During the first summer of the coronavirus pandemic, a diary entry by K Allado-McDowell initiates an experimental conversation with the AI language model GPT-3. Over the course of a fortnight, their exchange rapidly unfolds into a labyrinthine exploration of memory, language and cosmology. The first book to be co-created with the emergent AI, Pharmako-AI takes a hallucinatory journey into selfhood, ecology and intelligence via cyberpunk, ancestry and biosemiotics. Through a writing process akin to musical improvisation, Allado-McDowell and GPT-3 together offer a fractal poetics of AI and a glimpse into the future of literature. Pharmako-AI reimagines cybernetics for a world facing multiple crises, with profound implications for how we see ourselves, nature and technology in the 21st century.