The OpenIGTLink protocol defines a set of message formats for several data types that are frequently used for image-guided and robot-assisted interventions. Those formats are used to compose messages that are transferred from one device to another over the local area network. The application developers can choose their own transportation layer that fits for their application and environment (e.g. TCP, UDP, WebSocket).

Protocol Specifications

See Protocol Specification Page for detail.

Software Development Kits (SDKs)

To use OpenIGTLink in your software application, you need to either: 1) implement serialization/de-serialization of messages by your self, or 2) use existing libraries. C/C++ and Java libraries are currently available as free open-source software.


See OpenIGTLink C/C++ Library Page for detail.

We provide the OpenIGTLink C/C++ library as free open-source software under the BSD-style license. The OpenIGTLink library provides application program interface (API) to communicate with other software over the network. The OpenIGTLink library supports major platforms including Microsoft Windows, Linux, and macOS (Mac OS X). Those open-interface and multi-platform strategies will lead to the widespread use of OpenIGTLink, and ultimately help to establish the interoperability among a wide variety of components developed by different groups and companies in the community.


pyigtl is a Python implementation of OpenIGTLink. It supports protocol version 3, client and server mode, and the most commonly used message types.


AIM Lab at Worcester Polytechnic Institute is providing Java implementation of OpenIGTLink library as free open-source software. Please visit:

for more detail.

Development and Maintenance

The OpenIGTLink protocol is developed and maintained at by the OpenIGTLink community hosted at National Center for Image Guided Therapy, Brigham and Women’s Hospital. OpenIGTLink protocol is an open-source project; anyone is welcome to join the development.

The project is hosted at GitHub. There are several ways to participate the project:

Report Bugs / Request Features

If you find any issues or have feature request, please feel free to post to Issues in GitHub Issues.

As for feature requests, please note that we may not incorporate requested features into the protocol, in order to maintain the compatibility of the protocol with existing software/hardware.

Contribute Patches

The OpenIGTLink community is adapted to the collaborative development model on GitHub. GitHub’s instruction provides a very nice overview of collaborative development models and workflows.

Participate Project Weeks

There have been groups of people who organize small projects related to OpenIGTLink at biannual [Project Week] hosted by National Alliance for Medical Image Computing. Project Week is a hack-a-thon event focused on development of software platforms for medical image computing and computer assisted intervention. Please check Event page or contact Junichi Tokuda for the future projects.