claude-skills is a collection of specialized skills that extends Claude Code for full-stack development. Developers use it for programming languages, frameworks, infrastructure, APIs, testing, DevOps, security, data and machine learning, platform tasks, and project workflows.
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.
npx skills add Jeffallan/claude-skills --skill nestjs-expertgit clone --depth 1 https://github.com/Jeffallan/claude-skillsWrote 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.
[](https://agentmods.dev/skills/jeffallan/claude-skills/nestjs-expert)<a href="https://agentmods.dev/skills/jeffallan/claude-skills/nestjs-expert"><img src="https://agentmods.dev/badge/skills/jeffallan/claude-skills/nestjs-expert/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.
<a href="https://agentmods.dev/skills/jeffallan/claude-skills/nestjs-expert"><img src="https://agentmods.dev/badge/skills/jeffallan/claude-skills/nestjs-expert.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- Socket pass
- Snyk pass
- NVIDIA SkillSpector pass
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 | $0.00107 | $0.01720 |
| Opus 5 | $0.00053 | $0.00860 |
| Sonnet 5 | $0.00021 | $0.00344 |
| Haiku 4.5 | $0.00011 | $0.00172 |
Grade A, and why
nestjs-expert 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.
Copies of this mod
1 near-identical copy found in the catalogue:
- nestjs-expert — 94% identical, 2 lines differ
How it starts
The opening of the file, as written. The whole thing — 209 lines — stays where its author put it; the contents beside it link to each section on GitHub.
NestJS Expert
Senior NestJS specialist with deep expertise in enterprise-grade, scalable TypeScript backend applications.
Core Workflow
- Analyze requirements — Identify modules, endpoints, entities, and relationships
- Design structure — Plan module organization and inter-module dependencies
- Implement — Create modules, services, and controllers with proper DI wiring
- Secure — Add guards, validation pipes, and authentication
- Verify — Run
npm run lint,npm run test, and confirm DI graph withnest info - Test — Write unit tests for services and E2E tests for controllers
Reference Guide
Load detailed guidance based on context:
| Topic | Reference | Load When |
|---|---|---|
| Controllers | references/controllers-routing.md |
Creating controllers, routing, Swagger docs |
| Services | references/services-di.md |
Services, dependency injection, providers |
| DTOs | references/dtos-validation.md |
Validation, class-validator, DTOs |
| Authentication | references/authentication.md |
JWT, Passport, guards, authorization |
| Testing | references/testing-patterns.md |
Unit tests, E2E tests, mocking |
| Express Migration | references/migration-from-express.md |
Migrating from Express.js to NestJS |
Code Examples
Controller with DTO Validation and Swagger
// create-user.dto.ts
import { IsEmail, IsString, MinLength } from 'class-validator';
import { ApiProperty } from '@nestjs/swagger';
export class CreateUserDto {
@ApiProperty({ example: '[email protected]' })
@IsEmail()
email: string;
@ApiProperty({ example: 'strongPassword123', minLength: 8 })
@IsString()
@MinLength(8)
password: string;
}
// users.controller.ts
import { Body, Controller, Post, HttpCode, HttpStatus } from '@nestjs/common';
import { ApiCreatedResponse, ApiTags } from '@nestjs/swagger';
import { UsersService } from './users.service';
import { CreateUserDto } from './dto/create-user.dto';
@ApiTags('users')
@Controller('users')
export class UsersController {
constructor(private readonly usersService: UsersService) {}
@Post()
@HttpCode(HttpStatus.CREATED)
@ApiCreatedResponse({ description: 'User created successfully.' })
create(@Body() createUserDto: CreateUserDto) {
return this.usersService.create(createUserDto);
}
}
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.
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.
- 12d ago First seen · 209 lines · 107 tokens per session scan A 7d2809fbc805
nestjs-expert is a skill published in the GitHub repository Jeffallan/claude-skills (11,426 stars, last pushed 1mo ago), licensed MIT. It adds 107 tokens to every session and 1,720 once invoked, about $0.0005 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.
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