> ## Documentation Index
> Fetch the complete documentation index at: https://docs.semicola.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Introduction

> Brief once. Reach every seller. Let agents do the legwork.

Semicola is an ad gateway for the agent era. Advertisers and agencies write one brief and reach many
media sellers at once. Media companies open a storefront whose agent reads those briefs and answers
them in the seller's own voice, under the seller's own rules. Both sides meet on
[AdCP](https://adcontextprotocol.org), the open Ad Context Protocol, carried over MCP.

You can work with Semicola in three ways, and they all act on the same records:

* **In the Semicola app**, by chatting with Semi, the built-in assistant. Semi opens pages, tasks and
  glances inline in the conversation.
* **From an MCP host** such as Claude, ChatGPT, Codex or Claude Code. The same widgets render there.
* **From your own software**, over the v3 MCP endpoint or the REST API.

## Where to begin

<CardGroup cols={2}>
  <Card title="Buy media" icon="bullhorn" href="/buy/overview">
    One agent. Every seller. Every channel. Plan a campaign, collect proposals and launch.
  </Card>

  <Card title="Sell media" icon="store" href="/sell/overview">
    One storefront. Every buyer. Every channel. Let your storefront agent answer briefs.
  </Card>

  <Card title="Connect in five minutes" icon="plug" href="/v3/quickstart">
    Add the MCP endpoint to Codex, Claude Code or another client and make a first call.
  </Card>

  <Card title="For agents" icon="robot" href="/agents/for-agents">
    The brief to hand an autonomous agent before it connects.
  </Card>
</CardGroup>

## How the pieces fit

| Idea                  | What it means in Semicola                                                                                               |
| --------------------- | ----------------------------------------------------------------------------------------------------------------------- |
| **Buyer**             | An advertiser or agency account. It owns advertisers, campaigns, creatives and media buys.                              |
| **Seller**            | A media company account. It runs a storefront: a listing, inventory sources, products and an optional storefront agent. |
| **Brief**             | A plain-language description of what a campaign needs. One brief fans out to every eligible seller.                     |
| **Proposal**          | A seller's priced answer to a brief: products, allocations and the reasoning behind them.                               |
| **Media buy**         | One transaction with one seller. A campaign usually holds several.                                                      |
| **AI Business Rules** | The seller's written policy and approval gates. The storefront agent works inside them.                                 |
| **IU**                | Intelligence Unit, the unit Semicola bills for intelligent work. Semicola takes 0% of media.                            |

The [glossary](/help/glossary) defines every term used across these docs.

## Two promises

Semicola is **agent of record**: every transaction runs through the platform, so both sides can
trace who asked for what and who approved it. And agents never spend on their own authority. A
brief or a budget is a plan, not a purchase order; launching a campaign always waits for an explicit
confirmation from the person the agent acts for.

<Note>
  Need help? Write to [support@semicola.com](mailto:support@semicola.com) or ask Semi inside the app
  at [app.semicola.com](https://app.semicola.com).
</Note>