Holt-Winters triple exponential smoothing
Holt-Winters triple exponential smoothing - level + trend + seasonal component. Use for series with a repeating cycle (weekly retail traffic, monthly utility usage, quarterly revenue). Additive seasonality (constant amplitude) or multiplicative (amplitude grows with level). `period` is optional - if omitted, the kit auto-detects via autocorrelation on first differences and surfaces what it picked (with the ACF strength) so you can audit. Needs at least two full seasonal cycles to fit reliably.
Paid test badge: not yet. The checks above are free: we call the tool without paying and read the payment request it sends back. The Verified badge needs paid calls whose answers match the promised output, and nobody can buy a badge.
Endpoint
POST https://agent402.tools/api/forecast-holt-winters
| Category | Code and developer |
|---|---|
| Provider host | agent402.tools |
| Networks | algorand:wGHE2Pwdvd7S12BL5FaOP20EGYesN73ktiC1qzkkit8=, eip155:10, eip155:1329, eip155:137, eip155:143, eip155:42161, eip155:42220, eip155:43114, eip155:4663, eip155:8453, solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp, stellar:pubnet |
| Payment schemes | exact, upto |
| Self-reported calls, 30 days | 5 from 1 payers (the provider's figure, not ours) |
Our checks, last 30 days
| Day | Result | HTTP | Asked | Time |
|---|---|---|---|---|
| 2026-09-24 | valid payment request | 402 | $0.001 | 1049 ms |
Example input (from the provider)
{
"body": {
"horizon": 4,
"period": 4,
"values": [
10,
14,
18,
22,
11,
15,
19,
23,
12,
16,
20,
24
]
},
"bodyType": "json",
"method": "POST",
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"body": {
"properties": {
"alpha": {
"description": "Level smoothing, 0 < alpha < 1 (default 0.5)",
"type": "number"
},
"beta": {
"description": "Trend smoothing, 0 < beta < 1 (default 0.1)",
"type": "number"
},
"gamma": {
"description": "Seasonal smoothing, 0 < gamma < 1 (default 0.1)",
"type": "number"
},
"horizon": {
"description": "Number of future periods to forecast (1 to 1000)",
"type": "number"
},
"period": {
"description": "Optional seasonal period (e.g. 7 for daily/weekly, 12 for monthly/yearly). Auto-detected via ACF if omitted.",
"type": "number"
},
"seasonality": {
"description": "\"additive\" (default) or \"multiplicative\"",
"type": "string"
},
"values": {
"description": "Numeric series in chronological order (max 10000)",
"type": "array"
}
},
"required": [
"values",
"horizon"
]
},
"bodyType": {
"enum": [
"json",
"form-data",
"text"
],
"type": "string"
},
"method": {
"enum": [
"POST"
],
"type": "string"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method",
"bodyType",
"body"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"properties": {
"alpha": {
"type": "number"
},
"beta": {
"type": "number"
},
"forecast": {
"items": {
"type": "object"
},
"type": "array"
},
"gamma": {
"type": "number"
},
"horizon": {
"type": "integer"
},
"method": {
"type": "string"
},
"n": {
"type": "integer"
},
"period": {
"type": "integer"
},
"periodSource": {
"type": "string"
},
"seasonality": {
"type": "string"
}
},
"required": [
"method",
"n",
"horizon",
"period",
"periodSource",
"seasonality",
"alpha",
"beta",
"gamma",
"forecast"
],
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}