format is a query params

routes/prompt/index.js

@@ -35,7 +35,11 @@ const IMAGE_SIZES = {
 
 module.exports = async function (fastify, opts) {
   fastify.get('/:inputs', async function (request, reply) {
-    const { inputs } = request.params;
+    let { inputs } = request.params;
+    const { format } = request.query;
+    if (format) {
+      inputs = inputs + " " + format;
+    }
 
     const slug = inputs.replace(/[^a-zA-Z0-9-_ ]/g, "").replace(/ /g, "-");
 
@@ -46,8 +50,7 @@ module.exports = async function (fastify, opts) {
         .send(file);
     }
 
-    let size = inputs.split(" ").find(i => Object.keys(IMAGE_SIZES).includes(i)) || "square";
-    const { height, width } = IMAGE_SIZES[size];
+    const { height, width } = IMAGE_SIZES[format ?? "square"];
 
     const hfRequest = await inference.textToImage({
       inputs,