Programmatic advertising is shifting from prices won in auctions towards terms agreed in negotiation, but the shift is uneven and easy to overstate. A buyer does not need to take it on trust. Five indicators show whether it is happening in a given market: the share of spend running through deals, the format sellers use to make offers, whether counterparties have identifiable agents, whether terms other than price move during a deal, and whether both sides hold the same record of what was agreed. Each can be checked from a buyer's own reporting, contracts or public registries.

TL;DR. The move from auction to negotiation is best tracked through observable signals, not forecasts. The first signal is deal ID spend growing relative to open auction spend in a buyer's own DSP data. The second is sellers responding to briefs with standardised, machine-readable proposals such as IAB Tech Lab's OpenProposal. The third is counterparties listing agents in the IAB Tech Lab Agent Registry. The fourth and fifth are negotiation over non-price terms and a shared record of agreed terms that both parties hold.

What is the difference between an auction and a negotiation in programmatic?

In an auction, the price is won: a bid request arrives, buyers bid, and the highest qualifying bid clears in milliseconds. In a negotiation, the terms are agreed: a buyer proposes, a seller accepts, counters or declines, and both converge on a deal covering price, volume, placement and delivery conditions. Programmatic guaranteed and private marketplace deals already involve negotiation, mostly done by people over email.

What changes with AI agents is who negotiates. IAB Tech Lab's AAMP framework publishes reference buyer and seller agents, and AdCP from AgenticAdvertising.org defines tasks for discovery and media buy execution. The signals below show whether that capability is turning into practice.

Signal 1: Is deal ID spend growing relative to open auction spend?

The most direct signal sits in a buyer's own DSP reporting: the split of spend between open auction and deal IDs, broken down by inventory tier. A rising deal share in premium and mid-tier inventory, with open auction holding steady in the long tail, is what a shift towards negotiation looks like in practice.

The breakdown by tier matters. A rising deal share driven only by a few large programmatic guaranteed commitments says little about the wider market. The same rise spread across many smaller deals suggests negotiation is getting cheaper to do, which is the condition agents are meant to create. Track the number of active deals, not just their total value.

Signal 2: Are sellers sending standardised proposals?

When negotiation is done by software, offers have to be machine-readable. IAB Tech Lab's OpenProposal specification, part of AAMP, standardises how publishers define advertising products and packages and present them in RFP responses, so a buyer agent can compare offers from different sellers without translating each one.

The indicator is the format of what arrives after a brief goes out. For example, a hypothetical agency that sends the same brief to twenty publishers and gets back twenty differently structured spreadsheets is still in a manual market. If several of those responses arrive in a standard format describing products, packages and terms, the groundwork for agent negotiation is in place with those sellers.

Signal 3: Do counterparties have identifiable, authorised agents?

Negotiation between software only works if each side can tell which agent it is dealing with and who it represents. Two mechanisms make that observable. The IAB Tech Lab Agent Registry lets companies register the agents they bring to market, tied to their GPP ID and reviewed for validation information. Under AdCP, publishers declare which agents may sell their inventory in an adagents.json file on their own domain.

The indicator is coverage: how many of a buyer's top sellers have an agent listed in the Agent Registry, or publish an adagents.json file. The role is similar to the one ads.txt (2017) and sellers.json (2019) play for seller identity in the auction. A listing does not prove an agent behaves well, but an absence means negotiation with that seller will stay manual. The roles buyer and seller agents play are set out in What are AI agents in advertising?

Signal 4: Are terms other than price being negotiated?

An auction negotiates one thing: price. A real negotiation moves several terms at once, such as viewability floors, frequency caps, completion rates, flight dates and makegood conditions. A market that is genuinely shifting to negotiation will show deals in which those terms change between first proposal and final agreement.

There is early evidence that this is where negotiation is weakest. In Concourse Bench v1, a published simulation of AI buying agents negotiating with software-controlled sellers, 95 of the 110 contracts the buyers secured promised a viewability floor below 70%. The agents closed deals, but the non-price terms were soft.

The indicator for a buyer is a simple comparison: for each negotiated deal, list which terms differed between the opening offer and the signed version. If only price ever moves, the market has automated the auction's logic rather than moved beyond it. A mandate that sets minimum non-price terms, as described in how to write a media buying mandate, is the buyer's main control here.

Signal 5: Do both parties hold the same record of what was agreed?

In a negotiation, the record is the set of agreed terms, and in conventional programmatic, buyer and seller usually hold separate versions in separate systems. Reconciling them after delivery is manual, and disputes over makegoods depend on whose version is accepted.

The AdCP documentation states that payments, legal agreements, settlement, disputes, credits and makegoods remain account or platform integrations unless a specific AdCP contract covers them. AAMP standardises how agents communicate and how sellers describe offers, but does not by itself give both parties one shared record of commercial terms. That job sits with the marketplace or the contract.

The indicator is contractual: whether new deals name a single record of agreed terms, timestamped at agreement and retrievable by either party independently. Until that record exists, negotiated deals carry more dispute risk than auction buys, not less.

How should a buyer track these signals?

A quarterly review covering all five is enough. Pull the deal versus open auction split from DSP reporting. Count standardised RFP responses. Check the Agent Registry and adagents.json coverage for the top sellers. Compare opening and final terms on a sample of negotiated deals. Read the record clauses in new contracts. Movement on one signal alone proves little. Movement on three or more suggests the shift is real in that buyer's market.

Alkimi is one marketplace built for the fifth signal: buyer and seller agents, each verified as authorised by the party it represents, agree terms on a DealSheet that both sides hold, with people retaining approval rights over each deal.

Frequently asked questions

Is programmatic moving away from auctions?

Partly. The open auction continues to clear most long-tail impressions. The shift towards negotiation shows up mainly in premium and direct inventory, and can be tracked through deal share and the other signals above.

What is the clearest single signal of the shift?

Deal ID spend growing relative to open auction spend across many smaller deals, not just a few large ones, in a buyer's own DSP reporting.

What is OpenProposal?

OpenProposal is an IAB Tech Lab specification, part of AAMP, that standardises how publishers define advertising products and packages and present them in RFP responses.

How can a buyer tell if a seller has an AI agent?

Check whether the seller lists an agent in the IAB Tech Lab Agent Registry, or declares authorised agents in an adagents.json file on its domain under AdCP.

Why does a shared deal record matter for negotiation?

Negotiated deals have many terms. If buyer and seller hold different versions, settling makegoods and disputes depends on whose record is accepted.

What Are the Five Signals That Programmatic Is Shifting From Auctions to Negotiation?