ds2api vs Hopper

ds2api is a lightweight Go middleware server that acts as a protocol translation layer between AI clients and multiple provider APIs. It accepts requests in any major client format and converts them to the target provider format — covering OpenAI, Anthropic Claude, Google Gemini, and others. Multi-account rotation is built in: you can pool API keys across accounts to spread load and reduce rate-limit exposure. The project is minimal by design — a single Go binary that runs locally or in a container. It's aimed at developers and teams who work with multiple AI providers and want a single endpoint that handles format conversion and key rotation transparently. No vendor lock-in, no cloud dependency. ds2api is gaining traction in the local LLM and API arbitrage communities who run self-hosted models alongside commercial APIs and need a clean routing layer. The multi-account rotation feature is particularly relevant for power users who maintain multiple accounts across providers to work around per-account rate limits — a controversial-but-common practice.

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.