Workers RPC now supports cross-language communication between Python and JavaScript

Cross-Language RPC Introduced

Workers RPC, which previously allowed communication between Workers and Durable Objects, has been updated to support cross-language interoperability between Python and JavaScript. This expansion means developers can now call methods defined in a Python Worker from a JavaScript Worker, and vice versa.

Simplified Interoperability

Traditionally, enabling different programming languages to communicate requires custom APIs or language-agnostic serialization formats like protobuf. The updated Workers RPC system handles this translation automatically, eliminating the need for additional work or dependencies to facilitate communication between Python and JavaScript components.

Functional Parity and Type Conversion

Cross-language RPC calls function similarly to standard function calls, returning promises in JavaScript/TypeScript and futures in Python. Exceptions are propagated to the call site. The system also converts Structured Cloneable types passed as parameters or return values, for example, converting a JavaScript Date object to a Python datetime object.

Configuration and Usage

To enable cross-language RPC, developers only need to configure a Service binding. This allows for the creation of complex multi-language systems where different components can interact as if they were part of a single library, simplifying development workflows within the Workers platform.