Hopper is your AI agent for building and running mainframe software.
It drives TN3270 screens, reads source, JCL and spool, and fixes what broke, with your approval.
What teams use Hopper for
Testing and validation
Hopper's agent runs the screens and jobs a change touches and checks each result against the last good run, so you know what moved before you promote.
Incident response
When a job abends or a transaction fails, Hopper turns the job log into a report with the cause and a proposed fix, so whoever is on call starts from an answer instead of SDSF.
Nightly batch
Hopper keeps track of the overnight run, explains each failure by morning, and reruns jobs once you approve the fix, so the batch window closes on time.
Agents that work the green screen
Hopper reproduces the problem in TN3270, fixes the program behind it, and checks the screen again, while you approve each step.
Abends explained before you open SDSF
Hopper turns each failed job into a report with the cause and a proposed fix, and reruns it once you approve.
Bring your own agent with Hopper MCP
Hopper MCP lets the agents your team already uses read spool, fix code, rerun jobs and work 3270 screens, with Hopper checking every action against your permissions.
Set up for how you work
Start from the layout built for your job, then rearrange panes until it fits the way you work.
World-class security at every layer
Deploy in your VPC or on-prem
Run Hopper inside your own cloud account or data center, so source, job output and screen data stay inside your network.
Model-agnostic
Use the model your security team approves, hosted or self-hosted, and switch later without changing how your team works.
No model training
Your code, spool and screens are never used to train models, and every request runs with zero data retention.
Standard mainframe connectivity
Hopper connects through the z/OS interfaces you already run, TN3270, FTP and z/OSMF, so there is nothing to install on the mainframe.
Pricing
Hobby
Includes:
- No credit card required
- macOS, Windows, and Linux
- Connect to your own mainframe
- All core Hopper features
Enterprise
Everything in Hobby, plus:
- SAML SSO
- MCP Server Access
- Admin and Model Controls
- Org-wide Privacy Controls
- No Model Training
- Priority Support
- On-prem / VPC Deployment
- SOC 2 Type II report available under NDA
Download Hopper, connect to your LPAR, and start shipping
Hopper is a desktop application for z/OS engineers that bundles a TN3270 terminal, a datasets browser, a jobs browser and an AI agent into a single interface. In natural language, you can ask the AI Agent to read COBOL source, submit and monitor batch jobs, decode VSAM records and write changes under your supervision. Hopper runs on macOS, Windows and Linux.
Hopper runs on macOS, Windows and Linux. Hopper provides separate builds for Apple Silicon and Intel processors on macOS. On Windows, Hopper provides an x64 installer. On Linux, Hopper supports Debian and Ubuntu via a .deb package and any Linux distribution via an AppImage.
No. Hopper runs entirely on your laptop and requires no mainframe-side installation. Nothing runs on z/OS, so your sysprog does not need to deploy anything. Hopper connects to your mainframe over standard TN3270 and optional FTP protocols using your existing network connection.
Hopper connects to z/OS using two standard mainframe protocols: TN3270 for the live terminal session and FTP for datasets and the JES queue. TN3270 is required. FTP is optional but recommended; without FTP credentials, the datasets browser, jobs browser, builds and most agent tools stay disabled.
Hopper's AI agent reads COBOL and JCL source, submits and monitors jobs, decodes VSAM records and drives ISPF using plain English prompts. The agent operates across six tool categories spanning datasets, jobs, terminal, CICS, COBOL and data taps, and can chain work across subsystems in a single conversation turn.
Hopper's datasets tools list, read, write and allocate sequential datasets, PDSes and members.
Hopper's jobs tools submit JCL, wait for completion, read spool output and classify failures.
Hopper's terminal tools drive the TN3270 session, read screens and send keystrokes and attention keys.
CICS operations in Hopper include sign-on, transaction execution, resource installation and CEDA defines.
COBOL support in Hopper covers compilation, copybook parsing and VSAM record decoding.
Hopper's data tap tools snapshot VSAM data into a queryable local copy and run SQL against it.
Hopper's AI agent handles COBOL, JCL, REXX and CLIST. The agent traces how programs and datasets connect and works out what to edit for the task you describe. The agent reads the source directly from your PDSes and uses it within the current conversation.
Hopper's approval model separates read-only actions from mutating actions. Read-only actions such as listing members, reading source or querying spool run instantly without confirmation. Mutating actions such as writing a member, submitting a job or installing a CICS resource pause in chat for your explicit approval before anything on the mainframe changes.
Hopper stores FTP and CICS credentials in your operating system keychain, not in the application itself. Hopper replaces hidden fields on TN3270 screens, including passwords, with placeholders before screen content reaches the AI agent. The agent never sees raw credentials, and no credentials appear in chat history or exported conversation files.
Hopper is an AI-powered mainframe workspace that helps teams work faster in the systems they already operate. It supports day-to-day mainframe operations as well as modernization work by making it easier to navigate terminal screens, find and inspect applications, understand programs and job flows, and retrieve the information needed to take the next action.
Instead of manually moving through TN3270 screens, commands, and legacy workflows, teams can use agents to navigate the environment and surface relevant context. Hopper does not replace the mainframe or perform the modernization itself. It helps operators, developers, and modernization teams move through familiar and unfamiliar systems much faster while maintaining control over the underlying environment.
Hopper offers a free Hobby tier that requires no credit card and includes all core features. Hypercubic offers an Enterprise tier with custom pricing for organizations that need SAML SSO, MCP Server Access, admin and model controls, org-wide privacy controls, no model training, priority support, on-premises or VPC deployment and a SOC 2 Type II report available under NDA.
Join our community
Connect with builders using Hopper, follow product updates, and swap ideas with the Hypercubic team.