POST a small JSON description and get back a deck-ready PNG (or SVG). The endpoint is open and CORS-enabled, so it works from browsers, scripts, CI and anywhere else you can make an HTTP call. The same JSON opens in the builder.
| Field | Type | Description |
|---|---|---|
| title | string | Heading shown top-left of the chart at 22px bold. Every chart has one title row; an empty string hides it. max 140 chars · default "Mind Map" |
| centerrequired | string | The central topic, drawn as a bold pill in the middle, e.g. "Customer retention". Required. Keep it short; long text wraps onto two lines. max 80 chars |
| branchesrequired | object[] | Required: the first-level branches around the centre (up to 8; an empty list draws just the centre), each with optional nested `children` (up to 3 levels below the centre and 50 topics in total; extras are dropped with a warning). In the balanced layout they run clockwise: the first branches down the right side, the rest up the left. max 8 items |
| layout | string | "balanced" (default): branches split between the left and right of the centre so both sides are about the same height, the classic mind-map look. "right": every branch to the right of the centre, like an outline. "balanced", "right" · default "balanced" |
| width | integer | Chart width in pixels (640–2400, default 1280, which suits a 16:9 slide). PNG output renders at 2x. Height is always computed from the content. 640–2400 · default 1280 |
| palette | string[] | Hex colours applied in order to items that have no colour of their own. Pass the user's brand colours here when they name them. Default: indigo, sky, emerald, amber, red, gray. max 12 items · default ["#4f46e5","#0ea5e9","#10b981","#f59e0b","#ef4444","#6b7280"] |
| Field | Type | Description |
|---|---|---|
| namerequired | string | Branch label, drawn as a coloured pill. max 80 chars |
| color | string | Optional hex colour for this branch and everything under it, e.g. "#10b981". Without one, branches take the palette colours in order. max 40 chars |
| children | node[] | Sub-topics of this branch, top to bottom. max 12 items |
| Field | Type | Description |
|---|---|---|
| namerequired | string | Topic label, ideally a few words. Long labels wrap onto two lines, then truncate. max 80 chars |
| children | node[] | Sub-topics of this topic, top to bottom. max 12 items |
POST /api/render/mindmap returns image/png; add ?format=svg for SVG.GET /mindmap.png?d=<payload> and /mindmap.svg?d=<payload> render a chart from a link. The payload is the JSON body, raw-deflated and base64url-encoded. Nothing is stored: links are permanent and cached for a year./mindmap#d=<payload> opens the same chart in the builder for editing.GET /api/render/mindmap?demo=1 returns the demo chart.GET /api/schema/mindmap returns the JSON Schema, for code generators and AIs.Input is lenient where the intent is clear: numeric strings become numbers, out-of-range values are clamped, and unknown fields are ignored. Adjustments are listed in the X-Render-Warnings header. Anything unclear returns a 400 that says how to fix it:
{
"error": "Invalid payload",
"issues": [{ "path": "tasks", "message": "must be an array" }],
"example": { … }
}
Use the hosted MCP server instead. It gives Claude, Cursor and other MCP clients a create_mind_map tool that returns the image plus image, SVG and edit links. See the MCP page →