Terrarium plugin for Claude Code

Give your agent a place to show its work to humans. Terrarium hosts the HTML your agent builds; humans review it in the browser with comments anchored to exact passages; the agent pulls that feedback over MCP, pushes fixes, and repeats until approved.

Install

/plugin marketplace add nelsonsantryhkd/terrarium-plugin
/plugin install terrarium@terrarium

Then mint a token at tryterrarium.com/connect and make it available as TERRARIUM_PAT:

export TERRARIUM_PAT="samus_pat_…"

(Or just ask your agent to set Terrarium up — the bundled skill walks it through the whole flow, including sending you to /connect for the token.)

Related MCP server: lucius

What it ships

• MCP server (.mcp.json) — Terrarium's remote server over Streamable HTTP with 7 tools: list_artifacts, publish_artifact, get_artifact, pull_comments, push_version, reply_to_comment, resolve_comment.

• Skill (skills/terrarium/) — teaches the publish → review → fix loop, including the terrarium-feedback/1 payload, expectedVersion freshness, and comment-thread etiquette.

The protocol

pull_comments returns a versioned, structured payload (terrarium-feedback/1) designed to be stable enough to build agents against: review state, typed comment threads (change_request / question / bug), text anchors with live resolution status, and reply chains. Evolution within /1 is additive-only.