Eighteen months ago, agent-driven ad buying was a keynote topic. Today it is two competing standards stacks with shipped software, published by two different organizations that are openly not coordinating.
If you build adtech, both are about to show up in your pipes. Here is the short version.
Stack one: IAB Tech Lab's AAMP
AAMP (Agentic Advertising Management Protocols) launched in January 2026 and hit 2.0 in June. The philosophy: build on the rails that already move money. It wires OpenRTB, AdCOM, OpenDirect, and VAST together, with MCP and Google's Agent2Agent protocol as the agent interfaces.
Version 1.0 could only transact direct deals. The 2.0 release added programmatic: a Buyer Agent SDK with a three-layer agent hierarchy (orchestration, channel specialists, functional agents), a Seller Agent SDK that turns a static media kit into a storefront that adapts pricing to the buyer, and a Deals Library as the system of record with OpenDirect 2.1 support. Approval gates and audit logs keep humans at the sign-off points.
Stack two: AAO's AdCP
The Ad Context Protocol launched in October 2025 from a consortium including Yahoo, PubMatic, Optable, Scope3, Swivel, and Triton Digital. It is now governed by AgenticAdvertising.Org (AAO), a trade association with four equally weighted voting classes: brands, agencies, publishers, and technology providers. The reference sell-side implementation lives with the Prebid community.
AdCP was designed agent-native from the start. It is built directly on MCP, runs asynchronously so humans can approve while agents negotiate, and version 3.0 (April 2026) covers the full campaign lifecycle: discovery, media buys, creative production with brand.json, governance, and reporting across 20 media channels. It is in production at Snap, Pinterest, Reddit, Netflix, and Vox Media.
The actual differences
Governance. Tech Lab is the incumbent that already maintains VAST and OpenRTB. AAO is a new association built specifically for agentic advertising.
Design center. AAMP layers agents onto existing programmatic rails. AdCP defines new MCP-native tasks first and treats legacy systems as integration targets.
Coverage. AAMP is deepest at the transaction layer, with ARTF agent containers running inside bidder infrastructure. AdCP is broadest across the lifecycle, planning through reporting.
Interfaces. Both name MCP as a core protocol. A tool exposed as an MCP server serves agents on either stack without modification.
Verification. Neither stack validates the creative payload. Deal state and context move between agents; the correctness of what ships is out of scope for both specs.
The layer they share
Follow a video buy through either stack and the endpoint is identical: an ad server returns VAST XML. An InLine or Wrapper, MediaFiles, Impression pixels, TrackingEvents. Twenty channels of protocol surface on one side, one XML document on the other.
That document is where delivery fails. A missing Duration, an HTTP media URL on a CTV device that requires HTTPS, a wrapper chain past the player's depth limit: none of it is visible at the protocol layer. The deal confirms cleanly, the agents log success, and the impression dies at runtime with a VAST error code nobody is watching.
Human traffickers used to be the backstop. In an agent-to-agent transaction there is no trafficker. Validation has to be a tool the agent calls before the deal confirms, not a QA pass after launch.
The practical takeaway
You do not need to bet on a winner. MCP is the shared interface: AAMP's Buyer Agent SDK accepts additional MCP tool servers, and AdCP is MCP-native end to end. Anything you expose over MCP works in both stacks today.
That is how we ship vastlint: 187 rules grounded in the IAB VAST, OMID, and SIMID specs, deterministic JSON output, available as a hosted MCP endpoint, CLI, and libraries. Point either stack's agent at it and gate deal confirmation on a clean tag.
The protocols will keep changing. The payload has been VAST for two decades and will still be VAST when the governance questions settle.
The full comparison, with sources, is on the vastlint blog: AAMP vs AdCP: What IAB Tech Lab and AAO Are Each Building for Agentic Advertising.
SOCIAL SHARE CARD GENERATOR