Warning: This document is for an old version of Rasa. The latest version is 1.10.5.

Migration Guide

This page contains information about changes between major versions and how you can migrate from one version to another.

Rasa NLU 0.14.x and Rasa Core 0.13.x to Rasa 1.0


This is a release breaking backwards compatibility. It is not possible to load previously trained models. Please make sure to retrain a model before trying to use it with this improved version.


  • The scripts in rasa.core and rasa.nlu can no longer be executed. To train, test, run, … an NLU or Core model, you should now use the command line interface rasa. The functionality is, for the most part, the same as before. Some changes in commands reflect the combined training and running of NLU and Core models, but NLU and Core can still be trained and used individually. If you attempt to run one of the old scripts in rasa.core or rasa.nlu, an error is thrown that points you to the command you should use instead. See all the new commands at Command Line Interface.

  • If you have written a custom output channel, all send_ methods subclassed from the OutputChannel class need to take an additional **kwargs argument. You can use these keyword args from your custom action code or the templates in your domain file to send any extra parameters used in your channel’s send methods.

  • If you were previously importing the Button or Element classes from rasa_core.dispatcher, these are now to be imported from rasa_sdk.utils.

  • Rasa NLU and Core previously used separate configuration files <https://legacy-docs.rasa.com/docs/nlu/0.15.1/migrations/?&_ga=2.218966814.608734414.1560704810-314462423.1543594887#id1>. These two files should be merged into a single file either named config.yml, or passed via the --config parameter.

Script parameters

  • All script parameter names have been unified to follow the same schema. Any underscores (_) in arguments have been replaced with dashes (-). For example: --max_history has been changed to --max-history. You can see all of the script parameters in the --help output of the commands in the Command Line Interface.

  • The --num_threads parameter was removed from the run command. The server will always run single-threaded, but will now run asynchronously. If you want to make use of multiple processes, feel free to check out the Sanic server documentation.

  • To avoid conflicts in script parameter names, connectors in the run command now need to be specified with --connector, as -c is no longer supported. The maximum history in the rasa visualize command needs to be defined with --max-history. Output paths and log files cannot be specified with -o anymore; --out and --log-file should be used. NLU data has been standarized to be --nlu and the name of any kind of data files or directory to be --data.


  • There are numerous HTTP API endpoint changes which can be found here <http://rasa.com/docs/rasa/api/http-api/>.