MLawlz · Sep 24, 2026 · Oct 27, 2026 · Oct 27, 2026
diff --git a/.github/workflows/api-reference.yml b/.github/workflows/api-reference.yml
@@ -24,10 +24,10 @@ jobs:
     name: Build and publish to npmjs.com
     runs-on: ubuntu-latest
     steps:
-      - name: Setup Node.js 20
+      - name: Setup Node.js 24
         uses: actions/setup-node@v4
         with:
-          node-version: 20
+          node-version: 24
       - name: Checkout source code
         uses: actions/checkout@v4
       - uses: pnpm/action-setup@v3

diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
@@ -9,10 +9,10 @@ jobs:
     name: Build and publish to npmjs.com
     runs-on: ubuntu-latest
     steps:
-      - name: Setup Node.js 20
+      - name: Setup Node.js 24
         uses: actions/setup-node@v4
         with:
-          node-version: 20
+          node-version: 24
       - name: Checkout source code
         uses: actions/checkout@v4
       - name: Install pnpm

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
@@ -13,8 +13,8 @@ jobs:
       fail-fast: false
       matrix:
         node-version:
-          - "20"
-          - "18"
+          - "24"
+          - "22"
         os:
           - ubuntu-latest
           # - macos-latest

diff --git a/.github/workflows/version-bump.yml b/.github/workflows/version-bump.yml
@@ -27,7 +27,7 @@ jobs:
 
       - uses: actions/setup-node@v4
         with:
-          node-version: 20
+          node-version: 24
 
       - name: Compare version against base branch
         env:

diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Changelog
 
+## [5.0.0]
+
+- **Breaking**: Require Node.js 22 or later. `engines.node` is now `>=22` (was `>=18`), because Node.js 18 and 20 have reached end of life. There is no runtime change in this release, but installing it on Node.js 18 or 20 fails under package managers that enforce `engines` (Yarn 1, or npm and pnpm with `engine-strict`)
+
 ## [4.42.0]
 
 - Add Text-to-Speech: `client.tts.synthesize(request)` returns one text's complete audio (`TextToSpeechResponse`: `audio` plus the response headers as `requestId`, `region`, `model`, `voiceId`, `encoding`, `sampleRate`, `billedCharacters`, `audioDurationMs`, ...), `client.tts.stream(request)` returns it as the API generates it (`TextToSpeechStream`, an async iterable over a web `ReadableStream`), and `client.tts.session(params)` opens a WebSocket `TextToSpeechSession` for voice agents: `connect()`, `generate()` / `flush()` / `audio()`, `speak()`, `cancel()`, `keepAlive()`, `close()`, with `on("audio" | "flushDone" | "wordBoundaries" | "cancelled" | "termination" | "error" | "close", ...)`. Requests take the API's fields (`text`, `voice_id`, `model_id`, `language`, `sample_rate`, `encoding`, `container`, `bit_rate`); failures throw `TextToSpeechError` (`status`, `errorCode`, `param`, `requestId`, `retryable`, `retryAfter`, `errors`, `closeCode`, `body`). New client option `ttsBaseUrl` (default `https://tts.us.assemblyai.com`); `client.tts.createTemporaryToken()` mints a token for browser sessions. Text sent while `connect()` is pending is held and sent the moment the socket opens, so it need not wait for `Begin`

diff --git a/CLAUDE.md b/CLAUDE.md
@@ -465,7 +465,7 @@ Gotchas: `stream()` gives up a body that sends no audio for `readTimeout` ms (30
 - **Never expose API keys client-side** — use temporary auth tokens for browser streaming
 - **Sync timeout is a total deadline** — `transcribe()`, `transcribeLive()` and `openLive()` all default to a 180 s deadline spanning the whole request (upload plus transcription), and the sync API still caps audio at 120 s
 - **Dictation timeout is a total 300 s deadline** — `client.dictation` spans the upload, the transcription and the LLM pass in one deadline; the service caps audio at 120 s and accepts WAV or raw 16-bit PCM only
-- **Node >= 18 required**
+- **Node >= 22 required**
 - **Only runtime dependency**: ws (WebSocket library)
 - **Multi-runtime support**: Works in Node.js, Deno, Bun, Cloudflare Workers, and browsers
 

diff --git a/README.md b/README.md
@@ -67,6 +67,8 @@ pnpm add assemblyai
 bun add assemblyai
 ```
 
+On Node.js, the SDK requires version 22 or later. On Node.js 18 or 20, install version 4 instead: `npm install assemblyai@4`.
+
 Then, import the `assemblyai` module and create an AssemblyAI object with your API key:
 
 ```js

diff --git a/docs/compat.md b/docs/compat.md
@@ -5,8 +5,8 @@ such as the browser, Deno, Bun, Cloudflare Workers, etc.
 
 ## Node.js compatibility
 
-The SDK supports Node.js 18, 20, and 21.
-If you do use an older version of Node.js like version 16, you'll need to polyfill `fetch`.
+The SDK supports Node.js 22 and later.
+If you're still on Node.js 18 or 20, use version 4 of the SDK.
 
 ## Browser compatibility
 

diff --git a/package.json b/package.json
@@ -1,9 +1,9 @@
 {
   "name": "assemblyai",
-  "version": "4.42.0",
+  "version": "5.0.0",
   "description": "The AssemblyAI JavaScript SDK provides an easy-to-use interface for interacting with the AssemblyAI API, which supports async and real-time transcription and text-to-speech.",
   "engines": {
-    "node": ">=18"
+    "node": ">=22"
   },
   "exports": {
     ".": {
@@ -133,7 +133,7 @@
     "@rollup/plugin-terser": "^0.4.4",
     "@rollup/plugin-typescript": "^12.1.0",
     "@types/jest": "^29.5.13",
-    "@types/node": "^18.19.53",
+    "@types/node": "^22.20.5",
     "@types/websocket": "^1.0.10",
     "@types/ws": "^8.5.12",
     "@typescript-eslint/eslint-plugin": "^7.18.0",
-Original file line number
+Diff line change
@@ Expand Up / @@ -67,6 +67,8 @@ pnpm add assemblyai @@
     bun add assemblyai
     ```
+    On Node.js, the SDK requires version 22 or later. On Node.js 18 or 20, install version 4 instead: `npm install assemblyai@4`.
     Then, import the `assemblyai` module and create an AssemblyAI object with your API key:
     ```js
@@ Expand Down @@