KAkairos
Orders

Get a combined platform + exchange fee quote for a prospective trade

Prices a trade you are considering WITHOUT submitting it: for a market order (order_type=market, price omitted) the live orderbook is walked for quantity to compute a size-weighted executable price; for a limit order (order_type=limit) price is required and used as the resting quote. Shares the exact computation used by the WebSocket RFQ stream (subscribe_fee_quote), so the two surfaces can never price a trade differently. Quotes are display-only, degrade-open estimates (is_estimate: true) — the authoritative fee is computed at fill time. If no fresh orderbook is available, every numeric field is a "0" placeholder and pricing_unavailable: true; callers MUST check that flag rather than rendering the zeros as a real quote. Supported exchange_id values: polymarket, kalshi, predictfun. Auth & scope. Requires trade:read.

get/orders/fee-quote

Request

  • Base URL
    https://execution.kairos.trade
  • Auth
    API key in header X-Client-Id and API key in header X-Api-Key and API key in header X-Api-Secret

Query parameters

exchange_id'polymarket' | 'kalshi' | 'predictfun' required
Example:polymarket

One of polymarket, kalshi, predictfun.

market_idstring

Condition id (Polymarket). Required for Polymarket if token_id is omitted.

token_idstring
Example:71360012345678901234567890123456789012345678901234567890123456

CLOB token id (Polymarket) — preferred over market_id for book/fee lookup.

quantitystring required
Example:100

Decimal string. Number of shares/contracts to quote. Must be > 0.

side'buy' | 'sell' required
Example:buy

The quote is side-aware (walks the ask side for buy, the bid side for sell).

pricestring
Example:0.52

Decimal string in (0, 1]. Required when order_type=limit (the resting price). Omit for order_type=market to have the server price off the live book.

order_type'market' | 'limit' required
Example:market

market (taker, priced from the book) or limit (maker, priced at price).

Response

Combined platform + exchange fee quote.

avg_price_usdcstring required

Size-weighted executable price (VWAP for a market order), or the limit price for a limit order.

filled_sizestring required

Size the book can actually fill; equals requested_size when liquidity suffices.

requested_sizestring required

The size the caller asked to quote (echoes quantity).

sufficient_liquidityboolean required

False when the book cannot fill the full requested_size.

notional_usdcstring required

filled_size × avg_price_usdc.

platform_fee_usdcstring required

Kairos platform fee, based on the caller's fee tier. "0" if the tier lookup failed (fails open, never a phantom rate).

exchange_fee_usdcstring required

Venue-specific fee the caller is expected to pay. "0" on venues that only charge takers when this quote is a resting maker order.

venue_reserve_fee_usdcstring required

Fee the VENUE actually reserves to accept the order — distinct from exchange_fee_usdc. Some venues (Polymarket CLOB) can't know a resting limit will stay maker, so they reserve the taker estimate at placement regardless; buy-affordability checks must size off this field, not exchange_fee_usdc.

total_fee_usdcstring required

platform_fee_usdc + exchange_fee_usdc.

exchange_fee_notestring nullable

Human-readable note on the exchange fee, e.g. "1.8% taker fee".

total_cost_usdcstring required

All-in cost — for a buy, notional + fees; for a sell, proceeds = notional − fees.

pricing_unavailableboolean required

true when no executable price was available (no client price and no fresh orderbook) — every other numeric field is a placeholder "0" and MUST NOT be rendered as a real quote.

is_estimateboolean required

Always true — this is a display estimate; the authoritative fee is computed at fill time.

funding_tier't0_local' | 't1_prepositioned' | 't2_bridge' | 'reject' required

Which rails run to fund this order. t0_local means no collateral moves; only t2_bridge carries a bridge fee. It names the movement, not whether the balance suffices.

bridge_fee_usdcstring nullable required

Bridge fee in USDC. "0" below t2_bridge, and null exactly when bridge_quote_unavailable is true — an unknown fee is never rendered as $0.00. This fee is already included in total_cost_usdc, and buy-affordability checks must include it too.

bridge_eta_p50_msinteger nullable required

Median bridge fill time from Kairos's own completed intents, never a provider estimate. Present only once the route has ≥1,000 samples and its p90 ETA error is within ±10s.

bridge_eta_p95_msinteger nullable required

95th-percentile bridge fill time from Kairos's own completed intents. Present under the same gate as bridge_eta_p50_ms.

bridge_route_labelstring nullable required

The route in the user's words, naming the token the rail DELIVERS, e.g. "BNB USDT → Polymarket pUSD via Relay". Absent when nothing bridges.

bridge_min_txsinteger nullable required

On-chain transactions the bridge route needs, so a client can price the signing path. Absent when nothing bridges.

bridge_eta_state'measured' | 'not_yet_measured' nullable required

Whether the ETA above is a measurement or an admission that the route has not earned one. Absent when nothing bridges.

bridge_quote_unavailableboolean required

true when a bridge is needed and no quote landed. Consumers MUST render a "routing…" state and disable submit rather than showing any fee; bridge_fee_usdc is null in this state.

bridge_betaboolean required

true while tier-2 bridge funding is behind a flag, so the bridge row can be labelled beta.

Example response

{
  "avg_price_usdc": "0.52",
  "filled_size": "100",
  "requested_size": "100"
}

Changes

No recorded changes to this operation across all 1 revision of this API.