A guide for developing .NET command-line programs, which are tools operated by typing commands in a terminal. It covers command structure, dependency injection, help text, localisation, output, and exit codes.

It is for adding or changing commands, registering them, validating settings, formatting terminal output, translating help text, and writing focused tests.

It provides project-specific rules for keeping command handlers small, output predictable, and terminal and protocol integrations working correctly.

cli — Skill for Claude Code and Codex by AterDev/Perigon.CLI

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 AterDev/Perigon.CLI --skill cli

Clone the repo

git clone --depth 1 https://github.com/AterDev/Perigon.CLI

Made for: Claude Code, Codex.

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/aterdev/perigon.cli/cli/github.svg)](https://agentmods.dev/skills/aterdev/perigon.cli/cli)

Your own site

<a href="https://agentmods.dev/skills/aterdev/perigon.cli/cli"><img src="https://agentmods.dev/badge/skills/aterdev/perigon.cli/cli/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/aterdev/perigon.cli/cli"><img src="https://agentmods.dev/badge/skills/aterdev/perigon.cli/cli.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 52 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 346 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. Third-party audits

NVIDIA SkillSpector pass 7 Sept 2026

How audits are shown

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.

Model	Per session	Once invoked
Fable 5.1	$0.00052	$0.00346
Opus 5.5	$0.00021	$0.00138
Sonnet 5.5	$0.00010	$0.00069
Haiku 4.5	$0.00005	$0.00035

Measured 1mo ago against content hash 15e8944740c4, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

cli 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 1mo 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.

.agents/skills/cli/SKILL.md · 30 lines

What it actually says

CLI Development

Workflow

Identify the command surface under src/Apps/CommandLine.
Read command registration in src/Apps/CommandLine/Program.cs.
Read the invoked service before changing command behavior.
Keep command classes thin: parse settings, validate input, set context, call services, and format output.

Conventions

Inherit from AsyncCommand<TSettings> or AsyncCommand.
Put reusable behavior in CoreMod services, CodeGenerator, or Share instead of command classes.
Use CommandSolutionHelper.TrySetSolutionAsync when the command needs a current solution.
Use OutputHelper or AnsiConsole consistently with nearby commands.
Escape dynamic Spectre markup with Markup.Escape.
Return 0 for success and 1 for expected validation or operation failures.
Register new commands in DI and CommandApp.Configure, including aliases, examples, and localized descriptions.
Preserve raw MCP/stdio command paths. Do not add logos, logs, or human-readable output that can break protocol clients.

Localization And Tests

Add user-facing command text to both src/Share/Localizer.zh-CN.resx and src/Share/Localizer.en-US.resx.
Add focused tests under tests/StudioMod.Tests/Commands for command behavior, config output, or error handling.

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.

1mo ago First seen · 30 lines · 52 tokens per session scan A 15e8944740c4

Subscribe to this mod's changes

cli is a skill published in the GitHub repository AterDev/Perigon.CLI (54 stars, last pushed 1mo ago), licensed Apache-2.0. It adds 52 tokens to every session and 346 once invoked, about $0.0002 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 2026-08-30.

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