
Guides & Tutorials
13 min
Document Classification with an Open LLM API: 7,218 Documents, No Training Data, $0.05 per Thousand
We classified the full 20 Newsgroups test split with Qwen 3.8 27B over an OpenAI-compatible API, zero-shot, ten documents per request, with the label set enforced by a JSON schema. 72% accuracy on twenty classes with no labeled data, 70,000 documents an hour on one key, and a third of all errors inside three categories that overlap by definition. Few-shot examples doubled the cost and moved accuracy half a point.
text classificationzero-shotstructured output