codegen

A .NET code-generation workflow for producing C# and TypeScript source from code models and OpenAPI definitions. OpenAPI is a standard description of a web API, while Roslyn is Microsoft's toolkit for understanding C# code.

In plain words
What is it for?
Use it to generate DTOs, managers, controllers, REST APIs, C# HttpClient code, and Angular or Axios TypeScript request clients.
Why use it?
It provides a defined place for parsing API descriptions, applying templates, and keeping generated files predictable. Regression tests help catch unwanted changes in generated output.

Skill for Claude CodeCodex

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.

agentmods
npx agentmods add skills/aterdev/perigon.cli/codegen
Any agent
npx skills add AterDev/Perigon.CLI --skill codegen
Clone the repo
git clone --depth 1 https://github.com/AterDev/Perigon.CLI

Made for: Claude Code, Codex.

Per session 53 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 314 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00053 $0.00314
Opus 5 $0.00026 $0.00157
Sonnet 5 $0.00011 $0.00063
Haiku 4.5 $0.00005 $0.00031

Measured yesterday against content hash 854da80481c9, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

codegen 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 yesterday.

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/codegen/SKILL.md · 30 lines

What it actually says

Code Generation

Workflow

  1. Inspect the relevant generator in src/CodeGenerator/Generate.
  2. Inspect helpers in src/CodeGenerator/Helper before adding parsing logic.
  3. Inspect templates in src/CodeGenerator/Templates when output text changes.
  4. Inspect regression tests in tests/StudioMod.Tests/Generate.

Conventions

  • Prefer Roslyn APIs for C# syntax, symbols, namespaces, usings, attributes, and type analysis.
  • Prefer Microsoft.OpenApi APIs for OpenAPI traversal, schemas, and operations.
  • Keep parsing/model extraction in helpers and emitted output composition in generators or templates.
  • Avoid brittle string parsing when a structured API is available.
  • Keep generated output deterministic: stable ordering, whitespace, using lists, and no machine-specific paths.
  • Use raw string literals for embedded multi-line generated source.
  • Be careful around nullable values, enums, file uploads, path/query/body parameter placement, and special OpenAPI names.

Tests

  • Add focused tests under tests/StudioMod.Tests/Generate.
  • Use fixture OpenAPI files under tests/StudioMod.Tests/Generate/Fixtures.
  • For Roslyn helpers, use small source snippets that exercise the syntax or semantic case.
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. yesterday First seen · 30 lines · 53 tokens per session scan A 854da80481c9

Subscribe to this mod's changes

codegen is a skill published in the GitHub repository AterDev/Perigon.CLI (53 stars, last pushed 3d ago), licensed Apache-2.0. It adds 53 tokens to every session and 314 once invoked, about $0.0003 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 2026-08-30.

Related

Other skills, from other repositories

aspire

Build, upgrade, and operate Aspire 13.5.x C# or TypeScript application hosts with the current CLI, AppHost, ServiceDefaults, integrations, dashboard, testing, MCP, and deployment patterns for distributed apps. USE FOR: Aspire.AppHost.Sdk, Aspire.Hosting., DistributedApplication.CreateBuilder, apphost.mts…

managedcode/dotnet-skills · 145 tokens

microsoft-agent-framework

Build .NET AI agents, harnesses, and multi-agent workflows with Microsoft Agent Framework using the right agent type, sessions, tools, workflows, hosting protocols, and enterprise guardrails. USE FOR: building or reviewing .NET code that uses Microsoft.Agents., Microsoft.Extensions.AI, AIAgent, HarnessAgent…

managedcode/dotnet-skills · 138 tokens

wpf

Build and modernize WPF applications on .NET with correct XAML, data binding, commands, threading, styling, and Windows desktop migration decisions. USE FOR: working on WPF UI, MVVM, binding, commands, or desktop modernization; migrating WPF from .NET Framework to .NET; integrating newer Windows capabilities into a…

managedcode/dotnet-skills · 122 tokens

worker-services

Build long-running .NET background services with BackgroundService, Generic Host, graceful shutdown, configuration, logging, and deployment patterns suited to workers and daemons. USE FOR: background services; scheduled workers; hosted services; worker extraction; graceful shutdown, health checks, and service hosting…

managedcode/dotnet-skills · 109 tokens

azure-functions

Build, review, or migrate Azure Functions in .NET with correct execution model, isolated worker setup, bindings, DI, and Durable Functions patterns. USE FOR: working on Azure Functions in .NET; migrating from the in-process model to the isolated worker model; adding Durable Functions, bindings, or host configuration.…

managedcode/dotnet-skills · 113 tokens

maui

Build, review, or migrate .NET MAUI applications across Android, iOS, macOS, and Windows with correct cross-platform UI, platform integration, and native packaging assumptions. USE FOR: working on cross-platform mobile or desktop UI in .NET MAUI; integrating device capabilities, navigation, or platform-specific code…

managedcode/dotnet-skills · 121 tokens