Configure singleton documents in a Sanity Studio using the document.singletons registry. Use when a developer wants a fixed-id document (settings, navigation, footer) edited in place, hidden from the default content list, with no "create new" or "duplicate" affordances — or when migrating a userland singleton implementation or a third-party singleton plugin (e.g.
Install
npx skills add sanity-io/agent-toolkit --skill sanity-singletonsnpx skills add sanity-io/agent-toolkit --skill sanity-singletons -a claude-code -gnpx skills add sanity-io/agent-toolkit --skill sanity-singletons -a codex -ggemini skills install https://github.com/sanity-io/agent-toolkit.git --path skills/sanity-singletonsgh skill install sanity-io/agent-toolkit sanity-singletonsgit clone --depth 1 https://github.com/sanity-io/agent-toolkit /tmp/sanity-io__agent-toolkit
mkdir -p ~/.claude/skills ~/.agents/skills
cp -R /tmp/sanity-io__agent-toolkit/skills/sanity-singletons ~/.claude/skills/sanity-singletons # Claude Code
cp -R /tmp/sanity-io__agent-toolkit/skills/sanity-singletons ~/.agents/skills/sanity-singletons # Codex, Cursor, Gemini CLI, Copilot, OpenCode