# AEML GAUGE History — Seasonal Percentile Projection

> AEML GAUGE History — Seasonal Percentile Projection is a paid API for AI agents from aeml-x402.zeabur.app, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-13).

Returns seasonal percentile positioning, frequency, percentile distribution, method, and source for a monitored signal entity

## Facts

- Endpoint: GET https://aeml-x402.zeabur.app/gauge/history
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/aeml-gauge-history-seasonal-percentile-projection-bba36792
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_FCff9Tj2OFWoTjRbJ-GmS

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 aeml-gauge-history-seasonal-percentile-projection-bba36792
```

Example prompt: Pull the seasonal percentile history for BTC spot price (signal_id: crypto.spot, entity: btc) — I want to know what percentile today's price sits at, how frequently it's been here before, and the full percentile breakdown with method and source.

## When to prefer this

Use this endpoint when you need to understand how a current signal reading compares to its own seasonal historical distribution — not just its raw value, but its percentile rank within the same calendar period across years. Prefer this over the base /gauge endpoint when seasonal context and frequency positioning are the primary need. Use alongside /gauge/ruler for official threshold context or /gauge for the full core snapshot. Best when the question is 'is this historically unusual for this time of year?'

## Known failure modes

- Missing or invalid signal_id returns 422 or error — must use valid ASCII binomial notation like crypto.spot
- Missing or invalid entity returns 422 — entity must be a known catalog entry (check /gauge/catalog)
- Signal has no seasonal history data available — returns null history field
- Data source is stale or frozen — provenance.freshness will show 'stale' and dead_source may be set
- Signal exists but has no seasonal percentile method defined — may return null or 422
- Payment not fulfilled — x402 payment required; unpaid requests return 402

## How this service works

Add-on, historical placement: seasonal percentile for the current point, frequency, the percentile table, and the method and source used to compute them. Descriptive only, never a forecast or advice. No data -> 422 no_charge, not billed.

## Output

Returns a JSON object with: the signal_id and entity, the observed_at timestamp, seasonal percentile positioning of the current value, frequency distribution showing how often this level has been reached, full percentile thresholds (e.g. p10/p25/p50/p75/p90), methodology and source citation, provenance metadata (freshness, data lineage, age), a verifiable record_hash (sha256), and an Ed25519-signed _citation for offline trust verification. A nature field provides a neutral disclaimer that GAUGE provides observation only, not forecasts or recommendations.

## Request schema (JSON Schema)

```json
{
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "properties": {
  "input": {
   "type": "object",
   "properties": {
    "type": {
     "const": "http"
    },
    "method": {
     "type": "string",
     "enum": [
      "GET"
     ]
    },
    "queryParams": {
     "type": "object",
     "additionalProperties": false,
     "properties": {
      "signal_id": {
       "type": "string",
       "description": "required - signal id (genus.species); free list at GET /gauge/catalog (paged; ?all=1 for every line)",
       "examples": [
        "hydrology.river-level"
       ]
      },
      "entity": {
       "type": "string",
       "description": "required - monitored object id, paired with signal_id; free list at GET /gauge/catalog?signal_id=<signal_id> -> signals[0].entities[]",
       "examples": [
        "07010000"
       ]
      }
     },
     "required": [
      "signal_id",
      "entity"
     ]
    }
   },
   "required": [
    "type",
    "method",
    "queryParams"
   ]
  },
  "output": {
   "type": "object",
   "properties": {
    "type": {
     "const": "json"
    }
   },
   "required": [
    "type"
   ]
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json"
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/aeml-gauge-history-seasonal-percentile-projection-bba36792/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from aeml-x402.zeabur.app](https://www.zero.xyz/host/aeml-x402.zeabur.app/llms.txt)