Render reference

POST /api/v1/render — full request and response reference.

#Request

POST https://sankeykit.com/api/v1/render
Authorization: Bearer sk_live_YOUR_KEY
Content-Type: application/json

The body is JSON. flows is the only required field in the payload.

#Minimal request

{
	"flows": [
		{ "source": "Visitors", "target": "Signups", "value": 120 },
		{ "source": "Signups", "target": "Paid", "value": 30 }
	]
}

#Full request

Every field the schema accepts, used at once:

{
	"flows": [
		{
			"source": "a",
			"target": "b",
			"value": 2,
			"previousValue": 4
		},
		{
			"source": "a",
			"target": "c",
			"value": 1,
			"previousValue": 2
		},
		{
			"source": "b",
			"target": "d",
			"value": 1,
			"previousValue": 2
		},
		{
			"source": "b",
			"target": "e",
			"value": 1,
			"previousValue": 2
		}
	],
	"options": {
		"width": 901,
		"height": 500,
		"nodeWidth": 21,
		"nodePadding": 48,
		"snapEndNodes": true,
		"canvasBackground": "#FFFFFF",
		"nodeHeightScale": 0.46,
		"labelStyle": {
			"fontFamily": "'JetBrains Mono', monospace",
			"position": "left",
			"background": "#000000",
			"backgroundOpacity": 0.75,
			"layout": "compact",
			"title": {
				"show": true,
				"color": "#FFFFFF",
				"size": 8
			},
			"subtitle": {
				"show": true,
				"color": "#FFFFFF",
				"size": 8
			},
			"value": {
				"show": true,
				"color": "#FFFFFF",
				"size": 8,
				"prefix": "$",
				"suffix": "M",
				"decimals": 0
			},
			"previousValue": {
				"show": true,
				"color": "#FFFFFF",
				"size": 8,
				"prefix": "$",
				"suffix": "Y/Y",
				"mode": "absolute"
			}
		},
		"chartTitle": {
			"text": "Title",
			"size": 46,
			"color": "#FF0000",
			"align": "right"
		},
		"chartSubtitle": {
			"text": "Subtitle",
			"size": 10,
			"color": "#FF0000",
			"align": "right"
		},
		"chartFooter": {
			"text": "Footer",
			"size": 11,
			"color": "#000000",
			"align": "left"
		},
		"theme": "pastel",
		"colorPalette": [
			"#f9a8d4",
			"#fca5a5",
			"#fdba74",
			"#fde68a",
			"#bbf7d0",
			"#a5f3fc",
			"#bfdbfe",
			"#ddd6fe",
			"#fbcfe8",
			"#d9f99d"
		]
	},
	"nodeOverrides": [
		{
			"id": "a",
			"label": "aa",
			"color": "#F163EE",
			"subtitle": "A"
		},
		{
			"id": "b",
			"label": "bb",
			"color": "#63F1E6",
			"subtitle": "B",
			"yOffset": 100.11190795898438
		},
		{
			"id": "c",
			"label": "cc",
			"color": "#F163A7",
			"subtitle": "C",
			"yOffset": -40.38221740722656
		},
		{
			"id": "d",
			"label": "dd",
			"color": "#F1D063",
			"subtitle": "D",
			"yOffset": 20.206024169921875,
			"column": 1.5
		},
		{
			"id": "e",
			"label": "ee",
			"color": "#65F163",
			"subtitle": "E"
		}
	],
	"linkOverrides": [
		{
			"source": "b",
			"target": "e",
			"color": "#8283B5",
			"gradient": true
		},
		{
			"source": "a",
			"target": "b",
			"color": "#0005F1"
		},
		{
			"source": "a",
			"target": "c",
			"color": "#C54CC2"
		},
		{
			"source": "b",
			"target": "d",
			"color": "#3EDC06"
		}
	]
}

#Response

Format	Content type	Body
PNG	`image/png`	Raw PNG bytes

Every successful response also includes:

X-RateLimit-Limit: <monthly quota>
X-RateLimit-Remaining: <renders left this period>
X-RateLimit-Reset: <unix timestamp when quota resets>

See Limits for what these mean.

#Saving the output

curl https://sankeykit.com/api/v1/render \
  -H "Authorization: Bearer sk_live_YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d @request.json \
  -o chart.svg

Switch the output filename (and "format": "png" in the body) to save a PNG instead.

# Parameter reference

Generated from the live request schema in src/lib/server/render.ts — this table always matches what the API actually accepts.

Field	Type	Required	Default	Constraints	Description
`flows`	object[]	Required	—	—	The list of source-to-target flows that make up the chart. At least one is required.
`flows[].source`	string	Required	—	min length 1	Source node id.
`flows[].target`	string	Required	—	min length 1	Target node id.
`flows[].value`	number	Required	—	min 0	Flow magnitude. Determines link/node thickness.
`flows[].previousValue`	number	Optional	—	—	Optional prior-period value, used for period-over-period change labels.
`meta`	object	Optional	—	—	Optional metadata about the render request, not rendered on the chart itself.
`meta.title`	string	Optional	—	—	Internal title for this render, not displayed on the chart.
`meta.description`	string	Optional	—	—	Internal description for this render, not displayed on the chart.
`options`	object	Optional	{"width":960,"height":540,"format":"svg"}	—	Layout, styling and output options for the chart.
`options.width`	number	Optional	960	integer, min 1, max 7680	Output canvas width in pixels.
`options.height`	number	Optional	540	integer, min 1, max 7680	Output canvas height in pixels.
`options.padding`	object	Optional	—	—	Padding around the chart area, in pixels per side.
`options.padding.top`	number	Optional	—	—	Top padding in pixels.
`options.padding.right`	number	Optional	—	—	Right padding in pixels.
`options.padding.bottom`	number	Optional	—	—	Bottom padding in pixels.
`options.padding.left`	number	Optional	—	—	Left padding in pixels.
`options.nodeWidth`	number	Optional	—	integer, min 4, max 100	Width of node rectangles in pixels.
`options.nodePadding`	number	Optional	—	integer, min 0, max 100	Vertical gap between nodes in the same column, in pixels.
`options.iterations`	number	Optional	—	integer, min 0, max 500	Number of layout relaxation iterations used to reduce link crossings.
`options.align`	"justify" \| "left" \| "right" \| "center"	Optional	—	—	Horizontal alignment strategy for node columns.
`options.snapEndNodes`	boolean	Optional	—	—	Snap source/sink nodes with no incoming or outgoing links to the outer columns.
`options.mergeParallelLinks`	boolean	Optional	—	—	Combine multiple links between the same source/target pair into one.
`options.nodeHeightScale`	number	Optional	—	min 0.01, max 1	Scales node rectangle height relative to its flow value (0-1).
`options.canvasBackground`	string	Optional	—	—	CSS color for the chart background.
`options.theme`	string	Optional	—	—	Named built-in color theme to apply.
`options.colorPalette`	string[]	Optional	—	—	Custom ordered list of CSS colors used to color nodes/links.
`options.linkColorMode`	"source" \| "target" \| "gradient" \| "fixed"	Optional	—	—	How link color is derived: from the source node, target node, a gradient between them, or a fixed color.
`options.linkColor`	string	Optional	—	—	CSS color used for all links when linkColorMode is "fixed".
`options.linkOpacity`	number	Optional	—	min 0, max 1	Opacity applied to all links (0-1).
`options.labelStyle`	object	Optional	—	—	Styling for node labels.
`options.labelStyle.position`	"outward" \| "left" \| "right" \| "above" \| "below" \| "inside"	Optional	—	—	Where node labels are placed relative to their node.
`options.labelStyle.fontFamily`	string	Optional	—	—	Font family for all labels.
`options.labelStyle.fontSize`	number	Optional	—	—	Base font size in pixels for labels.
`options.labelStyle.color`	string	Optional	—	—	Default label text color.
`options.labelStyle.background`	string	Optional	—	—	Label background color (behind the text).
`options.labelStyle.backgroundOpacity`	number	Optional	—	min 0, max 1	Opacity of the label background (0-1).
`options.labelStyle.layout`	"stacked" \| "compact" \| "semi-compact"	Optional	—	—	How title/subtitle/value lines are arranged within a label.
`options.labelStyle.title`	object	Optional	—	—	Style overrides for the title line of a label.
`options.labelStyle.title.show`	boolean	Optional	—	—	Whether to show this label element.
`options.labelStyle.title.color`	string	Optional	—	—	CSS color for this label element.
`options.labelStyle.title.size`	number	Optional	—	—	Font size in pixels for this label element.
`options.labelStyle.subtitle`	object	Optional	—	—	Style overrides for the subtitle line of a label.
`options.labelStyle.subtitle.show`	boolean	Optional	—	—	Whether to show this label element.
`options.labelStyle.subtitle.color`	string	Optional	—	—	CSS color for this label element.
`options.labelStyle.subtitle.size`	number	Optional	—	—	Font size in pixels for this label element.
`options.labelStyle.value`	object	Optional	—	—	Style and formatting for the value line of a label.
`options.labelStyle.value.show`	boolean	Optional	—	—	Whether to show this label element.
`options.labelStyle.value.color`	string	Optional	—	—	CSS color for this label element.
`options.labelStyle.value.size`	number	Optional	—	—	Font size in pixels for this label element.
`options.labelStyle.value.prefix`	string	Optional	—	—	Text prepended to the formatted value, e.g. "$".
`options.labelStyle.value.suffix`	string	Optional	—	—	Text appended to the formatted value, e.g. "%".
`options.labelStyle.value.decimals`	number	Optional	—	integer	Number of decimal places to round the value to.
`options.labelStyle.value.locale`	string	Optional	—	—	BCP 47 locale used for number formatting, e.g. "en-US".
`options.labelStyle.previousValue`	object	Optional	—	—	Style and formatting for the period-over-period change line of a label.
`options.labelStyle.previousValue.show`	boolean	Optional	—	—	Whether to show this label element.
`options.labelStyle.previousValue.color`	string	Optional	—	—	CSS color for this label element.
`options.labelStyle.previousValue.size`	number	Optional	—	—	Font size in pixels for this label element.
`options.labelStyle.previousValue.prefix`	string	Optional	—	—	Text prepended to the change value.
`options.labelStyle.previousValue.suffix`	string	Optional	—	—	Text appended to the change value.
`options.labelStyle.previousValue.mode`	"percentage" \| "absolute" \| "raw"	Optional	—	—	How to express the change versus previousValue: percentage, absolute difference, or raw value.
`options.labelStyle.showSubtitle`	boolean	Optional	—	—	Whether to show the subtitle line at all.
`options.labelStyle.subtitleScale`	number	Optional	—	—	Scale factor applied to subtitle font size relative to the title.
`options.chartTitle`	object	Optional	—	—	Chart title text shown above the chart.
`options.chartTitle.text`	string	Optional	—	—	The text content to display.
`options.chartTitle.size`	number	Optional	—	—	Font size in pixels.
`options.chartTitle.color`	string	Optional	—	—	CSS text color.
`options.chartTitle.align`	"left" \| "center" \| "right"	Optional	—	—	Horizontal text alignment.
`options.chartSubtitle`	object	Optional	—	—	Chart subtitle text shown under the title.
`options.chartSubtitle.text`	string	Optional	—	—	The text content to display.
`options.chartSubtitle.size`	number	Optional	—	—	Font size in pixels.
`options.chartSubtitle.color`	string	Optional	—	—	CSS text color.
`options.chartSubtitle.align`	"left" \| "center" \| "right"	Optional	—	—	Horizontal text alignment.
`options.chartFooter`	object	Optional	—	—	Footer text shown below the chart.
`options.chartFooter.text`	string	Optional	—	—	The text content to display.
`options.chartFooter.size`	number	Optional	—	—	Font size in pixels.
`options.chartFooter.color`	string	Optional	—	—	CSS text color.
`options.chartFooter.align`	"left" \| "center" \| "right"	Optional	—	—	Horizontal text alignment.
`options.format`	"svg" \| "png"	Optional	svg	—	Output image format.
`options.scale`	number	Optional	—	min 1, max 3	Pixel density multiplier applied when rendering PNG output, from 1 to 3. Has no effect on SVG output. Free/non-paid accounts are always forced to 1x regardless of what's requested here.
`options.showAttribution`	boolean	Optional	—	—	Whether to show the "Made with SankeyKit.com" attribution link on the rendered chart. Defaults to true.
`nodeOverrides`	object[]	Optional	—	—	Per-node style and layout overrides, keyed by node id.
`nodeOverrides[].id`	string	Required	—	min length 1	Node id to override (must match a source/target used in flows).
`nodeOverrides[].label`	string	Optional	—	—	Display label shown instead of the node id.
`nodeOverrides[].subtitle`	string	Optional	—	—	Secondary line of text shown under the label.
`nodeOverrides[].tag`	string	Optional	—	—	Free-form tag, not rendered; used for grouping/color lookups.
`nodeOverrides[].color`	string	Optional	—	—	CSS color for this node, overriding the palette.
`nodeOverrides[].hidden`	boolean	Optional	—	—	Hide this node (and its links) from the output.
`nodeOverrides[].pinned`	boolean	Optional	—	—	Pin the node position so layout iterations do not move it.
`nodeOverrides[].column`	number	Optional	—	—	Force the node into a specific column position. Fractional values place the node between columns.
`nodeOverrides[].order`	number	Optional	—	integer	Vertical ordering hint within its column.
`nodeOverrides[].yOffset`	number	Optional	—	—	Manual vertical pixel offset applied after layout.
`nodeOverrides[].previousValue`	number	Optional	—	—	Optional prior-period value for this node, used for change labels.
`linkOverrides`	object[]	Optional	—	—	Per-link style overrides, keyed by source/target pair.
`linkOverrides[].source`	string	Required	—	min length 1	Source node id of the link to style.
`linkOverrides[].target`	string	Required	—	min length 1	Target node id of the link to style.
`linkOverrides[].color`	string	Optional	—	—	CSS color override for this specific link.
`linkOverrides[].opacity`	number	Optional	—	min 0, max 1	Opacity override for this specific link (0-1).
`linkOverrides[].gradient`	boolean	Optional	—	—	Blend this link's color from its source node to its target node. When true, "color" is ignored.