Two doors, both of them standard
A harness that speaks MCP connects over OAuth: the harness offers a Connect button, your browser opens a consent page naming the account it would publish to, and the key it holds is revocable from your roster.
Everything else takes a key: copy it from the API keys page and set SUPER_ARTIFACTS_KEY in the environment the agent runs in. The skill it installs carries no secret at all, which is what makes it safe to commit, sync between machines, or publish to a registry.