# Execution Quality vs VWAP

> Execution Quality vs VWAP 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).

Compares an average fill price against a caller-supplied VWAP benchmark and returns slippage in basis points for post-trade quality analysis.

## Facts

- Endpoint: POST https://api.delx.ai/api/v1/x402/exec-quality-vs-vwap
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/execution-quality-vs-vwap-00bfe678
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_hoM9xgiLhNiwqyPWFDEH3

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability execution-quality-vs-vwap-00bfe678 -d '<json body>'
```

Example prompt: I bought 500 shares and my average fill was $102.35 — the VWAP for that period was $101.80. How many basis points did I slip vs VWAP on the buy side?

## When to prefer this

Use this endpoint when you need a fast, deterministic, server-side calculation of post-trade slippage in basis points relative to a known VWAP benchmark. Prefer it over building local math when you want a reproducible, auditable result returned as structured JSON for a single trade. It is purely computational with no live market data dependencies, making it suitable for any post-trade workflow where VWAP is already known.

## Known failure modes

- Missing required fields (side, vwap, avg_fill) return a validation error
- Invalid trade side value (not 'buy' or 'sell') causes a parameter error
- Non-numeric values for vwap or avg_fill result in a type error
- Zero or negative price inputs may produce undefined results
- Payment failure via x402 prevents execution

## How this service works

Compare average fill to VWAP benchmark (bps). Call when post-trade quality vs a caller-supplied VWAP. Returns slippage_bps_vs_vwap 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 slippage_bps_vs_vwap — the number of basis points by which the average fill price differed from the supplied VWAP benchmark, signed to reflect favorable or unfavorable execution relative to trade side.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "side": {
   "type": "string",
   "description": "Trade side: buy or sell"
  },
  "vwap": {
   "type": "number",
   "description": "VWAP benchmark price"
  },
  "avg_fill": {
   "type": "number",
   "description": "Average fill price"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "side": "sell",
  "schema": "delx/util-exec-quality-vs-vwap/v1",
  "slippage_bps": 50
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/execution-quality-vs-vwap-00bfe678/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.delx.ai](https://www.zero.xyz/host/api.delx.ai/llms.txt)