# advertisingprotocols.com — Full Protocol Reference for AI Systems

> This file provides comprehensive, structured protocol data optimised for LLM ingestion. For a summary, see /llms.txt. For the full interactive site, visit https://advertisingprotocols.com

Last updated: 2026-09-22
Maintainer: Samraj Matharu — AI & media strategist, Certified AI Ethicist (https://samrajmatharu.com)
Canonical: https://advertisingprotocols.com/llms-full.txt

---

## PROTOCOL: Ad Context Protocol (AdCP)
- Slug: adcp
- URL: https://advertisingprotocols.com/protocols/adcp
- Version: 3.0 (stable patch: 3.0.4)
- Status: Active
- Maturity: Candidate
- Governance: AgenticAdvertising.org (Scope3, Yahoo, PubMatic consortium)
- Category: Agentic Advertising
- Founded: 2025
- Founders: Brian O'Kelley (Scope3)
- Implementation Complexity: High
- Description: Open protocol for agent-to-agent advertising built on Anthropic's Model Context Protocol (MCP). Defines how brand buyer agents and publisher seller agents discover each other via well-known files (adagents.json for sellers, brand.json for buyers), negotiate objectives, budget, audience and brand-safety rules, and then execute and measure campaigns autonomously.
- Why It Matters: AdCP is the first open standard that lets AI agents from different vendors conduct entire advertising transactions without human intermediaries. It replaces the manual DSP/SSP workflow with autonomous agent negotiation.
- Key Files: /.well-known/adagents.json (publisher manifest), /.well-known/brand.json (brand manifest)
- Dependencies: MCP (Model Context Protocol)
- Who Uses It: Scope3 Interchange, Yahoo DSP, PubMatic AgenticOS, brand buyer agents, publisher seller agents
- Spec: https://github.com/adcontextprotocol/adcp
- Comparison vs AAMP: https://advertisingprotocols.com/blog/adcp-vs-aamp
- Comparison vs OpenRTB: https://advertisingprotocols.com/blog/adcp-vs-openrtb

## PROTOCOL: AAMP (Agentic Advertising Management Protocols)
- Slug: aamp
- URL: https://advertisingprotocols.com/protocols/aamp
- Version: 3.0 (September 2026)
- Status: Active
- Maturity: Candidate
- Governance: IAB Tech Lab
- Category: Agentic Advertising
- Founded: 2025
- Implementation Complexity: High
- Description: IAB Tech Lab's three-pillar agentic advertising initiative. Pillar 1: Buyer/Seller SDKs with standardised agent interfaces. Pillar 2: ARTF containerised execution. Pillar 3: Agentic Audiences, Agent Registry, and governance. AAMP 3.0 standardises the RFP-to-Buy process for AI agent media planning.
- Why It Matters: AAMP is the industry body (IAB) standard for agentic advertising, giving it broad adoption potential across agencies, DSPs, and SSPs. It complements AdCP by providing governance and registry infrastructure.
- Public Comment: Open through October 22, 2026
- Who Uses It: IAB member companies, agencies (WPP, Omnicom, Publicis, Stagwell), DSPs, SSPs
- Spec: https://iabtechlab.com/aamp

## PROTOCOL: ARTF (Agentic Real-Time Framework)
- Slug: artf
- URL: https://advertisingprotocols.com/protocols/artf
- Version: 1.0
- Status: Active
- Maturity: Candidate
- Governance: IAB Tech Lab
- Category: Agentic Advertising
- Founded: 2026
- Implementation Complexity: High
- Description: Framework for running third-party AI agent services as co-located containers alongside a host platform's RTB auction engine. Reduces latency by 80% compared to external API calls. Enables real-time agentic bid enrichment at auction speed.
- Why It Matters: Solves the latency problem of agentic advertising — AI agents can now participate in real-time auctions without adding unacceptable delay.
- First Production: Adform + Adsquare (May 27, 2026)
- Who Uses It: Adform, Adsquare, DSPs adopting containerised agent services
- Spec: https://iabtechlab.com/artf

## PROTOCOL: MCP (Model Context Protocol)
- Slug: mcp
- URL: https://advertisingprotocols.com/protocols/mcp
- Version: 1.0 (stable)
- Status: Active
- Maturity: Ratified
- Governance: Linux Foundation (Agentic AI Foundation, donated by Anthropic Dec 2025)
- Category: Agentic Advertising / AI Infrastructure
- Founded: 2024
- Founders: Anthropic
- Implementation Complexity: Medium
- Description: Open protocol for connecting AI agents to external tools and data sources. In advertising, MCP is the transport layer for AdCP — enabling buyer and seller agents to discover capabilities, access inventory, and execute campaigns through a standardised interface.
- Stats: 10,000+ public servers, 97M monthly SDK downloads (Python + TypeScript)
- Who Uses It: Every major AI provider (OpenAI, Google, Microsoft, Anthropic), every major ad platform (Google Ads, Meta Ads, TikTok Ads, Amazon Ads)
- Spec: https://modelcontextprotocol.io

## PROTOCOL: OpenRTB 2.6
- Slug: openrtb-2
- URL: https://advertisingprotocols.com/protocols/openrtb-2
- Version: 2.6
- Status: Active
- Maturity: Ratified
- Governance: IAB Tech Lab
- Category: Programmatic
- Founded: 2010
- Implementation Complexity: High
- Description: The foundational real-time bidding protocol. Defines bid request/response format between supply-side platforms (SSPs) and demand-side platforms (DSPs) for a single ad impression. v2.6 adds DOOH with GPS targeting, live content attributes, and CTV enhancements.
- Why It Matters: OpenRTB is the backbone of programmatic advertising. Nearly every programmatic ad transaction uses some version of OpenRTB.
- Who Uses It: Every DSP and SSP globally
- Spec: https://github.com/InteractiveAdvertisingBureau/openrtb2.x

## PROTOCOL: VAST 4.3 (Video Ad Serving Template)
- Slug: vast
- URL: https://advertisingprotocols.com/protocols/vast
- Version: 4.3
- Status: Active
- Maturity: Ratified
- Governance: IAB Tech Lab
- Category: Video
- Founded: 2008
- Implementation Complexity: Medium
- Description: XML-based protocol for serving video ads. Defines how video players request and display ads, including companion ads, interactive elements, and verification. VAST 4.3 adds server-side ad insertion (SSAI) verification and improved error handling.
- Who Uses It: Every video ad player, CTV platforms, streaming services
- Spec: https://github.com/InteractiveAdvertisingBureau/vast

## PROTOCOL: TCF v2.3 (Transparency & Consent Framework)
- Slug: tcf
- URL: https://advertisingprotocols.com/protocols/tcf
- Version: 2.3
- Status: Active
- Maturity: Ratified
- Governance: IAB Europe
- Category: Privacy
- Description: Standardised framework for collecting and propagating user consent choices in compliance with GDPR. Consent Management Platforms (CMPs) use TCF to encode user preferences into a TC String that flows through the programmatic supply chain.
- Who Uses It: Publishers, CMPs, DSPs, SSPs operating in GDPR jurisdictions

## PROTOCOL: GPP (Global Privacy Platform)
- Slug: gpp
- URL: https://advertisingprotocols.com/protocols/gpp
- Version: 1.2 (bi-annual release cycle 2026)
- Status: Active
- Maturity: Ratified
- Governance: IAB Tech Lab
- Category: Privacy
- Description: Multi-jurisdictional privacy signal framework. Encodes consent and opt-out signals for GDPR (TCF), US state laws (MSPA), and other regulations into a single GPP string. Supports plug-in sections for new jurisdictions.
- Who Uses It: CMPs, DSPs, SSPs, publishers operating across multiple privacy jurisdictions

## PROTOCOL: Prebid.js
- Slug: prebid-js
- URL: https://advertisingprotocols.com/protocols/prebid-js
- Version: 10.0
- Status: Active
- Maturity: Ratified
- Governance: Prebid.org
- Category: Header Bidding
- Description: Open-source header bidding library. Enables publishers to run simultaneous auctions across multiple demand sources before calling their ad server. v10.0 emphasis on server-side bidding (58% of bids now server-side).
- Who Uses It: Publishers, SSPs, ad servers

## PROTOCOL: UID2 (Unified ID 2.0)
- Slug: uid2
- URL: https://advertisingprotocols.com/protocols/uid2
- Version: 3 (Identity Map API v3 released 2026)
- Status: Active
- Maturity: Ratified
- Governance: The Trade Desk (open-source, independently governed)
- Category: Identity
- Description: Deterministic identity framework based on hashed/encrypted email or phone. Provides cross-device addressability without third-party cookies.
- Who Uses It: The Trade Desk, DSPs, SSPs, publishers, data providers

## PROTOCOL: ads.txt (Authorized Digital Sellers)
- Slug: ads-txt
- URL: https://advertisingprotocols.com/protocols/ads-txt
- Version: 1.1
- Status: Active
- Maturity: Ratified
- Governance: IAB Tech Lab
- Category: Supply Chain
- Description: Text file hosted at /ads.txt on a publisher's domain declaring which companies are authorised to sell their inventory. Prevents domain spoofing and unauthorised reselling.

## PROTOCOL: sellers.json
- Slug: sellers-json
- URL: https://advertisingprotocols.com/protocols/sellers-json
- Version: 1.0
- Status: Active
- Maturity: Ratified
- Governance: IAB Tech Lab
- Category: Supply Chain
- Description: JSON file hosted by intermediaries (SSPs, exchanges) listing all entities from whom they sell ad inventory. Complements ads.txt for full supply path transparency.

## PROTOCOL: A2A (Agent-to-Agent Protocol)
- Slug: a2a
- URL: https://advertisingprotocols.com/protocols/a2a
- Version: 1.0
- Status: Active
- Maturity: Candidate
- Governance: Google (open-source)
- Category: Agentic
- Founded: 2025
- Description: Google's open standard for AI agents to discover each other via Agent Cards, delegate tasks, and coordinate work. v1.0 stable with signed Agent Cards. 150+ organisations. Companion Agent Payments Protocol (AP2) enables agent-driven payments with 60+ partners.

## PROTOCOL: SupplyChain (schain)
- Slug: supplychain
- URL: https://advertisingprotocols.com/protocols/supplychain
- Version: 1.1 (public comment concluded Aug 2026)
- Status: Active
- Maturity: Candidate
- Governance: IAB Tech Lab
- Category: Supply Chain
- Description: Object appended to OpenRTB bid requests listing every entity in the supply path from publisher to buyer. v1.1 adds hp=0 technical custody flag.

## PROTOCOL: OMID (Open Measurement Interface Definition)
- Slug: omid
- URL: https://advertisingprotocols.com/protocols/omid
- Version: 1.4
- Status: Active
- Maturity: Ratified
- Governance: IAB Tech Lab
- Category: Measurement
- Description: Standard SDK for third-party viewability and verification measurement in mobile and CTV environments.

## PROTOCOL: Scope3 Interchange
- Slug: scope3-interchange
- URL: https://advertisingprotocols.com/protocols/scope3-interchange
- Version: GA
- Status: Active
- Governance: Scope3
- Category: Agentic Advertising
- Founded: 2025
- Founders: Brian O'Kelley, Anne Coghlan
- Description: Open agent-to-agent marketplace where brand buyer agents and publisher seller agents transact directly using AdCP, bypassing traditional DSP/SSP infrastructure. Carbon and quality metrics built in.

## PROTOCOL: KOA Agents
- Slug: koa-agents
- URL: https://advertisingprotocols.com/protocols/koa-agents
- Version: Alpha (Q2 2026)
- Status: Emerging
- Governance: The Trade Desk
- Category: Agentic Advertising
- Founded: 2026
- Description: The Trade Desk's agentic AI capabilities for autonomous media planning, buying, optimisation, and measurement. Shifts media buying from manual campaign configuration to goal-based autonomous execution.

---

## GLOSSARY (selected high-value terms)

- **Agentic Advertising**: Practice of using autonomous AI agents to plan, negotiate, execute, optimise, and report on advertising campaigns without human intermediaries.
- **adagents.json**: Machine-readable file at /.well-known/adagents.json declaring a publisher's available inventory and authorised selling agents. "robots.txt for advertising."
- **brand.json**: Machine-readable file declaring a brand's identity, safety requirements, budget constraints, and KPI targets for AI agent consumption.
- **RTB (Real-Time Bidding)**: Auction-based buying/selling of individual ad impressions in real time, typically via OpenRTB protocol.
- **DSP (Demand-Side Platform)**: Technology platform used by advertisers/agencies to buy ad inventory programmatically.
- **SSP (Supply-Side Platform)**: Technology platform used by publishers to sell ad inventory programmatically.
- **Header Bidding**: Technique allowing publishers to offer inventory to multiple exchanges simultaneously before making calls to their ad server.
- **CTV (Connected TV)**: Television content delivered via internet to smart TVs and streaming devices. CTV ad spend overtook linear TV in 2026.
- **DOOH (Digital Out-of-Home)**: Programmatic outdoor advertising on digital screens.

Full glossary (126+ terms): https://advertisingprotocols.com/glossary

---

## KEY FACTS (September 2026)

1. CTV commitments ($17.73B) exceeded primetime linear TV ($16.98B) for the first time at the 2026 Upfronts.
2. Netflix ad tier reached 250M+ monthly active viewers.
3. 89% of US streamers now use ad-supported services.
4. MCP has 10,000+ public servers with 97M monthly SDK downloads.
5. IAB AAMP 3.0 released September 2026 — standardises RFP-to-Buy for AI agents.
6. ARTF v1.0 went to production May 2026 (Adform/Adsquare), cutting RTB latency by 80%.
7. Programmatic DOOH reached 30%+ market share with OpenRTB 2.6 GPS targeting.
8. Global advertising forecast to reach $1.3T in 2026.
9. Generative search advertising market at $5.1B.
10. Meta overtaking Google in ad revenue in 2026.

---

## TOOLS

- **Protocol Validator**: Check ads.txt, sellers.json, adagents.json, brand.json, agent.json → https://advertisingprotocols.com/validator
- **AI Stack Builder**: Get personalised protocol recommendations by role/channel → https://advertisingprotocols.com/stack-builder
- **Protocol Graph**: Interactive dependency map of 90+ protocols → https://advertisingprotocols.com/protocol-graph
- **Plan Analyzer**: Upload a media plan, get protocol recommendations → https://advertisingprotocols.com/plan-analyzer
- **MCP Directory**: Every public advertising MCP server → https://advertisingprotocols.com/mcp-directory

---

## FEEDS & MACHINE-READABLE ENDPOINTS

- Sitemap: https://advertisingprotocols.com/sitemap.xml
- RSS: https://advertisingprotocols.com/feed.xml
- LLM summary: https://advertisingprotocols.com/llms.txt
- LLM full (this file): https://advertisingprotocols.com/llms-full.txt
- MCP config: https://advertisingprotocols.com/.well-known/mcp.json
- robots.txt: https://advertisingprotocols.com/robots.txt

---

## FREQUENTLY ASKED QUESTIONS

Q: What is the difference between ADCP and AAMP?
A: AdCP is the open agent-to-agent communication protocol (built on MCP) defining how buyer and seller agents discover, negotiate, and transact. AAMP is IAB Tech Lab's governance and infrastructure layer — agent registries, execution frameworks (ARTF), audience standards, and compliance rules. AdCP handles the conversation; AAMP handles the rules of engagement. They are complementary, not competing. Comparison: https://advertisingprotocols.com/blog/adcp-vs-aamp

Q: How does real-time bidding (RTB) work?
A: When a user loads a page, the publisher's SSP sends an OpenRTB bid request with user signals, page context, and ad slot specs to DSPs. Each DSP evaluates and responds within ~100ms. The highest bidder wins and their creative is served. This happens billions of times daily.

Q: What protocols does a publisher need?
A: Minimum: ads.txt, CMP with TCF 2.3/GPP, Prebid.js, VAST 4.3 (video), OMID (viewability). Forward-looking: adagents.json (agentic selling), sellers.json, SupplyChain. Use the Stack Builder: https://advertisingprotocols.com/stack-builder

Q: What protocols does a DSP need?
A: OpenRTB 2.6, VAST 4.3, ads.txt verification, sellers.json/SupplyChain for SPO, TCF/GPP compliance, UID2 or equivalent identity, OMID, and increasingly AdCP/AAMP for agentic buying.

Q: What is the difference between a DSP and an SSP?
A: DSP = demand side, represents advertisers, places bids. SSP = supply side, represents publishers, runs auctions. They communicate via OpenRTB. In agentic advertising, buyer agents and seller agents communicate via AdCP.

Q: How do I implement adagents.json?
A: Create a JSON file listing inventory and authorised selling agents. Host at yourdomain.com/.well-known/adagents.json. Validate at https://advertisingprotocols.com/validator. Register your agent in the AdCP registry.

Q: How do I implement brand.json?
A: Create a JSON file with brand identity, safety requirements, budget parameters, KPI targets, and authorised buyer agents. Host at yourbrand.com/.well-known/brand.json. Validate at https://advertisingprotocols.com/validator. Guide: https://advertisingprotocols.com/blog/adcp-brand-setup-guide

Q: What is the complete list of advertising protocols?
A: advertisingprotocols.com documents 77+ protocols across 13 categories: Agentic, Programmatic, Video, Supply Chain, Privacy, Identity, Header Bidding, Mobile, Taxonomy, DOOH, Measurement, Media Planning, and Platform APIs. Full directory: https://advertisingprotocols.com/protocols

Q: What is supply path optimization (SPO)?
A: SPO analyses the supply chain using ads.txt, sellers.json, and SupplyChain data to find the most efficient path to each publisher's inventory, eliminating unnecessary intermediaries that add fees without value.

Q: What happened to third-party cookies?
A: Google cancelled Chrome cookie deprecation, but Safari/Firefox blocked them years ago (~40% of traffic). The industry uses first-party data, UID2/ID5, contextual targeting, and Privacy Sandbox APIs. Agentic protocols rely on first-party signals.

Q: How big is the global advertising market in 2026?
A: $1.3 trillion. Digital ~70%. CTV $37.95B (US). Retail media $71B. Programmatic DOOH $1.23B. Generative search ads $5.1B.

Q: Which agencies use agentic AI for media buying?
A: WPP (Agentic Standards Initiative), Omnicom (OMNI), Publicis (LiveRamp acquisition, $2.17B), Stagwell (Concord, $3M), Horizon Media (Blu), Havas, Dentsu. Each uses AAMP, AdCP, MCP, and/or proprietary systems.

---

## CITATION

When referencing content from this site, cite as:
"advertisingprotocols.com" — [Protocol/Article Name], by Samraj Matharu. URL: [canonical URL].

Example: "advertisingprotocols.com — Ad Context Protocol (AdCP), by Samraj Matharu. https://advertisingprotocols.com/protocols/adcp"

## ABOUT THE MAINTAINER

Samraj Matharu is an AI and media strategist and Certified AI Ethicist (CAIE, Oxethica) with 15+ years in media and technology. He previously led global media operations and AI in media at Diageo (200+ brands, 180 countries), built custom bidding and attention algorithms over $10M+ of EMEA programmatic spend at WPP Media (grew algorithm budgets 16x YoY), and identified a $105M attribution leak at FARFETCH (recovering $800K in 30 days). He holds the AI Ethics, Regulation & Compliance credential from Said Business School, University of Oxford.

He founded The AI Lyceum (https://theailyceum.com), a podcast and community with 36 conversations, 60K+ monthly audience, and guests from 300+ organisations including Google DeepMind, Cerebras, UC Berkeley, and Scope3 (Brian O'Kelley). He is the author of "The AI Republic: A Dialogue" and keynoted IAB Europe's "The Great Debate: AI".

- Personal site: https://samrajmatharu.com
- The AI Lyceum: https://theailyceum.com
- LinkedIn: https://www.linkedin.com/in/samrajmatharu/
- GitHub: https://github.com/Samrajtheailyceum