> ## 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.

# Buy from a seller

> Use when a buyer names one seller: check that seller is available to the advertiser, get its proposal or pick its products, refine, and stage the media buy.

Skill `buy-from-seller` · version 1.0.0 · for buyers.

## When to use

* A person says "buy on Larkstone Media" or otherwise names the seller they want.
* A person has a direct deal in mind and wants it staged on a campaign.
* A seller is missing from a proposal request and the person wants to know why.

To send a brief to every eligible seller instead, use [Set up a campaign](/skills/set-up-a-campaign).

## Before you start

* The account is ready to buy and the advertiser exists.
* A draft campaign exists for the work, or you have what [Set up a campaign](/skills/set-up-a-campaign)
  needs to create one.

## Steps

1. Call `get_status` and confirm the account and advertiser.
2. Find the seller with `search` and `kind: "seller"`, then call `get` with `kind: "seller"` and
   its id. Add `include: ["products"]` when the person wants to see the catalog.
3. Call `open_connections_page` with the `sellerId` so the person sees the seller's status for this
   advertiser.
4. If the seller is not active for the advertiser, call `save_connection` with
   `target: { kind: "seller", id }` and `advertiserActivation` with the `advertiserId` and
   `decision: "ENABLED"`. If the person wants the seller on every brief, send
   `selection: "ALWAYS_INCLUDE"` in a separate call.
5. Choose a path with the person:
   * **Proposal.** Call `request_proposals` with `campaignId`, `expectedCampaignRevision`,
     `expectedSellerId` set to the seller's id, and an `idempotencyKey`. Collect results as in
     [Set up a campaign](/skills/set-up-a-campaign), then call `refine_proposal` for any change
     the person asks for.
   * **Products.** Pick products and pricing options from the seller's catalog with the person.
6. Stage the buy with `save_media_buy`:
   * from a proposal: `fromProposalId` and an `idempotencyKey`;
   * from products: `campaignId`, `sellerId`, `products` (each with `productId`, `pricingOptionId`
     and `budget`), optionally `flight`, and an `idempotencyKey`.
7. Call `open_campaign_receipt` to show the staged buy. Launch belongs to
   [Manage a campaign](/skills/manage-a-campaign).

## Guardrails

* Reach the seller only through Semicola tools. Do not guess or call a seller's own agent URL.
* If the seller is excluded for the account, or not available in the advertiser's countries or
  channels, tell the person instead of changing their settings on your own.
* Respect the seller's answer. A seller may decline a refinement or a price below its floor.
* A staged buy books nothing. Do not describe it as bought.

## Done when

* The draft campaign has a staged media buy with the named seller, and the person has seen it on the
  receipt; or
* you have told the person why that seller cannot take this buy, and what would change that.