Is the Rust Dev skill free?

Yes. The skill itself is free from onsails/cc. SkillProof publishes the install command and an independent test verdict at no cost.

What is the Rust Dev SkillProof Score?

8.8/10 — installs cleanly 5/5, triggers reliably 5/5, output vs. baseline 7/10, docs & honesty 5/5.

How do I install Rust Dev?

Copy the install command from this page, run it in your terminal, and restart Claude Code. Skills live in ~/.claude/skills/ (global) or .claude/skills/ inside a project.

Can I use Rust Dev with Cursor, Copilot, Gemini CLI, Codex or other AI tools?

The SKILL.md format is native to Claude (Claude Code, Desktop, claude.ai). The instructions inside adapt to other assistants: Cursor rules, GitHub Copilot instructions, Windsurf rules, Custom GPTs, AGENTS.md for OpenAI Codex, and GEMINI.md for Google Gemini CLI — our conversion guides cover each, and the free converter on the tools page does the wrapping for you.

Rust Dev

Enforces FAIL FAST Rust: propagate every error, thiserror/anyhow, edition 2024

by onsails · onsails/cc

Tested · Works

Install — copy the command Download source ↗

Test report

Verdict: Tested · Works
Score: 8.8/10
Tested: Jul 17, 2026
Environment: Claude Code 2.x (agent harness)
Upstream re-checked: Aug 10, 2026 · b4df9d4

Ran the bundled check_crate_version.py live and it hit crates.io, returning serde 1.0.228 in ready-to-paste x.x form. On a 'read a port from a config file' task the no-skill baseline reached for unwrap_or_default() and unwrap_or(8080), silently swallowing a missing file and a bad value; under the skill's FAIL FAST rule the same function propagated both failures through a typed thiserror enum with source chains, which is exactly the anti-pattern the skill targets. No Rust toolchain was present so nothing was compiled, but the error-handling delta is concrete and objectively assessable. Install copies cleanly from a bare HOME and all three reference docs plus the workspace template exist.

Scored on four weighted criteria — install, triggering, output vs. baseline, docs. How scoring works

Installs cleanly 5/5
Triggers reliably 5/5
Output vs. baseline 7/10
Docs & honesty 5/5

What Rust Dev does

A standards-enforcement skill for Rust that pushes strict FAIL FAST error handling (propagate with ? or return Err, never swallow), thiserror-for-libraries / anyhow-for-binaries typing, workspace layout, and edition 2024. Activates when writing, reviewing, or fixing Rust code, managing Cargo dependencies, or scaffolding a new Rust project. Ships a crates.io version-lookup script and a lib+cli workspace template.

How to install Rust Dev

git clone https://github.com/onsails/cc
mkdir -p ~/.claude/skills
cd cc && cp -r rust-dev/skills/rust-dev ~/.claude/skills/rust-dev

Skills live in ~/.claude/skills/ (global) or .claude/skills/ (per-project). Restart Claude Code after installing.

Commands — how to trigger Rust Dev

/rust-dev Enforces FAIL FAST Rust: propagate every error, thiserror/anyhow, edition 2024

It also activates on plain-language prompts like these:

write a Rust function that reads a port number from a config file
review my Rust error handling for silently swallowed unwraps
scaffold a new Rust workspace with a lib crate and a cli crate

Frequently asked questions

Is the Rust Dev skill free?: Yes. The skill itself is free from onsails/cc. SkillProof publishes the install command and an independent test verdict at no cost.
Does Rust Dev work with Claude Code?: We tested it with Claude Code 2.x (agent harness) on Jul 17, 2026. Verdict: Tested · Works. Ran the bundled check_crate_version.py live and it hit crates.io, returning serde 1.0.228 in ready-to-paste x.x form. On a 'read a port from a config file' task the no-skill baseline reached for unwrap_or_default() and unwrap_or(8080), silently swallowing a missing file and a bad value; under the skill's FAIL FAST rule the same function propagated both failures through a typed thiserror enum with source chains, which is exactly the anti-pattern the skill targets. No Rust toolchain was present so nothing was compiled, but the error-handling delta is concrete and objectively assessable. Install copies cleanly from a bare HOME and all three reference docs plus the workspace template exist.
What is the Rust Dev SkillProof Score?: 8.8/10 — installs cleanly 5/5, triggers reliably 5/5, output vs. baseline 7/10, docs & honesty 5/5.
How do I install Rust Dev?: Copy the install command from this page, run it in your terminal, and restart Claude Code. Skills live in ~/.claude/skills/ (global) or .claude/skills/ inside a project.
Can I use Rust Dev with Cursor, Copilot, Gemini CLI, Codex or other AI tools?: The SKILL.md format is native to Claude (Claude Code, Desktop, claude.ai). The instructions inside adapt to other assistants: Cursor rules, GitHub Copilot instructions, Windsurf rules, Custom GPTs, AGENTS.md for OpenAI Codex, and GEMINI.md for Google Gemini CLI — our conversion guides cover each, and the free converter on the tools page does the wrapping for you.