egms-client

Async Python client for the archive of EGMS, the European Ground Motion Service (Copernicus Land Monitoring Service): ground velocity from Sentinel-1 InSAR over all of Europe.

• Authentication with a CLMS service key: no browser, no copied links.
• Search and download of Ortho L3 tiles (100 m, vertical and east-west), keeping only the mean-velocity GeoTIFF, cached on disk.
• Mosaics of tiles over any rectangle, with no resampling (extra raster).

Why a library

The EGMS Explorer is built for clicking. The archive behind it has an API, but the parts that matter are undocumented, and each one fails quietly:

All checked against the live archive on 3 November 2026.

Install

pip install egms-client           # auth, search, download
pip install "egms-client[raster]" # + mosaics (numpy, rasterio, pyproj)

Credentials

Create a service key at land.copernicus.eu: EU Login, profile, API Tokens, Create new token. You get a JSON file with client_id, user_id, private_key and token_uri. It does not expire; keep it out of your repository.

Use

import asyncio
from pathlib import Path

import httpx

from egms_client import EgmsArchive, ServiceKey, tiles_for_bounds
from egms_client.mosaic import mosaic

key = ServiceKey.from_json(Path("clms-service-key.json").read_text())


async def main() -> None:
    async with httpx.AsyncClient(timeout=120) as client:
        archive = EgmsArchive(client, key)
        print(await archive.releases())  # ['2020-2024', '2020-2025']

        # Rectangle in EPSG:3035 metres
        bounds = dict(minx=4_700_000, miny=1_900_000, maxx=4_799_999, maxy=1_999_999)
        tiffs = []
        for tile in tiles_for_bounds(*bounds.values()):
            path = await archive.fetch_tile(tile, "U", "2020-2025", Path("egms"))
            if path is not None:  # None: the tile is at sea or not covered
                tiffs.append(path)

    vertical = mosaic(tiffs, **bounds)
    print(vertical.values.shape, vertical.left, vertical.top)  # (1000, 1000) 4700000.0 2000000.0


asyncio.run(main())

fetch_tile keeps the GeoTIFF (~4 MB) and drops the ~60 MB ZIP. It remembers both outcomes in the directory (the file, or an …absent marker), so running it again for a whole country sends no request. The token is renewed five minutes before its hour runs out.

Bring your own HTTP

Everything EgmsArchive does is also exposed as pure functions, for callers with their own HTTP and retry layer: token_request / parse_token, search_body / parse_search / latest_hit, parse_releases, download_url / check_download / extract_tiff.

Data licence

EGMS is © European Union, Copernicus Land Monitoring Service, free and open under the Copernicus data policy: anything you publish from it must credit the source.

Extracted from Limen, which uses the vertical and east-west velocities per 1 km cell as ground motion features for landslide risk.

Development

uv sync
make check

License

Code: Apache-2.0.