AdCP, the Ad Context Protocol, is an open standard that gives AI agents one shared set of tasks for discovering, planning, buying and reporting on advertising, carried over MCP or A2A. It is published and governed by AgenticAdvertising.org, launched on 15 October 2025, and its current generally available version is 3.2. This FAQ answers 25 common questions and links to longer explainers.

TL;DR. AdCP defines what buyer and seller agents say to each other, MCP and A2A carry the messages, and AdCP works alongside OpenRTB rather than replacing it. Governance tasks let a separate agent check each buy against a plan a person approved, although campaign governance is still experimental in 3.x. Payment, settlement and delivery disputes stay with the parties and their contracts.

What are the basics of AdCP?

1. What is AdCP?

AdCP is an open protocol that lets AI agents work together across advertising platforms in a standard language, covering product discovery, media buying, creative, audience activation and brand governance, according to the AdCP FAQ. It is a specification, not a product or company, and anyone can implement it. For a longer definition, see What Is the AdCP Standard?

2. Who publishes and governs AdCP?

AdCP is maintained by AgenticAdvertising.org, a Delaware non-profit trade association with four equal voting classes: brands, agencies, publishers and technology providers. Protocol work happens in public working groups on GitHub, and the organisation's homepage lists 157+ members, including Yahoo, PubMatic, Scope3 and Samba TV.

3. When did AdCP launch, and which version is current?

AdCP launched in New York on 15 October 2025, with Yahoo, Optable, PubMatic, Scope3, Swivel and Triton Digital as founding members, according to the launch announcement. Version 3.2 became generally available on 30 September 2026, with 3.1 and 3.0 still maintained, according to the Versions and Compatibility page. Version 3.3 is in beta, and the AdCP FAQ says 4.0 is targeted for early 2027.

4. How does AdCP work in practice?

AdCP defines named tasks, each with a request and response set out in JSON Schema, that agents call at each step of a campaign, according to the AdCP introduction. A buyer agent asks sellers what they offer, receives products or proposals in a common shape, buys and then receives delivery reports. Version 3.2 turned the commercial steps into a compact set of tools, including list_products, request_proposals, accept_proposal and buy_products, with MCP schemas 71 to 94% smaller than in 3.1, according to What's new in AdCP 3.2.

5. Does adopting AdCP mean choosing it over other standards?

Not necessarily. IAB Tech Lab's AAMP and AdCP are developed separately, and the AdCP FAQ states that implementing AdCP does not require implementing AAMP. Alkimi is one worked example of a standard-neutral approach: it can work with agents built on AdCP or AAMP, with or without a DSP.

What does AdCP mean for buyers?

6. What can a buyer agent do with AdCP?

A buyer agent can discover inventory, negotiate proposals, place buys, send creative, activate audience data and receive reports through one interface. According to the AdCP FAQ, a brand can build its own or work through an agency or platform that implements the protocol.

7. How does a buyer agent find inventory?

Discovery has long run through get_products, which sends one brief to connected sellers and returns what they offer. Version 3.2 adds list_products and request_proposals, and lets a buyer refine a proposal, hold inventory and accept one exact snapshot of the agreed terms, according to What's new in AdCP 3.2.

8. Does AdCP only work for programmatic?

No. The AdCP FAQ says the protocol is built for direct-sold inventory, guaranteed deals and commerce media rather than the impression-level auction. The 3.3 beta lets scheduled, human-gated and offline media run through the same buy as programmatic, with fields for linear TV, print and digital out-of-home, according to What's new in AdCP 3.3. Channel detail is in Can AdCP Buy Beyond Programmatic?

9. How does AdCP handle audience data?

AdCP separates audiences a buyer owns from signals that others define. Email and phone identifiers sent through sync_audiences must be SHA-256 hashed by the buyer, and the Known Limitations page notes that such hashes remain pseudonymous, not anonymous, under GDPR and CPRA. More in How Does AdCP Handle Audiences and Signals?

10. Does AdCP replace a buyer's measurement stack?

No. The AdCP FAQ states that AdCP does not specify attribution or viewability and is not an MRC-accredited measurement standard; it carries delivery data into the tools a buyer already uses. Version 3.2 adds Reliable Reporting, still experimental, so a report the seller owes shows up as missing rather than silently disappearing.

What does AdCP mean for sellers and publishers?

11. What is a sales agent?

The AdCP glossary defines a sales agent as an MCP server that exposes publisher inventory for discovery and purchase, handling media buy creation and campaign management. According to the AdCP FAQ, development of one implementation, the Prebid Sales Agent, passed to the Prebid community in February 2026.

12. How does a publisher say which agents may sell its inventory?

A publisher hosts an adagents.json file at /.well-known/adagents.json on its own domain, listing the sales agents authorised to sell its properties. The AdCP FAQ adds that appearing in the list is not enough on its own: an agent must be granted a property on the domain being queried. See What Is adagents.json?

13. How does a seller know which agent is asking?

AdCP supports bearer authentication and optional request signing under RFC 9421, the IETF standard for HTTP Message Signatures. Signing is optional through 3.2 and planned to become mandatory for spend-committing operations in 4.0, according to the AdCP FAQ. An idempotency key means a retried request returns the original buy rather than creating a second; see How Does AdCP Verify Which Agent Is Asking?

14. Does a seller have to respond instantly?

No. OpenRTB works in milliseconds, while AdCP is asynchronous, running over seconds to days, so a platform processes a buy on its own timeline and returns status updates, according to the AdCP and OpenRTB page. In the 3.3 beta, a booking can also say when it will be confirmed.

How does AdCP keep humans in control?

15. What is Embedded Human Judgment?

Embedded Human Judgment is the principle, set out by AgenticAdvertising.org, that humans stay in the loop on decisions with real consequences. In the protocol, it lets deployments require human review before consequential execution, according to the AdCP FAQ. At launch, Scope3 co-founder Anne Coghlan told AdExchanger: "Where we are right now, there is always a human in the loop."

16. What does a governance agent do?

A governance agent is an external service a buyer configures to check campaign actions, such as budget limits and brand safety, before they execute. Both the buy-side orchestrator and the seller call check_governance against it, and the AdCP FAQ states that a seller cannot override its decision. The full model is in How Does AdCP Governance Check Budgets, Brand Safety and Human Approval?

17. Who keeps the audit trail?

According to the AdCP FAQ, the governance agent holds the consolidated audit trail, a timestamped record of every decision, approval and outcome, served through get_plan_audit_logs. A media buy does not generally name the person who placed it, because AdCP authenticates the calling agent and scopes the buy to the buyer's account.

18. Is AdCP governance ready for production?

Campaign governance, including sync_plans, check_governance and get_plan_audit_logs, is marked experimental in AdCP 3.x, and sellers that implement it declare it as an experimental feature, according to the AdCP FAQ. A buyer should check which governance features each seller declares before relying on them.

19. What does AdCP leave to contracts?

Invoicing, settlement and delivery disputes are handled outside the protocol, through the commercial relationship, according to the Known Limitations page. AdCP also authenticates agents, not the humans they act for.

How does AdCP fit with other standards?

20. How does AdCP relate to IAB Tech Lab's AAMP?

AAMP, the Agentic Advertising Management Protocols, is IAB Tech Lab's open-source umbrella for its agentic work, with components including OpenProposal and the Agentic Real Time Framework (ARTF), according to the AAMP repository. The AdCP FAQ describes AAMP as a separate initiative with some overlapping workflow concepts, developed under its own governance and not wire-compatible with AdCP. See AAMP, AdCP, A2A and MCP: Which Protocol Does What?

21. Does AdCP replace OpenRTB?

No. The AdCP FAQ describes the two as complementary: a publisher's agent might accept a create_media_buy task through AdCP and then use OpenRTB internally to deliver the impressions. As a consortium spokesperson told Digiday at launch: "Publishers and platforms can run both OpenRTB and AdCP simultaneously."

22. How does AdCP use MCP and A2A?

MCP and A2A define how agents communicate, and AdCP defines what they say about advertising. A get_products call has the same schema over either transport, and the AdCP FAQ sums it up: "MCP is the transport, AdCP is the protocol."

How should teams prepare agents that will meet more than one standard?

A protocol defines what agents say to each other, not whether a particular agent buys well, keeps to its brief or stops when it should. That is best tested before real money moves.

Alkimi's suite is built on that basis. Concourse benchmarks any buying agent without asking which standard it uses, and in Concourse Bench v1, 55 of 96 runs completed a buy. Its Gym lets buyers and sellers train their own agents and spar them against counterparty agents regardless of protocol, while its Marketplace is neutral, with a DealSheet written at agreement and held by both parties.

The idea underneath is earned autonomy, moving through Observe, Recommend, Draft, Human-approved action and Bounded automatic action. Agents take on the parts of media buying people do not enjoy; people keep the judgement and approve the deals that matter.

Frequently asked questions

23. Is AdCP open source?

Yes, the AdCP FAQ states that AdCP is open source under the Apache 2.0 licence, with no licence agreement or membership required. Any standards body is free to adopt, reference or align with it.

24. Is AdCP an IAB Tech Lab standard?

No, AdCP is maintained by AgenticAdvertising.org, which the AdCP FAQ describes as an independent specification body. AdCP does reuse IAB Tech Lab vocabularies, including OpenRTB, AdCOM, VAST, GPP, ads.txt and sellers.json.

25. How is AdCP different from agentic commerce protocols?

Commerce protocols such as Google's Universal Commerce Protocol, and the Agentic Commerce Protocol from OpenAI and Stripe, standardise checkout, payments and fulfilment in AI assistants. The AdCP FAQ describes AdCP as the advertising layer, meeting those protocols at the hand-off to checkout.

AdCP FAQ: 25 Questions About the Ad Context Protocol Answered