Apex Collections Patterns is published as a SKILL.md file in this catalog. At roughly 1,745 words the SKILL.md is on the longer end of the catalog distribution.
Apex Collections Patterns sits in the Engineering category under the engineering-misc sub-topic in the ClaudSkills catalog. There are 10 related skills indexed alongside it; comparing a few before installing usually reveals which fits your workflow best.
These notes are auto-generated from features detected in the SKILL.md file and from this catalog's structure — they aren't part of the source repository.
Use this skill when reviewing or writing Apex code that uses List, Set, or Map to aggregate, de-duplicate, or look up SObject data in triggers, batch classes, or service layers. The skill covers safe null handling, heap-efficient accumulation patterns, and idiomatic bulkification using Map<Id, List<SObject>>.
Apex Collections Patterns is a community-contributed Claude Code skill in the engineering-misc sub-category. It ships as a SKILL.md file that Claude Code auto-discovers under ~/.claude/skills/apex-collections-patterns/ and loads when your prompt matches the skill's trigger.
When to invoke it: Use when designing, reviewing, or debugging Apex code that relies on List, Set, or Map collections in triggers, batch classes, or service layers — especially for bulkification, heap management, and safe null handling. Trigger keywords: 'Map<Id, SObject>', 'containsKey', 'retainAll', 'putAll', 'Set intersection', 'heap limit', 'collection in loop', 'unbounded accumulation'.
The Apex Collections Patterns Claude Code skill is built for software engineers, backend developers, full-stack teams, and technical leads building and maintaining production systems. It's part of ClaudSkills (also referred to as Claude Skills or Claude Code Skills) — the open community-curated registry of 146,000+ SKILL.md files for Anthropic's Claude Code agent and the wider Claude ecosystem (Claude API, Claude Agent SDK).
mkdir -p ~/.claude/skills/apex-collections-patterns curl -L https://claudskills.com/skills/apex-collections-patterns/SKILL.md \ -o ~/.claude/skills/apex-collections-patterns/SKILL.md
Or just download SKILL.md directly and drop it into ~/.claude/skills/apex-collections-patterns/. Claude Code auto-discovers it on next session.
Skills live at ~/.claude/skills/apex-collections-patterns/SKILL.md on macOS/Linux, or %USERPROFILE%\.claude\skills\apex-collections-patterns\SKILL.md on Windows. See the full install guide for step-by-step instructions.
Open @claudskills_bot on Telegram, tap Open Desktop App, and the desktop app installs this skill for you. Or share the bot link with a colleague — they get the same one-tap install. Learn more →
The ClaudSkills desktop app installs any skill directly into ~/.claude/skills/ with one click — no terminal required. Pro starts at $9/mo or $149 lifetime.
For the full experience including quality scoring and one-click install features for each skill — upgrade to Pro.
SKILL.md from the source repository to ~/.claude/skills/apex-collections-patterns/SKILL.md and restart Claude Code. Both flows are detailed at claudskills.com/install/.SKILL.md file that lives under ~/.claude/skills/<name>/ and tells the Claude Code CLI agent how to perform a specific task (instructions, prompts, allowed tools). Skills are auto-discovered at session start. Apex Collections Patterns is one of 67,000+ skills indexed in the open ClaudSkills catalog, classified under the Engineering category. Learn more at /learn/what-is-a-claude-skill/.If you reference this skill in a blog post, paper, or documentation, you can cite it as:
@misc{apex-collections-patterns-2026,
author = {Pranav Nagrecha},
title = {Apex Collections Patterns [Claude Code skill]},
year = {2026},
publisher = {ClaudSkills},
url = {https://claudskills.com/skills/apex-collections-patterns/}
}Grade A · scanned 2026-07-06 — free static scan against the OWASP Agentic Skills Top 10.
No risk patterns were found in any of the ten OWASP-aligned categories. How grading works ›
Browse all Engineering skills in the ClaudSkills registry, or explore these other picks from the same category:
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SKILL.md files, not affiliated with, endorsed by, or sponsored by Anthropic.