# Key Capabilities

> Hatchling is a modern, standards-compliant Python build backend that replaces legacy setuptools for package building.

- Skill: `tools-only/key-capabilities` (Agent Skill, multi-file: 3 files)
- Install (CLI): `npx skillmds@latest add tools-only/key-capabilities`
- Raw SKILL.md: https://api.skillmd.com/api/skills/tools-only/key-capabilities/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Docs & Writing
- Author: tools-only (https://skillmd.com/u/tools-only)
- Updated: 2026-09-29
- Page: https://skillmd.com/skills/tools-only/key-capabilities

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# Hatchling

## Overview

Hatchling is a modern, standards-compliant Python build backend that replaces legacy setuptools for package building. It provides clear configuration through `pyproject.toml`, intelligent defaults, and extensibility through hooks and plugins. This skill enables understanding Hatchling's architecture, configuration options, and build customization capabilities.

## Key Capabilities

- **Configuration via pyproject.toml**: Standards-compliant PEP 621 metadata with sensible defaults
- **Build Targets**: Wheel and source distribution builds with extensive customization
- **Build Hooks**: Dynamic code execution during build for artifacts, version management, and compilation
- **Version Management**: Multiple version sources with automatic version injection
- **File Selection**: Git-aware VCS integration with glob pattern matching
- **Plugins**: Extensible architecture for custom builders, hooks, and metadata hooks

## Reference Documentation

This skill provides comprehensive reference documentation organized by topic. Each section links to detailed guides covering configuration, usage patterns, and examples.

### Project Configuration

- [Project Metadata & Configuration](./references/project-metadata/index.md) - Package metadata, dependencies, entry points, dynamic fields
- [Build System Configuration](./references/build-system/index.md) - Build backend setup, PEP 517/518, reproducible builds, environment variables

### Build Targets

- [Wheel Build Target](./references/wheel-target/index.md) - Wheel configuration, package discovery, file selection, editable installs
- [Source Distribution (Sdist) Target](./references/sdist-target/index.md) - Sdist configuration, VCS integration, legacy setup.py support
- [Build Target Types](./references/build-targets/index.md) - Wheel, sdist, binary, custom builders, multi-version builds
- [Build Targets Configuration Details](./references/target-config/index.md) - Target-specific hooks, dependencies, versions, precedence

### File Selection & Build Customization

- [File Selection & Patterns](./references/file-selection/index.md) - Git-style globs, include/exclude patterns, VCS integration, force-include
- [Build Hooks](./references/build-hooks/index.md) - Hook interface, execution order, custom hooks, version hooks, build data passing
- [Advanced Build Features](./references/advanced-features/index.md) - Dynamic dependencies, force-include, path rewriting, editable installs, build context

### Version & Metadata Management

- [Version Management](./references/version-management/index.md) - Version sources (code, regex, env), schemes, validation, build hooks
- [Metadata Hooks](./references/metadata-hooks/index.md) - Metadata hook interface, custom hooks, dynamic metadata generation
- [Context Formatting & Dynamic Configuration](./references/context-formatting/index.md) - Context variables, environment-based config, interpolation

### Plugin System

- [Plugin System & Extensibility](./references/plugins/index.md) - Builder, hook, metadata, version plugins, hatch-vcs, plugin development

### Build Environment & Integration

- [Build Environment Internals](./references/build-environment/index.md) - Environment config, dependencies, UV vs pip, Cython integration, isolation
- [Integration & Compatibility](./references/integration/index.md) - PEP standards compliance, setup.py migration, setuptools compatibility, CMake/extensions
- [Special Configuration Options](./references/special-config/index.md) - PEP 561 type hints, SPDX licenses, namespace packages, src-layout, extensions

### Core Concepts & Standards

- [Core Concepts & Best Practices](./references/core-concepts/index.md) - PEP 517 backend, minimal philosophy, VCS file selection, reproducible builds
- [Related Standards & Specifications](./references/standards/index.md) - Python packaging overview, PEP references, metadata specs, distribution formats

### Operational Guides

- [Command-Line Building](./references/cli-building/index.md) - hatch build commands, python -m build, pip install, output customization
- [Error Handling & Validation](./references/error-handling/index.md) - Path validation, file selection errors, version/license validation, heuristic failures
- [Release Notes & Version History](./references/release-notes/index.md) - Hatchling version history, feature additions, PEP 639 support, performance improvements