adcontextprotocol/adcp-client-python/build-retail-media-agent

Build a Retail Media Agent (Python)

Overview

A retail media agent sells advertising on a retailer's properties (sponsored products, homepage banners, search results). It extends the standard seller with catalog sync, event tracking, and performance feedback.

When to Use

• User wants to build a retail media network, commerce media platform, or sponsored products agent
• User mentions catalogs, product feeds, conversion tracking, or performance feedback

Not this skill:

• Standard seller without catalogs → skills/build-seller-agent/
• Generative seller → skills/build-generative-seller-agent/
• Signals/audience data → skills/build-signals-agent/

Before Writing Code

Same decisions as the seller skill, plus: what catalogs does the platform accept? What conversion events? Does the buyer send performance metrics back?

Architecture

Start from examples/seller_agent.py (the 9/9 passing seller reference), then add retail-specific tools. Same pattern: subclass ADCPHandler, use response builders, call serve().

from adcp.server import ADCPHandler, serve
from adcp.server.responses import (
    capabilities_response, products_response, media_buy_response,
    delivery_response, sync_accounts_response, sync_governance_response,
    creative_formats_response, sync_creatives_response, media_buys_response,
    sync_catalogs_response, log_event_response,
)
from adcp.server.test_controller import TestControllerStore
class MyRetailAgent(ADCPHandler):
    # All seller tools (see seller skill) PLUS retail-specific tools below
    ...
serve(MyRetailAgent(), name="my-retail-agent", test_controller=MyStore())

Seller Tools (Required)

Implement all tools from the seller skill. Copy the pattern from examples/seller_agent.py:

• get_adcp_capabilities → capabilities_response(["media_buy"])
• sync_accounts → sync_accounts_response(results)
• sync_governance → sync_governance_response(results)
• get_products → products_response(PRODUCTS)
• create_media_buy → media_buy_response(mb_id, packages)
• get_media_buys → media_buys_response(buys)
• list_creative_formats → creative_formats_response(formats)
• sync_creatives → sync_creatives_response(results)
• get_media_buy_delivery → delivery_response(deliveries, reporting_period=...)

See skills/build-seller-agent/SKILL.md for the exact response shapes of each.

If your retail platform supports guaranteed deals with negotiation, also implement the proposal workflow from the seller skill. Refined proposals must include proposal_id, name, and allocations[] with product_id + allocation_percentage (summing to 100) — see "Proposal Workflow (Guaranteed Deals)" in skills/build-seller-agent/SKILL.md.

Retail-Specific Tools

`sync_catalogs` — accept product catalog feeds

from adcp.server.responses import sync_catalogs_response
async def sync_catalogs(self, params, context=None):
    results = []
    for cat in params.get("catalogs", []):
        catalog_id = cat.get("catalog_id", f"cat-{uuid.uuid4().hex[:8]}")
        items = cat.get("items", [])
        catalogs[catalog_id] = cat
        results.append({
            "catalog_id": catalog_id,
            "action": "created",
            "item_count": len(items),
            "items_approved": len(items),
        })
    return sync_catalogs_response(results)

`log_event` — accept conversion events

from adcp.server.responses import log_event_response
async def log_event(self, params, context=None):
    events = params.get("events", [])
    return log_event_response(events_received=len(events), events_processed=len(events))

`provide_performance_feedback` — accept buyer metrics

async def provide_performance_feedback(self, params, context=None):
    # Return shape varies by success/error — consult `ProvidePerformanceFeedbackResponse` in `adcp.types`.
    return {"success": True, "sandbox": True}

`sync_event_sources` — register event tracking

async def sync_event_sources(self, params, context=None):
    results = []
    for src in params.get("event_sources", []):
        results.append({
            "event_source_id": src.get("event_source_id", f"es-{uuid.uuid4().hex[:8]}"),
            "action": "created",
        })
    return {"event_sources": results, "sandbox": True}

Compliance Testing

Same as the seller skill. Copy the TestControllerStore from examples/seller_agent.py and pass to serve():

serve(MyRetailAgent(), name="my-retail-agent", test_controller=MyStore())

SDK Quick Reference

All seller response builders apply, plus:

Validation

python agent.py &
npx -y -p @adcp/client adcp storyboard run http://localhost:3001/mcp media_buy_seller --json
npx -y -p @adcp/client adcp storyboard run http://localhost:3001/mcp media_buy_catalog_creative --json

Common Mistakes

Reference

• skills/build-seller-agent/SKILL.md — base seller skill (start there, add retail tools)
• skills/build-seller-agent/SKILL.md — complete seller tool shapes