swift6-migration

A repository guide for migrating Swift code to Swift 6, including its stricter concurrency checks. Swift concurrency is the system for running asynchronous work safely at the same time.

In plain words
What is it for?
Use it to preview the Swift-DocC guide locally and consult guidance while adapting code to Swift 6 concurrency requirements.
Why use it?
It provides documentation and build instructions for understanding and contributing to the migration guide.

Cursor rule

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 rules/steipete/agent-rules/swift6-migration
Clone the repo
git clone --depth 1 https://github.com/steipete/agent-rules
Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 27,928 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 $0.00000 $0.27928
Opus 5 $0.00000 $0.13964
Sonnet 5 $0.00000 $0.05586
Haiku 4.5 $0.00000 $0.02793

Measured 2d ago against content hash 2db582461cd8, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

swift6-migration 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 2d 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.

docs/swift6-migration.mdc · 4,049 lines

How it starts

The opening of the file, as written. The whole thing — 4,049 lines — stays where its author put it; the contents beside it link to each section on GitHub.

================================================ FILE: README.md

The Swift Concurrency Migration Guide

This repository contains the source for The Swift Concurrency Migration Guide, which is built using Swift-DocC.

Contributing

See the contributing guide for instructions on contributing to the Swift Migration Guide.

Building

Run docc preview Guide.docc in this repository's root directory.

After running DocC, open the link that docc outputs to display a local preview in your browser.

Note:

If you installed DocC by downloading a toolchain from Swift.org, docc is located in usr/bin/, relative to the installation path of the toolchain. Make sure your shell's PATH environment variable includes that directory.

If you installed DocC by downloading Xcode, use xcrun docc instead.

================================================ FILE: CODEOWNERS

Lines starting with '#' are comments.

Each line is a case-sensitive file pattern followed by one or more owners.

Order is important. The last matching pattern has the most precedence.

More information: https://docs.github.com/en/articles/about-code-owners

Please mirror the repository's file hierarchy in case-sensitive lexicographic

order.

  • @hborla @mattmassicotte @shahmishal @ktoso

================================================ FILE: CONTRIBUTING.md

Contributing to the Swift Migration Guide

Welcome the Swift community!

Contributions to the Swift project are welcomed and encouraged! Please see the Contributing to Swift guide and check out the structure of the community.

Read the full file on GitHub · 4,049 lines

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. 2d ago First seen · 4,049 lines · 0 tokens per session scan A 2db582461cd8

Subscribe to this mod's changes

swift6-migration is a cursor rule published in the GitHub repository steipete/agent-rules (5,695 stars, last pushed 4mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 27,928 tokens. 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.