IAB Tech Lab Agent Registry explained: what is listed, how to register, what buyers check

IAB Tech Lab, the industry's technical standards body, built and operates the registry. Its CEO, Anthony Katsur, introduced it as a way for partners to find an agent and understand its capabilities. He said IAB Tech Lab reviews each entry to make sure the necessary validation information is provided (IAB Tech Lab, 4 March 2026). The registry lives inside the Tools Portal, the same login that issues Global Privacy Platform (GPP) IDs and runs the Transparency Center.

The registry is the trust layer of AAMP, IAB Tech Lab's Agentic Advertising Management Protocols. AAMP has three pillars: agentic foundations, agentic protocols codified in buyer and seller agent kits, and the Agent Registry for trust and transparency (PPC Land on IAB Tech Lab's COO, 20 August 2026). Registration does not depend on using AAMP's kits. Any MCP or A2A agent can be listed, including agents that speak the rival AdCP protocol, as the snapshot below shows.

The registry is itself an MCP server. An agent can connect to it and ask for "seller agents" or "measurement agents" directly (IAB Tech Lab, 4 March 2026). On 9 November 2026 it offered nine tools, including list_agents, get_agent_manifest and verify_agent_health, behind a free 60-minute anonymous credential (registry auth.md).

The table lists every field the registry's REST API returned for each entry on 9 November 2026. The last column counts how many of the 53 entries had the field filled or the check passed. Field names are the API's own.

Source for every count: the registry's REST API, read with its documented anonymous credential on 9 November 2026 (registry auth.md).

Two fields need care. "Active" does not mean "verified": all 53 entries are active, yet seven lack a verified domain and 38 lack a verified GPP ID (IAB Tech Lab registry). And the iab_member flag read false for every entry, including companies that sit in IAB Tech Lab working groups, so do not read it as a membership test.

Source: IAB Tech Lab registry, counted 9 November 2026.

The "ad server" group is mostly large platforms exposing their advertising APIs over MCP. It includes Amazon Ads with three regional servers, Meta Ads MCP, TikTok for Business MCP and Google Ads MCP, the one entry that installs locally. The supply side is well represented, with Magnite, PubMatic, Equativ, Media.net and GumGum among the SSP entries. Buy-side entries are thinner: three DSPs and one agency agent. The buy side was thin from the start, since none of the first 10 entries in March 2026 was a DSP (PPC Land, 11 March 2026).

The protocols overlap more than the politics suggest. Ten entries expose get_adcp_capabilities, the capability discovery task of the rival AdCP protocol, and several also expose AdCP's get_products and create_media_buy tasks (IAB Tech Lab registry, 9 November 2026). So the IAB Tech Lab registry already doubles as a directory of AdCP sales agents.

1. Create a Tools Portal account. Registration is free for IAB Tech Lab members and non-members (IAB Tech Lab, 4 March 2026).
2. Get or confirm your company's GPP ID. Every registering company is associated with its GPP ID, which includes the TCF Global Vendor List ID for validation. GPP IDs are issued through the same portal (GPP Consent String Specification, "GPP Identifier").
3. Submit the entry. The minimum is an agent name, a primary domain and an endpoint URL. You can add legal name, protocol (MCP by default), category, maturity, description and logo. The form also takes a contact email, a support URL, up to 10 endorsements and an authentication flag (PPC Land, 11 March 2026).
4. Prove you own the domain. The registry returns a verification token to publish as a DNS TXT record. Once it resolves, the domain is marked verified.
5. Keep the endpoint reachable. The registry probes the endpoint and records whether it answers; any user can trigger the same check with verify_agent_health (registry auth.md).
6. Wait for review. IAB Tech Lab reviews each entry to confirm the necessary validation information is provided (IAB Tech Lab, 4 March 2026).
7. Maintain it. Update tools, maturity and contacts as the agent changes. A stale tool list is the first thing a careful buyer will notice.

A listing tells you an agent exists and who claims to run it. It does not certify the agent's behaviour, and IAB Tech Lab's material describes no "AAMP compliant" certification (Alkimi, 13 October 2026). Before you connect a buying or selling workflow, work through this list.

1. Legal entity. Does legal_name match the company you will contract with, and the name in its sellers.json or Global Vendor List entry?
2. Domain. Is domain_verified true? Does the endpoint sit on that domain, and if not, does the vendor document why?
3. GPP ID. Is gpp_verified true, and does the ID match the company's TCF vendor ID? Only 15 of 53 entries passed this check on 9 November 2026 (IAB Tech Lab registry).
4. Endpoint health. Run verify_agent_health yourself on the day you connect, not just at registration.
5. Maturity. Treat alpha and beta agents as test partners, not production counterparties.
6. Deployment type. A remote agent receives your prompts and data on the vendor's systems. A private agent runs inside your network. Decide which data each type may see; the risks are mapped in AI agents and data leakage.
7. Authentication. An endpoint with auth_required false should expose only read-only tools. Any tool that can create or change a buy needs credentials tied to your account.
8. Tools that move money. List every tool that creates, updates or cancels a media buy. AAMP 2.3 requires human approval for spend outside value thresholds on paths that commit spend (IAB Tech Lab, 30 July 2026). Set the same thresholds on your side.
9. Inventory authority. For a seller agent, confirm it may sell the inventory it offers. The registry does not yet verify this; IAB Tech Lab listed "ads.txt for agents" as a roadmap item (IAB Tech Lab, 4 March 2026). Check the publisher's ads.txt, sellers.json and, for AdCP agents, its adagents.json. The supply-chain checks are in SupplyChain, ads.txt and sellers.json together.
10. Endorsements. Certifications such as Open Measurement or SOC 2 usually apply to the company or another product, not to the agent. Ask what they cover.
11. Documentation and support. No documentation URL and no support URL means no one to call when a buy goes wrong.
12. Logs. Ask for a record of every tool call the agent makes on your behalf, with inputs, outputs and timestamps.

The two agentic standards each have a registry, and they work differently. IAB Tech Lab's registry is free and open to any company with a Tools Portal login. AgenticAdvertising.org's registry, which serves AdCP, lists only agents that an AgenticAdvertising.org member enrols, and making an agent public requires a paid membership tier. It also builds a separate graph of which agents publishers authorise in their adagents.json files (AdCP docs, "Registering an agent").

IAB Tech Lab's chief operating officer, Shailley Singh, lists "agent identity and registry functions" among 13 business functions that AAMP and AdCP both cover (PPC Land, 20 August 2026). The practical answer for a seller is to register in both places if it wants buyers from both camps to find it.

For the full comparison of the two standards, versions and adoption, see the AAMP vs AdCP tracker. For what your own stack needs before any agent can safely call it, see agent-ready ad infrastructure, and for what agencies already run in production, AI agents for media buying. The agentic advertising hub collects every related page.

• How long IAB Tech Lab's review of a new entry takes, and what share of submissions it rejects. The registry publishes neither.
• What the iab_member field is meant to show. It read false on every entry.
• Whether the rating, feedback and country-filter features announced in March 2026 have shipped. None appeared in the entry data on 9 November 2026.
• A third-party count of 49 entries from 41 companies on 19 October 2026 could not be traced to a published source. Our own reading on 17 October 2026 also found 49 entries.
• Any figure for money spent through registered agents. None has been published.

1. IAB Tech Lab, "Introducing the IAB Tech Lab Agent Registry" (4 March 2026, updated 12 August 2026). https://iabtechlab.com/introducing-the-iab-tech-lab-agent-registry/
2. IAB Tech Lab, "Navigating the Agentic Frontier: the IAB Tech Lab 2026 roadmap" (April 2026). https://iabtechlab.com/navigating-the-agentic-frontier-the-iab-tech-lab-2026-roadmap/
3. IAB Tech Lab, Agent & MCP Server Registry, web listing and REST API (read 9 November 2026). https://registry.iabtechlab.ai/
4. IAB Tech Lab, registry "auth.md" access specification (read 9 November 2026). https://registry.iabtechlab.ai/auth.md
5. IAB Tech Lab, "IAB Tech Lab releases AAMP 2.3" (30 July 2026). https://iabtechlab.com/press-releases/iab-tech-lab-releases-aamp-2-3-bringing-enterprise-grade-infrastructure-and-privacy-diligence-to-agentic-advertising/
6. IAB Tech Lab, "Global Privacy Platform: Consent String Specification", section "GPP Identifier" (accessed 9 November 2026). https://github.com/InteractiveAdvertisingBureau/Global-Privacy-Platform/blob/main/Core/Consent%20String%20Specification.md
7. PPC Land, "IAB Tech Lab's agent registry hits 10 with Amazon and new deployment types" (11 March 2026). https://ppc.land/iab-tech-labs-agent-registry-hits-10-with-amazon-and-new-deployment-types/
8. PPC Land, "AAMP and AdCP overlap on 13 functions, IAB Tech Lab COO says" (20 August 2026). https://ppc.land/aamp-and-adcp-overlap-on-13-functions-iab-tech-lab-coo-says/
9. Alkimi, "What is the AAMP standard and which platforms implement it?" (13 October 2026). https://www.alkimi.org/news/what-is-aamp-standard
10. AgenticAdvertising.org, AdCP documentation, "Registry API" (main branch, accessed 9 November 2026). https://github.com/adcontextprotocol/adcp/blob/main/docs/registry/index.mdx