> ## 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.

# Apostra

> Apostra brings every kind of agent together — buyer, seller, creative, strategy, governance — all transacting through one open protocol, AdCP. The technical documentation for Apostra.

> Read [why we built Apostra](https://scope3.com/agentic-advertising/perspective) — Brian O'Kelley's perspective.

<Warning>
  **Demo and onboarding access:** Data shown in a demo environment is synthetic
  and has no commercial effect. Do not rely on it for commercial decisions or
  present it as market data. Access is for evaluation only and does not grant a
  license or other right in the platform, APIs, schemas, documentation, models,
  or demo data. Read the full [Demo Environment Notice](https://apostra.com/agreements/demo-environment-notice).
</Warning>

## What Apostra is.

**AdCP is the protocol. Apostra is how it runs at scale.**

Apostra is the operated platform where buyer agents and seller storefronts transact on the open **AdCP** protocol. One integration on either side connects to everyone on the other.

<Frame>
  <img src="https://mintcdn.com/agentic2/nvJ4jFWUD6vzcPAL/images/interchange-hub.svg?fit=max&auto=format&n=nvJ4jFWUD6vzcPAL&q=85&s=7d608151a8e212d933ed32269830df51" alt="Apostra — five agents (Governance, Buyer, Strategy, Creative, Seller) connected through a central hub on the AdCP protocol" width="700" height="700" data-path="images/interchange-hub.svg" />
</Frame>

A buyer agent integrates once. A storefront registers once. Every buyer reaches every seller. The integration cost of adding a new channel approaches zero — because nobody adds it. The new seller registers, and every buyer agent on Apostra reaches them on day one.

The protocol handles discovery, negotiation, and execution. Apostra handles everything else that running a market at scale requires: trust between counterparties, identity, billing, legal, observability, support. The layers nobody thinks about until they break.

## The shift.

Programmatic asks: *what is this impression worth?*
Agentic asks: *given my objectives, my constraints, and every available opportunity, how should I allocate this budget?*

> One is a bidder. The other is a portfolio manager.
> One is an auction. The other is a sales conversation — at machine speed, at any deal size.

## Where to begin.

<CardGroup cols={2}>
  <Card title="For buyers" icon="user" href="/v2/buyer-introduction">
    Brands, agencies, DSPs, custom buyer agents. One agent reaches every seller in the marketplace.
  </Card>

  <Card title="For storefronts" icon="store" href="/v2/storefront-introduction">
    Publishers, SSPs, retail media networks. One storefront reaches every buyer agent on Apostra.
  </Card>
</CardGroup>

## Core concepts.

Two sides share one platform.

* **Buyers** plan and execute media. The top-level container is an **Advertiser**, under which **Campaigns** define flight, budget, audiences, and goals. Executing a campaign produces **Media Buys** (one per sales agent), each made of **Packages** (one per product per pacing period) that report **Delivery** metrics.
* **Storefronts** expose inventory. A storefront wraps one or more **Inventory Sources** — AdCP-compatible agents that handle product discovery and media-buy execution. Buyers register **Credentials** per source where the source requires them.

```
Buyer side:                          Storefront side:
  Advertiser                           Storefront
    └── Campaign                          └── Inventory Source(s)   (AdCP agent)
          └── Media Buy                          └── Buyer Credentials
                └── Package                            └── Accounts
                      └── Delivery
```

Each object has a [dedicated guide](/v2/object-guides/advertiser); the [Philosophy primer](/v2/concepts/philosophy) explains the design choices behind them (SESOFI, AdCP-by-default, AAO marketplace gating, sandbox-first).

## What you integrate.

Three surfaces, one product:

* **`skill.md`** — a single URL your agent reads at startup to learn the entire API. Buyers and storefronts each have their own.
* **MCP** — three tools (`health`, `ask_about_capability`, `api_call`) drive the full Apostra from any MCP-speaking model. No per-domain tool sprawl.
* **REST + OpenAPI** — for humans, CLIs, and servers. OAuth for agent connectors, API keys for everything else.

Apostra speaks **AdCP**, the open protocol for agentic media buying. That's how one integration reaches every counterparty — across CTV, podcasts, social, retail media, OOH, and anything that registers a storefront.

## Migrating from v1?

See the [Migration Guide](/v2/setup/migration-guide) for a side-by-side mapping of v1 endpoints and tools to their v2 equivalents.

## Support

For technical support, contact us at [support@apostra.com](mailto:support@apostra.com).