core-data-diag

core-data-diag is a skill for Claude Code from IGTA-Tech/claude-skills-research. It costs 48 tokens per session (7,512 once invoked), scanned A, original, no licence file.

A troubleshooting guide for Core Data, Apple's framework for storing structured app data, and SwiftData, its newer data framework.

In plain words
What is it for?
Use it to test schema changes, investigate Core Data or SwiftData issues, improve query performance, and safely move between the two frameworks.
Why use it?
It helps diagnose migration crashes, thread-use errors, slow repeated queries, and data-bridging problems while reducing the risk of losing existing data.

Skill for Claude Code

Written for Claude Code: a Claude Code plugin manifest.

Part of the axiom plugin — 90 skills, 7 commands, 21 agents, 4 hooks shipped together

Good fit Use it to test schema changes, investigate Core Data or SwiftData issues, improve query performance, and safely move between the two frameworks.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/igta-tech/claude-skills-research/core-data-diag
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 IGTA-Tech/claude-skills-research --skill core-data-diag
Clone the repo
git clone --depth 1 https://github.com/IGTA-Tech/claude-skills-research

Made for: Claude Code.

Or install axiom, the plugin that ships this one along with the rest of its 90 skills, 7 commands, 21 agents, 4 hooks.

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 core-data-diag

README.md
[![agentmods](https://agentmods.dev/badge/skills/igta-tech/claude-skills-research/core-data-diag/github.svg)](https://agentmods.dev/skills/igta-tech/claude-skills-research/core-data-diag)
Your own site
<a href="https://agentmods.dev/skills/igta-tech/claude-skills-research/core-data-diag"><img src="https://agentmods.dev/badge/skills/igta-tech/claude-skills-research/core-data-diag/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 core-data-diag

Your own site · 80×15
<a href="https://agentmods.dev/skills/igta-tech/claude-skills-research/core-data-diag"><img src="https://agentmods.dev/badge/skills/igta-tech/claude-skills-research/core-data-diag.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 48 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 7,512 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. A grade says what 26 rules found in the file — not that it is safe.
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 $0.00048 $0.07512
Opus 5 $0.00024 $0.03756
Sonnet 5 $0.00010 $0.01502
Haiku 4.5 $0.00005 $0.00751

Measured 10d ago against content hash 89bbf1f82cb6, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

core-data-diag scanned grade A with 1 finding 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 10d 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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

let results = try! context.fetch(request)
Axiom/.claude-plugin/plugins/axiom/skills/core-data-diag/SKILL.md · 920 lines

The source is not reproduced here

No licence file

A repository with no LICENSE is all rights reserved by default, so the body is not copied here. The metadata, the measurements and the link are.

Read it on GitHub

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. 10d ago First seen · 920 lines · 48 tokens per session scan A 89bbf1f82cb6

Subscribe to this mod's changes

core-data-diag is a skill published in the GitHub repository IGTA-Tech/claude-skills-research (2 stars, last pushed yesterday), with no licence file. It adds 48 tokens to every session and 7,512 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

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