OGC API - Features

OGC API - Features
Name	OGC API - Features
Status	Published
Version	1.0.1
Year	2022
Organization	Open Geospatial Consortium
Related standards	WFS, GeoJSON, HTML, OpenAPI
Domain	GIS, SDI, Web service

OGC API - Features is a modern OGC standard that defines a RESTful API for accessing, querying, and managing collections of geospatial features. It provides a simple, web-friendly interface that returns data in common formats like GeoJSON and HTML, enabling easier integration with mainstream web and mobile applications compared to previous OGC service standards. The standard is designed to be modular and extensible, promoting interoperability across diverse GIS platforms and SDI implementations.

Overview

The development of OGC API - Features represents a significant evolution from the complex XML-based SOAP protocols of traditional OGC web services towards lightweight, developer-friendly REST principles. Initiated by the Open Geospatial Consortium's APIs Standards Working Group, it aims to lower the barrier for sharing geospatial data on the web. The standard leverages common web technologies like the OpenAPI Specification for documentation and HTTP methods for operations, making it accessible to a broader community beyond specialized GIS professionals. Its release and promotion have been central to the OGC's broader OGC APIs initiative, which seeks to modernize the consortium's entire suite of interface standards.

Core Concepts

At its heart, OGC API - Features organizes data into *Collections*, which are named sets of related geographic features, such as all fire hydrants in a city or national park boundaries. Each feature, representing a real-world entity like a building or road, is accessible via a unique URL. The API supports core operations like listing collections, querying features within a collection with spatial filters (e.g., *bbox*), and retrieving individual features by ID. Responses are typically in GeoJSON, but the standard also mandates HTML representations for human-readable discovery in a web browser. Conformance to the specification is declared through a standardized *conformance* resource, ensuring clients can understand a server's capabilities.

Specifications and Parts

The standard is published as a multi-part specification under ISO/TC 211 and OGC project numbers, enhancing its formal international standing. The foundational **Part 1: Core** specifies the mandatory requirements for a basic features API. Additional parts define extensions for enhanced functionality, such as **Part 2: Coordinate Reference Systems by Reference** for complex CRS support, and **Part 3: Filtering** (based on CQL) for advanced query capabilities. Other modules in development or published as OGC Standards or Community Standards cover areas like **Sorting**, **Pagination**, and **Create, Replace, Update, and Delete (CRUD)** operations, allowing for a modular, building-block approach to implementation.

Implementation and Usage

Implementing OGC API - Features typically involves setting up a server that exposes geospatial databases through the defined REST endpoints, with many open-source and commercial GIS servers now offering support. Software libraries and frameworks in languages like Python, JavaScript, and Java facilitate both server and client development. Common use cases include powering interactive web maps on platforms like Leaflet or OpenLayers, feeding data into analytics dashboards, and enabling seamless data exchange between different agencies within a SDI. The use of OpenAPI allows for automatic client code generation, significantly simplifying integration for application developers at organizations like NASA or USGS.

Relationship to WFS

OGC API - Features is considered the successor to the Web Feature Service (WFS) standard, particularly the widely-implemented WFS 2.0. While WFS also provides access to vector features, it is based on SOAP and heavy XML schemas like GML, making it complex for general web use. OGC API - Features adopts a RESTful architecture, uses simpler encodings like GeoJSON, and aligns with modern web development practices. The OGC has published a **WFS 3.0** specification, which is essentially identical to the initial release of OGC API - Features, signaling a formal lineage and transition path for existing WFS implementations from entities like Esri or GeoServer.

Adoption and Impact

Adoption has grown rapidly across government, academic, and commercial sectors since its release. National mapping agencies like Ordnance Survey and Natural Resources Canada have deployed the standard to publish open data. It is a cornerstone of the European Union's INSPIRE directive for modernized data delivery and is supported by major cloud platforms like Microsoft Azure Maps and Google's geospatial services. The standard's impact lies in democratizing access to geospatial information, enabling a new generation of location-aware applications, and fostering greater interoperability in global projects like the United Nations' IGIF. Its success has directly inspired the development of other OGC API standards for coverages, processes, and records.

Category:Open Geospatial Consortium standards Category:Geographic information systems Category:Web APIs Category:Technical communication