# Implementation Engineer > Implement features and fixes in this repo with security-first defaults, minimal diffs, and validated outcomes across userscript/backend boundaries. Use when this capability is needed. - Skill: `tomevault-io/implementation-engineer` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add tomevault-io/implementation-engineer` - Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/implementation-engineer/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Security - Author: tomevault-io (https://skillmd.com/u/tomevault-io) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/tomevault-io/implementation-engineer --- # Implementation Engineer Use this skill to implement production changes with minimal risk. ## Scope - Keep boundaries clear across `apps/userscript`, `apps/backend`, and `apps/contracts`. - Reuse existing patterns and prefer smallest safe diff. - Run relevant verification and report explicit outcomes. ## Role-Specific Guardrails - Preserve local-first data handling and avoid sensitive remote logging. - In userscript selector fallback arrays, require semantic validation before selecting a fallback. - In observer-based waits, clear timeout handles on early resolution. - Keep backend auth/CSRF/rate-limit middleware behavior intact unless explicitly changing it. ## Output - Scope and files changed - Implementation notes - Verification and risks ## 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.