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HALOWERK marktwerk Slippage Simulator
x402
HALOWERK marktwerk Slippage Simulator is a paid API for AI agents from markt.halowerk.com, paid per call via x402, $0.004/call, status unknown (last checked 2026-10-12).
Simulates order fill against live visible order books on Binance, Coinbase, Kraken, OKX, or Bybit, returning average fill price, worst price, and slippage metrics for a given side and size.
Price / call$0.004
Success—
StatusUnknown
How this service works
Takes side, size and size_unit and simulates the fill against the visible book of Binance, Coinbase, Kraken, OKX or Bybit. avg_price is the size weighted fill price, worst_price the last level touched, slippage is stated against the mid and against the best price on the executing side, with the reference named. If the visible depth is not enough the answer is still valid and paid: insufficient_liquidity is true, filled_pct says how far it got and max_fillable_size names the size the book actuall
Output
Returns avg_price (size-weighted average fill price), worst_price (last order book level touched), slippage measured against both the mid price and the best price on the executing side with the reference named, and if depth is insufficient: insufficient_liquidity=true, filled_pct (how much of the order was filled), and max_fillable_size (maximum fillable quantity from visible book). Optionally includes taker fee layer on top of fill price.
Example use cases
Pre-trade slippage check for large order
“I'm about to market-buy 200,000 USDC worth of SOL on Coinbase — can you simulate the fill and tell me the average price I'd get and how much slippage I'm looking at versus the mid price?”
Liquidity depth test before OTC desk comparison
“Check if Binance has enough visible book depth to fill a 500 BTC sell order, and if not, tell me how much it can actually fill and what the fill percentage would be.”
Cross-venue slippage comparison for execution routing
“I want to buy 25 ETH — simulate the fill on Kraken vs OKX and show me the average fill price and slippage for each so I can decide where to route the order.”
Technical details
Endpoint
POSThttps://markt.halowerk.com/slippage?utm_source=zero.xyzWhen to prefer
Use this endpoint when you need pre-trade market impact and slippage estimation against real live order book depth on a specific centralized exchange. Prefer it over ticker-based mid-price estimates when order size is large enough to walk multiple book levels. It is especially valuable for execution routing decisions, OTC pricing benchmarks, or risk checks before placing large market or aggressive limit orders. Choose it over the multi-venue slippage walker when you want detailed single-venue fill analytics including fee-adjusted prices.
Side effects
- Invalid or unsupported symbol format returns a validation error
- Requested venue not among supported five exchanges returns error
- Size of zero or negative number rejected by schema validation
- Symbol not listed on the requested exchange may return empty book or error
- Partial fill scenario: insufficient_liquidity=true with filled_pct < 100 and max_fillable_size returned — call is still valid and charged
- Network or exchange connectivity issues may delay or fail book retrieval
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| side | string | buy consumes the ask side, sell the bid side. |
| size | number | Order size, in the unit given by size_unit. |
| venue | string | Exchange whose book is used. |
| symbol | string | Trading pair as BASE/QUOTE, for example ETH/USDC. |
| size_unit | string | base means size is in BASE, quote means size is in QUOTE. |
| include_fees | boolean | Adds the taker fee of the entry tier on top of the fill price. |
Tags
x402
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