FilterBLAST provides API for other developers, so they can make tools which will check for filter's updates or even auto-update filter files on users computer.
https://filterblast.xyz/api/ListFilters/
Returns list of available item filters in JSON-format.
By default the list includes only actual filters, if you want to also get outdated ones add ?outdated=show to the end of the link.
Each record in the list has unique key which you will need in other APIs to specify filter. Filter's data includes: Version, LastUpdate, PoEVersion, ForumThread, Presets. If filter has Color or Sound themes - they will be in data too.
List of presets has preset's name as key and recommended (by filter's author) filename for .filter file as value.
Color and sound themes listed simply as values.
There can also be DefaultPreset, DefaultColorTheme and DefaultSoundTheme which are self-explanatory.
https://filterblast.xyz/api/CheckVersion/?format=json&filter=key
Returns actual version and last update date of specified filter in json or text format.
If a filter is outdated then there will be also Outdated: true in the json data or note about that in text format.
It's better to check both Version and LastUpdate for changes, since sometimes filter's authors push small hotfixes by changing only date's value, or otherwise do few versions in one day.
https://filterblast.xyz/api/FilterFile/?filter=key
Returns whole source code of specified filter, which can be saved as .filter file.
There is also optional parameters, which may change resulting code:
&preset=name specifies desired Preset
&colortheme=name specifies desired Color Theme
&soundtheme=name specifies desired Sound Theme
&customization=hash-key will load user's customization, previosly saved on FilterBLAST. The hash-key is last part of the saved link (before the slash), for example: 1r76nrf. Saved customization will be applied on last version of the fiter, replacing default values with user's choices only for those options, which exist in old and new version. Saved customization also remembers selected preset and themes, so there's no need to use other parameters.