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Version: 9.5.x

Form Service Backend

The Form Service Backend is a Mia-Platform plugin that acts as a BFF (Backend For Frontend) for the Form Service Frontend.

How it works

The Form Service Backend works with the Form Service Frontend that provides the Form Builder and Form Visualizer UI. Further information about the frontend routes are available here

The backend service exposes the following APIs:

Form Builder

  • GET /builder/config: it returns the configuration needed to show the Form Builder visualizer;
  • POST /builder/schemas: it allows saving the created form;
  • GET /builder/schemas/{id}: it returns one form by ID;
  • PUT /builder/schemas/{id}: it updates one form by ID.

Form Visualizer

  • GET /visualizer/schemas/{id}: it returns a configured form that will be shown in the Form Visualizer;
  • POST /visualizer/forms: it saves the submitted data of a user that filled a form shown in the Form Visualizer;
  • GET /visualizer/forms/{id}: it returns a submitted form by ID, enabling the review of data provided by the end user;
  • PUT /visualizer/forms/{id}: it updates a submitted form by ID;
  • GET /visualizer/assignments/{assignmentId}/schema-id: (from version 1.2.0) it returns a form ID given a form assignment ID.

These endpoints are defined in the Form Service Backend and are called by the Form Service Frontend plugin (regardless being integrated in micro-lc or Headless CMS). Discover more about the frontend integration here.

Form data versioning support

From version 1.5.0 the Form-Service Backend supports the versioning of the form data, by including the parameter _v to the request performed to retrieve form data. The _v parameter specifies the version of the form data to be retrieved. If the ENABLE_VERSIONING environment variable is set to true, the _v parameter is forwarded to the service in charge of retrieving the form data.


Let us suppose that the submit_url has been set to http://microservice/resource. When the Form-Service Frontend triggers a request GET /visualizer/forms/{id}?_v=1 to the Form-Service Backend with a non-null _v parameter, the Form-Service Backend will trigger a request GET http://microservice/resource/{id}?_v=1

In order to obtain form data versioning, the calls to the Form-Service Frontend must be done including the _v parameter. See here for Form-Service Frontend usage.

Further details

Follow the pages below to know more about the Form Service Backend:


The Form Service Backend does not perform form validation. Validation is only performed in the frontend if the Form Service Frontend plugin is used.

We recommend building you own form validation in a dedicated backend microservice.

This may change in the future.