xq

name: xq description: > Use yq -p xml to read, extract, filter, or transform XML data from the command line instead of reading entire XML files. Load this skill for Maven projects (pom.xml), .NET projects (.csproj, .config, app.config), Java configuration (web.xml, persistence.xml, applicationContext.xml, Spring beans), build files (build.xml, .proj), or any XML configuration. Use when extracting Maven dependencies, checking project versions, listing artifacts, finding dependency scopes, analyzing .NET package references, inspecting servlet mappings, or auditing XML configs across a multi-module project. No separate tool installation needed — this is just yq with the -p xml flag. This skill applies even when the user says "what version is this pom", "list the dependencies", "check the target framework", "find Spring beans" — use yq -p xml instead of reading. Essential for large poms (50+ dependencies) or batch operations across multiple XML files. Saves 90-99% of tokens with surgical extraction.

XML manipulation with yq -p xml

Core rule

When you need to read, extract, filter or transform data from an XML file, use yq -p xml on the command line instead of reading the entire file.

yq natively parses XML with the -p xml flag, using the same jq-like filter syntax as for YAML. No additional tool is needed — if yq is installed, XML support is included.

Prerequisites: check/install yq

Same tool as YAML — check availability:

yq --version
# Must show: yq (https://github.com/mikefarah/yq/) version v4.x

If yq is not installed:

Warning: use mikefarah/yq (Go), NOT kislyuk/yq (Python). Only the Go version supports -p xml.

Shell compatibility

yq works natively in both Bash and PowerShell. For filters containing | (pipe), use cmd /c in PowerShell:

# Bash — single quotes work
yq -p xml -oy '.project.version' pom.xml
yq -p xml -oy '.project.dependencies.dependency[] | select(.scope == "test")' pom.xml

# PowerShell — simple filters work directly
yq -p xml -oy ".project.version" pom.xml

# Filters with | need cmd /c wrapping
cmd /c 'yq -p xml -oy ".project.dependencies.dependency[] | select(.scope == \"test\")" pom.xml'

Usage patterns

Extract a value from pom.xml

yq -p xml -oy '.project.version' pom.xml
# → 3.2.1

yq -p xml -oy '.project.groupId' pom.xml
# → com.axa.france

yq -p xml -oy '.project.artifactId' pom.xml
# → osmose-api

Extract properties / configuration block

yq -p xml -oy '.project.properties' pom.xml
# → java.version: "17"
#   spring-boot.version: 3.2.0
#   maven.compiler.source: "17"

List dependencies

yq -p xml -oy '.project.dependencies.dependency[].artifactId' pom.xml
# → spring-boot-starter-web
#   spring-boot-starter-data-jpa
#   postgresql
#   lombok

Count elements

yq -p xml -oy '.project.dependencies.dependency | length' pom.xml
# → 5

Filter with select

# Find test-scoped dependencies
yq -p xml -oy '.project.dependencies.dependency[] | select(.scope == "test") | .artifactId' pom.xml
# → spring-boot-starter-test

cmd /c 'yq -p xml -oy ".project.dependencies.dependency[] | select(.scope == \"test\") | .artifactId" pom.xml'

Extract from .csproj (C# projects)

yq -p xml -oy '.Project.PropertyGroup.TargetFramework' MyApp.csproj
yq -p xml -oy '.Project.ItemGroup.PackageReference[].+@Include' MyApp.csproj

Extract from Spring / web.xml

yq -p xml -oy '.web-app.servlet[].servlet-name' web.xml
yq -p xml -oy '.beans.bean[].+@class' applicationContext.xml

Access XML attributes

In yq, XML attributes are represented with +@ prefix:

yq -p xml -oy '.project.dependencies.dependency[0].+@type' pom.xml
# For: <dependency type="jar">

yq -p xml -oy '.root.element.+@id' config.xml
# For: <element id="123">

Modify XML in-place

yq -i -p xml -o xml '.project.version = "4.0.0"' pom.xml
yq -i -p xml -o xml '.project.properties.java-version = "21"' pom.xml

Convert XML to JSON or YAML

# XML → JSON
yq -p xml -o json '.project.properties' pom.xml
# → {"java.version": "17", "spring-boot.version": "3.2.0", ...}

# XML → YAML
yq -p xml -o yaml pom.xml

# Full conversion to file
yq -p xml -o json pom.xml > pom.json

yq -p xml -o json ".project.properties" pom.xml

Common XML file types