UDFs as API

Every UDF can be used as a file system.

Share your canvas to get a canvas token (fc_***); then call any UDF by name.

Output formats

UDFs can return data in various formats via the format query parameter:

Vector data formats

Format	Extension	Description
parquet	.parquet	Efficient columnar storage format
geojson	.geojson	Standard GeoJSON format
json	.json	JSON objects and GeoJSON
csv	.csv	Comma-separated values
mvt	.mvt	Mapbox Vector Tiles
feather	.feather	Apache Arrow IPC format
excel	.xlsx	Excel spreadsheet
xml	.xml	XML data
html	.html	HTML document

Raster data formats

Format	Extension	Description
png	.png	Lossless raster images
jpeg	.jpeg / .jpg	Compressed raster images
gif	.gif	Animated or static images
webp	.webp	Modern efficient image format
apng	.apng	Animated PNG images
svg	.svg	Scalable vector graphics
tiff	.tiff / .tif	GeoTIFF and TIFF rasters
npy	.npy	NumPy array binary format

Example usage

Use your canvas token and UDF name (from sharing your canvas):

Returning as JSON

https://udf.ai/fc_<CANVAS_TOKEN>/my_udf.json

Returning as CSV

https://udf.ai/fc_<CANVAS_TOKEN>/my_udf.csv

Returning as HTML

https://udf.ai/fc_<CANVAS_TOKEN>/my_udf.html

Tile endpoints

For map tile servers, use the tiles path with {z}/{x}/{y} template:

Vector tiles (MVT)

https://udf.ai/fc_<CANVAS_TOKEN>/my_udf/run/tiles/{z}/{x}/{y}?=mvt

Layer Name

When consuming Fused MVT tiles in tools that require a source-layer name (like Mapbox GL JS, MapLibre, or react-map-gl), the layer is always named udf.

Raster tiles (PNG)

https://udf.ai/fc_<CANVAS_TOKEN>/my_udf/run/tiles/{z}/{x}/{y}?=png

Integrations

These dynamic endpoints work with:

• DeckGL - Interactive maps
• Mapbox - Web maps
• QGIS - Desktop GIS
• Felt - Collaborative mapping
• Google Sheets - Spreadsheet import

UDF name in the URL

If you rename a UDF in Workbench, the API URL changes — the old URL (with the previous name) will no longer work. Update any clients or bookmarks that call the UDF by URL.