yq

yq is a skill for Claude Code from xdg/xdg-claude. It costs 22 tokens per session (194 once invoked), scanned A, original, Apache-2.0.

A command-line tool for reading selected values from YAML files. YAML is a text format commonly used for configuration, and a field is a named value inside that configuration.

In plain words
What is it for?
Use it to extract fields, choose a document from a multi-document YAML file, list values, or convert YAML to JSON for further processing.
Why use it?
It lets you inspect one needed value without loading an entire file into the agent’s context.

Skill for Claude Code

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

Part of the context-efficient-tools plugin — 5 skills shipped together

Good fit Use it to extract fields, choose a document from a multi-document YAML file, list values, or convert YAML to JSON for further processing.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/xdg/xdg-claude/yq
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 xdg/xdg-claude --skill yq
Clone the repo
git clone --depth 1 https://github.com/xdg/xdg-claude

Made for: Claude Code.

Or install context-efficient-tools, the plugin that ships this one along with the rest of its 5 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 yq

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

Your own site · 80×15
<a href="https://agentmods.dev/skills/xdg/xdg-claude/yq"><img src="https://agentmods.dev/badge/skills/xdg/xdg-claude/yq.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 22 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 194 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
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
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 5.1 $0.00022 $0.00194
Opus 5 $0.00011 $0.00097
Sonnet 5 $0.00004 $0.00039
Haiku 4.5 $0.00002 $0.00019

Measured 10d ago against content hash e34cd5b9dd4b, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

yq 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 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.

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.

context-efficient-tools/skills/yq/SKILL.md · 22 lines

What it actually says

yq

When you need a specific field from a YAML file, reach for yq rather than Read. Syntax mirrors jq.

yq '.field' file.yml

Assumes mikefarah/yq (Go-based). The Python kislyuk/yq fork has different syntax; if jq-style queries don't work, check which yq is on PATH.

Three things easy to forget:

  • -r -- raw string output (no surrounding quotes)
  • select(document_index == N) -- pick the Nth doc in a multi-document file (--- separators)
  • yq -o json file.yml | jq '...' -- escape hatch when yq syntax gets ugly

For anything else, yq --help.

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 · 22 lines · 22 tokens per session scan A e34cd5b9dd4b

Subscribe to this mod's changes

yq is a skill published in the GitHub repository xdg/xdg-claude (20 stars, last pushed 3d ago), licensed Apache-2.0. It adds 22 tokens to every session and 194 once invoked, about $0.0001 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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