Fits a constant-elasticity demand curve to the price and sales series you supply and retur
Fits a constant-elasticity demand curve to the price and sales series you supply and returns the elasticity with its standard error, t statistic, two-sided p value and a Student t confidence interval, not a normal one, because at eight observations the difference in interval width is double-digit percent and a too narrow interval is exactly the kind of number a machine reuses unchecked.
5000 (raw units)
price
1
calls / 30d
1
unique payers
2026-08-20
updated
Provider
handel.halowerk.com · discovered, not yet claimed by its owner
Payment (x402 accepts[])
[
{
"scheme": "exact",
"network": "eip155:8453",
"payTo": "0x2880EdfFF13100677Bf97A3CBdF3Bc34771C4E5E",
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"amount": "5000",
"maxTimeoutSeconds": 300
}
]Output schema
{
"bazaar": {
"info": {
"input": {
"body": {
"confidence_level": 0.95,
"currency": "EUR",
"observations": [
{
"period_start": "2026-01-05",
"price": 24.9,
"units_sold": 412
},
{
"period_start": "2026-01-12",
"price": 22.9,
"units_sold": 503
},
{
"period_start": "2026-01-19",
"price": 26.9,
"units_sold": 341
},
{
"period_start": "2026-01-26",
"price": 19.9,
"units_sold": 688
},
{
"period_start": "2026-02-02",
"price": 24.9,
"units_sold": 431
},
{
"period_start": "2026-02-09",
"price": 29.9,
"units_sold": 262
},
{
"period_start": "2026-02-16",
"price": 21.9,
"units_sold": 559
},
{
"period_start": "2026-02-23",
"price": 27.9,
"units_sold": 301
},
{
"period_start": "2026-03-02",
"price": 23.9,
"units_sold": 470
},
{
"period_start": "2026-03-09",
"price": 18.9,
"units_sold": 742
}
],
"price_grid": [
19.9,
21.9,
23.9,
25.9,
27.9
],
"unit_cost": 11.5
},
"bodyType": "json",
"method": "POST",
"type": "http"
}
},
"schema": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"body": {
"additionalProperties": false,
"properties": {
"confidence_level": {
"default": 0.95,
"description": "Confidence level for the elasticity interval. Student t, not normal.",
"enum": [
0.8,
0.9,
0.95
],
"type": "number"
},
"currency": {
"default": "EUR",
"description": "ISO 4217 code for every amount in this request. Not converted, only carried through.",
"maxLength": 3,
"minLength": 3,
"type": "string"
},
"include_competitor_price": {
"default": false,
"description": "Whether to add the log competitor price as a second regressor and report the cross-price elasticity. Every observation must then carry competitor_price.",
"type": "boolean"
},
"include_promotion": {
"default": false,
"description": "Whether to add the promotion indicator as a regressor.",
"type": "boolean"
},
"observations": {
"description": "Your own price and sales history for one SKU. Every amount is in the currency named at document level.",
"items": {
"additionalProperties": false,
"properties": {
"competitor_price": {
"description": "Competitor price in that period. Only used when include_competitor_price is true; you bring the figure, nothing is looked up.",
"exclusiveMinimum": 0,
"maximum": 100000000,
"type": "number"
},
"period_start": {
"description": "Optional period label as YYYY-MM-DD, passed through unchanged.",
"pattern": "^\\d{4}-\\d{2}-\\d{2}$",
"type": "string"
},
"price": {
"description": "Selling price in that period. Must be positive: the estimation is on logarithms.",
"exclusiveMinimum": 0,
"maximum": 100000000,
"type": "number"
},
"promotion": {
"default": false,
"description": "Whether the period was a promotion. Enters the fit as a separate indicator when include_promotion is true, so that a campaign is not attributed to the price.",
"type": "boolean"
},
"units_sold": {
"description": "Units sold at that price. A zero cannot enter a log-log fit and is excluded, reported and never silently dropped.",
"maximum": 1000000000,
"minimum": 0,
"type": "number"
}
},
"required": [
"price",
"units_sold"
],
"type": "object"
},
"maxItems": 2000,
"minItems": 4,
"type": "array"
},
"price_grid": {
"description": "Candidate prices to evaluate with predicted units and contribution. Evaluated at the fitted model, in the order you give them.",
"items": {
"exclusiveMinimum": 0,
"maximum": 100000000,
"type": "number"
},
"maxItems": 200,
"type": "array"
},
"unit_cost": {
"description": "Variable cost per unit. Required for the contribution-optimal price; without it only the elasticity is returned.",
"maximum": 100000000,
"minimum": 0,
"type": "number"
}
},
"required": [
"observations"
],
"type": "object"
},
"bodyType": {
"enum": [
"json",
"form-data",
"text"
],
"type": "string"
},
"method": {
"enum": [
"POST",
"PUT",
"PATCH"
],
"type": "string"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method",
"bodyType",
"body"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}
}
}Use it
curl
curl "https://handel.halowerk.com/v1/price-elasticity" # -> 402 Payment Required, accepts[] lists how to pay # retry with a PAYMENT-SIGNATURE (or PAYMENT header) once paid
JavaScript
const res = await fetch("https://handel.halowerk.com/v1/price-elasticity");
if (res.status === 402) {
const { accepts } = await res.json();
// pay one of accepts[] via an x402 client, then retry with the payment header
}Python
import httpx
res = httpx.get("https://handel.halowerk.com/v1/price-elasticity")
if res.status_code == 402:
accepts = res.json()["accepts"]
# pay one of accepts[] via an x402 client, then retry with the payment headerMachine-readable
Everything on this page is also available as clean JSON at /resources/15347.json, and this resource appears in /discovery/resources and /discovery/search.