# 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

### General
- 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](https://legacy-docs-v1.rasa.com/1.2.9/user-guide/command-line-interface/#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. 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](https://legacy-docs-v1.rasa.com/1.2.9/user-guide/command-line-interface/#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](https://sanic.readthedocs.io/en/latest/sanic/deploying.html#running-via-gunicorn).

- 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 standardized to be `--nlu` and the name of any kind of data files or directory to be `--data`.

### HTTP API
- There are numerous HTTP API endpoint changes which can be found [here](/content/docs/rasa/api/http-api/index.html).