Rust Domain Boundaries

What it does

When your agent uses it

• Reviewing Rust service domain boundaries
• Especially when replacing primitive String fields with newtypes
• Parse-dont-validate constructors
• Private invariants

Example prompts

• “/rust-domain-boundaries”

Requirements

• Compatibility (from SKILL.md): Codex, Claude Code, and other Agent Skills-compatible clients.

Workflow steps

7 steps, taken from the first numbered list in SKILL.md.

1. 1Find raw input boundaries: HTTP payloads, path/query parameters, config
2. 2Separate transport DTOs from domain types. Let serde deserialize incoming
3. 3Replace primitive strings with small types for ruled values: email addresses,
4. 4Give domain types private fields and smart constructors. Avoid unchecked
5. 5Return typed validation errors that map to useful HTTP responses without
6. 6Keep database and external API mapping explicit. Convert to raw strings at
7. 7Test invariants directly. Cover valid examples, malformed inputs, boundary

What it can do on your machine

Read from SKILL.md and the folder at commit 9e7b281. It shows what the files ask for, not the result of running them.

• Tool permissions

  Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

  From allowed-tools in the SKILL.md frontmatter.

• Runs code

  No scripts in the folder and no shell commands in SKILL.md (its code samples are rust).

  From the folder's file list and the shell code blocks in SKILL.md.

• Network

  No URLs in SKILL.md.

  From URLs in SKILL.md, links to its own repository left out.

• Credentials

  Names no API keys, tokens, secrets or passwords.

  From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

• Compatibility

  Codex, Claude Code, and other Agent Skills-compatible clients.

  From compatibility in the SKILL.md frontmatter.

Context cost

Rust Domain Boundaries loads about 971 tokens when it runs, and up to ~2.2k if it reads all its reference files. Until then it costs about 75 tokens; SKILL.md has 370 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it

~75

When it runs · the whole SKILL.md, loaded when a task matches

~971

With references · SKILL.md plus every file in references/, read only if the agent opens them

~2.2k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from hashgraph-online/awesome-codex-plugins at commit 9e7b281, republished under its MIT licence (© hashgraph-online). 370 words, ~971 tokens.

name

rust-domain-boundaries

description

Use when modeling, validating, refactoring, or reviewing Rust service domain boundaries, especially when replacing primitive String fields with newtypes, parse-don't-validate constructors, private invariants, TryFrom/FromStr parsers, request DTO boundaries, or property tests.

compatibility

Codex, Claude Code, and other Agent Skills-compatible clients.

license

MIT

metadata.version

0.1.0

metadata.displayName

Rust Domain Boundaries

metadata.category

Rust

metadata.tags

rust,domain-modeling,newtypes,validation,property-testing

#[derive(serde::Deserialize)]
pub struct SubscribeRequest {
    email: String,
    name: String,
}

pub struct SubscribeCommand {
    pub email: EmailAddress,
    pub name: SubscriberName,
}

impl TryFrom<SubscribeRequest> for SubscribeCommand {
    type Error = SubscribeValidationError;

    fn try_from(value: SubscribeRequest) -> Result<Self, Self::Error> {
        Ok(Self {
            email: EmailAddress::parse(value.email)?,
            name: SubscriberName::parse(value.name)?,
        })
    }
}

© hashgraph-online, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 3 other files (references) in plugins/LVTD-LLC/skills/skills/rust-domain-boundaries of hashgraph-online/awesome-codex-plugins.

• SKILL.md
• agents/openai.yaml
• references/newtype-patterns.md
• references/property-testing.md

Open the folder on GitHubat commit 9e7b281