Transport

Pass an object with one async submit(request) method. Protocol, authentication, retry, routing, and fanout remain application concerns.

import { mountForm } from "mlform/kit";

mountForm(container, {
  schema,
  transport: {
    async submit(request) {
      const response = await fetch("/api/predict", {
        method: "POST",
        headers: { "content-type": "application/json" },
        body: JSON.stringify(request.modelValues),
      });
      const output = await response.json();
      return {
        reports: [
          {
            backend: "default",
            mappedTo: "prediction",
            status: "ready",
            payload: output.prediction,
          },
        ],
        meta: { requestId: output.requestId },
        raw: output,
      };
    },
  },
});

Every report result declares its exact backend, mappedTo, and status. Use pending with context for client-side report fetches, or skipped for non-applicable reports. See Backend Contract.

For independent backend calls, createFanoutTransport runs every target concurrently and gives merge ordered fulfilled/rejected outcomes. Set failurePolicy: "fail-fast" only when partial results are invalid for the application.