devcontainer-setup

Devcontainer Setup Skill

Creates a pre-configured devcontainer with Claude Code and language-specific tooling.

When to Use

• User asks to "set up a devcontainer" or "add devcontainer support"
• User wants a sandboxed Claude Code development environment
• User needs isolated development environments with persistent configuration

When NOT to Use

• User already has a devcontainer configuration and just needs modifications
• User is asking about general Docker or container questions
• User wants to deploy production containers (this is for development only)

Workflow

flowchart TB
    start([User requests devcontainer])
    recon[1. Project Reconnaissance]
    detect[2. Detect Languages]
    generate[3. Generate Configuration]
    write[4. Write files to .devcontainer/]
    done([Done])

    start --> recon
    recon --> detect
    detect --> generate
    generate --> write
    write --> done

Phase 1: Project Reconnaissance

Infer Project Name

Check in order (use first match):

1. package.json → name field
2. pyproject.toml → project.name
3. Cargo.toml → package.name
4. go.mod → module path (last segment after /)
5. Directory name as fallback

Convert to slug: lowercase, replace spaces/underscores with hyphens.

Detect Language Stack

Language	Detection Files
Python	pyproject.toml, *.py
Node/TypeScript	package.json, tsconfig.json
Rust	Cargo.toml
Go	go.mod, go.sum

Multi-Language Projects

If multiple languages are detected, configure all of them in the following priority order:

1. Python - Primary language, uses Dockerfile for uv + Python installation
2. Node/TypeScript - Uses devcontainer feature
3. Rust - Uses devcontainer feature
4. Go - Uses devcontainer feature

For multi-language postCreateCommand, chain all setup commands:

uv run /opt/post_install.py && uv sync && npm ci

Extensions and settings from all detected languages should be merged into the configuration.