stack-detection

What I do

Guide the engineer agent in detecting the technology stack of the code being worked on, so the correct language and framework skills are loaded automatically.

When to use me

Load this skill at the start of any engineering task before loading stack-specific skills. Use it to determine which of the available stack skills to load.

Detection approach

Detect the stack by examining the files involved in the current task, the project root, and build configuration. Use the most specific signal available.

Step 1: Check the files being changed

Look at the file extensions and import statements in the files listed in the spec's Changes section:

Extension / pattern	Stack skill to load
.java	java-stack
.groovy, .gradle, .gradle.kts	groovy-stack
.go	go-stack
.rs, Cargo.toml	rust-stack
.py, .pyi	python-stack
.js, .mjs, .cjs, .ts, .mts	javascript-stack
.jsx, .tsx	javascript-stack + react-stack
.swift	Swift project (mockup renderer hint: swiftui-mockup-renderer)
.sql, migration files	database-stack

Step 2: Check project root markers

If the files being changed don't make the stack obvious, check the project root:

Marker	Stack skill
pom.xml, build.gradle, build.gradle.kts	java-stack (and/or groovy-stack for Gradle/Spock)
go.mod	go-stack
Cargo.toml, Cargo.lock	rust-stack
pyproject.toml, setup.py, requirements.txt, Pipfile	python-stack
package.json	javascript-stack
package.json with react dependency	javascript-stack + react-stack
tsconfig.json	javascript-stack
Package.swift, *.xcodeproj, *.xcworkspace	Swift project (mockup renderer hint: swiftui-mockup-renderer)

Step 3: Load multiple skills for mixed-stack work

If the task spans multiple stacks (e.g., a Go backend API + React frontend), load all relevant stack skills. There is no conflict — each skill covers its own domain.

Always load

Regardless of stack detection, always load these skills for any engineering task:

• implementation-principles
• testing-and-validation

Available stack skills

• java-stack — Java, JVM conventions, Spring, service design
• groovy-stack — Groovy, Gradle, DSLs, Spock testing
• go-stack — Go packages, concurrency, operational correctness
• rust-stack — Rust ownership, error handling, crate design
• python-stack — Python project structure, type safety, dependency management, testing
• javascript-stack — JavaScript, TypeScript, Node runtime safety
• react-stack — React components, state management, accessibility
• database-stack — Schema, migrations, queries, rollout safety

Supplementary skills

Load these when the task involves their domain, regardless of language:

• api-design-and-contracts — when API endpoints or contracts are involved
• integration-boundaries — when external service integrations are involved
• performance-optimization — when performance work is the goal
• security-review — when security-sensitive code is being written