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NAPI Config

The config schema of NAPI-RS.

TIP

All the fields in napi is optional.

Schema

ts
{
  napi?: {
    binaryName?: string
    targets?: string[],
    packageName?: string,
    npmClient?: string
    constEnum?: boolean
    dtsHeader?: string
    dtsHeaderFile?: string
    wasm?: {
      initialMemory?: number
      maximumMemory?: number
      browser?: {
        fs?: boolean
        asyncInit?: boolean
      }
    }
  }
}
Field Default Description
binaryName index The binary file name of generated .node file. Eg [NAME].[TRIPLE?].node becomes index.win32-x64-msvc.node
targets [] The target triples your project ships for, used for scaffolding and packaging. Setting it does not make napi build compile multiple targets — see the note below for the one thing napi build reads from it. Target triples could be found in the output of rustup target list command.
packageName undefined Override the name field in package.json. See Build#js-package-name for usage.
npmClient npm Specify a different NPM client for usage when executing NPM actions such as publishing.
constEnum false Whether to generate const enum for the generated index.d.ts file.
dtsHeader undefined Header string that prepend to the generated index.d.ts file.
dtsHeaderFile undefined File path that contains the header string that prepend to the generated index.d.ts file. If both dtsHeader and dtsHeaderFile are provided, dtsHeaderFile will be used
wasm.initialMemory 4000 (256mb) Initial memory size for the generated WebAssembly module. See WebAssembly.Memory for more details.
wasm.maximumMemory 65536 (4GiB) Maximum memory size for the generated WebAssembly module. See WebAssembly.Memory for more details.
wasm.browser.fs false Whether to enable the node:fs module polyfill for the generated WebAssembly module.
wasm.browser.asyncInit false Whether to enable the async initialization for the generated WebAssembly module.

INFO

targets drives scaffolding and packaging: napi new uses it to generate the CI matrix, napi create-npm-dirs creates one npm package per target, and napi artifacts collects the binaries built for these targets. Setting it does not make napi build compile multiple targets — napi build builds exactly one target per invocation, selected with its --target flag. The one thing napi build does read from targets is the WASI entry: it derives the .wasm binding filename from the WASI target listed there, and skips emitting the WASI binding files (<binaryName>.wasi.cjs and the related files) entirely when no WASI target is listed. The cross-compilation flags (--use-napi-cross, --cross-compile, --use-cross) have no config-file equivalent either: they can only be passed on the napi build command line.

What is target triple

See rustc/platform-support and LLVM/CrossCompilation

Targets are identified by their "target triple" which is the string to inform the compiler what kind of output that should be produced.

The triple has the general format <arch><sub>-<vendor>-<sys>-<abi>, where:

  • arch = x86_64, i386, arm, thumb, mips, etc.
  • sub = for ex. on ARM: v5, v6m, v7a, v7m, etc.
  • vendor = pc, apple, nvidia, ibm, etc.
  • sys = none, linux, win32, darwin, cuda, etc.
  • abi = eabi, gnu, android, macho, elf, etc.

Once you know which triples you ship, see Cross build for how to build each of them from your host.

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