Skip to main content

A2: Your first media buy

Free module — No account required. ~20 minutes with Addie. Prerequisite: A1.

Learning objectives

  • Execute the full media buy lifecycle: discovery, purchase, creative sync, delivery
  • Identify the agent roles involved: buyer agent, sales agent, creative agent, signals agent
  • Read and understand real protocol messages at each stage
  • Observe a live agent-to-agent transaction

Reading list

Protocol architecture

The complete architecture: domain map, identity layer, transaction domains, governance, and ecosystem layers.

MCP integration guide

How MCP works in practice: tool calls, response format, context management, async operations.

Capability discovery

How agents advertise their capabilities so other agents can discover what they offer.

AdAgents.json

The agent discovery mechanism — like robots.txt for advertising agents.

A2A guide

The Agent-to-Agent protocol — how specialized agents collaborate on complex campaigns.

Task lifecycle

How tasks move through states: from request to completion, including async operations.

Key terms

TermDefinition
Sales agentRepresents a publisher and exposes inventory via get_products. May also implement the Creative Protocol to handle creatives from the same endpoint.
Buyer agentRepresents a brand or agency and purchases media via create_media_buy
Brand agentManages brand identity and guidelines via brand.json
Creative agentAny agent implementing the Creative Protocol — produces and adapts advertising assets via build_creative. This can be a standalone service or a sales agent that declares "creative" in supported_protocols.
Signals agentProvides measurement and audience data via get_signals
adagents.jsonPublisher-hosted file declaring agent capabilities (like robots.txt for agents)
Tool discoveryThe process of an agent reading another agent’s capabilities to know what tasks it supports

What you’ll do with Addie

Tell Addie what you want: audience, goals, budget. Then walk through each step as it happens:
  1. Discoveryget_products against @cptestagent, examine real response structure
  2. Purchasecreate_media_buy with targeting and budget. Note the confirmed_at timestamp in the response — this is the seller’s order confirmation.
  3. Creativesync_creatives to deliver assets to the publisher
  4. Status checkget_media_buys to see lifecycle state, creative approvals, and valid_actions
  5. Deliveryget_media_buy_delivery to see results
You’ll see the actual protocol messages at each stage. By the end, you’ve bought media through an agent.

Assessment

DimensionWeightWhat Addie looks for
Conceptual understanding25%Can you describe the transaction flow and which agent handles what?
Practical knowledge35%Can you direct a media buy and interpret the delivery report?
Problem solving15%Can you reason about what happens when things go wrong?
Protocol fluency25%Do you use correct task names and agent roles?
Passing threshold: 70%.

Start this module

Start A2 with Addie

Open Addie and say “I’d like to start certification module A2.”
Next: A3: The AdCP landscape