Wasmer has released Wasmer 7, an upgrade of its WebAssembly runtime that introduces an experimental async API that enables full async support in Python. The update also brings support for dynamic linking to WASIX, broadening the platform’s support for Python packages.

Introduced January 30, Wasmer 7 introduces an experimental async API that offers first-class support for async functions in Python, unlocking powerful libraries such as SQLAlchemy and other Python packages that previously could not run, Wasmer said. The async API currently is available across the Singlepass, Cranelift, and LLVM back ends.

Wasmer 7 also enables support for dynamic linking in WASIX, the platform’s extension to WASI (WebAssembly System Interface), which unlocks support for a much broader ecosystem of Python packages and native modules, Wasmer said. Support for dynamic linking in WASIX removes a situation in which Python support in Wasmer was limited to the core interpreter, with many native libraries, such as Numpy or Pydantic, remaining unsupported. Wasmer 7 removes this limitation.

Wasmer 7 also upgrades the Cranelift compiler to the latest release and adds full support for WebAssembly exceptions using Cranelift’s new exception-handling APIs. To enable this, Wasmer’s builders integrated with the standard libunwind library, filling in missing pieces as the Cranelift compiler relies on its own unwinding implementation. By doing this, Wasmer uses the same unwinding mechanism for all compilers using WebAssembly exceptions.

Also in Wasmer 7, Wasmer now displays a compilation progress bar when building a module for the first time using the more heavy-duty LLVM compiler. In addition, when building large packages such as Python or PHP, optimizations are selectively disabled for extremely large functions, resulting in significantly faster compile times. For example, Python builds drop from ~90s to ~10s.

And Wasmer 7 bolsters RISC-V support with the addition of support for Singlepass. Previous Wasmer releases have supported RISC-V through LLVM and Cranelift. Wasmer 7 also introduces the LLVM RV32gc target.