vapor-backend

vapor-backend is a skill for Claude Code, Codex from j4flmao/agent-skills. It costs 75 tokens per session (4,671 once invoked), scanned A, original, MIT.

A guide for building server applications in Swift with Vapor, a Swift framework for handling web requests, databases, and WebSockets.

In plain words
What is it for?
Use it to create or document Vapor projects, REST APIs, WebSocket endpoints, database models and migrations, and request-processing middleware.
Why use it?
It gives coding agents consistent patterns for routes, database changes, middleware, configuration, and tests. This reduces the chance of an unstructured or incorrectly configured backend.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: positional $N argument; mentions Codex.

Good fit Use it to create or document Vapor projects, REST APIs, WebSocket endpoints, database models and migrations, and request-processing middleware.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/j4flmao/agent-skills/vapor
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 j4flmao/agent-skills --skill vapor
Clone the repo
git clone --depth 1 https://github.com/j4flmao/agent-skills

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.

agentmods badge for vapor-backend

README.md
[![agentmods](https://agentmods.dev/badge/skills/j4flmao/agent-skills/vapor/github.svg)](https://agentmods.dev/skills/j4flmao/agent-skills/vapor)
Your own site
<a href="https://agentmods.dev/skills/j4flmao/agent-skills/vapor"><img src="https://agentmods.dev/badge/skills/j4flmao/agent-skills/vapor/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.

agentmods 80×15 button for vapor-backend

Your own site · 80×15
<a href="https://agentmods.dev/skills/j4flmao/agent-skills/vapor"><img src="https://agentmods.dev/badge/skills/j4flmao/agent-skills/vapor.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 75 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 4,671 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 warn 7 Sept 2026
SkillSpector: 2 findings, up to high

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • high Privilege Escalation · line 52
    Code accesses credential files (SSH keys, AWS credentials, etc.). This could indicate credential theft attempts.
    Fix: Remove references to credential paths. Use environment variables or secrets managers. For docs, use placeholder paths (e.g., /path/to/config). Never load .env or token files in production code paths.
  • high Privilege Escalation · line 599
    Code accesses credential files (SSH keys, AWS credentials, etc.). This could indicate credential theft attempts.
    Fix: Remove references to credential paths. Use environment variables or secrets managers. For docs, use placeholder paths (e.g., /path/to/config). Never load .env or token files in production code paths.
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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00075 $0.04671
Opus 5 $0.00037 $0.02336
Sonnet 5 $0.00015 $0.00934
Haiku 4.5 $0.00007 $0.00467

Measured 11d ago against content hash ef62e1bc6a6f, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

vapor-backend 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 11d 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.

skills/backend/swift/vapor/SKILL.md · 624 lines

How it starts

The opening of the file, as written. The whole thing — 624 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Vapor Backend

Purpose

Define Vapor backend application architecture: async routes, Fluent ORM, middleware pipeline, and Swift Package Manager project structure.

Agent Protocol

Trigger

User request includes: vapor, vapor backend, vapor swift, fluent, vapor async, swift server, vapor route, vapor middleware, vapor websocket.

Input Context

  • Swift version (5.9+)
  • Vapor version (4.x)
  • Database driver (Fluent — PostgreSQL, MySQL, SQLite, MongoDB)
  • Hosting (Vapor Cloud, Docker, bare metal)
  • Features (REST, WebSocket, APNs, Leaf templates)

Output Artifact

A markdown document containing:

  • Project structure (SPM layout)
  • Route registration conventions
  • Controller pattern
  • Fluent model and migration setup
  • Middleware pipeline ordering
  • Environment-based configuration
  • Testing (XCTest, XCTVapor)
  • WebSocket endpoint setup

Response Format

Produce the artifact directly. No preamble, no postamble, no explanations. No filler, no hedging. Compress output.

Completion Criteria

  • SPM Package.swift correctly declares dependencies
  • Routes registered with route groups
  • Fluent models with proper migrations
  • Middleware pipeline ordered (auth -> logging -> error)
  • Environment configuration via .env files
  • Tests cover request lifecycle

Max Response Length

4096 tokens

Workflow

Step 1: Project Setup

# Install Vapor toolbox
brew install vapor

# Create project
vapor new OrderService --template web

# Or manually
mkdir OrderService && cd OrderService
swift package init --type executable

# Add Vapor and Fluent
swift package add https://github.com/vapor/vapor
swift package add https://github.com/vapor/fluent
swift package add https://github.com/vapor/fluent-postgres-driver

Step 2: Package.swift

// swift-tools-version:5.9
import PackageDescription

let package = Package(
  name: "OrderService",
  platforms: [.macOS(.v13)],
  dependencies: [
    .package(url: "https://github.com/vapor/vapor", from: "4.90.0"),
    .package(url: "https://github.com/vapor/fluent", from: "4.9.0"),
    .package(url: "https://github.com/vapor/fluent-postgres-driver", from: "2.8.0"),
    .package(url: "https://github.com/vapor/leaf", from: "4.3.0"),
    .package(url: "https://github.com/vapor/jwt", from: "4.3.0"),
  ],
  targets: [
    .executableTarget(
      name: "App",
      dependencies: [
        .product(name: "Vapor", package: "vapor"),
        .product(name: "Fluent", package: "fluent"),
        .product(name: "FluentPostgresDriver", package: "fluent-postgres-driver"),
        .product(name: "Leaf", package: "leaf"),
        .product(name: "JWT", package: "jwt"),
      ]
    ),
    .testTarget(name: "AppTests", dependencies: [.target(name: "App")]),
  ]
)

Read the full file on GitHub · 624 lines

Files

What ships with it

8 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.

  1. 11d ago First seen · 624 lines · 75 tokens per session scan A ef62e1bc6a6f

Subscribe to this mod's changes

vapor-backend is a skill published in the GitHub repository j4flmao/agent-skills (22 stars, last pushed 4d ago), licensed MIT. It adds 75 tokens to every session and 4,671 once invoked, about $0.0004 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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