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Tool· decorator

Tool.source

registers a custom source kind on a read(cfg) function

Python
source(kind, *, label="", config=None)

Returns Callable — the decorated read(cfg) function, unchanged

Parameters#

name type default description
kind str — the source kind id, e.g. "rest-api" — used in the picker and in a load's source_kinds=(...)
label str "" the human name shown in the source picker (defaults to kind)
config dict | UINode None a UI tree whose field values are passed to the function as a dict

Example#

Python
@tool.source("rest-api", label="REST API", config={"form": [{"text": {"name": "url"}}]})
def read(cfg) -> Table:
    return Table(fetch(cfg["url"]))

Notes#

The config's field values arrive as a plain dict; the function returns a Table. Once registered, the kind appears in every source picker, and a @tool.load step can restrict itself to it via source_kinds=("rest-api", …).

See also#

API: load · Source

Guides: Load steps · A file loader

By LSD Team · Last updated Jul 17, 2026 Ask on Discord View as Markdown