# Research: choose a weather API

Generated in the production Ergod web app on 20 September 2026 using
Hunyuan 3 (`openrouter/tencent/hy3`). The brief is for an explicitly
non-commercial weather-widget example. No private input data was used.

The first request asked for an official-source comparison of Open-Meteo and
the US National Weather Service API: geographic coverage, key requirements,
attribution or identification, a limitation and a worldwide-widget choice.
Ergod fetched four pages, wrote a Markdown brief and attached it in chat.

Review narrowed an overbroad NWS coverage statement to point forecasts and
removed an unsupported geographic parenthetical. A second request also moved
the 15-minute-data coverage citation from the terms to the API documentation.
The original and revised briefs are preserved, unedited. A final request
asked for a shorter answer in chat; `conversation.jpg` captures that exchange.
The final summary still uses "US-only" as shorthand in its last sentence;
the revised brief's forecast-office coverage wording is the precise version.

## Sources checked on September 20

- https://open-meteo.com/en/docs — worldwide model coverage, API-key field,
  and the geographic limitation on native 15-minute data.
- https://open-meteo.com/en/terms — free API access is non-commercial and has
  published request limits; service availability is not guaranteed.
- https://open-meteo.com/en/licence — data attribution under CC-BY 4.0.
- https://www.weather.gov/documentation/services-web-api — point forecasts
  use forecast-office grids, User-Agent identification is required, data is
  open, rate limits are not published and grid assignments may change.

The recommendation is tied to this example's scope and the documentation
available on the recording date. It is not an API uptime guarantee or a
claim about every NWS data product. The screenshot is an actual conversation,
cropped to exclude unrelated account navigation.