# AEML Gauge Census – Cross-Station Signal Census with Band/Percentile Filtering

> AEML Gauge Census – Cross-Station Signal Census with Band/Percentile Filtering is a paid API for AI agents from aeml-x402.zeabur.app, paid per call via x402, $0.09/call, status unknown (last checked 2026-09-13).

Returns the latest readings for all monitored entities across every signal, with filtering by statistical band, frequency label, and percentile to identify unusual or outlier stations.

## Facts

- Endpoint: GET https://aeml-x402.zeabur.app/gauge/census
- Price: $0.09/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-census-cross-station-signal-census-with-band-percentile-776d4a08
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_-QqG4cH6-auWrv9S2C0iJ

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-census-cross-station-signal-census-with-band-percentile-776d4a08
```

Example prompt: Do a full cross-station sweep on the gauge census and show me all entities currently sitting in an unusual band — filter to anything above the 75th percentile so I can spot the outliers across river gauges and shipping routes.

## When to prefer this

Choose this endpoint when you need a broad cross-entity, cross-signal sweep to identify outliers, anomalies, or unusual stations — rather than drilling into a single entity or signal. It is the right choice for surveillance tasks like 'find anything weird across all river gauges' or 'which signals are at extreme percentile levels right now.' For deep dives into a single entity-signal pair, prefer sibling endpoints like the flood-risk check or the specific triangle endpoints.

## Known failure modes

- Missing or invalid signal_id filter returns all rows (large payload — may be slow or expensive)
- Unknown band/frequency_label/percentile values may return empty rows array with count 0
- Payment not included or insufficient USDC returns 402 Payment Required
- Signal has no statistical history — stat_ruler and strata fields return null for those rows
- Freshness lag: observed_at may be stale if upstream data source has not updated
- Unverified sources flagged with unverified:true may reduce data reliability

## How this service works

[BATCH+PROOF] All entities for one signal at their latest reading, with band, frequency_label and percentile columns so you can rank across stations and screen for the unusual in one call. Cross-station comparison is the point: one river gauge alone tells you little, 200 of them ranked by distance-to-action tells you a lot. Descriptive only, never a forecast or advice. No data -> 422 no_charge, not billed.

## Output

Returns a JSON object with a count and an array of rows, each representing one entity-signal pair. Each row includes the signal_id, entity id and human-readable name, current metric readings (structure varies by signal type), statistical band and percentile (stat_ruler/strata), 7-day trend array, change delta and direction (rising/falling/stable), human-readable summary in Chinese (summary_zh), source provenance list, observed_at timestamp, lifecycle block if applicable, and OTS anchoring status. Allows downstream filtering and cross-station comparison at a glance.

## 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"
       ]
      }
     },
     "required": [
      "signal_id"
     ]
    }
   },
   "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-census-cross-station-signal-census-with-band-percentile-776d4a08/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)