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pydggsapi

pydggsapi is an OGC API – DGGS server implementation built with FastAPI, with IGEO7 as a natively supported Discrete Global Grid Reference System.

  • Repository: https://github.com/LandscapeGeoinformatics/pydggsapi
  • Authors:
    • Alexander Kmoch (University of Tartu)
    • Wai Tik Chan (University of Tartu)
    • Francis Charette-Migneault (Technologies Luqia, CRIM)
  • License: AGPL-3.0
  • Related Publications:

    • Chan, W. T., Charette-Migneault, F., Uuemaa, E., & Kmoch, A. (2026). pydggsapi: A query web service for Discrete Global Grid System (DGGS) collections. SoftwareX, 103042. DOI:10.1016/j.softx.2026.103042

    • Kmoch, A., Chan, W.T. (2025). pydggsapi. FOSS4G 2025 Conference Presentation.

What It Does​

pydggsapi implements the OGC API – DGGS candidate standard, exposing DGGS-indexed data over standardised REST endpoints. Any OGC-compliant client can query the server for cell data without knowing the underlying grid system.

Supported DGGS reference systems:

  • IGEO7 (ISEA7H Z7)
  • H3
  • HEALPix
  • rHEALPix

Supported data backends:

  • Clickhouse — columnar analytics for large vector datasets
  • Zarr — cloud-native array data (via xdggs)
  • Parquet — file-based tabular data

Key Endpoints​

EndpointDescription
GET /dggsList available DGGS reference systems
GET /dggs/{dggs_id}Describe a specific DGGS
GET /dggs/{dggs_id}/zonesList zones (cells) at a resolution
GET /dggs/{dggs_id}/zones/{zone_id}Get data for a specific cell
GET /collectionsList data collections
GET /collections/{coll}/dggs/{dggs_id}/zones/{zone_id}Get collection data for a cell

Quick Start​

pip install pydggsapi
uvicorn pydggsapi.main:app --reload

The server starts at http://localhost:8000. The interactive API docs are at http://localhost:8000/docs.

Configuration​

Configure data sources and DGGS settings via environment variables or a config file. Example for IGEO7 + Zarr backend:

dggs:
  - id: IGEO7
    type: ISEA7H_Z7
    resolutions: [5, 7, 9, 11]

collections:
  - id: sentinel2_ndvi
    backend: zarr
    path: s3://my-bucket/sentinel2_ndvi.zarr
    dggs: IGEO7
    resolution: 9

See Also​