Quotes

Send one. Sending both is 400 invalid_request, because a client bug that sends a stale stake alongside a computed contracts would otherwise trade a size the caller did not intend, and the response would look perfectly normal.

• A buy is sized in cash. Sizing a buy in contracts is refused: it would commit the player to whatever that quantity costs at fill time, which is the open exposure the stake-first model exists to prevent.
• An exit is sized in contracts. A partner holds a quantity — 68.6111 contracts — and to close it out by cash they would have to invert our fee arithmetic, including which way each rounding goes. Slightly high is an oversell; slightly low leaves an unsellable fraction behind. Naming the quantity moves that inversion to the side that owns the arithmetic.

A $50 stake at 120bps wagers $49.40. The fee is taken from the stake before contracts are bought, not added on top of it — so the gross cash committed is the authorizationAmount, and a fully filled order releases nothing. A player who agreed to stake $50 is never charged $50.60.

stake        50.00
platformFee   0.60   = 50.00 × 120bps
tradeAmount  49.40   ← what buys contracts
contracts    68.6111 = 49.40 ÷ 0.72

{
  "quoteId": "fc3be731-98dc-4c03-80ac-23576a708d9c",
  "contractId": "ctr_9f31c2…",
  "side": "YES",
  "action": "buy",

  "executionPrice": 0.72,        // WHAT YOU ARE CHARGED, 0–1
  "priceBasis": "book",          // book | reference

  "stake": 50,
  "predictaFee": 0.6,
  "predictaFeeBps": 120,
  "commercialTerms": { "termsId": "…", "feeBps": 120, "revShareBps": 0 },
  "venueFee": null,
  "tradeAmount": 49.4,
  "contracts": 68.6111,
  "potentialPayout": 68.61,
  "potentialProfit": 18.61,

  "expiresAt": "2026-08-20T04:44:02.120Z",
  "sourceTimestamp": "2026-08-20T04:43:27.496Z",
  "simulated": true,
  "freshness": { "level": "fresh", "ageSeconds": 5, "feed": "websocket" },
  "routing": { "consideredVenues": 1, "routable": false },

  "operatorMoney": {
    "currency": "USD",
    "authorizationAmount": "50.00",   // RESERVE THIS
    "actualDebit": "50.00",
    "releaseAmount": "0.00",
    "tradeAmount": "49.40",
    "platformFee": "0.60",
    "venueFee": "0.00",
    "venueFeeKnown": true
  },
  "operatorExitMoney": null
}

{
  …
  "action": "sell",
  "operatorMoney": null,              // deliberately null on an exit
  "operatorExitMoney": {
    "currency": "USD",
    "sellProceeds": "48.72",          // CREDIT THIS. Already net of both fees.
    "platformFee": "0.59",
    "venueFee": "0.00",
    "venueFeeKnown": true
  }
}

There is no venue, no venueListingId and no upstream market id anywhere on this surface. A contract is addressed only by its ctr_… id — the same one the catalogue publishes and the same one you read back on the order.

• A quote stands for 30 seconds by default. expiresAt is absolute: use it rather than starting your own timer at receipt.
• Expiry is evaluated against the stored timestamp, never one the client sends. A client that could assert its own quote's age could hold a favourable price and submit it after the market moved.
• An expired quote is 409 quote_expired and is never silently re-priced. Re-pricing executes at a number the player did not see, which is the precise failure quotes exist to prevent.
• A quote is spendable once. A second order against the same quoteId is 409 quote_already_used.
• A quote issued to one operator cannot be spent by another: 403 quote_not_yours.

Two different answers, because they are two different situations. A small bet on a slightly-behind price is ordinary business; a large one at the same moment is somebody acting on information we do not have yet.

The cap is checked against the ticket's stake, not the raw request: the ticket normalises and rounds what is actually being wagered, and gating on a number the ticket then changes would police the wrong figure.

The two sizing rules are enforced by the type signatures rather than by a runtime error, so a buy cannot be sized in contracts and an exit cannot be sized in cash.

const player = predicta.forUser('user-4471');

const buy  = await player.quoteBuy({ contractId, side: 'YES', stake: '50.00' });
// buy.operatorMoney.authorizationAmount  → "50.00", a branded Decimal string

const exit = await player.quoteSell({ contractId, side: 'YES', contracts: 68.6111 });
// exit.operatorExitMoney.sellProceeds    → "48.72"

const order = await player.submitOrder({ quoteId: buy.quoteId, clientOrderId: 'ticket-9031' });

Money comes back as a branded Decimal string that will not silently become a number, with toMinorUnits / addDecimal helpers for arithmetic. See the SDK.