Google Cloud rolls out server-side client libraries for Swift

Google Cloud has released server-side client libraries for Swift, betting the language has finally outgrown its client-side roots. The package, google-cloud-swift, targets Swift 6.2 and later and builds on SwiftNIO's asynchronous event loops, HTTP/2 multiplexing, gRPC transport and data-race-safety compiler flags.

Google's case for server-side Swift

"For years, Swift was perceived mainly as a UI language tied to Apple client devices," wrote Karl Weinmeister, director of developer relations, and software engineer Carlos O'Ryan in a Google Cloud blog post. "With Swift 6 and strict concurrency checking, it has matured into a viable systems and cloud language, pairing Rust-like data-race safety with predictable, reference-counted performance."

The two argue Swift manages to be both developer-friendly and suitable for low-level control of resources, something harder systems languages such as C++ or Rust struggle with. They cite its lightweight runtime, automatic reference counting (ARC) and expressive syntax, and they single out compile-time concurrency checking: "Data races are caught in your editor before a binary ever compiles or reaches production," they note.

Google says the libraries suit servers, containers and DevOps environments, including microservices built with Swift web frameworks such as Hummingbird or Vapor. "With google-cloud-swift, server-side Swift developers can write end-to-end cloud infrastructure with compile-time race safety, native async/await ergonomic APIs, and zero OS thread congestion," they declare.

A decade of false starts

The road to the server has been long. Apple open-sourced Swift in 2015, and developers soon began experimenting with backends. IBM made the language available on its Bluemix cloud in 2016, a server API working group was announced, and the first server-side Swift conference was announced in late 2017. The asynchronous SwiftNIO framework arrived in 2018, the same year the Swift Server Workgroup launched.

Progress stalled more than once. IBM reversed course in 2019, backing away from its Swift commitment, and Amazon's Smoke Framework for server-side Swift has seen little activity in recent years. The community kept going, and the release of Swift 6 in 2024, with data-race-safety checks, made the language more interesting for backend work.

Popularity and outlook

Adoption remains modest. Swift peaked at ninth place in the TIOBE index in January 2020 and now ranks 18th; Stack Overflow's 2025 developer survey places it 20th.

The Register notes that Swift may be more approachable than Rust or C++, but it is unclear how much that will matter as developers lean more and more on AI coding agents to write code.