Hopper

Hopper, made by Hypercubic, Inc., is the first agentic development environment for the mainframe, enabling users to navigate mainframe systems, write and debug code, and perform administrative tasks through AI agents and a traditional TN3270 terminal interface. AI agent capabilities navigate ISPF by panel ID, write JCL, decode job failures, and query VSAM data using natural language, and an integrated development workflow compiles, tests, and deploys code in a single prompt with approval checkpoints. Automated debugging decodes failed jobs from JESMSGLG, JESYSMSG, and SYSUDUMP into structured diagnostics, a native TN3270 terminal offers full keyboard support, multi-language support handles COBOL, JCL, REXX, and CLIST, and cross-platform availability covers macOS, Windows, and Linux with no mainframe-side installation.