Colormind

Gotchas & limits

• Every response carries content-type: text/html; charset=UTF-8 — confirmed on both a valid and a bodyless call this run — never application/json, despite the body being real JSON. Code that gates parsing on the content-type header will skip a response it should have parsed.
• A bodyless POST, or a plain GET to /api/, both return HTTP 200 with the literal plain-text body empty body — a live probe this run confirmed both cases identically. The API never signals the mistake with a status code, so a caller has to check the body content itself, not just the status.
• An unknown model value fails the same invisible way — a live POST this run with {"model":"nonexistentmodel"} returned HTTP 200 (confirmed identically across four probes, over both HTTP/2 and HTTP/1.1, with and without a Content-Type header) whose body is an openresty HTML error page titled 500 Internal Server Error. The 500 is only in the HTML, never in the status line, so if (res.status >= 500) never fires and a naive JSON.parse runs on markup. As with the empty body case above, check the body, not the status. Validate the model name up front against GET /list/, which returned {"result":["ui","default","the_fall","communist","maple_story","stellar_photography"]} live this run.
• POST /api without the trailing slash 301-redirects to /api/ — a live probe this run confirmed the redirect — and many HTTP clients silently downgrade a redirected POST to a GET, which then yields the bodyless empty body response above instead of a palette. Always POST to the slash-terminated path directly.