This is a basic appengine-based app to handle server-side map tile overlay as a custom map source.

It is currently deployed under "http://tilesource-153122.appspot.com"

For example:

• http://tilesource-153122.appspot.com/composite/im_fs-32_ct-64/
• http://tilesource-153122.appspot.com/composite/mb_fs-32/

The service provides a basic REST-ish interface:

• /composite/<tilespec>/ - Provides leaflet-based preview map.
• /composite/<tilespec>/tile?z={z}&x={x}&y={y} - Renders composite tiles at the given location.
• /composite/<tilespec>/tilejson - Renders a tilejson spec for given composite map.

Where <tilespec> is of the form [layer(-alpha?)]+ specifying, in order, layers and optional alpha values for compositing. See layer sources in tilesource.py.

Z levels of 7-17 appear to work...