> ## Documentation Index
> Fetch the complete documentation index at: https://docs.apostra.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Object Model
> The full v2 object hierarchy — every buyer-side and storefront-side resource, what it is, where it sits, and which guide covers it.
Apostra has two object hierarchies that meet at the AdCP wire. Buyers
plan and execute media; storefronts expose inventory. Both sides share one
platform and one auth model, but their objects are disjoint — an agent only
ever works inside the hierarchy that matches its job.
This page is the canonical map. Each side gets an ASCII tree, then a table per
object: what it is, its parent, what nests under it, and the guide that covers it.
**Media Buys and Packages are not directly creatable.** They are spawned by
the platform when a [Campaign](/v2/object-guides/campaign) executes — one
media buy per sales agent, one package per product per pacing period. You read
their status and tune them through the campaign update endpoint, never by
POSTing them directly.
## Buyer side
A buyer's world is rooted at the **Advertiser** and flows down to the
**Delivery** metrics that roll back up. Discovery, creatives, signals, and
audiences attach to the [Campaign](/v2/object-guides/campaign) — the focal
object.
```
Advertiser (top-level container, owns a Brand)
└── Campaign (discovery, performance, or directed)
├── Discovery Session (product search; produces Proposals)
├── Creative (manifest, attached at the campaign)
└── Media Buy (one per sales agent — spawned at execute)
└── Package (one per product per pacing period)
└── Delivery (impressions, spend, clicks)
```
| Object | What it is | Parent | Contains | Guide |
| --------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------- | --------------------------------------------------------------- | -------------------------------------------- |
| **Advertiser** | Top-level container for a buyer's media. Owns a brand, default optimization mode, and linked sales-agent accounts. | — | Campaign, Brand | [Advertiser](/v2/object-guides/advertiser) |
| **Campaign** | A campaign in `discovery`, `performance`, or `directed` mode, with a `management` state: `tracked` (a campaign the platform did not set up, mirrored read-only from a connected provider account) or `managed` (uses the canonical buyer product and media-buy lifecycle). A tracked `mode: directed` campaign projects one storefront-managed media buy. | Advertiser | Discovery Session, Creative, Media Buy, Audience, Frequency Cap | [Campaign](/v2/object-guides/campaign) |
| **Media Buy** | One AdCP transaction with one sales agent. Platform-managed campaigns spawn buys at execute; a directed campaign projects exactly one storefront buy. Its legacy `routingType` is temporary billing compatibility metadata derived from `BillingParty`; it is never a storefront or execution type. | Campaign | Package | [Media Buys](/v2/buyer/campaigns/media-buys) |
| **Package** | One seller line within a media buy. Platform-managed campaigns usually create one per product per pacing period; directed campaigns mirror the seller's native package grain. | Media Buy | Delivery | [Packages](/v2/buyer/campaigns/packages) |
| **Delivery** | Reported metrics that roll up per package: `impressions`, `spend`, `clicks`. Follows the AdCP `get_media_buy_delivery` shape. | Package | — | [Packages](/v2/buyer/campaigns/packages) |
| **Discovery Session** | A product-search conversation against sales agents. Refinable; produces ranked **Proposals** the campaign selects from. | Campaign | Proposal | [Discovery](/v2/guides/discovery) |
| **Creative** | A manifest-based asset uploaded under the campaign, auto-synced to media buys by accepted format. | Campaign | — | [Creative](/v2/object-guides/creative) |
| **Signal** | A targeting or optimization input (audience, contextual, outcome) discovered from signal agents via AdCP. | Campaign / Advertiser | — | [Signal](/v2/object-guides/signal) |
| **Audience** | A target or suppress list attached to a campaign. | Campaign | — | [Signal](/v2/object-guides/signal) |
| **Property List** | A named include/exclude set of domains, apps, or deals applied to packages without a full re-execute. | Campaign | — | [Campaign](/v2/object-guides/campaign) |
| **Event Source** | A conversion-tracking source (pixel, server event) referenced by event-based optimization goals. | Advertiser | — | [Campaign](/v2/object-guides/campaign) |
| **Brand** | The brand identity and manifest behind an advertiser — name, assets, safety, and story. | Advertiser | — | [Brand Story](/v2/object-guides/brand-story) |
## Storefront side
A storefront's world is rooted at the **Storefront** and wraps one or more
AdCP-compatible **Inventory Sources**. Buyers register **Credentials** per
source where the source requires them; those credentials gate the buyer
accounts that transact through the storefront.
```
Storefront (the sales-agent surface buyers see)
├── Business Profile (identity, terms, positioning)
├── Operating Instructions (versioned; exactly one active)
├── Material(s) (versioned marketing evidence)
│ └── Rendition(s) (blocks + reusable visual assets)
└── Inventory Source(s) (AdCP agent — discovery + execution)
├── Component Cache (raw products/components, when supported)
└── Buyer Credentials (per source, where required)
└── Buyer accounts (the accounts that transact)
```
| Object | What it is | Parent | Contains | Guide |
| -------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ----------------- | ---------------------------------------------------------- | ------------------------------------------------------------------------------------ |
| **Storefront** | The sales-agent surface a buyer connects to. Wraps inventory sources, a business profile, and operating instructions. | — | Inventory Source, Business Profile, Operating Instructions | [Storefront](/v2/object-guides/storefront) |
| **Inventory Source** | A source that provides supply to the storefront. It may be an external AdCP sales agent, an ad-server-backed source, a linked source, or a modular source. | Storefront | Component Cache, Buyer Credentials | [Storefront](/v2/object-guides/storefront) |
| **Component Cache** | Cached raw products/components exposed by a source, when the source supports them. Used for merchandising and wholesale reads; passthrough source calls can still be live. | Inventory Source | — | [Inventory sources](/v2/storefront/inventory-sources/overview) |
| **Buyer Credentials** | A buyer's registered account for one inventory source, where the source requires per-buyer credentials. | Inventory Source | Buyer accounts | [Storefront](/v2/object-guides/storefront) |
| **Buyer accounts** | The buyer-side accounts linked through credentials that actually transact against the source. | Buyer Credentials | — | [Storefront](/v2/object-guides/storefront) |
| **Operating Instructions** | Versioned guidance that steers how the storefront responds to demand. Exactly one version is active at a time. | Storefront | — | [Storefront](/v2/object-guides/storefront) |
| **Business Profile** | The storefront's identity and positioning — name, terms, and how it presents to buyers. | Storefront | — | [Storefront](/v2/object-guides/storefront) |
| **Material** | Seller marketing evidence such as a PDF, presentation, image, site snapshot, or spreadsheet. Every source refresh creates an immutable revision; derived renditions report their extraction completeness explicitly. | Storefront | Rendition | [Seller v3 workflows](/v2/setup/v3/seller-workflows#add-and-inspect-seller-material) |
| **Rendition** | A versioned derivation of one Material source revision, preserving page, slide, or sheet units; ordered semantic blocks; tables and geometry; diagnostics; and rights-aware visual assets. Original and preview bytes stay out of model context behind expiring signed access. | Material | Semantic Block, Visual Asset | [V3 tool reference](/v2/setup/v3/tool-reference#read-structured-results) |
| **Semantic Block** | A bounded, independently paged text, list, table, caption, note, OCR, or accessibility block with a stable source locator and extraction provenance. | Rendition | — | [V3 tool reference](/v2/setup/v3/tool-reference#read-structured-results) |
| **Visual Asset** | A reusable image, chart, logo, or diagram with deterministic identity, dimensions, placement, provenance, confidentiality, and explicit reuse rights. | Rendition | — | [Seller v3 workflows](/v2/setup/v3/seller-workflows#add-and-inspect-seller-material) |
| **Proposal** | An offer a storefront returns in response to discovery — products, pricing, and terms a buyer can select. | Inventory Source | — | [Discovery](/v2/guides/discovery) |
| **Creative Review** | A storefront's approval or rejection of a buyer's creative, with reviewer attribution. | Storefront | — | [Creative](/v2/object-guides/creative) |
| **Media-Buy Approval** | A storefront's sign-off on an incoming media buy before it goes live. | Storefront | — | [Storefront](/v2/object-guides/storefront) |
The two hierarchies meet at the AdCP wire: a buyer's **Media Buy** is the same
transaction a storefront approves through **Media-Buy Approval**, and a buyer's
**Discovery Session** is answered by a storefront's **Proposals**. Read the
[Philosophy primer](/v2/concepts/philosophy) for why the surfaces are split.
## Where to go next
Why v2 splits buyer and storefront, uses SESOFI, and defaults to AdCP.
Every term in the docs, alphabetized with links to the deep guides.
The focal buyer object — how a plan becomes media buys and packages.
Wrap inventory sources, manage credentials, and connect buyer accounts.