# fstwthr — plain-text weather

fstwthr.com is a free, keyless weather service for the web, terminal,
and AI agents. All endpoints serve the same canonical Forecast in
multiple formats. Government-sourced data only (NOAA for US, MET
Norway for global) — no aggregator middlemen.

## How to fetch weather

- Plain text:  curl https://fstwthr.com/{slug}
- JSON:        curl https://json.fstwthr.com/{slug}
- YAML:        curl https://yaml.fstwthr.com/{slug}
- Minimal HTML: https://min.fstwthr.com/{slug}
- One-liner:   curl 'https://fstwthr.com/{slug}?format=3'
- Compare:     curl https://fstwthr.com/compare/{slug}/{slug}
- MCP server:  https://mcp.fstwthr.com/mcp

## Supported slugs

- US cities (e.g. /denver, /boulder, /new-york).
- US ZIP codes (33.8k ZCTAs, e.g. /80302, /10001).
- Famous global cities (e.g. /london, /paris, /tokyo, /sydney).
- Any city Nominatim resolves (long tail).
- Disambiguate with comma + region:
  - US state code: /portland,me, /portland,or
  - ISO country code: /london,gb, /london,ky

## Query params

- ?units=metric  — °C / kph / hPa output (default imperial)
- ?voice=snark|hype  — stylistic dial on the natural-language summary
- ?format=1..4   — wttr.in-style compact one-liners on the text path
- ?fmt=text|json|yaml|min|modern  — explicit format override (wins
  over host / UA negotiation)

## MCP tools

The MCP server at https://mcp.fstwthr.com/mcp exposes these tools:

- get_weather(location, units?) — current conditions + short forecast
- get_forecast(location, days?, units?) — 7-day forecast
- get_timeline(location, hours?, units?) — next-12-hours hourly outlook
  ("what's it doing later today?")
- get_alerts(location) — active severe-weather alerts (US only)
- get_best_window(location, activity?, units?) — when to be outside
  (hourly window when available, else today vs tomorrow)
- get_activity_weather(location, activity?, units?) — go / caution /
  avoid verdict for a specific outdoor activity, with the factors + best
  window ("can I bike to work?", "is it safe to drive?")
- compare_weather(locations[], units?) — compare 2–4 places and pick the
  nicest ("Boulder or Golden this afternoon?")
- get_nowcast(location) — radar-derived current precipitation (US)

## Stability

URL shape and JSON schema are stable. Breaking changes get a new
subdomain or path prefix (v2.fstwthr.com, etc.); the current shape
will continue to work indefinitely.

## Attribution

Weather data by NOAA (United States) and MET Norway (global). Always
free + keyless for non-commercial use.

## See also

- /llms-full.txt — long-form description including the canonical
  Forecast JSON schema.
- /about — human-readable landing page (same content shaped for
  reading).