def short_desc(self):
    return 'Schedule a run for all available spiders'

def run(self, args, opts):
    url = 'http://localhost:6800/schedule.json'
for s in self.crawler.spiders.list():
    values = {'project': 'YOUR_PROJECT_NAME', 'spider': s}
data = urllib.parse.urlencode(values)
req = urllib.request.Request(url, data)
response = urllib.request.urlopen(req)
log.msg(response)
Run multiple scrapy spiders at once using scrapyd