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Order Book Depth Notional
x402
Order Book Depth Notional is a paid API for AI agents from api.delx.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).
Computes the total notional value (price × size sum) available within N levels of an order book side ladder
Price / call$0.001
Success—
StatusUnknown
How this service works
Sum price*size depth notional for a side ladder. Call when risk needs notional available within N levels. Returns depth_notional and levels_used as deterministic JSON for $0.001 USDC via x402 on Base. First-party local math only—no RPC, live market feed, API keys, storage, or mediagen. Advisory only; the caller owns capital, risk, and production controls.
Output
Returns a deterministic JSON object containing depth_notional (the total sum of price × size across all provided ladder levels) and levels_used (the count of levels included in the calculation). No external data sources are consulted — the math is performed locally on the supplied input array.
Example use cases
Pre-trade liquidity check for large order
“I'm about to place a large buy order and need to know how much notional is available in the top 8 ask levels of this order book: [{price:50100,size:2},{price:50105,size:5},{price:50110,size:3},{price:50115,size:8},{price:50120,size:4},{price:50125,size:6},{price:50130,size:1},{price:50135,size:7}] — can you sum up the total depth notional for me?”
Risk limit check against available depth
“Our risk system needs to verify that there's at least $500,000 notional available within the top 5 bid levels before we execute. Here are the levels: [{price:2000,size:50},{price:1999,size:80},{price:1998,size:60},{price:1997,size:40},{price:1996,size:90}]. What's the total depth notional and how many levels were used?”
Market impact estimation for algo execution
“I'm running a VWAP algo and need to know the total notional depth across these 12 ask ladder levels to estimate market impact: [{price:30500,size:10},{price:30510,size:15},{price:30520,size:8},{price:30530,size:20},{price:30540,size:5},{price:30550,size:12},{price:30560,size:7},{price:30570,size:18},{price:30580,size:9},{price:30590,size:14},{price:30600,size:11},{price:30610,size:6}]. Sum up the price times size for all of them.”
Technical details
Endpoint
POSThttps://api.delx.ai/api/v1/x402/ob-depth-notionalWhen to prefer
Choose this endpoint when you have an order book ladder snapshot in memory and need a fast, deterministic, locally-computed notional depth calculation without touching any external market feed, RPC, or API key. Ideal for risk systems, pre-trade checks, and algo execution engines that need reproducible math on caller-supplied data at minimal cost ($0.001 USDC). Prefer over custom implementations when you want auditable, consistent computation without managing the arithmetic yourself.
Side effects
- Missing or malformed levels array returns an error
- Levels array entries missing price or size fields cause computation failure
- Empty levels array may return zero notional or an error
- Non-numeric price or size values cause validation failure
- Payment failure via x402 prevents endpoint access
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| levels | array | Array of {price,size} ladder levels |
Output
Schema · Response
{
"type": "json",
"example": {
"schema": "delx/util-ob-depth-notional/v1",
"levels_used": 2,
"depth_notional": 498.5
}
}Tags
x402
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