PySTAC extension generator¶

pystac-ext-generator is a generic Python command-line application that turns a STAC Extension JSON Schema into a standalone Python module containing PySTAC-compatible extension classes.

The input schema determines the class name, registration URI, fields, types, and applicable STAC objects. Declared nested objects become additional value classes; Collection summary helpers are generated when the schema exposes summary fields. The generator is not tied to a particular extension or scientific domain.

pystac-ext-generator schema.json -o extension.py

Import the generated class from extension.py and use its ext() method to wrap a PySTAC object. The generated module runs independently of the generator. Embedded offline schema validation is available with --include-validation.

Start here¶

• Install the CLI.
• Generate and use your first extension.
• Work with generated fields and nested classes.
• Bundle external references.
• Look up CLI options or the Python API.
• Understand schema discovery and validation.

Python 3.10 or later is required. Lean modules such as Themes need only PySTAC. Embedded validation and schema-dependent union decoding additionally need jsonschema; wide factories use typing-extensions. Generated code never requires Click, Jinja2, Ruff, or pystac-ext-generator.