Hopper

Hopper is the first agentic development environment for the mainframe. It's Cursor for mainframes. It combines a real TN3270 terminal, mainframe-aware panels for datasets, jobs, members, and spool output, and an AI agent that can operate across z/OS workflows. The agent can inspect datasets, read and edit PDS members, write JCL, submit jobs, parse JES output, explain failures, and help developers debug mainframe workflows faster. Hopper is available on Windows, Linux, and macOS.