> ## Documentation Index
> Fetch the complete documentation index at: https://docs.interchange.io/llms.txt
> Use this file to discover all available pages before exploring further.
# How Interchange uses AdCP (buy side)
> How Interchange, as a buyer platform, uses the Ad Context Protocol to discover and transact across many sellers — and where it conforms, extends, or doesn't implement a surface.
Interchange is built on the [Ad Context Protocol (AdCP)](https://docs.adcontextprotocol.org). This page covers the
**buy side** — how Interchange, acting as a buyer platform, *consumes* AdCP across many sellers.
This is the buy-side view. For the seller (supply) side — connecting your own AdCP sales agent as a storefront
source — see [Connect your sales agent](/v2/storefront/inventory-sources/connect-your-agent). When this page and
the AdCP spec disagree on what the *protocol* means, the AdCP spec wins.
## The cross-seller pattern
The defining difference between AdCP and Interchange on the buy side is the same everywhere: **AdCP defines a task
against one agent; Interchange runs it across many.** That fan-out is our core scaling layer.
| AdCP task (single seller) | Interchange (many sellers) |
| --------------------------------------- | ---------------------------------------------------------------------------------------- |
| `get_products` | **Discover Products** — one brief fanned out to every reachable agent, merged and ranked |
| `get_signals` | cross-agent signal discovery |
| `create_media_buy` / `update_media_buy` | a **Campaign** that spawns one media buy per seller |
| `get_media_buy_delivery` | aggregated reporting rolled up across all sellers |
## Conformance (buy side)
**Status:** **1:1** conforms as written · **+ext** with a Scope3 scaling layer · **none** not implemented yet.
| AdCP surface | Status | What Interchange does |
| ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| [`get_products`](https://docs.adcontextprotocol.org/docs/media-buy/task-reference/get_products) | +ext | Cross-seller fan-out of one brief; adds a discovery session, brief enrichment, and ranking. See [Discover Products](/v2/buyer/discovery/tasks/discover-products). |
| [`sync_catalogs`](https://docs.adcontextprotocol.org/docs/media-buy/task-reference/sync_catalogs) | 1:1 | Matches the spec; the catalog is also injected into the discovery fan-out. |
| [`create_media_buy`](https://docs.adcontextprotocol.org/docs/media-buy/task-reference/create_media_buy) | +ext | Buyers create a **Campaign** that spawns one media buy per seller. See [Create a campaign](/v2/buyer/campaigns/tasks/create-campaign). |
| [`update_media_buy`](https://docs.adcontextprotocol.org/docs/media-buy/task-reference/update_media_buy) | +ext | Campaign-level update cascade; a capability guard blocks updates an upstream agent can't support. |
| [`get_media_buy_delivery`](https://docs.adcontextprotocol.org/docs/media-buy/task-reference/get_media_buy_delivery) | +ext | Aggregated reporting across all sellers. |
| [`get_media_buys`](https://docs.adcontextprotocol.org/docs/media-buy/task-reference/get_media_buys) | +ext | Campaign-granularity list; most-restrictive status rollup. |
| `list_creatives` / [`build_creative`](https://docs.adcontextprotocol.org/docs/creative/task-reference/build_creative) | +ext | Campaign-scoped manifests; conversational creative sessions. |
| `get_signals` | +ext | Cross-agent signal discovery. |
| [`sync_audiences`](https://docs.adcontextprotocol.org/docs/media-buy/task-reference/sync_audiences) / [`sync_event_sources`](https://docs.adcontextprotocol.org/docs/media-buy/task-reference/sync_event_sources) / [`log_event`](https://docs.adcontextprotocol.org/docs/media-buy/task-reference/log_event) | +ext | First-party audience + event stores feeding the Measurement Engine. |
| Measurement taxonomy | +ext | A Bayesian incrementality engine. See [Measurement & incrementality](/v2/guides/measurement-incrementality). |
| `list_accounts` / `sync_accounts` | +ext / 1:1 | A three-stage buyer model (credentials → available → linked). |
| [`provide_performance_feedback`](https://docs.adcontextprotocol.org/docs/media-buy/task-reference/provide_performance_feedback) | none | Not implemented; an internal optimization loop substitutes. |
| [`get_creative_delivery`](https://docs.adcontextprotocol.org/docs/creative/task-reference/get_creative_delivery) | none | Not implemented; reporting currently stops at the package level. |
## Where the truth lives
The protocol's source of truth.
The seller (supply) side — bring your AdCP agent in as a storefront source.
The cross-seller discovery surface.
How a campaign spawns media buys across sellers.