skill CX Codex

cryptokit — Claude Code skill: what it does, how to install

Q: How do I install cryptokit in Claude Code?

Run `npx skills add dpearson2699/swift-ios-skills --skill cryptokit -a claude-code`, then run `npx skills add dpearson2699/swift-ios-skills --skill cryptokit -a claude-code` again. The skill file is at `~/.claude/skills/cryptokit/SKILL.md`.

Guides Swift cryptography work with Apple CryptoKit for hashes, encryption, signatures, and key exchange.

Install into Claude Code · Skills CLI (Vercel) All methods and platforms ↓

npx skills add dpearson2699/swift-ios-skills --skill cryptokit -a claude-code

Open on GitHub

What cryptokit does

This skill steers an agent toward Apple CryptoKit when editing Swift cryptography code. It covers SHA-2 and SHA-3 hashing, HMAC, AES-GCM, ChaChaPoly, P256, P384, P521 and Curve25519 signatures, plus ECDH, HPKE, ML-KEM, X-Wing, Secure Enclave keys, and CommonCrypto migration.

Its guidance includes one-shot and incremental hashes, HMAC verification, authenticated encryption with additional data, signing, and HKDF-based symmetric key derivation. For new Swift 6.3+ primitive code, it recommends CryptoKit over CommonCrypto and lower-level Security APIs.

Core primitives start at iOS 13+, while HPKE needs iOS 17+ and SHA-3 or post-quantum APIs need iOS 26+. That makes the deployment target a release blocker for those features.

What it helps with

hash Swift data with SHA-256
verify an HMAC without manual comparisons
encrypt a message with AES-GCM
sign data with a P256 key
migrate CommonCrypto primitive code

Example prompts for the agent

"Write Swift code that hashes a file incrementally with CryptoKit."
"Add AES-GCM encryption with authenticated data to this Swift code."
"Show P256 ECDH key agreement and derive a key with HKDF."

How to install cryptokit

1Skills CLI (Vercel)

npx skills add dpearson2699/swift-ios-skills --skill cryptokit -a claude-code

2Manually: put the files in place

~/.claude/skills/cryptokit/SKILL.md

Copy the whole skill folder; for one project use .claude/skills/cryptokit/

1Skills CLI (Vercel)

npx skills add dpearson2699/swift-ios-skills --skill cryptokit -a codex

2Manually: put the files in place

.agents/skills/cryptokit/SKILL.md

For all projects use ~/.agents/skills/

1Skills CLI (Vercel)

npx skills add dpearson2699/swift-ios-skills --skill cryptokit -a cursor

2Manually: put the files in place

.cursor/skills/cryptokit/SKILL.md

Cursor also reads .agents/skills/ and .claude/skills/

1GitHub CLI

gh skill install dpearson2699/swift-ios-skills cryptokit

2Manually: put the files in place

.github/skills/cryptokit/SKILL.md

1Skills CLI (Vercel)

npx skills add dpearson2699/swift-ios-skills --skill cryptokit -a gemini-cli

2Platform CLI

gemini skills install https://github.com/dpearson2699/swift-ios-skills --path skills/cryptokit

Manually: put the files in place

.devin/skills/cryptokit/SKILL.md

The legacy .windsurf/skills/ path still works

Skills CLI (Vercel)

npx skills add dpearson2699/swift-ios-skills --skill cryptokit -a opencode

Step by step, with commands for each platform: How to install skills in Claude Code: five ways

Questions about cryptokit

How do I install cryptokit in Claude Code?

Run npx skills add dpearson2699/swift-ios-skills --skill cryptokit -a claude-code, then run npx skills add dpearson2699/swift-ios-skills --skill cryptokit -a claude-code again. The skill file is at ~/.claude/skills/cryptokit/SKILL.md.

What does cryptokit do?

It gives an agent instructions for using Apple CryptoKit in Swift. The material covers hashing, HMAC, symmetric encryption, signatures, and key agreement.

Which iOS versions support the CryptoKit APIs?

Core CryptoKit primitives are available from iOS 13+. HPKE requires iOS 17+, while SHA-3 and post-quantum APIs require iOS 26+.

Similar skills

All skills for Security →

swiftdata-pro Paul Hudson A skill for writing, reviewing, and improving SwiftData code with modern APIs and best practices. Essential when working with SwiftData-based projects in Swift. CX Codex +1 9,300installs cmux-architecture manaflow-ai Guides modular Swift package architecture, strict 5-layer dependency inversion, and Swift 6 concurrency rules in the cmux codebase. CX Codex +1 4,900installs swiftui-patterns affaan-m Guides AI agents on modern SwiftUI architecture: @Observable state, type-safe navigation, and view performance. Useful when building or reviewing iOS and macOS UI. CX Codex +1 4,600installs swift-expert https://github.com/Jeffallan A Swift skill that walks the agent through architecture, SwiftUI state, async/await and actors, with build checks in between. Built for iOS and macOS work. CX Codex +1 4,100installs spm-build-analysis AvdLee Analyzes Swift Package Manager dependencies, build plugins, and Xcode module graphs. It helps developers track down bottlenecks in clean and incremental build times. CX Codex +1 3,400installs xcode-compilation-analyzer AvdLee A skill that explains why an Xcode build drags: it reads build timings and Swift frontend diagnostics, finds the expensive spots in your code, and returns a fix plan. CX Codex +1 3,400installs

From the same set86

weatherkit Teaches coding agents how to query Apple WeatherKit in Swift apps. Helps retrieve forecasts, parse alerts, and handle measurement formatting. CX Codex +1 3,500installs shareplay-activities Get guidance for building GroupActivities sessions, from shared media playback to syncing app state. Useful when adding collaborative features to Apple-platform apps. CX Codex +1 3,500installs cloudkit Guides CloudKit and iCloud sync setup in iOS and macOS apps, covering SwiftData, CKSyncEngine, and conflict resolution. CX Codex +1 3,300installs activitykit Build and review iOS Live Activities and Dynamic Island interfaces with ActivityKit. Useful for app states that need to stay visible and change over time. CX Codex +1 3,300installs spritekit A skill that gives your coding agent a SpriteKit reference: scenes, sprites, physics, particles and SwiftUI integration for 2D games. CX Codex +1 3,200installs avkit Guides AI agents through building iOS media playback UI, configuring AVPlayerViewController, SwiftUI VideoPlayer, and Picture-in-Picture. CX Codex +1 3,200installs realitykit A skill for building AR scenes with RealityKit and ARKit: RealityView, anchors, raycasts, gestures. Useful when your iOS app needs 3D content. CX Codex +1 3,200installs mapkit Guides the agent through MapKit and CoreLocation code in Swift apps: maps, markers, geocoding, routes, geofencing. CX Codex +1 3,200installs