When developing GRASS GIS software, you may want to share your development with the community. There are several ways to probably get your code into the standard GRASS GIS release. Another option is to host the software on your own web page - in this case we can add a link to our "GRASS Add-ons" section. We strongly recommend you follow the coding style described in SUBMITTING files (which you find in the GRASS source code). Optionally, for group based development we can offer access to the GRASS AddOns-SVN repository which we grant to trustable people who agree to the GRASS rules of code contributions (see below):

  • Legal aspects of code contributions (RFC2): these rules have to be accepted to gain SVN write access.
  • Coding standards: Check your code against the rules defined in the document SUBMITTING. This ensures a smooth integration into the standard GRASS code base and avoids portability problems.
  • In general, please generate differences to the current SVN instead of sending full files:
    svn diff -x -u [file.c] > grass.diff
  • For more details, see HowToSVN Creating local diffs. Please submit the patch to GRASS Trac.
  • More details about How to Contribute


Testing is highly welcome: of your own or existing code as well as of proposed changes (e.g. in GRASS Trac). So, how to work with source code patches:

Static code checking is done at https://scan.coverity.com/projects/grass

Development of Add-ons (extensions)

  • To request access to our SVN repository, see this document
  • Source code of the Add-on:
    • the code may be hosted on your server; or preferably
    • submit it to the GRASS Add-on SVN repository: We maintain a public SVN repository. Ask the GRASS developers to gain write access, agreeing to the Legal aspects of code contributions (RFC2) and the code SUBMITTING standards (see here).
    • Eventually please list your new GRASS Add-on on the Wiki: go here

GRASS GIS Quality Control

The development team invests time and efforts to verify the quality of GRASS GIS by commit peer review, manual, and automatic tests:

Development >> Code submission | Last change: 20-Jan-2019