Primer doesn’t use GPT-3
Primer NLP Engines are pre-trained NLP models that can read and summarize long bodies of text, pulling out key concepts, recognizing and identifying individuals who might be mentioned, and identifying patterns and structures that might elude human readers.

For instance, a financial company might use Primer Engine to read masses of 10K regulatory filings, “with the aim of identifying all of the companies that have increasing competitive risk exposure to China,” says Sean Gourley, Primer’s CEO.
An intelligence agency might use a different Primer Engine to identify existing quotes from a foreign official, and then run a sentiment analysis on them — analyzing the quotes to indicate positive or negative sentiment.
Though the engines come pre-trained by Primer, the company can also work with clients to fine-tune the models for specific tasks or data sets.

Source: https://www.axios.com/primer-nlp-models-business-ai-45f8175d-d0bb-4642-a0c9-b33891544916.html