{"type":"rich","version":"1.0","provider_name":"Transistor","provider_url":"https://transistor.fm","author_name":"WebAssembly Unleashed","title":"WASI Preview 3: Native async for WebAssembly components | WebAssembly Unleashed","html":"<iframe width=\"100%\" height=\"180\" frameborder=\"no\" scrolling=\"no\" seamless src=\"https://share.transistor.fm/e/9796189b\"></iframe>","width":"100%","height":180,"duration":2195,"description":"WASI Preview 3 is a turning point for WebAssembly outside the browser, and this episode explains why. F5's Joel Moses and Oscar Spencer are joined by Bailey Hayes, CTO of Cosmonic, to break down what “native async” really means for the component model, why it took two years to land, and how it changes the way we build polyglot, composable cloud systems.\n \nAt the center of P3 is first-class async and concurrency in the canonical ABI. That isn’t just a nicer developer experience, it’s a host-level capability: runtimes can understand who’s waiting on what across composed components, propagate async handles through the stack, and apply backpressure using standardized stream types. Bailey walks through how this shows up in practical interfaces like WASI HTTP, where response bodies become streams and service chaining becomes far more natural, without the awkward P2-era workarounds.\n \nThe conversation gets concrete on performance. Bailey shares real benchmark results showing order-of-magnitude gains when moving from serialized execution patterns to true concurrency, along with what changed mechanically from P2 to P3, including simpler interfaces, bidirectional streams, time zone support, better durations, and exit codes.\n \nThey also talk about ecosystem impact: how P3 affects different languages, what it unlocks for JavaScript via JSPI, why Go still needs cooperative threading to be truly native, and why the rise of “vibed-out” runtimes is accelerating component model adoption. Bailey closes with what’s next in WASI evolution, her thoughts on Preview 4, and what additional capabilities could meaningfully expand what developers can do, including a future WebCrypto-style interface.\n \nIf you’ve been waiting for WebAssembly to feel like a real distributed systems runtime, P3 is the milestone to understand.\nRead the WASI P3 launch blog: https://bytecodealliance.org/articles/WASI-0.3\nCheck out Bailey's work on Cosmonic.com","thumbnail_url":"https://img.transistorcdn.com/nel8t5t39fJ08i-oK5mm4uOFU61C435UuftGYakjq2U/rs:fill:0:0:1/w:400/h:400/q:60/mb:500000/aHR0cHM6Ly9pbWct/dXBsb2FkLXByb2R1/Y3Rpb24udHJhbnNp/c3Rvci5mbS85YTJk/ODUwZTdhNDNiZjQy/MDUwZGZjM2ZiN2Rk/Y2IwMy5wbmc.webp","thumbnail_width":300,"thumbnail_height":300}