Unity Explorer MCP Scene Iteration

A failed or missing explorer MCP connection is the expected starting state, not a blocker. The MCP server lives inside the Explorer process, so ConnectionRefused or no explorer server at all only means the Explorer is not running yet — continue into the intent gate below; Setup launches it and binds the tools. Once bound, the mcp__explorer__* tools are self-describing and the authoritative catalog: read names, arguments, and output shapes there rather than assuming a tool is missing.

Coming in through the Creator Hub MCP? When the Creator Hub's editor MCP is connected (skill creator-hub-mcp; tools mcp__creator-hub__*), the Explorer is reached through it: launch_preview starts the scene preview with this MCP server on, and the runtime tools below are re-published live as explorer_<name> (explorer_screenshot, explorer_walk, …; explorer_call(tool, arguments) is the fallback while they bind). In that case skip Setup below entirely — no claude mcp add, no bind gate, no port 8123 probe — and go straight to the iteration loop with those tool names. The reference files apply unchanged. One extra rule applies on that path: before launch_preview, check preview_status and the OS process list (pgrep -fl '[M]acOS/Explorer' on macOS, Get-Process Decentraland on Windows), because stop_preview can return {ok: true} while the Explorer keeps running and the next launch then never connects — see "Preview lifecycle" in creator-hub-mcp.

Gates

Certain points in this skill are gates: you ask, call no tool after asking, and let the user answer. A gate opens only on their reply — never on your own judgment, never on their silence, never because a workaround is available to you. Running as a subagent, you cannot open a gate at all — there is no user to ask: stop and report the pending decision to your caller with your recommendation, rather than passing the gate on your own authority. Doing so violates the gate even when the workaround happens to work. The gates, in order: the skills-install gate and restart gate (below), the intent gate (pre-flight), the launch/kill gate (Setup step 1), and the bind gate (Setup step 2).

Load the SDK skills (before anything, either way)

This skill only covers driving the Explorer; the SDK7 API knowledge (composite-first rule, component reference) lives in the other topic skills of the decentraland/sdk-skills package this skill ships from (entry point sdk-scenes). You need them whether or not the Explorer ends up in play, so do this before the pre-flight below.

Load them: session skills first, then the filesystem — scene-local (.claude/skills/ in the scene folder) and global (~/.claude/skills/). This is done when you can name the topic skills available to you — not when you've noticed they exist. If they cannot be loaded — e.g. only unity-explorer-mcp itself was installed, not the whole package — skills-install gate: pull in the rest of the package's topic skills from that same source? Recommend it. On yes, ask at which level — scene-local or global — and run the matching command: