Edgee Codex Compressor vs Hopper

Edgee Codex Compressor is an open-source Rust-based AI gateway that sits between your coding agent (Claude Code, OpenAI Codex, or any LLM client) and the API. It losslessly compresses tool call results, file reads, shell outputs, and other large context payloads before they hit Anthropic or OpenAI's token counters — extending your effective context window by an average of 26-35% without changing any outputs. The core insight is that most of what fills context windows in coding agents is repetitive: boilerplate file content, repeated error messages, verbose JSON responses, and tool output that could be summarized without information loss. Edgee intercepts these at the gateway level, applies a combination of deduplication, semantic compression, and caching, then decompresses before passing to the model so the LLM sees full fidelity content. For developers regularly hitting Claude Code Pro session limits, this is a practical workaround. No code changes, no API key swapping — just point your coding client at the local Edgee proxy. The full source is on GitHub under the Edgee organization (the same team that builds Edgee, the analytics and CDN privacy gateway).

Hopper, from YC S24 startup Hypercubic, is the first agentic development environment purpose-built for mainframe systems. It lets AI agents navigate TN3270 terminals autonomously, write and submit JCL jobs, monitor JES output, debug failed jobs by analyzing spool data, query VSAM datasets, compile and run COBOL code, and manage CICS transactions—all via natural language prompts. Tasks that traditionally took mainframe specialists hours of manual TN3270 navigation can now be expressed as a single instruction. The technical challenge here is real: mainframes don't have nice REST APIs or modern dev tooling. They run on green-screen terminal protocols from the 1970s, and the humans who know how to operate them are retiring faster than they can be replaced. Hopper essentially wraps the entire mainframe interaction surface in an agent-friendly interface, translating intent into the arcane sequences of keystrokes and JCL that mainframes actually require. The product is free for individual developers (all core features, macOS/Windows/Linux) with Enterprise pricing for SSO, on-prem deployment, and SOC 2 reports. Hypercubic's team includes alumni from Cognition, Apple, and Windsurf. Given that mainframes still process an estimated $3 trillion in daily commerce and the COBOL developer shortage is acute, Hopper is targeting a genuinely underserved market with unusual urgency.