> ## Documentation Index
> Fetch the complete documentation index at: https://docs.adcontextprotocol.org/llms.txt
> Use this file to discover all available pages before exploring further.

# A3: The AdCP landscape

> Module A3: Survey of every AdCP domain — media buy, creative, catalogs, accounts, signals, governance, sponsored intelligence, and the Trusted Match Protocol. Free 15-minute interactive overview.

# A3: The AdCP landscape

> [!NOTE]
>
> **Free module** — No account required. \~15 minutes with Addie. Prerequisite: [A2](/dist/docs/3.3.0-beta.0/learning/foundations/a2-protocol-architecture).

This is the survey course. Touch everything, go deep on nothing. You'll get a map of the entire AdCP ecosystem — every protocol domain, every discovery mechanism, every governance layer. Designed to pique your curiosity and show you where to go deeper.

Completing A1 + A2 + A3 earns the **AdCP basics** credential.

## Learning objectives

* Describe what `brand.json` is and why advertisers, publishers, sellers, and platforms use it
* Explain `adagents.json` and how publishers authorize agents for inventory
* Name all eight AdCP protocol domains and what each covers
* Identify which areas you want to explore deeper in a role track
* Recognize the three trust primitives that make the ecosystem safe: authenticated identity, signed governance tokens, and agent/account isolation

## Reading list

> **[Brand protocol](/dist/docs/3.3.0-beta.0/brand-protocol/index)**
>
> Brand identity claims, brand.json discovery, and brand hierarchy. Four variants: house portfolio, brand agent, redirects, minimal.

> **[Seller setup](/dist/docs/3.3.0-beta.0/brand-protocol/seller-setup)**
>
> How seller identity, property relationships, and signing keys fit with publisher authorization.

> **[Governance overview](/dist/docs/3.3.0-beta.0/governance/overview)**
>
> The governance protocol: property governance, brand governance, content standards, creative governance, and campaign governance.

> **[Campaign governance](/dist/docs/3.3.0-beta.0/governance/campaign)**
>
> Always-on compliance: ties campaigns to media plans, validates every transaction through three independent parties.

> **[Policy registry](/dist/docs/3.3.0-beta.0/governance/policy-registry)**
>
> Community-maintained library of advertising regulations and standards that brands reference by ID.

> **[Embedded Human Judgment](/dist/docs/3.3.0-beta.0/governance/embedded-human-judgment)**
>
> The five principles behind AdCP governance — how humans stay in control when agents act autonomously.

> **[Creative protocol](/dist/docs/3.3.0-beta.0/creative/index)**
>
> The creative protocol: assets, formats, manifests, creative agents, and 20 channels of adaptation.

> **[Signals overview](/dist/docs/3.3.0-beta.0/signals/overview)**
>
> The signals protocol: audience segments, contextual signals, measurement data, and optimization.

> **[Sponsored Intelligence](/dist/docs/3.3.0-beta.0/sponsored-intelligence/overview)**
>
> Conversational brand experiences in AI assistants — a genuinely new advertising model.

> **[Trusted Match Protocol](/dist/docs/3.3.0-beta.0/trusted-match)**
>
> Real-time execution: context match and identity match activate packages at serve time across all surfaces.

> **[Capability discovery](/dist/docs/3.3.0-beta.0/protocol/get_adcp_capabilities)**
>
> How agents advertise what they support so other agents can discover them.

> **[Accounts protocol](/dist/docs/3.3.0-beta.0/accounts/overview)**
>
> The commercial layer: advertisers, operators, authentication, billing, and account lifecycle.

> **[Security Model](/dist/docs/3.3.0-beta.0/building/concepts/security-model)**
>
> How AdCP defends against unauthorized spend, cross-tenant leakage, replay attacks, and SSRF across the ecosystem.

## What you'll cover with Addie

Addie walks through each domain with a quick live example — just enough to understand what each area does:

**Discovery and community:**

* `brand.json`: a machine-readable identity record at `/.well-known/brand.json` for advertisers, publishers, sellers, and platforms
* `adagents.json`: how publishers declare properties and authorize sales or governance agents for inventory
* Community registry: how agents and brands find each other
* AgenticAdvertising.org: working groups, industry councils, how the spec evolves

**Trust primitives (how the ecosystem stays safe):**

* **Authenticated identity** — cryptographic proof of which agent is calling, not a header claim the seller has to take on faith
* **Signed governance context** — approval tokens from the buyer's governance agent that bind a plan to a specific seller and phase, verifiable by auditors years later
* **Agent and account isolation** — every piece of state is scoped to the calling agent and the account it is acting on; cross-tenant reads are rejected with a generic "not found"

**Protocol domains:**

* **Accounts** — commercial identity, operator-billed vs agent-billed, account lifecycle, `get_adcp_capabilities`
* **Media buy** — proposals, forecasting, refinement, packages, keyword targeting, geo-proximity
* **Creative** — formats vs manifests, 20 channels, AI-powered generation with `build_creative`
* **Signals** — audience data, privacy-compliant signals, conversion tracking, attribution
* **Governance** — content standards, property lists, the Oracle model for AI-driven brand safety, campaign governance (multi-party validation, budget authority, policy registry)
* **Sponsored Intelligence** — conversational brand experiences, cost-per-conversation instead of CPM ([experimental](/dist/docs/3.3.0-beta.0/reference/experimental-status) in 3.0)
* **Trusted Match Protocol** — impression-time execution: context match (content fit) and identity match (user eligibility), cross-publisher frequency capping, works across web, mobile, CTV, AI assistants, and retail media ([experimental](/dist/docs/3.3.0-beta.0/reference/experimental-status) in 3.0, feature id `trusted_match.core`)
* **Brand Protocol** — `brand.json` resolution, brand identity claims, brand hierarchy
* **Registry** — entity resolution, agent discovery, community directory

## Assessment

| Dimension | Weight | What Addie looks for |
| - | - | - |
| Breadth | 35% | Can you describe what each protocol domain does? |
| Discovery mechanisms | 25% | Do you understand brand.json, adagents.json, and capability discovery? |
| Key concepts | 25% | Can you explain format vs manifest, billing models, the Oracle model, and context match vs identity match (TMP's two-operation model)? |
| Synthesis | 15% | Can you connect concepts across domains without prompting? |

Passing threshold: 70%.

## Start this module

> **[Start A3 with Addie](https://agenticadvertising.org/chat)**
>
> Open Addie and say "I'd like to start certification module A3."

**Next:** Choose your role track — [Publisher](/dist/docs/3.3.0-beta.0/learning/tracks/publisher), [Buyer](/dist/docs/3.3.0-beta.0/learning/tracks/buyer), or [Platform](/dist/docs/3.3.0-beta.0/learning/tracks/platform)


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