Couchbase has released version 1.4.0 of its Go SDK, introducing key features such as Transparent Compression, Client Certificate Authentication, and Multi Network Configuration Support, alongside Response Time Observability. Transparent Compression allows automatic compression and decompression of documents, improving bandwidth and transmission efficiency. Client Certificate Authentication, available for Enterprise Edition users, enhances security by using X.509 certificates for server authentication. Response Time Observability includes ThresholdLogTracer implementation for diagnosing slow operations and Orphan Response Logging for tracking responses from timed-out requests. Multi Network Configuration Support enables the SDK to connect to clusters with different internal and external network setups, while bug fixes and updates are detailed in the release notes. Users can access the latest version through "go get gopkg.in/couchbase/gocb.v1" or by cloning the repository.