# Userscript Implementation > Implement and harden Tampermonkey userscript features with CSP-safe UI patterns and strict sync privacy defaults. Use when this capability is needed. - Skill: `tomevault-io/userscript-implementation` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add tomevault-io/userscript-implementation` - Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/userscript-implementation/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Coding & Dev Tools - Author: tomevault-io (https://skillmd.com/u/tomevault-io) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/tomevault-io/userscript-implementation --- # Userscript Implementation Use this skill for userscript-specific behavior, metadata, DOM extraction, and portal compatibility. ## Scope - Validate Tampermonkey metadata changes (`@match`, `@grant`, `@connect`). - Keep UI rendering CSP-safe and portal-compatible. - Preserve sync privacy model and multi-card behavior. ## Role-Specific Guardrails - Keep `@connect` least-privilege. - Prefer class-based styling and `GM_addStyle` for new UI. - For selector fallback arrays, continue evaluation until semantic card validation passes. - In observer + timeout flows, clear pending timers on early resolve. ## Output - Behavioral impact by portal/card - Verification and manual-check outcomes - Risks and compatibility notes ## Canonical References - Workflow gates: `docs/workflow/gates.md` - Handoff contract: `docs/workflow/handoff-format.md` --- > Converted and distributed by [TomeVault](https://tomevault.io/claim/laurenceputra) — claim your Tome and manage your conversions.