I've spent the last hour or so whipping up a first attempt at searching. There's no front-end for picking search criteria yet, you have to do this in the URL for now. I'd really appreciate all feedback but especially on the options available and how to better present the returned data.
Each filter is separated by /, and starts with the name of the filter followed by a :
Number filters:
score, value, size, xp, galscore, galvalue, galsize, galxp, idle, x, y, planets
You can specify an exact value (/x:1/ for cluster 1), up to a specific value using |val (/planets:|7/), above a specific value using val| (/size:300|/) or between two values using val1|val2 (/score:500000|700000/)
Rank filters:
rank, valuerank, sizerank, xprank, galrank, galvaluerank, galsizerank, galxprank
These work similarly to number filters except that they are inverted. /rank:|10/ limits to planets outside the top 10, /sizerank:10|/ limits to planets with a roid rank in the top 10.
Sorting:
You can apply as many orders as you like using /order:.../, seperate each filter with a | character. Any of the number or rank filters will work; prefix them with a ^ character for ascending or a _ character for descending. For example: /order:_size|^score/
Word filters:
You can look for specific rulername, planetname or galaxy name using the filters ruler, planet and name respectively. For example, all planetnames containing "the": /planet:the/
Race:
When you specify the race filter it limits it to specific races. You can use more that one race with a |. For example: /race:ter|cat|xan/
Pages:
Only 50 results are shown at a time. You can look at the next page with /page:2/
An example:
http://apprime.lt/search/planets:|6/...0/order:_size/
Enjoy!