napi-rs · Brooooooklyn · Mar 27, 2026 · Mar 17, 2026 · Mar 25, 2026 · Mar 25, 2026
diff --git a/cli/package.json b/cli/package.json
@@ -66,15 +66,15 @@
     "@octokit/rest": "^22.0.1",
     "clipanion": "^4.0.0-rc.4",
     "colorette": "^2.0.20",
-    "emnapi": "^1.7.1",
+    "emnapi": "^1.9.1",
     "es-toolkit": "^1.41.0",
     "js-yaml": "^4.1.0",
     "obug": "^2.0.0",
     "semver": "^7.7.3",
     "typanion": "^3.14.0"
   },
   "devDependencies": {
-    "@emnapi/runtime": "^1.7.1",
+    "@emnapi/runtime": "^1.9.1",
     "@oxc-node/core": "^0.0.35",
     "@std/toml": "npm:@jsr/std__toml@^1.0.11",
     "@types/inquirer": "^9.0.9",

diff --git a/cli/src/api/__tests__/build.spec.ts b/cli/src/api/__tests__/build.spec.ts
@@ -17,7 +17,7 @@ import { fileURLToPath } from 'node:url'
 
 import ava, { type TestFn } from 'ava'
 
-import { generateTypeDef, writeJsBinding } from '../build.js'
+import { buildProject, generateTypeDef, writeJsBinding } from '../build.js'
 import { getSystemDefaultTarget } from '../../utils/index.js'
 
 const __dirname = dirname(fileURLToPath(import.meta.url))
@@ -183,3 +183,92 @@ napi-build = { path = "${napiBuildPath}" }
   const jsContent = await readFile(jsPath, 'utf-8')
   t.regex(jsContent, /module\.exports\.sum = nativeBinding\.sum/)
 })
+
+test('should throw on emnapi version mismatch in wasm build', async (t) => {
+  const { projectDir } = t.context
+  const crateName = 'wasm_version_check'
+  const binaryName = 'wasm-version-check'
+  const packageName = 'wasm-version-check'
+  const version = '0.1.0'
+
+  const napiPath = posixJoin(repoRoot, 'crates', 'napi').replaceAll(
+    win32Sep,
+    posixSep,
+  )
+  const napiDerivePath = posixJoin(repoRoot, 'crates', 'macro').replaceAll(
+    win32Sep,
+    posixSep,
+  )
+  const napiBuildPath = posixJoin(repoRoot, 'crates', 'build').replaceAll(
+    win32Sep,
+    posixSep,
+  )
+
+  await mkdir(join(projectDir, 'src'), { recursive: true })
+
+  const cargoToml = `[package]
+name = "${crateName}"
+version = "${version}"
+edition = "2021"
+
+[lib]
+crate-type = ["cdylib"]
+
+[dependencies]
+napi = { path = "${napiPath}", features = ["noop"] }
+napi-derive = { path = "${napiDerivePath}", features = ["noop"] }
+
+[build-dependencies]
+napi-build = { path = "${napiBuildPath}" }
+`
+
+  await writeFile(join(projectDir, 'Cargo.toml'), cargoToml)
+  await writeFile(
+    join(projectDir, 'package.json'),
+    `${JSON.stringify(
+      {
+        name: packageName,
+        version,
+        napi: {
+          binaryName,
+          targets: ['wasm32-wasi-preview1-threads'],
+        },
+      },
+      null,
+      2,
+    )}\n`,
+  )
+  await writeFile(
+    join(projectDir, 'build.rs'),
+    'fn main() {\n    napi_build::setup();\n}\n',
+  )
+  await writeFile(
+    join(projectDir, 'src', 'lib.rs'),
+    'use napi_derive::napi;\n\n#[napi]\npub fn sum(a: i32, b: i32) -> i32 {\n    a + b\n}\n',
+  )
+
+  // Create fake @emnapi/core and @emnapi/runtime with mismatched versions
+  const fakeVersion = '0.0.0-fake'
+  for (const pkg of ['@emnapi/core', '@emnapi/runtime']) {
+    const pkgDir = join(projectDir, 'node_modules', pkg)
+    await mkdir(pkgDir, { recursive: true })
+    await writeFile(
+      join(pkgDir, 'package.json'),
+      JSON.stringify({ name: pkg, version: fakeVersion, main: 'index.js' }),
+    )
+    await writeFile(
+      join(pkgDir, 'index.js'),
+      `module.exports = { version: "${fakeVersion}" }`,
+    )
+  }
+
+  const error = await t.throwsAsync(() =>
+    buildProject({
+      target: 'wasm32-wasi-preview1-threads',
+      cwd: projectDir,
+    }),
+  )
+
+  t.truthy(error)
+  t.regex(error!.message, /emnapi version mismatch/)
+})
diff --git a/cli/src/api/__tests__/create-npm-dirs.spec.ts b/cli/src/api/__tests__/create-npm-dirs.spec.ts
@@ -1,12 +1,15 @@
 import { existsSync } from 'node:fs'
 import { mkdir, readFile, rm, writeFile } from 'node:fs/promises'
+import { createRequire } from 'node:module'
 import { tmpdir } from 'node:os'
 import { join } from 'node:path'
 
 import ava, { type TestFn } from 'ava'
 
 import { createNpmDirs } from '../create-npm-dirs.js'
 
+const require = createRequire(import.meta.url)
+
 const test = ava as TestFn<{
   tmpDir: string
   packageJsonPath: string
@@ -208,3 +211,32 @@ test('should handle WASM targets correctly with publishConfig', async (t) => {
   t.truthy(scopedPackageJson.browser)
   t.truthy(scopedPackageJson.dependencies)
 })
+
+test('should set @emnapi/core and @emnapi/runtime versions to match emnapi for WASM targets', async (t) => {
+  const { tmpDir, packageJsonPath } = t.context
+
+  const packageJson = {
+    name: 'test-emnapi-versions',
+    version: '1.0.0',
+    napi: {
+      binaryName: 'test-emnapi-versions',
+      targets: ['wasm32-wasi-preview1-threads'],
+    },
+  }
+
+  await writeFile(packageJsonPath, JSON.stringify(packageJson, null, 2))
+
+  await createNpmDirs({
+    cwd: tmpDir,
+    packageJsonPath: 'package.json',
+  })
+
+  const scopedDir = join(tmpDir, 'npm', 'wasm32-wasi')
+  const scopedPackageJson = JSON.parse(
+    await readFile(join(scopedDir, 'package.json'), 'utf-8'),
+  )
+
+  const emnapiVersion = require('emnapi/package.json').version
+  t.is(scopedPackageJson.dependencies['@emnapi/core'], emnapiVersion)
+  t.is(scopedPackageJson.dependencies['@emnapi/runtime'], emnapiVersion)
+})
diff --git a/cli/src/api/build.ts b/cli/src/api/build.ts
@@ -569,6 +569,19 @@ class Builder {
       'wasm32-wasi-threads',
     )
     this.envs.EMNAPI_LINK_DIR = emnapi
+    const emnapiVersion = require('emnapi/package.json').version
+    const projectRequire = createRequire(join(this.options.cwd, 'package.json'))
+    const emnapiCoreVersion = projectRequire('@emnapi/core').version
+    const emnapiRuntimeVersion = projectRequire('@emnapi/runtime').version
+
+    if (
+      emnapiVersion !== emnapiCoreVersion ||
+      emnapiVersion !== emnapiRuntimeVersion
+    ) {
+      throw new Error(
+        `emnapi version mismatch: emnapi@${emnapiVersion}, @emnapi/core@${emnapiCoreVersion}, @emnapi/runtime@${emnapiRuntimeVersion}. Please ensure all emnapi packages are the same version.`,
+      )
+    }
     const { WASI_SDK_PATH } = process.env
 
     if (WASI_SDK_PATH && existsSync(WASI_SDK_PATH)) {

diff --git a/cli/src/api/create-npm-dirs.ts b/cli/src/api/create-npm-dirs.ts
@@ -1,7 +1,10 @@
+import { createRequire } from 'node:module'
 import { join, resolve } from 'node:path'
 
 import { parse } from 'semver'
 
+const require = createRequire(import.meta.url)
+
 import {
   applyDefaultCreateNpmDirsOptions,
   type CreateNpmDirsOptions,
@@ -122,11 +125,14 @@ export async function createNpmDirs(userOptions: CreateNpmDirsOptions) {
           node: '>=14.0.0',
         }
       }
+      const emnapiVersion = require('emnapi/package.json').version
       const wasmRuntime = await fetch(
         `https://registry.npmjs.org/@napi-rs/wasm-runtime`,
       ).then((res) => res.json() as Promise<PackageMeta>)
       scopedPackageJson.dependencies = {
         '@napi-rs/wasm-runtime': `^${wasmRuntime['dist-tags'].latest}`,
+        '@emnapi/core': emnapiVersion,
+        '@emnapi/runtime': emnapiVersion,
       }
     }
 

diff --git a/examples/napi/package.json b/examples/napi/package.json
@@ -68,6 +68,7 @@
     "timeout": "10m"
   },
   "dependencies": {
-    "@emnapi/core": "^1.7.0"
+    "@emnapi/core": "1.9.1",
+    "@emnapi/runtime": "1.9.1"
   }
 }
diff --git a/wasm-runtime/package.json b/wasm-runtime/package.json
@@ -44,10 +44,12 @@
     "tslib": "^2.8.1"
   },
   "dependencies": {
-    "@emnapi/core": "^1.7.1",
-    "@emnapi/runtime": "^1.7.1",
     "@tybys/wasm-util": "^0.10.1"
   },
+  "peerDependencies": {
+    "@emnapi/core": "^1.7.1",
+    "@emnapi/runtime": "^1.7.1"
+  },
   "scripts": {
     "build": "rollup -c rollup.config.js",
     "test": "node --test"

diff --git a/yarn.lock b/yarn.lock
@@ -112,7 +112,17 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@emnapi/core@npm:^1.1.0, @emnapi/core@npm:^1.7.0, @emnapi/core@npm:^1.7.1":
+"@emnapi/core@npm:1.9.1":
+  version: 1.9.1
+  resolution: "@emnapi/core@npm:1.9.1"
+  dependencies:
+    "@emnapi/wasi-threads": "npm:1.2.0"
+    tslib: "npm:^2.4.0"
+  checksum: 10c0/00e7a99a2bc3ad908ca8272ba861a934da87dffa8797a41316c4a3b571a1e4d2743e2fa14b1a0f131fa4a3c2018ddb601cd2a8cb7f574fa940af696df3c2fe8d
+  languageName: node
+  linkType: hard
+
+"@emnapi/core@npm:^1.1.0":
   version: 1.8.1
   resolution: "@emnapi/core@npm:1.8.1"
   dependencies:
@@ -122,7 +132,16 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@emnapi/runtime@npm:^1.1.0, @emnapi/runtime@npm:^1.7.1":
+"@emnapi/runtime@npm:1.9.1, @emnapi/runtime@npm:^1.9.1":
+  version: 1.9.1
+  resolution: "@emnapi/runtime@npm:1.9.1"
+  dependencies:
+    tslib: "npm:^2.4.0"
+  checksum: 10c0/750edca117e0363ab2de10622f8ee60e57d8690c2f29c49704813da5cd627c641798d7f3cb0d953c62fdc71688e02e333ddbf2c1204f38b47e3e40657332a6f5
+  languageName: node
+  linkType: hard
+
+"@emnapi/runtime@npm:^1.1.0":
   version: 1.8.1
   resolution: "@emnapi/runtime@npm:1.8.1"
   dependencies:
@@ -140,6 +159,15 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@emnapi/wasi-threads@npm:1.2.0":
+  version: 1.2.0
+  resolution: "@emnapi/wasi-threads@npm:1.2.0"
+  dependencies:
+    tslib: "npm:^2.4.0"
+  checksum: 10c0/1e3724b5814b06c14782fda87eee9b9aa68af01576c81ffeaefdf621ddb74386e419d5b3b1027b6a8172397729d95a92f814fc4b8d3c224376428faa07a6a01a
+  languageName: node
+  linkType: hard
+
 "@epic-web/invariant@npm:^1.0.0":
   version: 1.0.0
   resolution: "@epic-web/invariant@npm:1.0.0"
@@ -343,7 +371,8 @@ __metadata:
   version: 0.0.0-use.local
   resolution: "@examples/napi@workspace:examples/napi"
   dependencies:
-    "@emnapi/core": "npm:^1.7.0"
+    "@emnapi/core": "npm:1.9.1"
+    "@emnapi/runtime": "npm:1.9.1"
     "@napi-rs/cli": "workspace:*"
     "@napi-rs/triples": "workspace:*"
     "@napi-rs/wasm-runtime": "workspace:*"
@@ -1364,7 +1393,7 @@ __metadata:
   version: 0.0.0-use.local
   resolution: "@napi-rs/cli@workspace:cli"
   dependencies:
-    "@emnapi/runtime": "npm:^1.7.1"
+    "@emnapi/runtime": "npm:^1.9.1"
     "@inquirer/prompts": "npm:^8.0.0"
     "@napi-rs/cross-toolchain": "npm:^1.0.3"
     "@napi-rs/wasm-tools": "npm:^1.0.1"
@@ -1378,7 +1407,7 @@ __metadata:
     ava: "npm:^7.0.0"
     clipanion: "npm:^4.0.0-rc.4"
     colorette: "npm:^2.0.20"
-    emnapi: "npm:^1.7.1"
+    emnapi: "npm:^1.9.1"
     empathic: "npm:^2.0.0"
     env-paths: "npm:^4.0.0"
     es-toolkit: "npm:^1.41.0"
@@ -1823,8 +1852,6 @@ __metadata:
   version: 0.0.0-use.local
   resolution: "@napi-rs/wasm-runtime@workspace:wasm-runtime"
   dependencies:
-    "@emnapi/core": "npm:^1.7.1"
-    "@emnapi/runtime": "npm:^1.7.1"
     "@rollup/plugin-alias": "npm:^6.0.0"
     "@rollup/plugin-commonjs": "npm:^29.0.0"
     "@rollup/plugin-inject": "npm:^5.0.5"
@@ -1842,6 +1869,9 @@ __metadata:
     rollup: "npm:^4.53.1"
     rollup-plugin-polyfill-node: "npm:^0.13.0"
     tslib: "npm:^2.8.1"
+  peerDependencies:
+    "@emnapi/core": ^1.7.1
+    "@emnapi/runtime": ^1.7.1
   languageName: unknown
   linkType: soft
 
@@ -6766,15 +6796,15 @@ __metadata:
   languageName: node
   linkType: hard
 
-"emnapi@npm:^1.7.1":
-  version: 1.8.1
-  resolution: "emnapi@npm:1.8.1"
+"emnapi@npm:^1.9.1":
+  version: 1.9.1
+  resolution: "emnapi@npm:1.9.1"
   peerDependencies:
     node-addon-api: ">= 6.1.0"
   peerDependenciesMeta:
     node-addon-api:
       optional: true
-  checksum: 10c0/a95b167083ee485a84a06202b693f9588bc32080dba82b5752bf805959e97005db1e0cb82ebfe9f35129858b7325f7161c63e97dc78e756a8d6a61443eca79bc
+  checksum: 10c0/d2dfc4f7ab1999a77147a924776e8d4d852776a2d246a88a1aff2090774c43d087ab1045ec83e22b999acd4bbef80298c519b0705938384945f4842a1df38f40
   languageName: node
   linkType: hard