AI Agent Runtime is part of DevStudio — a free, in-browser collection of developer utilities that work without sign-up, installation, or any backend service. Sandboxed Claude Code skill runtime — skill picker (skill-maker IDB + paste JSON) + capability allowlist + gateway-internal agent_sandbox executor + append-only tool-call event stream, all running entirely on your device. Because the page never uploads what you paste, you can run sensitive payloads, configuration files, secrets, or production data through it with confidence: nothing leaves your browser tab. Use AI Agent Runtime for ad-hoc debugging, code review, log triage, release prep, learning a new format, or as a quick scratchpad while you build. If you use this tool a lot, pair it with Code Navigator, DevOps Debugger, Diagram Designer, and the rest of the DevStudio toolkit for related developer workflows.