HotDocs Core Assembly Service Overview

HotDocs Core Assembly Service provides document assembly services via a web Application Programming Interface (API).


The Assembly Service is a web API that provides HotDocs' core document assembly functionality. It enables you to use either HotDocs Developer 11 or HotDocs Author templates to generate and display an interview that gathers answer data from template users, then combines that answer data with the non-changing text in the template to assemble completed documents. To do this, the assembly service processes the business logic (rules) a template author creates in the template to show or hide conditional text, calculate needed values, and replace the placeholder fields in the template with the answer data collected in the HotDocs interview.

You access the Assembly Service's functionality using its REST API. This API provides a set of methods for displaying the interview and assembling HotDocs templates. Other web applications (such as the HotDocs Advance) can call the methods contained in the HotDocs Core Assembly Service. You can also use these methods yourself, to integrate Core Assembly Service's document assembly functionality with your own software.


Generally, you install HotDocs Advance first, then install the Assembly Service. Once you install these services, you access the Core Assembly Service to create an Assembly Session, which encapsulates both the optional presentation of an interview and assembly of documents based on a template. The service also provides access to all the associated documentation that helps you do this, including:

  • HotDocs Core Assembly Service Release Notes – alerts you to any new features or bug fixes added with each new release
  • Help documentation – contains the service install guide and an overview of the service, along with information to help you integrate your web application with the service
  • JavaScript API documentation – documents the JavaScript API calls you can make to invoke and control the interview runtime
  • Web API documentation – documents (using Swagger) the RESTful web API calls you can make to the assembly service to assemble a template and a set of answers into final document

Licence Key

HotDocs Core Assembly Service requires a license key to run. You must provide this key when installing Core Assembly Services. If you do not have a valid licence key, Core Assembly Service will not function. If your license key has expired, you can update your license key.

Integration with the Assembly Service

See Integrations Overview for more information.