Stats created by a batch Async Stats Job (https://dev.twitter.com/ads/reference/1/post/stats/jobs/accounts/%3Aaccount_id) are made available via the GET version of the Jobs API (https://dev.twitter.com/ads/reference/1/get/stats/jobs/accounts/%3Aaccount_id), and the url attribute in the response links to a file in .zip format.
I’m documenting this here because the GET API was not documented until just today, and the TON API https://ton.twimg.com/advertiser-api-async-analytics seems entirely undocumented at this point.
The format of the content available at this API would be more obvious if Twitter returned a Content-Type header; we suggest Content-Type: application/zip. I’d also recommend documenting the download portion in the newly-released V0 -> V1 migration guide https://dev.twitter.com/ads/analytics/migration-guide-v0-v1
Example headers currently returned by https://ton.twimg.com/advertiser-api-async-analytics:
HTTP/1.1 200 OK Date: Thu, 31 Mar 2016 17:42:55 GMT Server: Apache content-md5: S7Vd0EqxMr0lej+1vVYFYw== etag: "S7Vd0EqxMr0lej+1vVYFYw==" expires: Mon, 04 Apr 2016 21:31:38 GMT last-modified: Mon, 28 Mar 2016 21:27:27 GMT x-connection-hash: b443912b9fd4b2c90b6f8e23620040a4 x-response-time: 7 x-ton-expected-size: 332 x-ton-expires: Mon, 04 Apr 2016 21:27:27 GMT Cache-Control: max-age=31536000 Content-Length: 332 Accept-Ranges: bytes Via: 1.1 varnish Age: 245477 X-Served-By: cache-tw-lax1-cr1-3-TWLAX1 X-Cache: HIT X-Content-Type-Options: nosniff