Published: 17 September 2026

TL;DR: A CTV publisher preparing to receive agentic proposals needs a sell-side mandate that goes further than a standard programmatic floor configuration. It needs CPM floors by content category and daypart, buyer category restrictions, audience data conditions, minimum deal sizes, and approval thresholds for proposals outside the standard parameters. A publisher whose sell-side mandate is incomplete when the first agentic proposal arrives will find their sell-side agent either accepting deals it should not accept or declining all proposals while waiting for human intervention.

When a buy-side agent sends a proposal under the Agent Communication Protocol (AdCP), it expects a response governed by the sell-side agent's parameters. The sell-side agent either accepts the proposal, counter-proposes, or declines. For that response to be commercially correct, the sell-side agent needs a sell-side mandate that reflects the publisher's actual commercial requirements.

For most CTV publishers, their existing programmatic configuration is not sufficient as a sell-side mandate. Programmatic floor prices are set at an inventory level and enforced by SSP logic. A sell-side mandate for agentic negotiation needs to be more granular, more explicitly documented, and more complete as a statement of what the publisher will and will not agree to.

CPM Floors by Content Category and Daypart

A CTV publisher's CPM floor is not a single number. Live sport inventory commands a different floor from drama on-demand. Peak daypart inventory commands a different floor from off-peak. If the sell-side mandate states a single CPM floor, the sell-side agent will either accept below-floor proposals for premium content categories or decline above-floor proposals for lower-value categories.

The first step in setting up a sell-side mandate is defining CPM floors by content category and daypart. This is the same work the publisher's programmatic team does when setting up SSP floor rules, but expressed as a documented mandate parameter rather than a platform configuration. The sell-side agent applies the relevant floor to each incoming proposal, rather than applying a blanket floor.

Buyer Category Restrictions

CTV publishers and broadcasters have established category restrictions for which types of advertiser can appear against which content. A financial services advertiser may not be permitted to appear against children's programming. A fast food advertiser may not be permitted against health content. These restrictions exist whether the deal is negotiated by humans or agents.

A sell-side mandate needs to include buyer category restrictions in the same form that the publisher currently applies to direct IO deals. The sell-side agent applies these restrictions to incoming proposals before evaluating the CPM. A proposal that passes the CPM floor but fails the buyer category restriction should be declined automatically.

The practical step is to translate the publisher's existing buyer category policy into mandate parameters. This is not new policy work. It is the work of expressing existing policy in a form that an agent can apply consistently.

Audience Data Conditions

Some CTV publishers offer first-party audience data to buyers as part of a deal. Some publishers restrict which audience data they will share with which buyer categories. A sell-side mandate needs to specify the audience data conditions that govern what the sell-side agent will offer or accept in relation to audience data.

This includes: which audience segments the publisher will share with agentic buyers, under what conditions that sharing is permitted, and whether there are buyer categories that are excluded from audience data access regardless of other deal terms.

Minimum Deal Sizes

CTV publishers and broadcasters have minimum deal sizes below which a direct bilateral deal is not commercially worthwhile. These minimums exist for direct IO deals and should be expressed in the sell-side mandate as well. A sell-side agent that accepts very small bilateral deals may create operational overhead that outweighs the revenue.

The sell-side mandate should state the minimum deal size in budget terms, below which the sell-side agent declines proposals rather than negotiating. This threshold may vary by content category: a minimum for live sport inventory may differ from a minimum for on-demand drama.

Approval Thresholds for Non-Standard Proposals

Not every agentic proposal will fit neatly within the standard sell-side parameters. A buy-side agent may propose terms that are within the CPM floor but include non-standard audience data conditions, or a deal size that is significantly above the publisher's typical bilateral deal scale.

A sell-side mandate needs approval thresholds for proposals that are outside the standard parameters. The sell-side agent declines or holds these proposals rather than accepting them, and triggers a human review. The threshold should be specific: which conditions trigger a hold, and what the expected review turnaround is.

What Happens When the Sell-Side Mandate Is Incomplete

A sell-side mandate that is incomplete when the first agentic proposal arrives creates one of two failure modes.

The first: the sell-side agent applies whatever parameters it has and accepts proposals it should not accept. A missing buyer category restriction means the agent accepts a proposal from a category the publisher would have declined if a human had reviewed it. A missing daypart floor means the agent accepts below-floor CPMs for peak inventory.

The second: the sell-side agent escalates every non-trivial proposal to a human because the mandate does not provide enough guidance to respond automatically. The publisher receives the efficiency benefit of agentic negotiation on the buy side but retains the operational overhead of human review on the sell side.

Neither outcome is what the publisher intended. The solution is to complete the sell-side mandate before the publisher's agents begin accepting incoming proposals. The mandate work is not technically complex. It is a documentation exercise that requires the publisher's programmatic, sales, and legal teams to agree on the parameters that currently exist in different places across their organisation, and express them as a single coherent mandate document.