# TruthBear Gauge/Region Environmental Chain

> TruthBear Gauge/Region Environmental Chain is a paid API for AI agents from api.truthbear.co, paid per call via x402, $0.25/call, status unknown (last checked 2026-09-14).

Runs a sequential three-leg local environment chain (air quality AQI → precipitation/dry-wet → river stage/streamflow) for a single location, returning confidence based on how many legs return data.

## Facts

- Endpoint: GET https://api.truthbear.co/gauge/region
- Price: $0.25/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/truthbear-gauge-region-environmental-chain-90a3b1e5
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_YXL1sXFSFU7qpn4ncM8kk

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 truthbear-gauge-region-environmental-chain-90a3b1e5
```

Example prompt: Can you pull the full three-leg environmental chain for Austin, Texas — air quality index, recent precipitation and dry-wet status, and the nearest river stage and streamflow — and tell me how many legs came back with data?

## When to prefer this

Choose this endpoint when you need a corroborated, multi-source environmental snapshot — air quality, precipitation history, and river hydrology — for a single location in one call. It is ideal when you want confidence-weighted environmental context rather than a single reading, and when you need data provenance from authoritative sources (EPA, ERA5, USGS). Prefer it over single-variable APIs when the use case requires cross-domain environmental confirmation (e.g., flood risk, outdoor safety, field research baseline). It is not suitable for forecasting or advisory outputs.

## Known failure modes

- 422 no_charge: no data available for any leg at the given location — call is not billed
- Invalid or unrecognized location parameter returns an error
- Partial data: one or two legs lit, confidence score reflects available legs only
- Network timeout reaching upstream sources (EPA/CAMS, ERA5, USGS)
- Location outside coverage area for one or more upstream sources

## How this service works

[3-LEG] Local three-leg environment chain, one location (?loc=): leading air quality (AQI) -> current precipitation, rain and 30-day dry-wet -> realized nearest river stage and streamflow (confirmation gate). A chain, not one reading: confidence = how many legs are lit, in order. Sources: EPA/CAMS, ERA5, USGS. Descriptive only, never a forecast or advice. No data -> 422 no_charge, not billed. $0.25 per call.

## Output

A sequential three-leg environmental report for the given location: (1) leading air quality AQI from EPA/CAMS, (2) current precipitation and 30-day dry-wet status from ERA5, (3) nearest river stage and streamflow from USGS as a confirmation gate. Confidence is expressed as the number of legs that returned data (0–3). If no data is available for any leg, returns HTTP 422 with a no_charge code and is not billed. The response is descriptive only — no forecasts or advice are provided.

## 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": {
      "loc": {
       "type": "string",
       "description": "required - location id; full list at free /gauge/preview",
       "examples": [
        "us-stlouis",
        "us-memphis",
        "us-losangeles",
        "us-fresno",
        "us-phoenix",
        "us-denver"
       ],
       "x-accepted-values": {
        "shown": 6,
        "total": 12,
        "all": "https://api.truthbear.co/schemas/gauge-region.input.json"
       }
      }
     },
     "required": [
      "loc"
     ]
    }
   },
   "required": [
    "type",
    "method",
    "queryParams"
   ]
  },
  "output": {
   "type": "object",
   "properties": {
    "type": {
     "const": "json"
    },
    "example": {}
   },
   "required": [
    "type"
   ]
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "legs": {
   "air": {
    "airquality.aqi": {
     "band": "below_moderate",
     "source_ref": "https://open-meteo.com/en/docs/air-quality-api(Copernicus CAMS)",
     "record_hash": "sha256:614778264bba65021acbc1bf522d5f2b4f22599190614bed03c2139a96bd7a31"
    },
    "airquality.pm25": {
     "band": "below_moderate",
     "source_ref": "https://open-meteo.com/en/docs/air-quality-api(Copernicus CAMS)",
     "record_hash": "sha256:2df3210c2a75ac7b1e5652c45649b7d1d3014400338096edd32d3f0afe1e330d"
    }
   },
   "river": {
    "band": "below_action",
    "source_ref": "https://waterdata.usgs.gov/monitoring-location/07010000/",
    "record_hash": "sha256:a3986d8689a1d9f6e8b4b92c2318d5af64291cdedbdbd3d706e0049e16fcb42e"
   },
   "precipitation": {
    "precipitation.daily": {
     "band": "below_moderate",
     "source_ref": "https://open-meteo.com/en/docs(ECMWF / archive ERA5)",
     "record_hash": "sha256:011f2bf5882fc9bdef3eb11a4ad2fadb13e99edc45e1628efed88d899715cb53"
    },
    "precipitation.wetness30d": {
     "band": "unrated",
     "source_ref": "https://open-meteo.com/en/docs(ECMWF / archive ERA5)",
     "record_hash": "sha256:cecdb2c3f4fe8e3c7bbf73b735b99d0396fb19564cbe6c80cb09dde3ef3fa1f8"
    }
   }
  },
  "name": "St. Louis, MO",
  "grade": "screening-level, not decision-grade",
  "scope": {
   "full": "https://api.truthbear.co/scope/v1",
   "verifiability": "unknown",
   "monitoring_not_forecast": true,
   "intelligence_not_command": true
  },
  "nature": "This API supplies data organisation and trend description only. It is not a recommendation to act; the decision is yours. Purely descriptive - no judgement, no prediction. Official source plus record_hash; verify with the free /gauge/verify.",
  "location": "us-stlouis",
  "provenance": {
   "freshness": "fresh",
   "age_hours_now": 15,
   "freshness_basis": "cadence=default; fresh<=24h; recent<=192h; dead_source>1440h; age_basis=request-time(now minus observed_at)"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/truthbear-gauge-region-environmental-chain-90a3b1e5/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.truthbear.co](https://www.zero.xyz/host/api.truthbear.co/llms.txt)