> ## Documentation Index > Fetch the complete documentation index at: https://assetpay.gg/docs/llms.txt > Use this file to discover all available pages before exploring further. # Quick Buy (Self-Trade) > Merchant-side quick buy: pass an itemId, a per-unit price ceiling and an amount, and AssetPay buys the cheapest listings up to it. Available for CS2 and Rust. Merchant-facing equivalent of [`POST /client/trading/withdraw/quick`](/docs/api-reference/trading/withdraw-quick). Instead of naming specific listings, you pass an `itemId`, a per-unit ceiling, and an amount — AssetPay buys the cheapest available listings at or below your ceiling and delivers them to the supplied `tradeUrl`. The merchant's USD wallet is debited. **Available for CS2 and Rust.** Other games are rejected with `QUICK_BUY_UNSUPPORTED_GAME` (32). For Rust, `phase` and `delivery: "instant"` are not available (CS2-only options). **Authentication:** Merchant API Key (`api-key` header) **Scope:** `CORE_ACCESS` ## Request ```http theme={null} POST https://api.assetpay.gg/secure/buy/quick Content-Type: application/json api-key: ap_... { "tradeUrl": "https://steamcommunity.com/tradeoffer/new/?partner=12345&token=ABCDEFGH", "itemId": "dc3c4460d814ac35", "maxPrice": 67.39, "amount": 3, "delivery": "instant", "externalId": "self_qb_001" } ``` ### Body Parameters | Parameter | Type | Required | Description | | ---------------- | ------ | -------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `tradeUrl` | string | Yes | Steam trade URL of the account receiving the items | | `itemId` | string | Yes\* | Item id from `/secure/prices` (CS2 catalog id, or any listing id of the item for Rust). 5–256 chars. Provide this **or** `marketHashName`; `itemId` wins when both are sent. | | `marketHashName` | string | Yes\* | Exact market hash name (e.g. `AK-47 \| Redline (Field-Tested)`), resolved to the item. Ignored when `itemId` is supplied. | | `maxPrice` | number | Yes | **Gross** per-unit price ceiling in USD (fee-inclusive — same basis as the `withdraw` price in `/secure/prices`). Max \$100,000. | | `amount` | number | Yes | How many units to buy. Integer, 1–200. | | `externalIds` | array | No | One reference of your own per requested unit (each 1–128 chars), applied to the pre-filled rows in order. Must hold **exactly** `amount` entries. Accepted in place of the item id by both [cancel](/docs/api-reference/secure/cancel-buy-item) endpoints. | | `delivery` | string | No | `"standard"` or `"instant"`. Defaults to `"standard"`. `"instant"` is CS2-only. | | `phase` | string | No | **CS2 only.** Doppler phase to buy: `"Phase 1"`–`"Phase 4"`, `"Ruby"`, `"Sapphire"`, `"Black Pearl"`, `"Emerald"`. Prices against that phase's floor for the requested delivery mode. Combines with `delivery: "instant"`, though many phases have no instant listing — check `phases[].withdraw.instant` on /secure/prices first. | | `game` | string | No | `"730"` (CS2) or `"252490"` (Rust). Defaults to `"730"`. | | `autoCancel` | number | No | **CS2 only.** Minutes after creation to automatically cancel any unit still undelivered. Integer, 30-720. Defaults to `30`; send `720` to disable. Rejected on Rust with `VALIDATION_FAILED`. See [Automatic cancellation](/docs/guides/withdrawals#automatic-cancellation). | | `externalId` | string | No | Your unique tracking ID | \* Provide either `itemId` or `marketHashName`. ## Response Returns a full [`Trade`](/docs/reference/types#trade) object with `source: "self"`. As with the client quick withdrawal, `items` contains **one pre-filled row per requested unit** (carrying the ceiling `price` + `delivery`, same minimal shape as a standard buy item) and `totalPrice` is the **worst-case lock** (`amount × maxPrice`). Each row is bound to a real listing as fills arrive; unfilled rows go to `failed` and the unfilled / below-ceiling remainder is refunded — all asynchronously via the trade webhook. Once settled, `totalPrice` reflects the actual spend. ```json theme={null} { "requestId": "...", "success": true, "data": { "id": "trade-uuid", "type": "withdraw", "source": "self", "status": "initiated", "game": "730", "externalId": "self_qb_001", "merchantId": "merchant-uuid", "clientSteamID": "76561198012345678", "clientTradeUrl": "https://steamcommunity.com/tradeoffer/new/?partner=12345&token=ABCDEFGH", "items": [ { "id": "dc3c4460d814ac35", "appid": 730, "tradable": true, "amount": 1, "status": "initiated", "offer": { "price": 67.39, "delivery": "instant" } }, { "id": "dc3c4460d814ac35", "appid": 730, "tradable": true, "amount": 1, "status": "initiated", "offer": { "price": 67.39, "delivery": "instant" } }, { "id": "dc3c4460d814ac35", "appid": 730, "tradable": true, "amount": 1, "status": "initiated", "offer": { "price": 67.39, "delivery": "instant" } } ], "totalPrice": 202.17, "createdAt": "2026-05-31T12:00:00.000Z", "updatedAt": "2026-05-31T12:00:00.000Z" } } ``` ## How the wallet debit works The merchant's available wallet balance must cover the worst-case lock (`amount × maxPrice`) at the time of the call. The funds are locked immediately; on each fill the sourcing portion settles to HOUSE and the AssetPay fee to HOUSE\_FEES, and the unfilled units plus any below-ceiling savings are released back to your balance. ## The `initiated` approval callback also fires `/secure/buy/quick` reuses the same approval pipeline as the client quick withdrawal. After the trade is created (status `initiated`), AssetPay sends an [approval callback](/docs/guides/callbacks#the-initiated-callback-for-withdrawals) with `trade.source === "self"`. The trade does not proceed until you respond — note the callback carries the **pre-filled rows** (each at the ceiling price) and the worst-case `totalPrice`, since the actual fills aren't known yet. * To auto-approve your own self-trades, return `2xx` whenever `trade.source === "self"`. * To reject, respond with `4xx`; the trade is failed and the wallet lock is released. * Self-trade quick buys still **require an active callback URL** — without one the call fails immediately with `MERCHANT_NO_CALLBACK_URL` (1705). ## Rate Limits | Merchant Status | Limit | | --------------- | -------------------- | | Verified | 5,000 requests / min | | Unverified | 50 requests / min | ## Errors Same set as [`POST /client/trading/withdraw/quick`](/docs/api-reference/trading/withdraw-quick#errors). Common: `QUICK_BUY_UNSUPPORTED_GAME` (32, unsupported game), `MERCHANT_BALANCE_LOW` (12), `MERCHANT_NO_CALLBACK_URL` (1705), `INVALID_TRADEURL` (13), `INSUFFICIENT_STOCK` (42, Rust: nothing sourceable at or below `maxPrice`), `VALIDATION_FAILED` (1001).