# Token Buy Receipt Shortfall — Local Finite-Change Elasticity

> Token Buy Receipt Shortfall — 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 2026-10-15).

Computes the local finite-change elasticity of a token buy receipt shortfall, measuring how sensitive the shortfall is to small percentage-point changes in a chosen input variable.

## Facts

- Endpoint: POST https://market.datapackvibe.com/x402/assistant-bx-token-buy-receipt-elasticity?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/token-buy-receipt-shortfall-local-finite-change-elasticity-039c28dd
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_cAHX_e9dLpFrdqUMNJifY

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-buy-receipt-shortfall-local-finite-change-elasticity-039c28dd -d '<json body>'
```

Example prompt: Calculate the local finite-change elasticity for a token buy shortfall where I expected 1000 tokens but only received 950, perturbing the expected_tokens field by 1% steps.

## When to prefer this

Choose this endpoint when you need a deterministic, mathematically rigorous local sensitivity measure for a token buy receipt shortfall rather than a live market scan or simulation. It is ideal when you have a fixed pair of expected vs. actual token observations and want to quantify how elastically the shortfall responds to marginal input changes, without needing real-time pricing data or trade execution capabilities.

## Known failure modes

- expected_tokens set to 0 or below (violates exclusiveMinimum constraint — validation error)
- actual_tokens or expected_tokens exceed maximum of 10,000,000,000,000,000 — out-of-range error
- step_percent outside [0.01, 10] range — parameter validation failure
- Missing or malformed baseline object — schema validation error
- Invalid field enum value (not 'expected_tokens' or 'actual_tokens') — rejected with 422

## How this service works

Token buy receipt shortfall — Local finite-change elasticity: Local finite-change elasticity for Token buy receipt shortfall. 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

Returns a bounded local finite-change elasticity report for the token buy receipt shortfall, including the computed elasticity coefficient indicating how the shortfall ratio responds to a small percentage-point perturbation in the specified input field (expected_tokens or actual_tokens). The result is deterministic given the supplied observations and does not constitute a live market scan or trade recommendation.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "field": {
   "enum": [
    "expected_tokens",
    "actual_tokens"
   ],
   "type": "string",
   "default": "expected_tokens"
  },
  "baseline": {
   "type": "object",
   "default": {
    "actual_tokens": 950,
    "expected_tokens": 1000
   },
   "required": [
    "expected_tokens",
    "actual_tokens"
   ],
   "properties": {
    "actual_tokens": {
     "type": "number",
     "default": 950,
     "maximum": 10000000000000000,
     "minimum": 0
    },
    "expected_tokens": {
     "type": "number",
     "default": 1000,
     "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-buy-receipt-shortfall-local-finite-change-elasticity-039c28dd/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)