# EU Power Dispatch – Cheapest Window Finder

> EU Power Dispatch – Cheapest Window Finder is a paid API for AI agents from energy.halowerk.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-15).

Given a desired operating duration (1–24 hours), returns the contiguous time window in the next 24 hours with the lowest average EPEX spot electricity price in Germany/EU.

## Facts

- Endpoint: POST https://energy.halowerk.com/optimizer/cheapest-window
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/eu-power-dispatch-cheapest-window-finder-627615b0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_T0PAF6de01_g-3f3mZql2

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 eu-power-dispatch-cheapest-window-finder-627615b0 -d '<json body>'
```

Example prompt: Find me the cheapest contiguous 3-hour window to run my compute cluster today using EU spot electricity prices.

## When to prefer this

Choose this endpoint when you need to schedule a flexible, duration-bounded workload (compute, EV charging, battery charging, industrial process) at the lowest possible electricity cost using real EU/German EPEX spot market data. Prefer it over static scheduling or generic time-of-use tariffs when actual intraday spot prices matter and your load can shift within a 24-hour window.

## Known failure modes

- Invalid duration_hours (less than 1 or greater than 24) returns a 422 validation error
- Payment not provided or rejected returns a 402 challenge (x402 protocol)
- Upstream ENTSO-E or SMARD data temporarily unavailable causes a 503 or empty result
- Requesting a window longer than available forecast data returns an error or truncated result

## How this service works

Flexible-load agents buy this endpoint to schedule a contiguous operating window at the lowest average electricity price.

## Output

Returns the optimal contiguous time window (start time, end time) within the next 24 hours that has the lowest average EPEX spot electricity price for the requested duration, along with the average price and likely the per-hour price breakdown for that window.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "duration_hours": {
   "type": "integer",
   "default": 2,
   "maximum": 24,
   "minimum": 1
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/eu-power-dispatch-cheapest-window-finder-627615b0/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)