> ## 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. # Buyer Workflows > Use v3 to create buyer objects, request seller proposals, stage media buys, and launch a campaign. These workflows require an enrolled Buyer account. Call `get_status` first and use `switch_account` if the active account is a Seller or organisation. ## Buyer workflow at a glance 1. Create or select an advertiser. 2. Create a campaign with its brief, flight, and budget. 3. Request proposals from ready sellers. 4. Accept a quoted proposal or stage returned products. 5. Inspect the staged media buys and resolve any draft issues. 6. Launch the campaign explicitly. ## 1. Create an advertiser Creating requires `name` and `brand`. Choose the primary currency deliberately: it defaults to USD when omitted and becomes locked after the first campaign or seller binding. `sandbox` is also immutable after creation. ```json theme={null} { "name": "Acme Europe", "brand": "acme.example", "primaryCurrency": "EUR", "sandbox": true } ``` Retain the returned `advertiserId`. To update, send it with only the fields to change. Do not send `sandbox` on an update. ## 2. Create a campaign Creation requires `advertiserId`, `name`, `flight`, `budget`, and an `idempotencyKey`. Write the brief from the buyer's stated goal, audience, and what is being promoted. ```json theme={null} { "advertiserId": "ADVERTISER_ID", "name": "Autumn launch", "brief": "Reach sustainability leaders in the Netherlands with Acme's autumn product launch.", "flight": { "startAt": "2026-09-01T00:00:00Z", "endAt": "2026-09-30T23:59:59Z" }, "budget": { "total": 50000, "currency": "EUR", "pacing": "even" }, "idempotencyKey": "acme-autumn-create-v1" } ``` Creation does not launch. Retain the returned `campaignId` and `revision`. ## 3. Choose sellers and request proposals `get_status` returns `readyDestinations` with the seller IDs accepted by `request_proposals`. These are seller/storefront IDs, not account IDs. ```json theme={null} { "campaignId": "CAMPAIGN_ID", "expectedCampaignRevision": 1, "sellerIds": ["10", "24"], "evaluation": { "instructions": "Prefer contextual relevance and transparent fixed pricing." }, "idempotencyKey": "acme-autumn-proposals-v1" } ``` For a fresh round, the call waits up to 30 seconds per seller and ordinarily returns a terminal `complete`, `partial`, or `failed` result. A concurrent call using the same idempotency key may instead see `running`; retry that same key until it becomes terminal. Each seller may return: * `quoted` with qualified Proposal IDs; * `products` with a `productQueryId`; or * `failed` with a bounded error. Repeating the same idempotency key returns the same proposal round. Use a new key only when intentionally asking sellers for a fresh round. Evaluation instructions are recorded but are not yet applied to ranking; review the returned results yourself. ## 4. Stage a media buy ### Accept a quoted proposal ```json theme={null} { "fromProposalId": "sfp1:QUALIFIED_PROPOSAL_ID", "idempotencyKey": "acme-autumn-accept-proposal-v1" } ``` The proposal version must still be current and belong to the campaign. The result is a draft media buy; accepting a proposal does not launch it. The current schema requires `idempotencyKey` on every call, although proposal acceptance derives retry safety from the qualified proposal version and does not consume the supplied key. ### Stage returned products For a seller that returned products without a Proposal, preserve every returned identity field and use that seller's `productQueryId` as the idempotency key: ```json theme={null} { "campaignId": "CAMPAIGN_ID", "sellerId": "10", "products": [ { "productId": "QUALIFIED_PRODUCT_ID", "inventorySourceId": "200", "salesAgentId": "SELLER_AGENT_ID", "budget": 5000 } ], "idempotencyKey": "PRODUCT_QUERY_ID" } ``` Do not reconstruct qualified IDs. `inventorySourceId` and `salesAgentId` distinguish products that may otherwise look identical across seller routes. Creation-time `flight` and top-level `budget` are not supported by `save_media_buy`; allocate with `products[].budget`, then update the draft's flight in a separate call using `mediaBuyId`. ## 5. Inspect staged work List media buys under the campaign: ```json theme={null} { "kind": "media_buy", "filter": { "campaignId": "CAMPAIGN_ID" } } ``` The Buyer projection reports phase, pause state, and flight. It does not retain Proposal evidence after the acceptance response, so preserve the `proposalSource` fields returned by `save_media_buy` when that audit link matters. There is no cross-campaign Buyer media-buy list; select a campaign first. Buyer reads currently project `isArchived: false` because the underlying read does not expose media-buy archive state. Do not use that field or an `isArchived: true` search as proof that no archived buy exists. There is no separate confirmation call in v3. At this step, inspect each draft, apply any supported correction with `save_media_buy({ mediaBuyId: ... })`, and continue only when the staged set is the one you intend to launch. ## 6. Launch explicitly Launch is an update to an existing campaign, not part of campaign creation: ```json theme={null} { "campaignId": "CAMPAIGN_ID", "expectedRevision": 1, "desiredPhase": "active", "idempotencyKey": "acme-autumn-launch-v1" } ``` Do not combine launch with pause or archive in the same call. A launch can partially write downstream execution state even when no media buy activates; read the structured error, fix the cause, re-read the campaign revision, and retry deliberately. ## Lifecycle operations * `isPaused: true` pauses an active campaign; `false` reactivates it. * `isArchived: true` archives it. * `desiredPhase: "canceled"` and unarchive are not implemented in v3; use v2. * A tracked campaign is read-only until it is adopted or duplicated through the existing v2 workflow. * `autonomy` fields are accepted for forward compatibility but are not persisted yet. See [Preview limitations](/v2/setup/v3/limitations) before replacing a v2 buyer integration.