# Data sources

A data source is *not* an XML tag — it's declared in a config's `sources:` section (see
{doc}`../screen-design/config-format`) and fetched from a template with `source("name")`, which calls
`.fetch()` on it and hands the result straight to Jinja:

```yaml
sources:
  weather:
    source: weather.yr
    params:
      lat: 55.64277
      lon: 13.20638
      altitude: 17
```

```xml+jinja
{% set forecast = source('weather').nextHour(timestamp, 8) %}
<text>{{ forecast.airTemperature }}°C</text>
```

Whatever `.fetch()` returns is whatever that source type says it returns — some are plain dicts/lists,
others (calendar, weather) are small model objects with helper methods. Each page below documents both
the `params:` a source type accepts and what `.fetch()` gives back.

| `source:` name | Returns | Docs |
| --- | --- | --- |
| `request` | Parsed JSON, or raw text if the response isn't JSON | {doc}`request` |
| `calendar.ical` | An `ICalendarModel` wrapping a parsed ICS feed | {doc}`calendar` |
| `calendar.google` | A list of raw Google Calendar API event dicts | {doc}`calendar` |
| `weather.yr` | A `WeatherForecastModel` | {doc}`weather` |
| `transportation.trafiklab.departureBoard` | A list of departure dicts | {doc}`transportation` |

```{toctree}
:hidden:

request
calendar
weather
transportation
```