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fishbowl

Build & Distribute

What you’ll build: A Rust program compiled to WASI and packaged as a fishbowl package.

Prerequisites: Custom Package →, Rust toolchain with wasm32-wasip1 target

WASI packages (Rust)

Section titled “WASI packages (Rust)”

WASI packages run inside the fishbowl filesystem and support blocking I/O. The build process requires one post-processing step.

Compile

Section titled “Compile”
target/wasm32-wasip1/release/mybin.wasm
cargo build --target wasm32-wasip1 --release

Apply asyncify:

Terminal window
pnpm --filter @fishnet/build-tools run wasi-asyncify \
  target/wasm32-wasip1/release/mybin.wasm \
  dist/mybin.wasm

Write the JS harness

Section titled “Write the JS harness”
src/index.ts
import { createWasiBin } from '@fishnet/runtime/wasm'
import type { Extension } from '@fishnet/core'


export default function myWasiPackage(): Extension {
  return {
    bins: {
      mybin: createWasiBin(import.meta.url),
      // Resolves mybin.wasm from the same directory as this file
    },
  }
}

Bundle for the registry

Section titled “Bundle for the registry”
Terminal window
pnpm --filter @fishnet/registry-tools run generate-registry

Emscripten packages (C/C++)

Section titled “Emscripten packages (C/C++)”
Terminal window
emcc myprogram.c -o dist/myprogram.js \
  -sASYNCIFY \
  "-sASYNCIFY_IMPORTS=['wasi_snapshot_preview1.fd_read','fd_read','fd_write','__asyncjs__*']" \
  -sMODULARIZE \
  -sEXPORT_ES6

Further reading

Section titled “Further reading”