# Token Bid-Ask Spread Local Finite-Change Elasticity

> Token Bid-Ask Spread Local Finite-Change Elasticity is a paid API for AI agents from market.datapackvibe.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-16).

Computes local finite-change elasticity for a token's bid-ask spread given supplied baseline quote observations and a step percentage.

## Facts

- Endpoint: POST https://market.datapackvibe.com/x402/assistant-bx-token-quote-spread-elasticity?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/token-bid-ask-spread-local-finite-change-elasticity-e3566dbb
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_9IGGajwBigCzD7RGpedc-

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 token-bid-ask-spread-local-finite-change-elasticity-e3566dbb -d '<json body>'
```

Example prompt: Calculate the local finite-change elasticity for a token's ask spread using a baseline bid of 0.98 and ask of 1.02, stepping 1 percent — I want to see how elastic the ask side is.

## When to prefer this

Use this endpoint when you need a deterministic, single-point local elasticity measure for a token's bid-ask spread from your own supplied quote observations, rather than a live market data scan or a full scenario grid. It is ideal when you have a known baseline and want a fast, cheap ($0.01 USDC) finite-difference sensitivity estimate for the spread on either the bid or ask side.

## Known failure modes

- Invalid field value (not 'bid' or 'ask') returns a validation error
- Baseline bid or ask at or below zero returns a minimum-value constraint error
- step_percent outside the 0.01–10 range returns a bounds error
- Missing or malformed baseline object returns a schema validation error
- Payment not included or insufficient USDC causes a 402 payment required response

## How this service works

Token bid-ask spread — Local finite-change elasticity: Local finite-change elasticity for Token bid-ask spread. Supplied token observations only. Deterministic calculation or caller-threshold verdict, not a live scan, safety proof or trade recommendation. Specialised preset in a shared 50-profile, 20-operation engine. 0.01 USDC includes one bounded local finite-change elasticity report.

## Output

A bounded local finite-change elasticity report for the selected field (bid or ask) of the token's bid-ask spread, computed deterministically from the supplied baseline prices and step percentage. Returns a numeric elasticity value or threshold verdict, not a live market scan or trade recommendation.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "field": {
   "enum": [
    "ask",
    "bid"
   ],
   "type": "string",
   "default": "ask"
  },
  "baseline": {
   "type": "object",
   "default": {
    "ask": 1.02,
    "bid": 0.98
   },
   "required": [
    "ask",
    "bid"
   ],
   "properties": {
    "ask": {
     "type": "number",
     "default": 1.02,
     "maximum": 10000000000000000,
     "minimum": 0,
     "exclusiveMinimum": 0
    },
    "bid": {
     "type": "number",
     "default": 0.98,
     "maximum": 10000000000000000,
     "minimum": 0,
     "exclusiveMinimum": 0
    }
   },
   "additionalProperties": false
  },
  "step_percent": {
   "type": "number",
   "default": 1,
   "maximum": 10,
   "minimum": 0.01
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/token-bid-ask-spread-local-finite-change-elasticity-e3566dbb/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from market.datapackvibe.com](https://www.zero.xyz/host/market.datapackvibe.com/llms.txt)