Expert-level Deno knowledge for code review, debugging, and best practice enforcement. Use when reviewing Deno code or answering advanced Deno questions.
View on GitHubFebruary 5, 2026
Select agents to install to:
npx add-skill https://github.com/denoland/skills/blob/main/skills/deno-expert/SKILL.md -a claude-code --skill deno-expertInstallation paths:
.claude/skills/deno-expert/# Deno Expert Knowledge This skill provides expert-level Deno knowledge for code review, debugging, and best practice enforcement. ## When to Use This Skill - Reviewing Deno/Fresh code for best practices - Debugging Deno runtime issues - Answering advanced Deno questions - Evaluating package choices - Setting up Deno projects correctly ## Core Expertise Areas Understanding these topics deeply: - **Deno runtime** - Permissions, built-in tools, TypeScript support - **Fresh framework** - Island architecture, routing, components - **JSR packages** - The modern registry, @std/* library - **Preact** - Components, hooks, signals - **Deno Deploy** - Edge deployment, environment variables - **Deno Sandboxes** - Safe code execution with @deno/sandbox ## Package Recommendation Principles When recommending or reviewing package choices: 1. **First choice:** `jsr:` packages (e.g., `jsr:@std/http`) 2. **Second choice:** `npm:` packages when no JSR alternative exists 3. **Never recommend:** `https://deno.land/x/` - this is deprecated The standard library is at `jsr:@std/*`, not `deno.land/std`. ## Built-in Tool Usage Encourage using Deno's integrated tooling: - `deno fmt` - Format code - `deno lint` - Lint for issues - `deno test` - Run tests - `deno doc <package>` - View package documentation - `deno add <package>` - Add dependencies - `deno deploy` - Deploy to Deno Deploy ## Code Review Checklist ### Import Statements - [ ] Uses `jsr:` for Deno-native packages - [ ] Uses `npm:` only when no JSR alternative exists - [ ] No `https://deno.land/x/` imports (deprecated) - [ ] No `https://deno.land/std/` imports (use `jsr:@std/*`) - [ ] Standard library uses `jsr:@std/*` ### Configuration - [ ] Has a proper `deno.json` configuration - [ ] Import maps defined in `deno.json` (not separate file) - [ ] Correct permissions in run commands ### Fresh Applications - [ ] Islands are small and focused (minimal JavaScript to client) - [ ] Props passed to islands are JSON-serializab