For the English abstract and full text of the article please see the attached PDF-File (English version follows Russian version). ABSTRACT The article considers an example of extending the program for information modeling of elements of the metal bridge. Over just the past few years there has been a significant progress and qualitative leap in design of building structures transforming it from twodimensional drawings to information modeling (BIM technology). This transition became possible due to modern software. Unlike the creation of twodimensional drawings and three-dimensional model of the construction in the CAD system, the process of information modeling creates a database that contains information about each element of the building. This approach allows to store and modify information about the object throughout the whole lifecycle of the project. Revit and Tekla are the most popular products in Russia. With their help it takes little time to assemble an information model for a typical building because these programs contain large libraries with the elements. However, when designing a unique building it is necessary to add new elements and plug-ins (extensions) to the program. Plug-ins can significantly reduce the design time. Almost all of the programs for BIM allow the usage of such extensions. Tekla has a very convenient functionality for automation. With this program it is possible to extend the functionality using the Tekla Open API, which uses C# programming language. The article considers the automation process of placing the bolts in the nodes of the main through trusses of the metal bridge. To achieve this, a C# program (plug-in) that performs the placing of the bolts has been created. Examples of dialog boxes created with the help of the Tekla Open API that illustrate the implementation of the proposed algorithm are provided. Keywords: information model, computer-aided design system, BIM-technologies, Open API interface, adaptation, plug-in, truss, node, bridge.