Expert Specl
Expert for Specl, a modern specification language and model checker for concurrent and distributed systems. Covers the full Specl language, CLI toolchain, distributed protocols (Raft, Paxos, consensus, BFT), concurrent algorithms, and formal verification. Use when: writing/debugging .specl files, modeling distributed systems, verifying safety properties, analyzing invariant violations, optimizing state space exploration, or translating TLA+. Keywords: specl, model checking, formal verification, TLA+, distributed systems, consensus, Raft, Paxos, BFT, invariants, state space, specification language.
Security AStatic scan found no risk patternsHow grading works ›
From the source SKILL.md
Specl is an exhaustive model checker for concurrent and distributed systems. Write a spec (state machine), and the checker explores every reachable state to verify invariants or produce minimal counterexample traces.
What this skill does
Expert Specl is a community-contributed Claude Code skill in the engineering-misc sub-category. It ships as a SKILL.md file that Claude Code auto-discovers under ~/.claude/skills/expert-specl/ and loads when your prompt matches the skill's trigger.
When to invoke it: Use when: writing/debugging .specl files, modeling distributed systems, verifying safety properties, analyzing invariant violations, optimizing state space exploration, or translating TLA+.
Who uses this skill
The Expert Specl Claude Code skill is built for software engineers, backend developers, full-stack teams, and technical leads building and maintaining production systems. It's part of ClaudSkills (also referred to as Claude Skills or Claude Code Skills) — the open community-curated registry of 158,000+ 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/expert-specl
curl -L https://claudskills.com/skills/expert-specl/SKILL.md \
-o ~/.claude/skills/expert-specl/SKILL.md
Or just download SKILL.md directly and drop it into ~/.claude/skills/expert-specl/. Claude Code auto-discovers it on next session.
Skills live at ~/.claude/skills/expert-specl/SKILL.md on macOS/Linux, or %USERPROFILE%\.claude\skills\expert-specl\SKILL.md on Windows. See the full install guide for step-by-step instructions.
Telegram
📱 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.
Frequently asked questions
How do I install the Expert Specl Claude Code skill?
Install via the ClaudSkills desktop app (one click) or copy
SKILL.md from the source repository to
~/.claude/skills/expert-specl/SKILL.md and restart Claude Code. Both flows are detailed at
claudskills.com/install/.
What does the Expert Specl skill do?
Expert for Specl, a modern specification language and model checker for concurrent and distributed systems. Covers the full Specl language, CLI toolchain, distributed protocols (Raft, Paxos, consensus, BFT), concurrent algorithms, and formal verification. Use when: writing/debugging .specl files, modeling distributed systems, verifying safety properties, analyzing invariant violations, optimizing state space exploration, or translating TLA+. Keywords: specl, model checking, formal verification, TLA+, distributed systems, consensus, Raft, Paxos, BFT, invariants, state space, specification language.
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 Expert Specl skill?
Use Expert Specl when your Claude Code task falls under the Engineering category — specifically in the engineering misc 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 Expert Specl" or describe the task and let Claude pick). Browse related skills at
/category/engineering/.
What is a Claude Code skill and how does the Expert Specl 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. Expert Specl is one of 67,000+ skills indexed in the open ClaudSkills catalog, classified under the Engineering category. Learn more at
/learn/what-is-a-claude-skill/.
Attribution & license
Cite this skill
If you reference this skill in a blog post, paper, or documentation, you can cite it as:
APA
danwt. (2026). Expert Specl [Claude Code skill]. ClaudSkills. https://claudskills.com/skills/expert-specl/
BibTeX
@misc{expert-specl-2026,
author = {danwt},
title = {Expert Specl [Claude Code skill]},
year = {2026},
publisher = {ClaudSkills},
url = {https://claudskills.com/skills/expert-specl/}
}Embed this skill
Promote, attribute, or link this skill from your own README, blog post, or documentation. All three snippets are free to use — no sign-up, no API key. More distribution surfaces →
Badge
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Security scan
Grade A · scanned 2026-07-23 — free static scan against the OWASP Agentic Skills Top 10.
No risk patterns were found in any of the ten OWASP-aligned categories. How grading works ›
- ✓ Prompt injection
- ✓ Data exfiltration
- ✓ Supply chain
- ✓ Reverse shell
- ✓ Credentials
- ✓ Execution
- ✓ Filesystem
- ✓ Persistence
- ✓ Obfuscation
- ✓ Network
Show this grade on your repo (click to copy):
[](https://claudskills.com/skills/expert-specl/#security)
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