TL;DR: Two standards are used for direct agent-to-agent advertising transactions. The industry framework is IAB Tech Lab's Agentic Advertising Management Protocols (AAMP), which adds agent communication, reference buyer and seller agents and the OpenProposal specification to existing advertising standards. Alongside it, AdCP (Ad Context Protocol), published by AgenticAdvertising.org, defines a set of tasks agents use to negotiate and execute buys.

For a buy-side agent to transact directly with a publisher's sell-side agent, both parties need to speak the same protocol: a shared standard that defines the format of messages, the structure of deal proposals, the sequence of negotiation steps, and the format of the final deal record. Without a common protocol, agents from different platforms cannot communicate, and cross-platform agent-to-agent transactions are not possible.

Two standards are central to this in 2026.

AAMP: Agentic Advertising Management Protocols

AAMP is IAB Tech Lab's open-source framework for agentic advertising, announced in early 2026. It extends existing advertising standards for use by agents rather than replacing them.

As an umbrella framework, AAMP brings together several components.

Agent communication. The agentic-direct component covers agent communication and orchestration. IAB Tech Lab also publishes a reference buyer agent and a reference seller agent.

Products and proposals. OpenProposal, part of AAMP 3.0, defines how publishers define their products and packages and present them in RFP responses.

Discovery and deal types. The registry-agent-example component covers agent discovery, and IAB Tech Lab runs an Agent Registry, where companies list the agents they bring to market and IAB Tech Lab reviews entries for validation information. According to IAB Tech Lab, AAMP's support for the Deals API covers programmatic guaranteed, preferred deals, private marketplaces and the open marketplace, as well as linear GRPs. The framework also includes the Agentic RTB Framework and agentic-audiences.

For buyers and publishers, the useful checks are concrete: which AAMP components a marketplace uses and at which version, whether its agents are listed in the IAB Tech Lab Agent Registry, and which deal types it supports.

AdCP (Ad Context Protocol), published by AgenticAdvertising.org

AdCP is published and governed by AgenticAdvertising.org, an industry body separate from IAB Tech Lab. As of October 2026, the current version is 3.2.

AdCP is a task protocol that runs across the campaign: inventory discovery, media buys, creative, signals, governance checks and delivery reporting. Agents use these tasks over MCP or A2A.

Deal record. AdCP's documentation states that settlement, disputes and makegoods remain account or platform integrations unless a specific AdCP contract covers them. On Alkimi, the agreed terms are written to the DealSheet: a bilateral document held by both parties, which either party can retrieve and read independently.

How the two protocols work together

AAMP and AdCP aim at the same problem from different bodies. AAMP builds agent capability onto IAB Tech Lab's existing standards. AdCP defines its own set of campaign tasks. Neither, on its own, gives buyer and seller a single shared record of the agreed terms; that sits with the marketplace.

A buyer choosing a marketplace for agent-to-agent transactions should ask which standard it supports, at which version, and for which deal types, and how the agreed terms are recorded for both parties.

A marketplace that cannot answer those questions specifically is describing an intention rather than a capability.

What interoperability means in practice

The value of open standards is interoperability. A buy-side agent built to an open agentic standard such as IAB Tech Lab's AAMP or AdCP can, in principle, negotiate with any sell-side agent built to the same standard, regardless of which platform each agent runs on. A buyer does not need to deploy a different agent for each marketplace; a single agent built to an open standard can connect to any marketplace or publisher that has implemented that standard.

This is the same model that OpenRTB created for auction-based programmatic: a shared standard that allowed any DSP to connect to any SSP without bespoke integration work. AAMP and AdCP both aim to do the same for bilateral agent-to-agent negotiation. In 2026, adoption is still in early stages; not every platform has implemented either standard fully, and interoperability in practice is more limited than it will be once adoption broadens.