Viceroy

Q: What is a Claude Code skill and how does the Viceroy skill fit in?

A Claude Code skill is a SKILL.md file that lives under ~/.claude/skills/<name>/ and tells the Claude Code CLI agent how to perform a specific task (instructions, prompts, allowed tools). Skills are auto-discovered at session start. Viceroy is one of 67,000+ skills indexed in the open ClaudSkills catalog, classified under the Dev Tools category. Learn more at https://claudskills.com/learn/what-is-skill-md/.

Category: Dev Tools · Sub-category: package-mgmt · Last updated: 2026-06-13

lang:rust

Runs Fastly Compute WASM applications locally with Viceroy, specifically for Rust and Component Model projects. Use when starting a local Fastly Compute dev server with Viceroy, configuring fastly.toml for local backend overrides and store definitions, running Rust unit tests with cargo-nextest against the Compute runtime, debugging Compute apps locally, adapting core WASM modules to the Component Model, or troubleshooting local Compute testing issues (connection refused, missing backends, store config). For non-Rust Compute work or understanding the Compute API, prefer the fastlike skill instead — its source code is easier to understand as a Fastly Compute API reference.

From the source SKILL.md

Viceroy is Fastly's official local testing environment for Compute applications. It emulates the Fastly Compute platform, allowing you to develop and test WASM services locally.

What this skill does

Viceroy is a community-contributed Claude Code skill in the package-mgmt sub-category. It ships as a SKILL.md file that Claude Code auto-discovers under ~/.claude/skills/viceroy/ and loads when your prompt matches the skill's trigger.

When to invoke it: Use when starting a local Fastly Compute dev server with Viceroy, configuring fastly.toml for local backend overrides and store definitions, running Rust unit tests with cargo-nextest against the Compute runtime, debugging Compute apps locally, adapting core WASM modules to the Component Model, or troubleshooting local Compute testing issues (connection refused, missing backends, store config).

Who uses this skill

The Viceroy Claude Code skill is built for developers, power users, and teams automating repetitive workflows and improving developer experience. It's part of ClaudSkills (also referred to as Claude Skills or Claude Code Skills) — the open community-curated registry of 116,000+ SKILL.md files for Anthropic's Claude Code agent and the wider Claude ecosystem (Claude API, Claude Agent SDK).

How to install

Free

Manual install (2 steps)

mkdir -p ~/.claude/skills/viceroy
curl -L https://claudskills.com/skills/viceroy/SKILL.md \
  -o ~/.claude/skills/viceroy/SKILL.md

Or just download SKILL.md directly and drop it into ~/.claude/skills/viceroy/. Claude Code auto-discovers it on next session.

Skills live at ~/.claude/skills/viceroy/SKILL.md on macOS/Linux, or %USERPROFILE%\.claude\skills\viceroy\SKILL.md on Windows. See the full install guide for step-by-step instructions.

📱 Install from your phone or desktop Telegram

Open @claudskills_bot on Telegram, tap Open Desktop App, and the desktop app installs this skill for you. Or share the bot link with a colleague — they get the same one-tap install. Learn more →

Pro

One-click install via the desktop app

The ClaudSkills desktop app installs any skill directly into ~/.claude/skills/ with one click — no terminal required. Pro starts at $9/mo or $149 lifetime.

Pro

For the full experience including quality scoring and one-click install features for each skill — upgrade to Pro.

See pricing → Download desktop app

Frequently asked questions

How do I install the Viceroy Claude Code skill?

Install via the ClaudSkills desktop app (one click) or copy SKILL.md from the source repository to ~/.claude/skills/viceroy/SKILL.md and restart Claude Code. Both flows are detailed at claudskills.com/install/.

What does the Viceroy skill do?

Is this skill free to install?

Yes. ClaudSkills is an open registry — every skill keeps its source repository's license, and manual install via copy is free. ClaudSkills Pro ($9/mo, $79/yr, or $149 one-time) adds one-click install via the desktop app and a multi-signal Quality Score.

When should I use the Viceroy skill?

Use Viceroy when your Claude Code task falls under the Dev Tools category — specifically in the package mgmt area. Claude Code auto-discovers installed skills and invokes the right one based on the task description, so you can also ask Claude directly (e.g. "use Viceroy" or describe the task and let Claude pick). Browse related skills at /category/tools/.

What is a Claude Code skill and how does the Viceroy skill fit in?

A Claude Code skill is a SKILL.md file that lives under ~/.claude/skills/<name>/ and tells the Claude Code CLI agent how to perform a specific task (instructions, prompts, allowed tools). Skills are auto-discovered at session start. Viceroy is one of 67,000+ skills indexed in the open ClaudSkills catalog, classified under the Dev Tools category. Learn more at /learn/what-is-a-claude-skill/.

Attribution & license

Source: https://github.com/fastly/fastly-agent-toolkit/blob/HEAD/skills/viceroy/SKILL.md
License: MIT
Author: fastly

Cite this skill

If you reference this skill in a blog post, paper, or documentation, you can cite it as:

APA

fastly. (2026). Viceroy [Claude Code skill]. ClaudSkills. https://claudskills.com/skills/viceroy/

BibTeX

@misc{viceroy-2026,
  author    = {fastly},
  title     = {Viceroy [Claude Code skill]},
  year      = {2026},
  publisher = {ClaudSkills},
  url       = {https://claudskills.com/skills/viceroy/}
}

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