Audience Activation Protocol RFC

Status: Request for Comments
Last Updated: July 25, 2025

Abstract

The Audience Activation Protocol defines a standard Model Context Protocol (MCP) interface for AI-powered audience activation and management systems. This protocol enables AI assistants to help marketers discover, activate, and manage audiences through natural language interactions.

Overview

The Audience Activation Protocol provides:

Natural language audience discovery based on marketing objectives
Multi-platform audience discovery in a single request
Audience activation for specific platforms and accounts
Transparent pricing with CPM and revenue share models
Audience size reporting with unit types (individuals, devices, households)

Core Concepts

Agent Integration

The Audience Activation Protocol operates within the broader Ad Tech Ecosystem Architecture, enabling audience agents to directly integrate with and activate audiences on decisioning platforms (DSPs, injective platforms).

Direct Integration Model: Audience agents contract directly with decisioning platforms, eliminating intermediary reporting and usage tracking. Once audiences are activated on a decisioning platform, all usage reporting, billing, and campaign metrics are handled directly by that platform.

Request Roles and Relationships

Every audience discovery request involves two key roles:

Orchestrator

The platform or system making the API request to the audience platform:

Examples: Scope3, Claude AI assistant, trading desk platform, campaign management tool
Responsibilities: Makes API calls, handles authentication, manages the technical interaction
Account: Has technical credentials and API access to the audience platform

Principal

The entity on whose behalf the request is being made:

Examples: Advertiser (Nike), agency (Omnicom), brand team, media buyer
Responsibilities: Owns the campaign objectives, budget, and business relationship
Pricing: May have negotiated rates, contract terms, or access to private audiences

How This Works in Practice

Request Flow: Orchestrator → Audience Platform (on behalf of Principal) → Decisioning Platform
Authentication: Orchestrator authenticates with technical credentials
Authorization: Principal's identity determines available audiences and pricing
Activation: Audiences are activated for Principal's account on the decisioning platform
Billing: Principal is responsible for usage costs and campaign spend

Example Scenarios

Scenario 1: Marketplace Agent with Personalized Catalog (Agency)

Orchestrator: Claude AI assistant (making API calls)
Principal: Omnicom (agency running campaign for Nike)
Audience Agent: LiveRamp (marketplace agent, Omnicom has account for personalized catalog)
Decisioning Platform: The Trade Desk (where audiences will be used)
Flow: Claude (on behalf of Omnicom) → LiveRamp (Omnicom's personalized catalog with negotiated rates and private data) → delivers to Omnicom's account on The Trade Desk

Scenario 2: Marketplace Agent with Personalized Catalog

Orchestrator: Scope3 platform (connecting audiences to agents)
Principal: Nike (advertiser setting up their agent)
Audience Agent: Experian (marketplace agent, Nike has account for personalized catalog)
Decisioning Platform: Nike Advertising Agent (running on Scope3 platform)
Flow: Scope3 (on behalf of Nike) → Experian (Nike's personalized catalog with owned data and custom rates) → delivers to Nike's advertising agent (hosted by Scope3)

Scenario 3: Private Audience Agent

Orchestrator: Scope3 platform (connecting audiences to agents)
Principal: Walmart (retailer setting up their agent)
Audience Agent: Walmart (private agent, only visible to Walmart)
Decisioning Platform: Walmart Advertising Agent (running on Scope3 platform)
Flow: Scope3 (on behalf of Walmart) → Walmart audience agent (private, owned, no cost) → delivers to Walmart's advertising agent for workflow orchestration

Scenario 4: Marketplace Agent with Public Catalog

Orchestrator: Claude AI assistant (making API calls)
Principal: Startup Brand (new advertiser with no existing accounts)
Audience Agent: LiveRamp (marketplace agent, public catalog access)
Decisioning Platform: The Trade Desk (where audiences will be used)
Flow: Claude (on behalf of Startup Brand) → LiveRamp (public catalog, standard pricing) → delivers to Startup Brand's account on The Trade Desk

Scenario 5: Data Provider with Multi-Platform Deployment

Orchestrator: Agency trading desk platform
Principal: Media Agency (looking for contextual segments)
Audience Agent: Peer39 (contextual data provider)
Decisioning Platforms: Multiple SSPs (Index Exchange, OpenX, PubMatic)
Flow: Trading desk (on behalf of Agency) → Peer39 (returns same segments deployed across multiple SSPs) → Agency can activate on any/all SSPs

Audience Agent Types

Private Audience Agents

Agents owned by the principal with exclusive access:

Examples: Walmart's internal audience platform, retailer first-party data
Business Model: No audience costs (workflow orchestration only)
Access: Only visible and accessible to the owning principal
Discovery: Not discoverable by other principals
Authentication: Owner-only access, no external visibility
Usage Reporting: Optional (no billing, just workflow tracking)

Marketplace Audience Agents

External agents that license audience data with catalog-based access:

Examples: LiveRamp, Experian, data providers
Business Model: CPM, revenue share, or licensing fees
Usage Reporting: Required for billing reconciliation

Catalog Access Levels:

Public Catalog: Available to any orchestrator without principal registration
- Standard marketplace pricing
- Platform-wide segments only (available to all decisioning platform users)
- No account specification needed in requests
- All segments already live (scope: "platform-wide")
Personalized Catalog: Requires principal account with the audience agent
- All platform-wide segments (same as public catalog)
- PLUS account-specific segments (custom audiences, private data)
- Mixed pricing: negotiated rates for some, standard rates for others
- Account field required in requests for account-specific deployments

Authentication Patterns

Private: Owner-only authentication (e.g., Walmart authenticates to their own agent)
Marketplace: Orchestrator authentication determines catalog access level
- Public catalog: Orchestrator credentials sufficient
- Personalized catalog: Requires principal account with audience agent

Segment ID Structure

Audience discovery involves multiple segment identifiers at different stages:

Audience Agent Segment ID

The identifier used by the audience agent for their internal segment tracking:

Example: "polk_001382" (Polk's segment as known to LiveRamp)
Usage: Used in get_audiences responses and activate_audience requests
Scope: Internal to the audience agent platform

Decisioning Platform Segment ID

The identifier assigned by the decisioning platform after activation:

Example: "liveramp_polk_dallas_lexus" (TTD's ID for the activated segment)
Usage: Returned in activate_audience responses and used for campaign targeting
Scope: Internal to the decisioning platform
Timing: Only available after successful activation
Variability: May differ by platform and account for the same audience

Agent vs Data Provider

Agent: The audience platform facilitating access (e.g., LiveRamp, Experian)
Data Provider: The original source of the audience data (e.g., Polk, Acxiom, Peer39)

An audience agent may host segments from multiple data providers in their marketplace.

Coverage Percentage

Coverage percentage indicates what portion of the agent's total addressable audience this segment covers:

99%: Matches nearly all identifiers the agent has (very broad audience)
50%: Matches about half the agent's identifiers (medium audience)
1%: Matches very few identifiers the agent has (very niche audience)

This is relative to each audience agent's capabilities - a 50% coverage audience from LiveRamp may be larger than a 99% coverage audience from a niche data provider.

Pricing Models

CPM: Cost per thousand impressions
Revenue Share: Percentage of media spend
Both: Some audiences offer choice between models
Included: No additional cost (e.g., with media buys)

Protocol Specification

get_audiences

Discovers relevant audiences based on a marketing specification across multiple platforms.

Request

Request Example:

{
  "audience_spec": "Premium automotive intenders in major urban markets",
  "deliver_to": {
    "platforms": [
      {
        "platform": "index-exchange",
        "account": "agency-123-ix"        // Optional - for account-specific segments
      },
      {
        "platform": "openx"                // No account = platform-wide segments only
      },
      {
        "platform": "pubmatic",
        "account": "brand-456-pm"
      }
    ],
    "countries": ["US", "CA"]
  },
  "filters": {
    "catalog_types": ["marketplace"],
    "max_cpm": 5.0,
    "min_coverage_percentage": 10
  },
  "max_results": 5
}

All Platforms Example (discover all available deployments):

{
  "audience_spec": "Contextual segments for luxury automotive content",
  "deliver_to": {
    "platforms": "all",                   // Returns all platforms where segments are deployed
    "countries": ["US"]
  },
  "filters": {
    "data_providers": ["Peer39"],         // Optional filter by data provider
    "catalog_types": ["marketplace"]
  }
}

Response

{
  "audiences": [{
    "audience_agent_segment_id": "peer39_luxury_auto",
    "name": "Luxury Automotive Context",
    "description": "Pages with luxury automotive content and high viewability",
    "audience_type": "marketplace",
    "data_provider": "Peer39",
    "coverage_percentage": 15,
    "deployments": [                      // Array of deployments across platforms
      {
        "platform": "index-exchange",
        "account": "agency-123-ix",
        "is_live": true,
        "scope": "account-specific",
        "decisioning_platform_segment_id": "ix_agency123_peer39_lux_auto"
      },
      {
        "platform": "index-exchange",
        "account": null,                  // Platform-wide version also available
        "is_live": true,
        "scope": "platform-wide",
        "decisioning_platform_segment_id": "ix_peer39_luxury_auto_gen"
      },
      {
        "platform": "openx",
        "account": null,
        "is_live": true,
        "scope": "platform-wide",
        "decisioning_platform_segment_id": "ox_peer39_lux_auto_456"
      },
      {
        "platform": "pubmatic",
        "account": "brand-456-pm",
        "is_live": false,
        "scope": "account-specific",
        "estimated_activation_duration_minutes": 60
      }
    ],
    "pricing": {
      "cpm": 2.50,
      "currency": "USD"
    }
  }]
}

activate_audience

Activates an audience for use on a specific platform/account.

Request

{
  "audience_agent_segment_id": "peer39_luxury_auto",
  "platform": "pubmatic",                   
  "account": "brand-456-pm"                 // Required for account-specific activation
}

Response

{
  "decisioning_platform_segment_id": "pm_brand456_peer39_lux_auto",
  "estimated_activation_duration_minutes": 60
}

check_audience_status

Checks the deployment status of an audience on a decisioning platform.

Request

{
  "audience_agent_segment_id": "peer39_luxury_auto",
  "decisioning_platform": "index-exchange",
  "account": "agency-123-ix"                // Optional - only for account-specific segments
}

Response

{
  "status": "deployed",
  "deployed_at": "2025-01-15T14:30:00Z"
}

Typical Flow

Data Provider Multi-Platform Flow (e.g., Peer39)

Discovery: Call get_audiences with multiple platforms to see all deployments at once
Review: See which platforms have segments live vs. requiring activation, compare segment IDs across platforms
Select: Choose which platforms to use based on campaign needs and existing deployments
Activate: For any platforms where segments aren't live, call activate_audience
Monitor: Use check_audience_status to track activation progress
Launch: Run campaigns across multiple SSPs using the platform-specific segment IDs
Report: Report usage separately for each platform where the audience was used

Marketplace Audience Agent Flow

Discovery: Call get_audiences multiple times to explore different audience options - response varies by authentication (public vs personalized catalog)
Review: Evaluate audience options, pricing, and deployment.is_live status for the specific decisioning platform
Commit: Principal decides to proceed with specific audiences for their media execution
Activate: For account-specific segments that aren't live, call activate_audience to deploy from audience agent to decisioning platform
Monitor: Use check_audience_status to track activation progress between agents
Launch: Once deployed, launch the media execution (campaigns, PMPs, direct buys, etc.) on the decisioning platform

Private Audience Agent Flow

Discovery: Call get_audiences on owned audience agent (Walmart), with no licensing costs
Review: Check deployment.is_live status for workflow orchestration (no pricing review needed)
Commit: Principal decides to proceed with owned audiences for their media execution
Activate: If not live, call activate_audience for workflow orchestration from owned agent to decisioning platform
Monitor: Use check_audience_status to track activation progress
Launch: Once deployed, launch the media execution using owned audiences

Error Codes

AUDIENCE_AGENT_SEGMENT_NOT_FOUND: Audience agent segment ID doesn't exist
ACTIVATION_FAILED: Could not activate audience
ALREADY_ACTIVATED: Audience already active
DEPLOYMENT_UNAUTHORIZED: Can't deploy to platform/account
INVALID_PRICING_MODEL: Pricing model not available
AGENT_NOT_FOUND: Private audience agent not visible to this principal
AGENT_ACCESS_DENIED: Principal not authorized for this audience agent

Implementation Notes

Authentication

Each MCP session involves two levels of identification:

Orchestrator Authentication

The technical credentials used by the orchestrator to authenticate with the audience platform:

API Keys: Technical access credentials for the orchestrator platform
Session Scope: Determines what operations the orchestrator can perform
Platform Permissions: What audience platforms the orchestrator can access

Principal Authorization

The principal's identity determines business-level access and pricing:

Account Relationship: Whether the principal has a direct relationship with the audience platform
Pricing Tier: Negotiated rates, marketplace rates, or enterprise discounts
Audience Access: Private audiences, premium segments, or marketplace-only access
Billing Account: Where usage charges are applied

Authentication Flow

Caller authenticates with audience agent using their credentials
Audience agent determines catalog access level based on authentication
Responses reflect the authenticated party's available options and rates

Orchestrator Implementation Guidelines

Agent Discovery and Access

Private Agents: Only show to owning principal (e.g., only show Walmart's agent to Walmart)
Marketplace Agents: Always discoverable, but catalog access varies by principal account status

Error Handling by Agent Type

Private: Return AGENT_NOT_FOUND for non-owners
Marketplace: Always allow requests but return appropriate catalog level
- Public catalog: Generic marketplace offerings with standard pricing
- Personalized catalog: Principal's custom data, negotiated rates, and owned segments

User Experience Considerations

Setup Flow: Marketplace agents with public catalogs enable immediate audience discovery
Account Benefits: Principals with marketplace agent accounts get their own data plus negotiated rates
Privacy: Private agents ensure data sovereignty for owned audiences

Multi-Platform Considerations

Response Format

All responses contain deployments array showing audience availability across platforms
Enables efficient multi-platform discovery and activation planning

Platform-Specific Segment IDs

Same audience may have different segment IDs on different platforms
Account-specific deployments may have different IDs than platform-wide deployments
Always use the correct decisioning_platform_segment_id for each platform/account combination

Efficient Discovery

Data providers like Peer39 can return all their deployments in one response
Reduces API calls from N (one per platform) to 1
Particularly valuable for contextual data providers with wide SSP distribution

Best Practices

Check is_live status before attempting activation
Allow 24-48 hours for audience activation
Understand the difference between size units
Consider both pricing options when available
Use multi-platform queries when discovering audiences across SSPs
Store platform-specific segment IDs for campaign execution

Next Steps

See the Audience Agent reference implementation

Abstract​

Overview​

Core Concepts​

Agent Integration​

Request Roles and Relationships​

Orchestrator​

Principal​

How This Works in Practice​

Example Scenarios​

Audience Agent Types​

Private Audience Agents​

Marketplace Audience Agents​

Authentication Patterns​

Segment ID Structure​

Audience Agent Segment ID​

Decisioning Platform Segment ID​

Agent vs Data Provider​

Coverage Percentage​

Pricing Models​

Protocol Specification​

get_audiences​

Request​

Response​

activate_audience​

Request​

Response​

check_audience_status​

Request​

Response​

Typical Flow​

Data Provider Multi-Platform Flow (e.g., Peer39)​

Marketplace Audience Agent Flow​

Private Audience Agent Flow​

Error Codes​

Implementation Notes​

Authentication​

Orchestrator Authentication​

Principal Authorization​

Authentication Flow​

Orchestrator Implementation Guidelines​

Agent Discovery and Access​

Error Handling by Agent Type​

User Experience Considerations​

Multi-Platform Considerations​

Response Format​

Platform-Specific Segment IDs​

Efficient Discovery​

Best Practices​

Next Steps​

Abstract

Overview

Core Concepts

Agent Integration

Request Roles and Relationships

Orchestrator

Principal

How This Works in Practice

Example Scenarios

Audience Agent Types

Private Audience Agents

Marketplace Audience Agents

Authentication Patterns

Segment ID Structure

Audience Agent Segment ID

Decisioning Platform Segment ID

Agent vs Data Provider

Coverage Percentage

Pricing Models

Protocol Specification

get_audiences

Request

Response

activate_audience

Request

Response

check_audience_status

Request

Response

Typical Flow

Data Provider Multi-Platform Flow (e.g., Peer39)

Marketplace Audience Agent Flow

Private Audience Agent Flow

Error Codes

Implementation Notes

Authentication

Orchestrator Authentication

Principal Authorization

Authentication Flow

Orchestrator Implementation Guidelines

Agent Discovery and Access

Error Handling by Agent Type

User Experience Considerations

Multi-Platform Considerations

Response Format

Platform-Specific Segment IDs

Efficient Discovery

Best Practices

Next Steps