VCS Extension Specification

• Title: VCS
• Identifier: https://stac-extensions.github.io/vcs/v0.1.0/schema.json
• Field Name Prefix: vcs
• Scope: Catalog, Collection, Item, Link
• Extension Maturity Classification: Proposal
• Owner: @m-mohr

This document explains the VCS Extension to the SpatioTemporal Asset Catalog (STAC) specification.

It describes a version control system (VCS) reference, e.g. the repository, branch or revision that a catalog or an application originates from. It is typically used on a link with the vcs relation type (see the Application Extension). The fields use system-neutral terms so the extension is not limited to Git.

• Examples:
  • Item example: Shows the basic usage of the extension in a STAC Item
• JSON Schema
• Changelog

Fields

The fields in the table below can be used in these parts of STAC documents:

• Catalogs
• Collections
• Item Properties (incl. Summaries in Collections)
• Assets (for both Collections and Items, incl. Item Asset Definitions in Collections and Asset Templates)
• Links (incl. Link Templates)
• Bands

Field Name	Type	Description
vcs:type	string	The type of version control system. See below for common values.
vcs:branch	string	The line of development, e.g. main.
vcs:revision	string	The exact revision, e.g. a Git commit hash, Subversion revision or Perforce changelist.
vcs:tag	string	The release marker, e.g. v1.0.0.

At least one of the fields must be provided where the extension is used.

Common vcs:type values are git, svn, hg, perforce, bzr, cvs, fossil and tfvc. Other values can be used.

The fields use neutral terms that map to the system-specific names:

Concept	Field	Git	Subversion	Mercurial	Perforce	Fossil
Exact revision	vcs:revision	commit	revision	changeset	changelist	check-in
Line of dev.	vcs:branch	branch	path (/branches)	branch	stream	branch
Release marker	vcs:tag	tag	path (/tags)	tag	label	tag

Contributing

All contributions are subject to the STAC Specification Code of Conduct. For contributions, please follow the STAC specification contributing guide Instructions for running tests are copied here for convenience.

Running tests

The same checks that run as checks on PRs are part of the repository and can be run locally to verify that changes are valid. To run tests locally, you'll need npm, which is a standard part of any node.js installation.

First you'll need to install everything with npm once. Just navigate to the root of this repository and on your command line run:

npm install

Then to check markdown formatting and test the examples against the JSON schema, you can run:

npm test

This will spit out the same texts that you see online, and you can then go and fix your markdown or examples.

If the tests reveal formatting problems with the examples, you can fix them with:

npm run format-examples