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 agentmods add skills/prisma-labs-dev/apple-skills/guide-swiftdatanpx skills add Prisma-Labs-Dev/apple-skills --skill guide-swiftdatagit clone --depth 1 https://github.com/Prisma-Labs-Dev/apple-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/prisma-labs-dev/apple-skills/guide-swiftdata)<a href="https://agentmods.dev/skills/prisma-labs-dev/apple-skills/guide-swiftdata"><img src="https://agentmods.dev/badge/skills/prisma-labs-dev/apple-skills/guide-swiftdata.svg" alt="Measured on agentmods" height="20"></a>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 | $0.00038 | $0.00476 |
| Opus 5 | $0.00019 | $0.00238 |
| Sonnet 5 | $0.00008 | $0.00095 |
| Haiku 4.5 | $0.00004 | $0.00048 |
Grade A, and why
guide-swiftdata 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 5d 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.
What it actually says
Guide Skill — This is an expert workflow/pattern guide, not API reference documentation. Originally from twostraws/SwiftData-Agent-Skill by Paul Hudson. MIT License.
SwiftData Patterns
Write and review SwiftData code for correctness, modern API usage, and adherence to project conventions. Report only genuine problems — do not nitpick or invent issues.
Core Instructions
- Target Swift 6.2 or later, using modern Swift concurrency.
- Prefer SwiftData across the board. Do not suggest Core Data unless the feature cannot be solved with SwiftData.
- Do not introduce third-party frameworks without asking first.
Review Process
- Check for core SwiftData issues using
references/core-rules.md. - Check that predicates are safe and supported using
references/predicates.md. - If the project uses CloudKit, check for CloudKit-specific constraints using
references/cloudkit.md. - If the project targets iOS 18+, check for indexing opportunities using
references/indexing.md. - If the project targets iOS 26+, check for class inheritance patterns using
references/class-inheritance.md.
If doing partial work, load only the relevant reference files.
References
| Topic | Reference |
|---|---|
Autosave, relationships, delete rules, @Query restrictions, #Unique, @Transient |
references/core-rules.md |
| Supported predicates, dangerous patterns that crash at runtime, unsupported methods | references/predicates.md |
CloudKit constraints: no #Unique, optional requirements, eventual consistency |
references/cloudkit.md |
| Database indexing (iOS 18+), single and compound property indexes | references/indexing.md |
Model subclassing (iOS 26+), @available requirements, predicate filtering |
references/class-inheritance.md |
What ships with it
5 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.
- 5d ago First seen · 41 lines · 38 tokens per session scan A 517426661483
guide-swiftdata is a skill published in the GitHub repository Prisma-Labs-Dev/apple-skills (323 stars, last pushed 25d ago), licensed MIT. It adds 38 tokens to every session and 476 once invoked, about $0.0002 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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