n8n Binary and Data Every n8n item carries two independent slots: for structured data and for file bytes. They travel side by side through the workflow. File contents — the actual PDF, image, or zip — live in , never in . Get that split wrong and you read an empty field, lose a file mid-flow, or hand an AI agent a tool input it can't use. This skill covers where binary lives, how to read and write it, how to keep it from being silently stripped, the hard wall between binary and the AI-agent tool boundary, and why chat surfaces need a URL instead of raw bytes. --- The three rules that prevent…