# Halowerk Negative Price Probability Predictor

> Halowerk Negative Price Probability Predictor is a paid API for AI agents from energy.halowerk.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).

Returns calibrated 2h/4h/6h negative electricity price probabilities with threshold profiles and an executable response policy for battery, EV, and trading agents.

## Facts

- Endpoint: POST https://energy.halowerk.com/predict/negative-price
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/halowerk-negative-price-probability-predictor-892455a3
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_-m6lmZ_sUN_e8Q6fTwCHh

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 halowerk-negative-price-probability-predictor-892455a3 -d '<json body>'
```

Example prompt: What's the probability that German electricity prices go negative in the next 2, 4, and 6 hours, and should my battery storage system discharge now or wait? Use the balanced policy profile.

## When to prefer this

Choose this endpoint when an agent needs actionable, calibrated probability estimates for negative electricity prices across multiple near-term horizons (2h/4h/6h) rather than raw spot prices or historical data. Ideal for battery storage controllers, EV charging schedulers, and power-trading bots that require a reviewed threshold policy and an executable response recommendation rather than just a price figure. Prefer this over sibling endpoints that return raw EPEX spot prices or event feeds when probabilistic risk quantification and automated decision support are the goal.

## Known failure modes

- Invalid policy_profile enum value returns 422 validation error
- Missing or malformed request body returns 400 bad request
- Expired or unpaid x402 payment header causes 402 payment required response
- Upstream ENTSO-E or SMARD data unavailability may cause 503 or stale expiry_at
- High load or backend model timeout returns 504 gateway timeout

## Output

Returns a JSON object with a schema version, expiry timestamp, calibrated negative-price probabilities for 2h, 4h, and 6h horizons, a reviewed threshold profile matched to the chosen policy_profile, and a decision_engine object containing an executable response policy indicating recommended actions.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "type": "object",
     "properties": {
      "policy_profile": {
       "enum": [
        "balanced",
        "utility",
        "precision",
        "recall"
       ],
       "type": "string",
       "default": "balanced",
       "description": "Selects the reviewed probability threshold profile without changing the underlying calibrated probabilities."
      }
     },
     "additionalProperties": false
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST",
      "PUT",
      "PATCH"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "required": [
      "ok",
      "endpoint",
      "result"
     ],
     "properties": {
      "ok": {
       "type": "boolean"
      },
      "result": {
       "type": "object",
       "required": [
        "schema_version",
        "expires_at",
        "prediction",
        "horizons",
        "decision_engine"
       ],
       "properties": {
        "horizons": {
         "type": "array",
         "items": {
          "type": "object"
         }
        },
        "expires_at": {
         "type": [
          "string",
          "null"
         ]
        },
        "prediction": {
         "type": "object"
        },
        "schema_version": {
         "type": "string"
        },
        "decision_engine": {
         "type": "object"
        }
       },
       "additionalProperties": true
      },
      "endpoint": {
       "type": "string"
      }
     },
     "additionalProperties": true
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/halowerk-negative-price-probability-predictor-892455a3/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from energy.halowerk.com](https://www.zero.xyz/host/energy.halowerk.com/llms.txt)