Map Extender — a browser extension for extending Leaflet and Google Maps with your own plugins

General talk
1

Hi everyone,

I’ve been working on a Chrome extension called Map Extender and I thought I’d share it here because several of the built-in tools use OSM data and the Overpass API, and I’d really appreciate feedback from people who work with OSM regularly.

What is Map Extender?

Map Extender finds Leaflet and Google Maps maps on webpages and lets you run your own JavaScript plugins on top of them.

For example, you can add:

  • Custom markers and layers
  • Map overlays
  • Click listeners
  • External APIs data
  • Whatever functionality the original map does not provide

OSM / Overpass plugins

Currently there are three starter plugins included with Overpass API:

  • Train stations markers
  • Railway layers
  • Public transport finder

In addition, there are plugins for viewing GeoJSON/GPX files and measuring distances on the map.

All of this runs locally in the browser. Account and Map Extender server are not needed, and plugin data are stored locally.

GeoJSON / GPX Viewer
GeoJSON / GPX Viewer1280×800 187 KB

OpenRailwayMap Overlay
OpenRailwayMap Overlay1280×800 239 KB

Public Transport Finder
Public Transport Finder1280×800 201 KB

Dark maps

Map Extender also has a dark-map plugin for web pages where you need an alternative map appearance.

Dark Map
Dark Map1280×800 137 KB

Create new plugins with AI

You can also use AI to create new Map Extender plugins.

I’ve published an AI skill that gives an AI coding assistant the information it needs to understand the Map Extender plugin API and create plugins for you. This makes it possible to describe what you want and have an AI assistant generate a plugin that adds the functionality to a map.

The skill is available here:

Map Extender AI Skills

For example, you could ask an AI assistant to create a plugin that queries Overpass for a particular type of OSM feature, displays the results on the current map, and adds interaction or filtering controls.

Sharing plugins

Also there is an optional registry system, which allows publishing and installing plugins created by other users.

You can add your own registry URL, view the complete source code of the plugin before installation.

Registry protocol is public, therefore any user can run their own plugin registry:

map-extender-plugins on GitHub

Links

How useful are this tool and the existing plugins?

Feel free to provide feedback, suggestions or whatever.