# weatherAI.io Decision API

> One call turns the weather into a decision. Ask whether and when to do an activity at a place and date,
> or which of the next days is best; get a verdict, a 0-100 score, the best time windows, the risks and a
> one-line summary.

- Decide one day: GET https://api.weatherai.io/v1/decide?location={place}&activity={activity}&when={today|tomorrow|yyyy-MM-dd}
- Best of the next days: GET https://api.weatherai.io/v1/best-day?location={place}&activity={activity}&days={1-14}
- MCP server (Streamable HTTP) for AI agents: https://api.weatherai.io/mcp (tools: decide, best_day, list_activities, get_usage)
- Auth: header X-API-Key or Authorization: Bearer (free key: https://www.weatherai.io/signup); ?key= for URL-only clients
- Activities: GET https://api.weatherai.io/v1/activities (running, cycling, outdoor-event, beach, laundry-drying, stargazing, hiking, golf, tennis, dog-walking, gardening, fishing, sailing, drone-flying, exterior-painting, concrete-pour, roofing, crop-spraying, outdoor-work, driving)
- Optional: from / to (hours of the day), units=imperial, detail=hourly (decide only)
- OpenAPI: https://api.weatherai.io/openapi.json
- Docs: https://www.weatherai.io/docs
- Pricing: 1,000 free calls every month, then £0.0012 per successful call from prepaid credit (VAT included). Errors are not charged. best-day is one call however many days it compares.

## Example
GET /v1/decide?location=London&activity=running&when=tomorrow
{"verdict":"good","score":82,"best_windows":[{"start":"2026-10-18 07:00","end":"2026-10-18 10:00","score":91}],
 "risks":[{"type":"rain","severity":"high","from":"2026-10-18 14:00","to":"2026-10-18 18:00","detail":"70% chance of rain"}],
 "summary":"Good conditions for a run in London; best 07:00–10:00. Watch for rain from 14:00."}