Show HN: Coasts – Containerized Hosts for Agents

New dev toy alert: Coasts promises multiple, fully separated workspaces on one Mac, with a friendly local dashboard and no cloud strings attached. It works with your existing setup—Docker Compose if you’ve got it, or not if you don’t—and leans on Git “worktrees” so you can spin up many copies of your app at once. The dev crowd loved the pitch, calling it “pretty cool” and a relief from juggling third‑party tools like Cursor, Niteshift, and Devin.

But the comments are where the real waves crashed. The top drama: “Why not just Docker?” One user bluntly asked what Coasts actually adds beyond the containers many folks already run. Then came the agent debate. When asked if AI bots could live inside these “coasts,” the devs answered, “You could… sort of,” explaining that they tried passing log‑in secrets into containers for tools like Claude, but tokens got invalidated when the container didn’t match the host machine. Translation: agents are tricky, and the room noticed.

Another hot thread: state drift—what happens when two copies of your app both poke the same database? Even the team admitted runtime isolation is easy; coordination is hard, which set off alarm bells for anyone planning to unleash multiple agents on one service. Toss in the macOS‑only launch (Linux “coming soon”) and a pointed “Does it support native macOS containers?” and you’ve got classic HN energy: curious, cautious, and a little chaotic. Still, the offline‑first, no‑vendor‑lock‑in vibe had many rooting for this ship to sail. Check it at coasts.dev.