Media buy protocol

AdCP media buy protocol walkthrough — follow a campaign from brief to delivery across CTV, display, and audio using one unified workflow.

Sam is a media buyer at Pinnacle Agency. His client just greenlit a $50,000 Q2 campaign for Acme Outdoor’s Trail Pro 3000 — premium video and display across sports and outdoor lifestyle publishers. Three sellers to evaluate. Creatives to match. A governance review before anything goes live.

Last time he ran a campaign this size, it took two weeks. Four dashboards. Four logins. A spreadsheet to compare proposals that were never in the same format. He entered the same flight dates into four different systems.

This walkthrough follows Sam through the same campaign on AdCP — one protocol that replaces four platform-specific workflows.

Step 1: Write the brief

Sam starts with what he knows: the campaign objectives.

In AdCP, the brief is natural language inside get_products. Sam doesn’t need to learn each publisher’s targeting taxonomy or inventory categories — he describes what he wants, and each sales agent interprets it against their own inventory:

const products = await Promise.all(
  sellers.map(seller => seller.getProducts({
    buying_mode: "brief",
    brief: "Premium video inventory on sports and outdoor lifestyle publishers. Q2 flight, $50K budget. Adults 25-54, US and Canada.",
    brand: { domain: "acmeoutdoor.com" },
    account: { brand: { domain: "acmeoutdoor.com" }, operator: "pinnacle-agency.com" }
  }))
);

One brief. Three sellers. Same JSON structure back.

Agency language → protocol terms

What Sam says	What the protocol calls it
Campaign brief	brief field on get_products
Media plan	Products returned from get_products
IO / insertion order	create_media_buy
Trafficking creatives	sync_creatives to each seller
Campaign report	get_media_buy_delivery across agents
Flight dates	start_time / end_time on the media buy or packages

Step 2: Compare proposals

Products come back in a standard format. For the first time, Sam sees pricing, delivery forecasts, targeting options, and creative requirements — all side by side:

Seller	Product	CPM	Forecast	Format
StreamHaus	CTV sports pre-roll	$28	890K impressions	SSAI 30s video
OutdoorNet	Adventure lifestyle display	$12	2.1M impressions	300x250, 728x90
PodTrail	Outdoor podcast mid-roll	$22	340K impressions	Audio 30s + companion

No CSVs. No spreadsheets. No manual data entry. The products are comparable because every seller returns the same schema.

Sam wants to narrow down. He switches to refine mode, telling each agent exactly how to adjust:

const refined = await seller.getProducts({
  buying_mode: "refine",
  refine: [
    {
      scope: "request",
      ask: "Only guaranteed packages. Must include completion rate SLA above 80%."
    }
  ],
  brand: { domain: "acmeoutdoor.com" },
  account: { brand: { domain: "acmeoutdoor.com" }, operator: "pinnacle-agency.com" }
});

The refine array lets Sam layer constraints without starting over. Each refinement narrows the previous result set.

Step 3: Match creatives

Each product has creative requirements. Sam’s platform calls list_creative_formats on each seller to understand exactly what they need:

• StreamHaus needs SSAI-compatible 30s video (MP4, specific codecs)
• OutdoorNet needs display banners (300x250 and 728x90)
• PodTrail needs 30s audio plus a 300x250 companion banner

Sam’s creative team already has assets in their library. The platform matches existing manifests to each seller’s format requirements and flags the gap — PodTrail needs an audio cut that doesn’t exist yet.

const result = await seller.syncCreatives({
  account: { brand: { domain: "acmeoutdoor.com" }, operator: "pinnacle-agency.com" },
  creatives: [
    {
      creative_id: "video_30s_trail_pro",
      name: "Trail Pro 3000 - 30s CTV Spot",
      format_id: { agent_url: "https://streamhaus.example", id: "ssai_30s" },
      assets: { video: { url: "https://cdn.pinnacle-agency.example/trail-pro-30s.mp4", mime_type: "video/mp4" } }
    },
    {
      creative_id: "display_trail_pro_300x250",
      name: "Trail Pro 3000 - Display 300x250",
      format_id: { agent_url: "https://outdoornet.example", id: "display_300x250" },
      assets: { image: { url: "https://cdn.pinnacle-agency.example/trail-pro-300x250.png", mime_type: "image/png" } }
    }
  ]
});
if (result.errors) {
  console.error('Sync failed:', result.errors);
} else {
  console.log(`Synced ${result.creatives.length} creatives`);
}

Step 4: Launch the campaign

Sam creates the media buy. One call per seller, same structure everywhere:

const buy = await seller.createMediaBuy({
  account: { brand: { domain: "acmeoutdoor.com" }, operator: "pinnacle-agency.com" },
  brand: { domain: "acmeoutdoor.com" },
  start_time: "2026-04-01T00:00:00Z",
  end_time: "2026-06-30T23:59:59Z",
  packages: [{
    product_id: "streamhaus_sports_preroll_q2",
    budget: 25000,
    pricing_option_id: "cpm_standard",
    creative_assignments: [{ creative_id: "video_30s_trail_pro" }]
  }]
});

The seller validates the creatives and either approves the buy or sends it through review. Sam doesn’t log into any dashboard — the protocol handles status updates.

Step 5: Governance checks

Before any money moves, Sam’s governance agent validates the buy:

• Budget: $25K is within Sam’s authorized spending limit
• Brand safety: StreamHaus is on Acme Outdoor’s approved publisher list
• Compliance: Targeting parameters meet regulatory requirements for US and Canada
• Creative: All creatives carry required provenance metadata

If the buy exceeds Sam’s authority — say, if the total across all sellers hit $75K — the governance agent escalates to his manager. The campaign pauses at pending_approval until a human signs off.

Campaign governance requires the orchestrator to register the campaign plan via sync_plans before any governance checks. The plan defines authorized parameters — budget limits, channels, flight dates, and compliance policies — against which all subsequent actions are validated. The full governance sequence is sync_plans → check_governance (proposed) → create_media_buy → check_governance (committed by seller). See Campaign Governance for the complete specification.

What governance looks like in the protocol

// Step 1: Register the campaign plan with the governance agent
const plan = await governance.syncPlans({
  plans: [{
    plan_id: "acme-q2-trail-pro",
    brand: { domain: "acmeoutdoor.com" },
    objectives: "Q2 Trail Pro 3000 launch across sports and outdoor lifestyle publishers",
    budget: { total: 50000, currency: "USD", authority_level: "agent_limited" },
    flight: { start: "2026-04-01T00:00:00Z", end: "2026-06-30T23:59:59Z" },
    countries: ["US", "CA"]
  }]
});

// Step 2: Check governance before sending to seller (intent check)
const check = await governance.checkGovernance({
  plan_id: "acme-q2-trail-pro",
  caller: "https://orchestrator.pinnacle-agency.example",
  tool: "create_media_buy",
  payload: buy
});

if (check.status === "denied") {
  // Don't proceed — governance rejected the plan
}

// Step 3: Send the buy to the seller with governance_context attached
const governanceContext = check.governance_context;
const mediaBuy = await seller.createMediaBuy({ ...buy, governance_context: governanceContext });

// Step 4: The seller independently calls check_governance with media_buy_id +
// planned_delivery before confirming — validating against the same plan

Step 6: Match at serve time

The campaign is approved and live. When a user loads a StreamHaus page, opens OutdoorNet’s app, or asks an AI assistant a question, the publisher’s TMP Router evaluates which of Sam’s packages should activate.

Two operations run separately — Context Match asks “does this content fit the package’s targeting?” while Identity Match asks “is this user eligible?” The publisher joins both responses locally. Sam’s buyer agent never sees user identity and content context together — the structural separation is built into the protocol.

The same flow works on every surface. Sam didn’t write surface-specific activation code for CTV versus web versus AI. TMP handles all of them.

How TMP activates a package

When a user visits a StreamHaus article about hiking gear:

1. StreamHaus sends a Context Match request with the article’s content signals and Sam’s available packages
2. Sam’s buyer agent responds: “Activate pkg-outdoor-display — this hiking content matches the targeting”
3. StreamHaus sends a separate Identity Match request with a user token and ALL of Sam’s active packages
4. Sam’s buyer agent responds: “This user is eligible for pkg-outdoor-display (intent_score: 0.82)”
5. StreamHaus joins the results locally and activates the line item

See the Trusted Match Protocol for the full specification.

Step 7: Monitor delivery

The campaign is running. Sam monitors through a single view — his platform calls get_media_buy_delivery on each seller and merges the results:

const delivery = await seller.getMediaBuyDelivery({
  account: { brand: { domain: "acmeoutdoor.com" }, operator: "pinnacle-agency.com" },
  media_buy_ids: [buy.media_buy_id],
  include_package_daily_breakdown: true
});

Every seller reports in the same format: impressions, clicks, spend, completion rates. Sam sees one dashboard instead of four. When StreamHaus underdelivers on the CTV package, he reallocates budget to OutdoorNet — one update_media_buy call instead of logging into two platforms.

The full picture

Sam went from four dashboards to one protocol. The same tasks that bought CTV inventory also bought display and audio — no platform-specific code, no manual data translation, no spreadsheet reconciliation.

Before AdCP	With AdCP
4 dashboards, 4 logins	1 protocol, 1 view
Manual CSV comparison	Standardized product proposals
Platform-specific creative specs	list_creative_formats on any seller
4 campaign setup workflows	create_media_buy everywhere
Manual reporting reconciliation	get_media_buy_delivery aggregated
Per-surface activation ad-ops	TMP matches packages on any surface automatically

Go deeper

• Product discovery: How get_products works — briefs, wholesale mode, proposals, and refinement
• Campaign lifecycle: Managing media buys — status transitions, updates, and approvals
• Optimization: Delivery and reporting — metrics, dimensional breakdowns, and feedback loops
• Governance: Campaign governance — how the three-party trust model protects Sam’s spend
• Creative: Creative walkthrough — how Maya builds the creatives Sam uses
• Real-time matching: Trusted Match Protocol — how packages activate at serve time via Context Match and Identity Match
• Get certified: The Buyer track teaches the full media buy workflow through interactive modules