Deprecations and Removals

#4964: The endpoint /conversations/<conversation_id>/execute is now deprecated. Instead, users should use
the /conversations/<conversation_id>/trigger_intent endpoint and thus trigger intents instead of actions.
#4978: Remove option use_cls_token from tokenizers and option return_sequence from featurizers.
By default all tokenizer add a special token (__CLS__) to the end of the list of tokens.
This token will be used to capture the features of the whole utterance.
The featurizers will return a matrix of size (number-of-tokens x feature-dimension) by default.
This allows to train sequence models.
However, the feature vector of the __CLS__ token can be used to train non-sequence models.
The corresponding classifier can decide what kind of features to use.

Features

#400: Rename templates key in domain to responses.
templates key will still work for backwards compatibility but will raise a future warning.
#4902: Added a new configuration parameter, ranking_length to the EmbeddingPolicy, EmbeddingIntentClassifier,
and ResponseSelector classes.
#4964: External events and reminders now trigger intents (and entities) instead of actions.
Add new endpoint /conversations/<conversation_id>/trigger_intent, which lets the user specify an intent and a
list of entities that is injected into the conversation in place of a user message. The bot then predicts and
executes a response action.
#4978: Add ConveRTTokenizer.
The tokenizer should be used whenever the ConveRTFeaturizer is used.
Every tokenizer now supports the following configuration options:
intent_tokenization_flag: Flag to check whether to split intents (default False).
intent_split_symbol: Symbol on which intent should be split (default _)

#1988: Remove the need of specifying utter actions in the actions section explicitly if these actions are already
listed in the templates section.
#4877: Entity examples that have been extracted using an external extractor are excluded
from Markdown dumping in MarkdownWriter.dumps(). The excluded external extractors
are DucklingHTTPExtractor and SpacyEntityExtractor.
#4902: The EmbeddingPolicy, EmbeddingIntentClassifier, and ResponseSelector now by default normalize confidence
levels over the top 10 results. See migration-to-rasa-1.7{.interpreted-text role="ref"} for more details.
#4964: ReminderCancelled can now cancel multiple reminders if no name is given. It still cancels a single
reminder if the reminder's name is specified.

#4774: Requests to /model/train do not longer block other requests to the Rasa server.
#4896: Fixed default behavior of rasa test core --evaluate-model-directory when called without --model. Previously, the latest model file was used as --model. Now the default model directory is used instead.
New behavior of rasa test core --evaluate-model-directory when given an existing file as argument for --model: Previously, this led to an error. Now a warning is displayed and the directory containing the given file is used as --model.
#5040: Updated the dependency networkx from 2.3.0 to 2.4.0. The old version created incompatibilities when using pip.
There is an imcompatibility between Rasa dependecy requests 2.22.0 and the own depedency from Rasa for networkx raising errors upon pip install. There is also a bug corrected in requirements.txt which used ~= instead of ==. All of these are fixed using networkx 2.4.0.
#5057: Fixed compatibility issue with Microsoft Bot Framework Emulator if service_url lacked a trailing /.
#5092: DynamoDB tracker store decimal values will now be rounded on save. Previously values exceeding 38 digits caused an unhandled error.