mandate if the environment is vague.

Format. What will be served: the ad format, sizes or durations, and the creative specifications the buyer must meet. A mismatch here is found at trafficking, which is late and expensive.

Audience. Who the inventory reaches and how that audience is defined: contextually, from the publisher's first-party data, or from a third-party segment. Where targeting relies on personal data, the basis for processing it has to be established before the campaign runs, and the description should make the data source clear.

Pricing terms. The price, the pricing basis, the currency, what the price includes, and the deal type it applies to. AAMP's support for the Deals API covers programmatic guaranteed, preferred deals, private marketplaces, the open marketplace and linear GRPs, according to IAB Tech Lab, so the deal type is a term an agent needs stated, not inferred.

Flight. Start and end dates, pacing expectations, booking lead time and the conditions under which the buyer or seller can change or cancel the booking.

Measurement. How delivery will be counted, which viewability definition applies, which verification vendor if any, how often reporting arrives and what happens if delivery falls short. The MRC's viewable impression guidelines, published in 2014, give a common baseline, but an offer still has to say which threshold it commits to.

Why does measurement belong in the proposal and not after the deal?

Measurement terms written into the offer are terms both sides can be held to. Terms left until after the deal are terms each side interprets for itself. Evidence from agent negotiation suggests the gap is real: in Concourse Bench v1, a controlled benchmark of AI buyers negotiating with automated sellers, 95 of the 110 contracts signed in completed buys promised a viewability floor below 70%. A completed buy and a well-protected buy are not the same thing.

A standard proposal format makes measurement terms visible and comparable. It does not, by itself, make a buyer agent insist on them. That depends on the mandate the buyer sets.

What happens to a proposal once both sides agree?

OpenProposal covers how an offer is described and how an RFP response is represented. Once a buyer and seller agree terms, the question shifts from "what was offered?" to "what was agreed, and does each side hold the same version?". Delivery disputes, makegoods and settlement are judged against that agreed record, and the proposal is only its starting point.

Alkimi, an agentic advertising marketplace, works within IAB Tech Lab's AAMP framework and addresses that second question: buy-side and sell-side agents agree terms on a shared DealSheet that both parties hold, with humans keeping approval rights at the deal level.

Frequently asked questions

Who publishes OpenProposal?

IAB Tech Lab publishes OpenProposal as part of AAMP, its Agentic Advertising Management Protocols. The specification is open source on GitHub.

Is OpenProposal part of AAMP?

Yes. IAB Tech Lab describes OpenProposal as part of AAMP 3.0, alongside components for agent communication, reference buyer and seller agents, agent discovery and audiences.

What does OpenProposal standardise?

How publishers define advertising products and packages and represent them in RFP responses, so a buyer agent can compare offers from different sellers in one format.

Does OpenProposal replace the Deals API?

No. OpenProposal describes what a publisher is offering before a deal is struck. AAMP's support for the Deals API covers the deal types under which the agreed buy then runs.

What should a publisher do first to prepare for OpenProposal?

Read the specification on GitHub, then audit the existing product catalogue for gaps: any product whose inventory, format, audience, pricing terms, flight or measurement basis is unstated will be hard for a buyer agent to evaluate.

What Is OpenProposal? How Do Publishers Describe Products and Packages to Buyer Agents?