Core AdTech Standards.
The transaction, video, deals, object, taxonomy, and supply-chain rails that modern and agentic advertising still depend on.
Agentic advertising will not replace the core adtech standards stack. It will call into it, extend it, and depend on it. OpenRTB, AdCOM, VAST, OpenDirect, Deals API, ads.txt, app-ads.txt, sellers.json, and SupplyChain Object remain part of the operating substrate.
Agents may change the interface. They do not remove the rails.
Fast read
- What it is
- A guide to the core transaction, video, deals, object, taxonomy, and supply-chain standards that modern and agentic advertising run on: OpenRTB, AdCOM, VAST, OpenDirect, Deals API, ads.txt, app-ads.txt, sellers.json, and SupplyChain Object.
- What it is not
- Not a claim that agents replace these rails, and not implementation advice. Versions, public-comment status, and guidance change — validate against official documentation.
- Why it matters
- Agentic systems will transact through these standards. If an agent automates buying through opaque or misdeclared paths, it scales bad decisions faster.
- Best for
- AdTech, MarTech, media, publisher, DSP / SSP, data, agency, and brand teams building or evaluating agentic advertising on top of programmatic infrastructure.
- Main risk
- Treating the core rails as legacy. The OpenRTB 2.x line still receives roughly monthly updates, the Deals API was finalized in February 2026, and the supply-chain files are how buyers verify who is selling.
- Best next read
- AdCP, IAB Agentic Standards, Privacy & Consent Standards, and Measurement & Media Quality.
Why the old rails still matter.
Most agentic-advertising conversations start with new protocols. The buying those protocols describe still settles on standards that have run programmatic for years — and that are still actively maintained. The OpenRTB 2.x line receives roughly monthly non-breaking updates, and the newest specification in this stack, the Deals API, was finalized in February 2026.
- 01
Agents need transaction rails
OpenRTB and AdCOM define how impressions are put up for bid, described, and transacted. Agent-initiated buys still resolve into bid requests and responses.
- 02
Agents need deal rails
OpenDirect carries automated guaranteed workflows; the Deals API moves agreed deal terms between systems. Negotiation without a settlement object stays manual.
- 03
Agents need delivery rails
VAST still structures how video ads reach players, including CTV. What an agent plans is bounded by what the template can deliver, track, and report.
- 04
Agents need trust rails
ads.txt, app-ads.txt, sellers.json, and the SupplyChain Object are how buyers verify supply paths. Automation raises the cost of skipping that check.
The framing
Agentic advertising will still depend on the old rails. Agents need workflow protocols, runtime standards, transaction objects, privacy constraints, measurement trust, and research evidence.
The core transaction layer.
Four specifications carry the transaction itself. Versions below were checked against official IAB Tech Lab pages and GitHub releases in June 2026 — validate current status before implementation.
- Real-time bidding
OpenRTB 2.6
Role. The API specification for putting individual ad impressions up for bid in real time.
Why it matters. The current release is OpenRTB v2.6-202606 (June 2026) in the canonical GitHub repository, which receives roughly monthly non-breaking updates. The 2.x line is the actively maintained, widely deployed line — not legacy. OpenRTB 3.0 exists as a separate spec line released in 2017.
Agentic question. When an agent initiates a buy, which system translates intent into bid requests and responses — and who owns that translation?
- Shared object model
AdCOM 1.0
Role. The Advertising Common Object Model: shared objects for ads, placements, and context, used by OpenRTB 3.0 and OpenDirect 2.x.
Why it matters. The current release is AdCOM 1.0-202606 (June 2026). A common object vocabulary is exactly what agent-to-agent transactions need so that every payload does not reinvent media description.
Agentic question. Do agentic payloads describe ads, placements, and context with shared objects — or with one-off schemas that break interoperability?
- Automated guaranteed
OpenDirect 2.1
Role. The API specification automating direct-sold and guaranteed inventory transactions: RFP, negotiation, and order management. Uses AdCOM for media description.
Why it matters. The current version is 2.1 (July 2024). Direct and guaranteed deals carry a meaningful share of premium budgets — agentic buying that ignores them only automates the auction.
Agentic question. Can an agent run an RFP-to-order workflow through standard objects, or does direct buying stay manual while auctions get automated?
- Deal synchronization
Deals API 1.0
Role. Standardizes one-way pushing of static deal terms from origin systems (for example SSPs and curation platforms) to receiving systems (for example DSPs).
Why it matters. Finalized February 6, 2026 — the newest specification in this set. It targets manual deal entry, a friction point agents would otherwise inherit. It is too new for adoption claims; validate current status.
Agentic question. When agents negotiate deals, what carries the agreed terms between systems without manual re-entry?
The video and CTV layer.
Video delivery has its own rail. However an agent plans or buys video, the ad still reaches the player through a standardized template — and CTV is where that template is evolving fastest.
- Video ad delivery
VAST 4.3 + CTV Addendum 2024
The XML template for structuring ad tags that serve ads to video players. VAST 4.3 (released December 2022) carried CTV-focused changes, and the VAST CTV Addendum 2024 (final, July 2024) extends guidance for connected TV. If agents plan and buy video, delivery still resolves through this template.
- Interactive video
SIMID
The official IAB Tech Lab page lists SIMID 1.2 as the current standard for interactive video creative — a container that keeps ad code isolated from the player while enabling player–creative communication. Validate current status before implementation.
The CTV stake
CTV is where agentic media plans meet hard delivery constraints. What a player can render, track, and report is bounded by the template and its addenda.
The supply-chain transparency layer.
Agentic systems make supply-chain transparency more important, not less. If agents automate buying through opaque paths, they can scale bad decisions faster.
- Authorized sellers
ads.txt 1.1
Publishers publicly declare, via a text file on their domain, which companies are authorized to sell their inventory. Version 1.1 (2022) added the OWNERDOMAIN and MANAGERDOMAIN variables.
- Apps + CTV
app-ads.txt 1.0
Extends ads.txt to apps distributed through mobile and CTV app stores. Version 1.0 has been final since 2019.
- Seller identity
sellers.json
Ad systems publish a public JSON file of their seller accounts so buyers can discover and verify the entities that are direct sellers of — or intermediaries in — the sale of digital advertising. Final specification, July 2019.
- Path visibility
SupplyChain Object 1.0
Lets buyers see all parties selling or reselling a given bid request as a chain of nodes. Usable as an extension with OpenRTB 2.5 and part of the source object in OpenRTB 2.6 and 3.0; designed to work in tandem with sellers.json.
Public documentation also describes ads.cert 2.0, a cryptographic security suite for programmatic; several of its protocols are listed as future work rather than released, so validate current status before depending on it.
Taxonomies and data transparency.
Shared classification is the quiet dependency. If agents exchange signals about content and audiences, they need a common vocabulary for what those signals mean — and a disclosure standard for where the data came from.
- Content classification
Content Taxonomy 3.1
A common language for describing content for contextual targeting and brand safety. The 3.x line expands to 1,500+ categories from roughly 400 in 2.x, and IAB Tech Lab urges migration off the deprecated 2.x line. Version 3.1 is current.
- Audience classification
Audience Taxonomy 1.1
Standardizes the naming of audience segments across demographic, interest, and purchase-intent tiers, so different vendors describe the same segment the same way. Version 1.1 (October 2020) remains the latest.
- Data labeling
Data Transparency Standard
Public documentation describes a “data label” disclosure schema — provenance, collection method, recency — for audience segments, with a compliance program at datalabel.org. Listed at version 1.1 (January 2021); validate current status before relying on it.
Where this connects to AdCP and AAMP.
AdCP is an agent workflow and task protocol. The IAB Tech Lab agentic work — AAMP and related efforts — addresses runtime, signal exchange, and trust. Neither layer removes the rails on this page: agent-initiated work ultimately settles on them.
| Rail | What it provides | What the agentic layer still needs from it |
|---|---|---|
| OpenRTB 2.6 | Real-time transaction of individual impressions | Agent-initiated buys still resolve into bid requests and responses; workflow tasks sit above the auction, not instead of it. |
| AdCOM 1.0 | Shared objects for ads, placements, and context | Agent payloads need a common media vocabulary instead of one-off schemas per integration. |
| OpenDirect 2.1 | Automated guaranteed: RFP, negotiation, order management | Agentic deal-making needs standard objects for direct-sold inventory, not just auction access. |
| Deals API 1.0 | One-way sync of static deal terms between systems | Terms an agent negotiates need a standard path from origin to receiving systems without manual re-entry. |
| VAST 4.3 + CTV Addendum | Video ad delivery to players, including CTV | Agent-planned video still has to render, track, and verify through the template and its addenda. |
| ads.txt / app-ads.txt / sellers.json | Public declarations of authorized sellers and seller identity | Agents need machine-checkable supply declarations before spend is automated. |
| SupplyChain Object 1.0 | Per-request visibility of every selling and reselling party | Agentic buying needs every hop visible so opaque paths are not automated at scale. |
No Fluff POV.
The core adtech standards are not the exciting part of agentic advertising. That is exactly why they matter. The agentic layer will be judged on whether it can transact, deliver, deal, and verify — and all four verbs resolve to the standards on this page.
- Treat the core rails as the substrate, not legacy. The actively maintained lines still receive updates — roughly monthly for OpenRTB 2.x.
- Map every agentic workflow to the transaction object it eventually settles on. If there is no settlement object, the workflow is a demo.
- Make supply-chain verification — ads.txt, app-ads.txt, sellers.json, SupplyChain Object — a precondition for automated spend, not an afterthought.
- Use shared object models and taxonomies before inventing new schemas for agent payloads.
- Version-watch the stack: monthly OpenRTB updates, new specifications like the Deals API, and CTV addenda keep changing the implementation surface.
The point
The fastest way to break agentic buying is to automate spend across rails nobody verified.
Primary sources to validate.
Standards references last validated: June 2026. Specifications, APIs, public-comment status, release candidates, certification programs, and implementation guidance change. Validate against official documentation before implementation.
Primary sources to validate 14 sources
- OpenRTB 2.x Specification Repository ↗ Official GitHub
Canonical home of the OpenRTB 2.x real-time bidding API spec. Latest release OpenRTB v2.6-202606 (June 11, 2026); the repo states the spec receives non-breaking updates roughly monthly — the 2.x line is actively maintained, not legacy. Supports: OpenRTB current version (2.6-202606), Monthly non-breaking update cadence, Canonical spec link.
- AdCOM — Advertising Common Object Model (repository) ↗ Official GitHub
Canonical repo for AdCOM, the shared object model (ads, placements, context) used by OpenMedia specs including OpenRTB 3.0 and OpenDirect 2.x. Latest release AdCOM 1.0-202606 (June 11, 2026). Supports: AdCOM current version (1.0-202606), AdCOM description, Canonical spec link.
- OpenDirect — IAB Tech Lab standards page ↗ Official standards page
Describes OpenDirect as the API spec automating direct / guaranteed digital ad sales (RFP, negotiation, order management). Current version 2.1, updated July 8, 2024; uses AdCOM for media description. Supports: OpenDirect description, OpenDirect current version (2.1, July 2024).
- Deals API — IAB Tech Lab standards page ↗ Official standards page
Official page for Deals API v1.0, finalized February 6, 2026 after a public comment period that closed January 31, 2026. Standardizes one-way pushing of static deal terms from origin systems (e.g., SSPs, curation platforms) to receiving systems (e.g., DSPs). Newest spec in this set — make no adoption claims. Supports: Deals API version (1.0), Finalization date (Feb 6, 2026), Deals API description.
- deal-api repository (deal1.0.md) ↗ Official GitHub
Repo hosting the Deals API 1.0 specification document (deal1.0.md at repo root). Supports: Canonical Deals API spec link.
- VAST — IAB Tech Lab standards page ↗ Official standards page
VAST (Video Ad Serving Template) is the XML schema for transferring video ad metadata from ad servers to players. Version table lists VAST 4.3 (December 2022) as latest, plus the VAST CTV Addendum 2024 (final, July 2024). Supports: VAST description, VAST current version (4.3), CTV Addendum 2024.
- VAST 4.3 specification (PDF, released December 2022) ↗ Official docs
The VAST 4.3 spec PDF, self-titled 'Released December 2022'. Headline 4.3 changes were CTV-focused (user-activity recognition, direct creative asset access). Supports: VAST 4.3 release date (December 2022), What changed in 4.3.
- ads.txt / app-ads.txt — IAB Tech Lab page ↗ Official standards page
ads.txt (Authorized Digital Sellers) lets publishers publicly declare which companies are authorized to sell their inventory; app-ads.txt extends it to mobile and CTV apps. Current versions: ads.txt 1.1 (2022, adds OWNERDOMAIN/MANAGERDOMAIN) and app-ads.txt 1.0 (final, 2019). Supports: ads.txt description and version (1.1, 2022), app-ads.txt version (1.0, 2019).
- sellers.json — IAB Tech Lab page ↗ Official standards page
sellers.json lets buyers discover and verify the entities that are direct sellers of, or intermediaries in, the sale of digital advertising. Final specification dated July 31, 2019 (no version label) — still current. Supports: sellers.json description, Final status, July 31, 2019 (no version label).
- SupplyChain Object specification (supplychainobject.md) ↗ Official GitHub
SupplyChain Object 1.0: lets buyers see all parties selling or reselling a given bid request via a chain of nodes. Usable as an extension with OpenRTB 2.5; part of the source object in OpenRTB 2.6 and 3.0. Works in tandem with sellers.json. Supports: SupplyChain Object version (1.0), Relationship to OpenRTB 2.6/3.0 and sellers.json.
- Content Taxonomy — IAB Tech Lab standards page ↗ Official standards page
The Content Taxonomy is a common language for describing content for contextual targeting and brand safety. Current version 3.1; the 3.x line expands to 1,500+ categories versus ~400 in the deprecated 2.x line. Supports: Content Taxonomy description, Current version (3.1), 2.x deprecation.
- Audience Taxonomy — IAB Tech Lab standards page ↗ Official standards page
The Audience Taxonomy standardizes naming of audience segments (demographic, interest, purchase-intent tiers) across vendors. Current version 1.1, final, released October 2020 — still the latest as of June 2026. Supports: Audience Taxonomy description, Current version (1.1, Oct 2020).
- IAB Tech Lab Taxonomies repository ↗ Official GitHub
Machine-readable taxonomy files. 'Content Taxonomy 3.1.tsv' and 'Audience Taxonomy 1.1.tsv' are the newest taxonomy files as of June 2026. Supports: Verification that 3.1 / 1.1 are the latest taxonomy versions, Canonical data files.
- Data Transparency Standard — IAB Tech Lab page ↗ Official standards page
The Data Transparency Standard ('data label') is a disclosure schema bringing transparency to audience data in the data marketplace. Version 1.1, final, dated January 26, 2021, with a compliance program at datalabel.org. Supports: Data Transparency Standard description, Version 1.1 (Jan 26, 2021).
Platform capabilities and naming change quickly. Last validated: June 12, 2026. Check current documentation before implementation.Standards references last validated: June 2026. Specifications, APIs, public-comment status, release candidates, certification programs, and implementation guidance change. Validate against official documentation before implementation.
Building agentic workflows on top of existing adtech rails?
The operating work is to map agent workflows to the transaction, delivery, deal, and trust rails they settle on — before automation scales a path nobody verified.