cryptokit

cryptokit is a skill for Claude Code from dpearson2699/swift-ios-skills. It costs 96 tokens per session (3,708 once invoked), scanned A, original, no licence file.

A guide to using Apple's CryptoKit for common cryptographic tasks in Swift. Cryptography protects data and verifies identities through hashing, encryption, signatures, and key exchange.

In plain words
What is it for?
Use it to hash data, create HMACs, encrypt with AES-GCM or ChaChaPoly, sign data, exchange keys, use Secure Enclave keys, and migrate cryptographic code.
Why use it?
It helps you use Apple's cryptographic building blocks correctly instead of implementing sensitive algorithms yourself.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the ios-engineering-skills plugin — 16 skills shipped together , and of apple-kit-skills, all-ios-skills

Good fit Use it to hash data, create HMACs, encrypt with AES-GCM or ChaChaPoly, sign data, exchange keys, use Secure Enclave keys, and migrate cryptographic code.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/dpearson2699/swift-ios-skills/cryptokit
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 dpearson2699/swift-ios-skills --skill cryptokit
Clone the repo
git clone --depth 1 https://github.com/dpearson2699/swift-ios-skills

Made for: Claude Code.

Or install ios-engineering-skills, the plugin that ships this one along with the rest of its 16 skills.

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 cryptokit

README.md
[![agentmods](https://agentmods.dev/badge/skills/dpearson2699/swift-ios-skills/cryptokit/github.svg)](https://agentmods.dev/skills/dpearson2699/swift-ios-skills/cryptokit)
Your own site
<a href="https://agentmods.dev/skills/dpearson2699/swift-ios-skills/cryptokit"><img src="https://agentmods.dev/badge/skills/dpearson2699/swift-ios-skills/cryptokit/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 cryptokit

Your own site · 80×15
<a href="https://agentmods.dev/skills/dpearson2699/swift-ios-skills/cryptokit"><img src="https://agentmods.dev/badge/skills/dpearson2699/swift-ios-skills/cryptokit.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 96 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,708 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
  • Socket pass 28 Mar 2026
  • Snyk pass 28 Mar 2026
How audits are shown
Origin unknown 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 $0.00096 $0.03708
Opus 5 $0.00048 $0.01854
Sonnet 5 $0.00019 $0.00742
Haiku 4.5 $0.00010 $0.00371

Measured 9d ago against content hash 1d5c571d4e89, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

cryptokit 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 9d 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/cryptokit/SKILL.md · 488 lines

The source is not reproduced here

A licence we could not identify

The repository carries a LICENSE file, but it is custom or dual enough that GitHub cannot name it and neither can this catalogue. Unknown terms are not permission, so the body is not copied here. Read the licence at the source and decide for yourself.

Read it on GitHub

Files

What ships with it

2 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. 9d ago First seen · 488 lines · 96 tokens per session scan A 1d5c571d4e89

Subscribe to this mod's changes

cryptokit is a skill published in the GitHub repository dpearson2699/swift-ios-skills (1,086 stars, last pushed 1mo ago), with no licence file. It adds 96 tokens to every session and 3,708 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.

Related

Other skills, from other repositories

uikit-bridging

How to bridge UIKit into a SwiftUI app correctly when SwiftUI's API is genuinely insufficient. Covers UIViewRepresentable lifecycle, sizeThatFits, font-design inheritance, animation suppression, and the small set of legitimate use cases. Use this skill whenever the swiftui-native-first skill points you here for a…

troyjthomas/ios-agent-skills · 70 tokens

kotlin-exposed-patterns

JetBrains Exposed ORM patterns including DSL queries, DAO pattern, transactions, HikariCP connection pooling, Flyway migrations, and repository pattern.

hashgraph-online/awesome-codex-plugins · 36 tokens

kotlin-ktor-patterns

Ktor server patterns including routing DSL, plugins, authentication, Koin DI, kotlinx.serialization, WebSockets, and testApplication testing.

hashgraph-online/awesome-codex-plugins · 34 tokens

kotlin-coroutines-flows

Kotlin Coroutines and Flow patterns for Android and KMP — structured concurrency, Flow operators, StateFlow, error handling, and testing.

hashgraph-online/awesome-codex-plugins · 35 tokens

generators

Code generator skills that produce production-ready Swift code for common app components. Use when user wants to add logging, analytics, onboarding, review prompts, networking, authentication, paywalls, settings, persistence, error monitoring, CI/CD pipelines, localization, push notifications, deep linking, testing…

rshankras/claude-code-apple-skills · 176 tokens

attributed-string

AttributedString patterns for rich text formatting, alignment, selection, and SwiftUI integration. Use when working with styled text, text editing, or AttributedString APIs.

rshankras/claude-code-apple-skills · 37 tokens