Import seems to work!

app/controllers/settings/imports_controller.rb

@@ -57,6 +57,8 @@ class Settings::ImportsController < Settings::BaseController
               csv << [row.data['uri']]
             when :lists
               csv << [row.data['list_name'], row.data['acct']]
+            when :filters
+              csv << [row.data['title'], row.data['context'], row.data['keywords'], row.data['action'], row.data['expires_at']]
             end
           end
         end

app/models/form/import.rb

@@ -33,6 +33,13 @@ class Form::Import
     '#domain' => 'domain',
     '#uri' => 'uri',
     'List name' => 'list_name',
+
+    # Filters
+    'Title' => 'title',
+    'Context' => 'context',
+    'Keywords' => 'keywords',
+    'Action' => 'action',
+    'Expire after' => 'expires_at',
   }.freeze
 
   class EmptyFileError < StandardError; end
@@ -114,10 +121,11 @@ class Form::Import
     return @csv_data if defined?(@csv_data)
 
     csv_converter = lambda do |field, field_info|
-      if :type == :filters
+      case type.to_sym
+      when :filters
         case field_info.header
         when 'Context', 'Keywords'
-          field&.split(',')&.map(&:strip)&.presence
+          Oj.load(field)
         when 'Expire after'
           field.blank? ? nil : Time.zone.parse(field)
         else

app/services/bulk_import_row_service.rb

@@ -39,6 +39,13 @@ class BulkImportRowService
       FollowService.new.call(@account, @target_account) unless @account.id == @target_account.id
 
       list.accounts << @target_account
+    when :filters
+      filter = @account.custom_filters.find_or_initialize_by(title: @data['title'])
+      filter.context = @data['context']
+      filter.keywords = @data['keywords'].map { |keyword| CustomFilterKeyword.new(keyword: keyword) }
+      filter.action = @data['action'].to_sym
+      filter.expires_at = @data['expires_at']
+      filter.save!
     end
 
     true