List the vocabulary: all 36 values kind may take, each with a one-line purpose. Call it first, before choosing a kind — several kinds are not box-and-arrow diagrams and are easy to miss — then get_example for a starting document. No arguments. Static and local: no I/O, about 4 KB, the same answer every call, in a fixed order that keeps related kinds (graphs, grids, shapes, charts) adjacent.

Get the smallest valid document of one kind, as JSON ready to edit: the fastest way to the right field names. kind is one exact value from list_kinds, e.g. flow. Use it after list_kinds has settled the kind, and get_schema only for a field the example leaves out. Static and local: the document drawspec example <kind> prints, under 1 KB, identical every call; it passes validate_document as is. An unknown kind is an error result naming list_kinds.

Get the JSON Schema (draft 2020-12) for one kind's documents: every field it accepts, with types, limits and descriptions, plus only the shared $defs it refers to. kind is one value from list_kinds, e.g. sequence. Use it when get_example does not show a field you need. Local and deterministic: 3 to 13 KB per kind, cut from the ~150 KB published schema. Referential rules (unique ids, edges that land on real nodes) are beyond JSON Schema — validate_document checks those.

Check whether render_document would refuse this document, and exactly where. It renders with the same theme and discards the drawing, so it passes only what draws; every violation comes back at once, so one pass is one edit. Call it while writing or editing; skip it when about to render anyway, since render_document refuses in the same shape. Local, deterministic, milliseconds. Refusals are error results with JSON text {"ok": false, "error": "DocumentError", "message": "...", "violations": [{"pointer": "/edges/0/to", "message": "..."}]}: error is e.g. DocumentError or FitError, pointer is RFC 6901 (empty for the whole document), and violations is never empty.

Draw the document. Use it when it is ready to show; while still fixing errors, validate_document returns just the verdict. Returns one content block by format: svg (default) self-contained SVG text, safe inline in Markdown; png a base64 image/png block (needs the server's drawspec[png] extra, slowest); text plain text for a code block, only for kinds with a text form. width/height override the document's size; with text, width is cells per line and height and theme are ignored. Local, deterministic, writes nothing. Refusals are error results with JSON text {"ok": false, "error": "DocumentError", "message": "...", "violations": [{"pointer": "/edges/0/to", "message": "..."}]}: error is e.g. DocumentError or FitError, pointer is RFC 6901 (empty for the whole document), and violations is never empty.