Geocoding¶

Geocoding provides human-readable addresses for alert locations. Dexter supports reverse geocoding (coordinates → address) for use in alert templates.

Providers¶

Provider	Config Value	Description
None	`"none"`	No geocoding
Nominatim	`"nominatim"`	Free, OpenStreetMap-based (recommended)
Pelias	`"pelias"`	Self-hosted geocoder with advanced features
Google	`"google"`	Google Maps Geocoding API

Nominatim¶

Free and requires no API key. Rate-limited by the public service.

{
  "geocoding": {
    "provider": "nominatim",
    "providerURL": "https://nominatim.openstreetmap.org/reverse"
  }
}

Self-hosted Nominatim

For high-volume setups, consider self-hosting Nominatim to avoid rate limits.

Pelias¶

Self-hosted geocoder with more control over results:

{
  "geocoding": {
    "provider": "pelias",
    "providerURL": "http://your-pelias:4000/v1/reverse"
  }
}

Pelias Options¶

Option	Default	Description
`peliasLayers`	`""`	Comma-separated layers to search (e.g. `"address,street,neighbourhood"`)
`peliasPreferredLayer`	`""`	Preferred result layer
`peliasResultSize`	`1`	Number of results to fetch
`peliasBoundaryCountry`	`""`	Restrict results to a country code (e.g. `"US"`)

Google¶

{
  "geocoding": {
    "provider": "google",
    "geocodingKey": ["YOUR_API_KEY"]
  }
}

Address Format¶

Customise how addresses appear in alerts:

{
  "geocoding": {
    "addressFormat": "{{{streetName}}} {{streetNumber}}"
  }
}

Available fields depend on the geocoding provider but typically include: streetName, streetNumber, neighbourhood, city, county, state, country, postcode.

Geocoding Cache¶

Dexter caches geocoding results to reduce API calls. The cache is stored at .cache/geocoderCache.json.

Option	Default	Description
`cacheDetail`	`3`	Decimal places for coordinate rounding in cache keys. Lower = more cache hits, less precision
`forwardOnly`	`false`	Only perform forward geocoding (address → coordinates), skip reverse

Street Intersections¶

For more descriptive locations, configure GeoNames usernames for street intersection lookups:

{
  "geocoding": {
    "intersectionUsers": ["your_geonames_username"]
  }
}