7.4

Using a deprecated parameter is notified triggering a E_USER_DEPRECATED error (e.g. using the type parameter will generate a Specifying types in urls has been deprecated deprecation message).
When delete with an empty id an Elasticsearch\Common\Exceptions\RuntimeException\Missing404Exception exception is thrown. Previously it was a Elasticsearch\Common\Exceptions\RuntimeException\InvalidArgumentException.

7.0

Requirement of PHP 7.1 instead of 7.0 that is not supported since 1 Jan 2019. See PHP supported version for more information.
Elasticsearch 7.0 deprecated APIs that accept types, introduced new typeless APIs, and removed support for the default mapping. Read this blog post for more information.
Added type hints and return type declarations where possible #897

6.7

{type} part in indices.put_mapping API is not required anymore, see new specification here

6.0

[Search Templates]: PutTemplate endpoint has been removed (see Elasticsearch Breaking Changes), use PutScript instead.
#674 ClientBuilder::defaultLogger() method was removed. It is recommended to create the logger object manually.