A guide for writing Rust code with the facet ecosystem, a collection of libraries for describing, validating, serializing, and reporting errors from Rust data.

Use it when working with Facet derives, JSON or CSV data, command-line configuration, validation, errors, structural diffs, or date, decimal, and time types.

It helps you use facet-specific code and translate patterns from Serde, Rust’s common serialization framework, without guessing which attributes or libraries apply.

facet — Skill for Claude Code by neoeinstein/claude-plugins

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 neoeinstein/claude-plugins --skill facet

Clone the repo

git clone --depth 1 https://github.com/neoeinstein/claude-plugins

Made for: Claude Code.

Or install rust-best-practices, the plugin that ships this one along with the rest of its 2 skills.

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/neoeinstein/claude-plugins/facet/github.svg)](https://agentmods.dev/skills/neoeinstein/claude-plugins/facet)

Your own site

<a href="https://agentmods.dev/skills/neoeinstein/claude-plugins/facet"><img src="https://agentmods.dev/badge/skills/neoeinstein/claude-plugins/facet/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/neoeinstein/claude-plugins/facet"><img src="https://agentmods.dev/badge/skills/neoeinstein/claude-plugins/facet.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 88 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,516 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 unknown 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.

Model	Per session	Once invoked
Fable 5.1	$0.00088	$0.01516
Opus 5.5	$0.00035	$0.00606
Sonnet 5.5	$0.00018	$0.00303
Haiku 4.5	$0.00009	$0.00152

Measured 2mo ago against content hash 4890ab4d1c5f, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

facet 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 2mo 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.

plugins/rust-best-practices/skills/facet/SKILL.md · 76 lines

The source is not reproduced here

No licence file

Read it on GitHub

Files

What ships with it

7 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.

2mo ago First seen · 76 lines · 88 tokens per session scan A 4890ab4d1c5f

Subscribe to this mod's changes

facet is a skill published in the GitHub repository neoeinstein/claude-plugins (4 stars, last pushed 5d ago), with no licence file. It adds 88 tokens to every session and 1,516 once invoked, about $0.0004 per session on Opus 5.5. 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.

Languages Rust

facet next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
facetneoeinstein/claude-plugins	Skill	4	5d ago	none	A	88	Claude Code
rust-patternsaffaan-m/ECC	Skill	299k	yesterday	MIT	A	28	Claude Code, Kiro
update-v8-versionopeninterpreter/openinterpreter	Skill	69k	3d ago	Apache-2.0	A	86	Codex
dd-code-generationDataDog/pup	Skill	1.0k	today	Apache-2.0	A	16	Claude Code
omh-rustrlaope/oh-my-hermes	Skill	5.2k	today	MIT	A	74	Claude Code, Codex
swiftidebosun-ai/swiftide	Skill	802	yesterday	MIT	A	43	Claude Code, Codex
azure-keyvault-secrets-rustbenjaminasterA/antigravity-awesome-skills	Skill	465	yesterday	MIT	A	0	Claude Code, Codex