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.

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

It lets you inspect one needed value without loading an entire file into the agent’s context.

yq — Skill for Claude Code by xdg/xdg-claude

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.

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.

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.

Model	Per session	Once invoked
Fable 5.1	$0.00022	$0.00194
Opus 5.5	$0.00009	$0.00078
Sonnet 5.5	$0.00004	$0.00039
Haiku 4.5	$0.00002	$0.00019

Measured 2mo ago against content hash e34cd5b9dd4b, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, 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 2mo 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.

2mo 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 6d ago), licensed Apache-2.0. It adds 22 tokens to every session and 194 once invoked, about $0.0001 per session on Opus 5.5. 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.

yq next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
yqxdg/xdg-claude	Skill	20	6d ago	Apache-2.0	A	22	Claude Code
imagegenopenai/codex	Skill	133k	yesterday	Apache-2.0	A	113	Codex
playwright-climicrosoft/playwright	Skill	99k	yesterday	Apache-2.0	A	19	Claude Code
local-ai-agentsmicrosoft/ai-agents-for-beginners	Skill	79k	4d ago	MIT	A	200	Claude Code, Codex
systematic-debuggingobra/superpowers	Skill	313k	3d ago	MIT	A	21	Claude Code
next-cache-components-adoptionvercel/next.js	Skill	143k	yesterday	MIT	A	95	Claude Code
next-partial-prefetching-adoptionvercel/next.js	Skill	143k	yesterday	MIT	A	103	Claude Code