# TruthBear Agriculture Region Gauge (3-Leg Chain)

> TruthBear Agriculture Region Gauge (3-Leg Chain) is a paid API for AI agents from api.truthbear.co, paid per call via x402, $0.25/call, status unknown (last checked 2026-09-15).

Returns a sequential three-leg agricultural stress chain for a grain belt region: soil drought severity (USDM) → heat stress and growing degree days (NASA POWER) → realized crop vigor VHI (NOAA STAR), with confidence scored by how many legs are lit in order.

## Facts

- Endpoint: GET https://api.truthbear.co/gauge/agri-region
- Price: $0.25/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/truthbear-agriculture-region-gauge-3-leg-chain-65cb93cb
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_UGueY2uwiLUkY8fMjYN3p

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-agriculture-region-gauge-3-leg-chain-65cb93cb
```

Example prompt: Can you pull the full agriculture stress chain for us-iowa — check whether the soil drought is translating into actual crop damage using the drought, heat stress, and VHI legs?

## When to prefer this

Choose this endpoint when you need a cross-agency, sequentially confirmed view of agricultural stress — not just a single drought or NDVI reading, but a confirmation gate that checks whether soil drought has actually propagated to crop damage. Ideal when downstream decisions (commodity trading, insurance, food supply monitoring) require multi-source corroboration rather than a single signal. Prefer over raw USDM or NDVI queries when chain confidence and ordered confirmation matter.

## Known failure modes

- 422 no_charge: no data available for the requested location, not billed
- Invalid loc parameter: location ID not in accepted list returns an error
- Partial chain: one or more upstream data sources temporarily unavailable reduces confidence score
- Network timeout from upstream agencies (USDM, NASA POWER, NOAA STAR)

## How this service works

[3-LEG] Agriculture chain, one grain belt (?loc=us-iowa): leading soil drought (USDM D0-D4) -> current heat stress and growing degree days -> realized crop vigour VHI - did the drought actually reach the crop (confirmation gate). A chain, not one reading: confidence = how many legs are lit, in order. Sources: USDM/NDMC, NASA POWER, NOAA STAR. Descriptive only, never a forecast or advice. No data -> 422 no_charge, not billed. $0.25 per call.

## Output

A JSON object containing the three sequential chain legs — (1) USDM soil drought category (D0–D4), (2) NASA POWER heat stress and growing degree day accumulation, (3) NOAA STAR Vegetation Health Index — plus an overall confidence score reflecting how many legs are consecutively lit. Returns 422 no_charge if data is unavailable for the requested region, with no billing charge.

## 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": [
      "loc"
     ],
     "properties": {
      "loc": {
       "type": "string",
       "examples": [
        "us-iowa",
        "us-illinois",
        "us-nebraska",
        "us-kansas",
        "ar-pampas",
        "br-matogrosso"
       ],
       "description": "required - location id; full list at free /gauge/preview",
       "x-accepted-values": {
        "all": "https://api.truthbear.co/schemas/gauge-agri-region.input.json",
        "shown": 6,
        "total": 12
       }
      }
     },
     "additionalProperties": false
    }
   }
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "const": "json"
    },
    "example": {}
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "legs": {
   "heat": {
    "band": "below_warning",
    "source_ref": "https://open-meteo.com/en/docs (temperature_2m_max/min; GDD base 10 degC 86/50)",
    "record_hash": "sha256:454bc7664c8f82954a12a52f1f425223c1dfb9d72ced46320a22a804cd0e8271"
   },
   "drought": {
    "band": "normal",
    "source_ref": "https://open-meteo.com/en/docs/historical-weather-api(ERA5 soil moisture)",
    "record_hash": "sha256:5c5f46fb816028010748b0c081adade34d0330efd1b07401410e697d03b6580c"
   },
   "crop_vhi": {
    "band": "normal",
    "source_ref": "https://www.star.nesdis.noaa.gov/smcd/emb/vci/VH/(get_TS_admin.php CROP VHI)",
    "record_hash": "sha256:3a2dae57b8bb21c1b8cf83bb25d2aace7204dc9a80fc62782a1f1621183a67d4"
   }
  },
  "name": "US Corn Belt - Iowa",
  "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-iowa",
  "provenance": {
   "freshness": "stale",
   "age_hours_now": 423,
   "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-agriculture-region-gauge-3-leg-chain-65cb93cb/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)