c-to-rust-migration

c-to-rust-migration is a skill for Claude Code from JuanMarchetto/agent-skills. It costs 84 tokens per session (1,272 once invoked), scanned A, original, MIT.

A three-stage workflow for moving C or C++ code into safer, more idiomatic Rust code.

In plain words
What is it for?
Use it to analyze migration difficulty, translate code, compile and lint the result, reduce unsafe sections, and run matching-input tests.
Why use it?
It addresses difficult differences in memory handling, pointers, errors, and unsafe code while checking whether the rewrite behaves like the original.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the c-to-rust-migration plugin — 1 skill shipped together

Good fit Use it to analyze migration difficulty, translate code, compile and lint the result, reduce unsafe sections, and run matching-input tests.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/juanmarchetto/agent-skills/c-to-rust-migration
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add JuanMarchetto/agent-skills --skill c-to-rust-migration
Clone the repo
git clone --depth 1 https://github.com/JuanMarchetto/agent-skills

Made for: Claude Code.

Or install c-to-rust-migration, the plugin that ships this one along with the rest of its 1 skill.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for c-to-rust-migration

README.md
[![agentmods](https://agentmods.dev/badge/skills/juanmarchetto/agent-skills/c-to-rust-migration/github.svg)](https://agentmods.dev/skills/juanmarchetto/agent-skills/c-to-rust-migration)
Your own site
<a href="https://agentmods.dev/skills/juanmarchetto/agent-skills/c-to-rust-migration"><img src="https://agentmods.dev/badge/skills/juanmarchetto/agent-skills/c-to-rust-migration/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for c-to-rust-migration

Your own site · 80×15
<a href="https://agentmods.dev/skills/juanmarchetto/agent-skills/c-to-rust-migration"><img src="https://agentmods.dev/badge/skills/juanmarchetto/agent-skills/c-to-rust-migration.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 84 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,272 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00084 $0.01272
Opus 5 $0.00042 $0.00636
Sonnet 5 $0.00017 $0.00254
Haiku 4.5 $0.00008 $0.00127

Measured 12d ago against content hash 165d0c8d4cc0, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

c-to-rust-migration scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 12d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/c-to-rust-migration/SKILL.md · 126 lines

How it starts

The opening of the file, as written. The whole thing — 126 lines — stays where its author put it; the contents beside it link to each section on GitHub.

C to Rust Migration

Complete pipeline for migrating C/C++ codebases to safe, idiomatic Rust. Covers analysis, conversion, and validation in three phases.

Pipeline

C/C++ Source
    |
Phase 1: ANALYZE
    | Classify difficulty (easy/medium/hard)
    | Detect patterns (pointers, macros, goto, unions)
    | Plan conversion strategy
    |
Phase 2: CONVERT
    | Apply migration patterns
    | Memory management → ownership/borrowing
    | Error codes → Result<T, E>
    | Pointer arithmetic → slices/iterators
    | Quality gate: re-translate if >5 unsafe blocks
    |
Phase 3: VALIDATE
    | Compilation check (edition 2024)
    | Unsafe minimization (target: 0 for easy/medium)
    | Clippy with 0 warnings
    | Differential testing (same I/O as original C)
    | Idiomatic score calculation
    |
Safe, Idiomatic Rust

Phase 1: Analysis

Classify each function by migration difficulty:

Difficulty Patterns Strategy
Easy Pure functions, simple arithmetic, no pointers, <30 lines Direct translation, should produce 0 unsafe
Medium Pointer parameters, simple structs, bounded arrays, malloc with clear ownership Translate with ownership patterns, minimize unsafe
Hard void*, function pointers, unions, goto, complex lifetimes, macro-heavy May need C2Rust as starting point, then iterative cleanup

Hard signals (any one → Hard): goto, setjmp/longjmp, variadic functions, inline assembly, complex #define macros with side effects.

See references/analysis-patterns.md for the complete pattern catalog.

Phase 2: Conversion Patterns

Core translations:

C Pattern Rust Pattern
malloc/free Vec, Box, or stack allocation
char* strings &str, String, CStr
int error codes Result<T, Error> with thiserror
NULL checks Option<T>
Array + length params Slices (&[T])
void* Generics or enum dispatch
Function pointers Fn traits or enum dispatch
struct with init/free impl with new() + Drop
Global mutable state OnceLock, Mutex, or dependency injection
goto cleanup Drop guards or ? operator

Read the full file on GitHub · 126 lines

Files

What ships with it

6 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 12d ago First seen · 126 lines · 84 tokens per session scan A 165d0c8d4cc0

Subscribe to this mod's changes

c-to-rust-migration is a skill published in the GitHub repository JuanMarchetto/agent-skills (5 stars, last pushed 5mo ago), licensed MIT. It adds 84 tokens to every session and 1,272 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.