# AEML GAUGE History Series – Time-Series Snapshot Export

> AEML GAUGE History Series – Time-Series Snapshot Export is a paid API for AI agents from aeml-x402.zeabur.app, paid per call via x402, $0.09/call, status unknown (last checked 2026-09-14).

Returns the full time-series of historical snapshots for a given signal and entity, ordered by date, for research, actuarial, and base-rate analysis.

## Facts

- Endpoint: GET https://aeml-x402.zeabur.app/gauge/history-series
- Price: $0.09/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/aeml-gauge-history-series-time-series-snapshot-export-a00e4e88
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_DgS0-HOSjKRNNueXNGzbI

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-series-time-series-snapshot-export-a00e4e88
```

Example prompt: Pull the full historical snapshot series for the crypto.spot signal on BTC going back 400 days and give it to me as JSON — I need the snapshot_date, current values, and band for each entry for base-rate research.

## When to prefer this

Use this endpoint when you need the full historical time series for a specific signal-entity pair for research, actuarial modeling, or base-rate analysis. Prefer this over the free /gauge/history-preview when you need complete depth (up to 1000 days) and full schema fields including record_hash and band. Use when you need CSV export for spreadsheet or model ingestion. This is the right choice when you need verifiable, citable historical snapshots with Ed25519-signed provenance rather than just a live current reading.

## Known failure modes

- Missing or invalid signal_id or entity returns an error
- Requesting more than 1000 days is capped at the maximum allowed
- Signal/entity combination with no data returns empty series
- Invalid format parameter may return an error or default to JSON
- Paid endpoint — missing or invalid x402 USDC payment returns 402 Payment Required
- Some signals have coarser granularity (weekly vs daily) which may affect series density

## How this service works

[TIME SERIES EXPORT] Full retained series for one signal and entity (?days=, ?format=json or csv): every snapshot up to days (default 400, cap 1000) with snapshot_date, observed_at, data_age_hours, current, band and record_hash. For research, actuarial and base-rate work. Free 7-snapshot shape preview at /gauge/history-preview. Descriptive only, never a forecast or advice. No data -> 422 no_charge, not billed.

## Output

Returns a JSON (or CSV) object containing an array of time-ordered snapshots for the requested (signal_id, entity) pair. Each snapshot includes snapshot_date, observed_at, data_age_hours, current value, band classification, and record_hash. The response also includes count, days covered, signal_id, entity, format, grade (data quality disclosure), scope, nature disclaimer, and an optional _citation object with Ed25519-signed verifiable provenance.

## Request schema (JSON Schema)

```json
{
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method",
    "queryParams"
   ],
   "properties": {
    "type": {
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "signal_id",
      "entity"
     ],
     "properties": {
      "days": {
       "type": "string",
       "description": "optional - lookback window in days; default 400, minimum 1, capped at 1000. Windows are UTC days (snapshot_date), not local days"
      },
      "entity": {
       "type": "string",
       "examples": [
        "07010000"
       ],
       "description": "required - object id within that line, e.g. 07010000 (see /gauge/coverage)"
      },
      "format": {
       "type": "string",
       "description": "optional - json (default) or csv"
      },
      "signal_id": {
       "type": "string",
       "examples": [
        "hydrology.river-level"
       ],
       "description": "required - line id, e.g. hydrology.river-level (see /gauge/coverage)"
      }
     },
     "additionalProperties": false
    }
   }
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "const": "json"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

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

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/aeml-gauge-history-series-time-series-snapshot-export-a00e4e88/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)