Design Agent API

The Design Agent works differently from the rest of the SVGMaker API. Instead of one call producing one image, you describe what you need and the agent plans the work, draws it, lays it out and exports it. You get back a single download holding every file it produced.

Because real design work takes minutes rather than milliseconds, the API is asynchronous. Every request returns immediately with a session id, and you collect the result by watching a stream or receiving a webhook.

Quick start

Every request is authenticated with your API key in the x-api-key header. It is the same key you use for the rest of the SVGMaker API — create one in your account settings.

One endpoint starts everything. Send a brief and the turn begins immediately; omit the brief and you get an empty session you can post to later.

Body fields

Send as multipart/form-data when attaching files, or JSON when not.

Response (202)

The two URLs already carry a short-lived token, so they need no API key header. They expire, and every turn returns fresh ones.

Attach your own artwork and the agent designs around it — converting it, tracing it, resizing it, or matching its style in something new.

Three ways, all ending at the same download_url. Pick whichever fits your app.

Post to an existing session and the agent picks up where it left off, keeping everything it already made. Each turn is charged on its own.

The response carries a fresh stream_url and poll_url for the new turn. You can attach files and callback_url here too.

Stopping a turn

Send type: "user.interrupt" to stop work in flight. The reply tells you whether there was anything running to stop.

Deleting a session

Removes the session and everything it produced, including the agent's working files.

Add a callback_url to any request that starts a turn and the signed result is POSTed to your server when the work is done.

Spending is usage based. A short job costs less than a long one, and every turn is capped, so a large brief can never run away with your balance.

Each completed event and webhook tells you what the turn cost and what is left:

Buy credits on the pricing page. The same pack works across the whole SVGMaker API.

Errors carry a code and a sentence written for the person who will read it. A turn that fails after it has started reports the same pair on an error event rather than an HTTP status.

You can start 5 designs per minute per API key. Starting a new session and continuing an existing one share that budget, since both start a turn.

Going over returns 429 with a Retry-After header telling you how many seconds to wait.