fullstack-build · terehov · Sep 10, 2026 · Sep 10, 2026 · Sep 10, 2026
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
@@ -13,7 +13,7 @@ jobs:
         strategy:
             fail-fast: false
             matrix:
-                node-version: ['20', '22', '24', '26', 'latest']
+                node-version: ['22', '24', '26', 'latest']
 
         env:
             CI: true
@@ -35,18 +35,18 @@ jobs:
               run: npm run check-bundle-size
 
             # Run the full test suite on every supported Node version.
-            # Coverage + Codecov report only on the minimum supported version (20)
+            # Coverage + Codecov report only on the minimum supported version (22)
             # to avoid redundant uploads and overhead.
             - name: Run tests (with coverage)
-              if: matrix.node-version == '20'
+              if: matrix.node-version == '22'
               run: npm run coverage
 
             - name: Run tests
-              if: matrix.node-version != '20'
+              if: matrix.node-version != '22'
               run: npm test
 
             - name: Report coverage
-              if: matrix.node-version == '20'
+              if: matrix.node-version == '22'
               uses: codecov/codecov-action@v5
               with:
                   token: ${{ secrets.CODECOV_TOKEN }}

diff --git a/.nvmrc b/.nvmrc
@@ -1 +1 @@
-16
+22
diff --git a/.vscode/settings.json b/.vscode/settings.json
@@ -1,3 +1,3 @@
 {
-  "js/ts.tsdk.path": "node_modules/@typescript/native-preview"
+  "js/ts.tsdk.path": "node_modules/typescript"
 }
diff --git a/AGENTS.md b/AGENTS.md
@@ -35,7 +35,8 @@ npm run test:e2e-apps # Framework E2E: real Next.js (Turbopack) + TanStack Start
 ## Build System
 
 - **ESM-only.** There is no CJS build and no `require("tslog")` — v5 dropped dual publishing.
-- **tsgo** (`@typescript/native-preview`, the TypeScript 7 native compiler) emits the ESM output (`dist/esm/`) and the declaration files (`dist/types/`).
+- **tsc** from `typescript` 7 (the native compiler) emits the ESM output (`dist/esm/`) and the declaration files (`dist/types/`).
+- `typescript` 7 has no JS compiler API, so a second install, `typescript-6` (`npm:typescript@6`), serves the bundler-compatibility tests: ts-loader gets `compiler: "typescript-6"`, and `vitest.config.ts` aliases `typescript` → `typescript-6` for the inlined `@rollup/plugin-typescript`.
 - **esbuild** (`build.js`) bundles the browser IIFE (`dist/browser/index.js`, global `tslog`) from `src/index.browser.ts`.
 - `"type": "module"` — the project is ESM throughout.
 - `npm run build` = `clean-dist` (wipes `dist/` so stale files never ship) → `build-types` → `build-esm` → `build-browser` → `prepare-publish`.
@@ -143,7 +144,7 @@ src/
 - **master** — stable releases, CI runs on push/PR
 - **development** — active development branch
 - Pre-commit hook via **Husky v9** (`.husky/pre-commit`) runs: test → check (biome) → build
-- CI: GitHub Actions on Node 20 (coverage + browser), Bun (latest), Deno (v2.x); uploads to Codecov
+- CI: GitHub Actions on Node 22, 24, 26 and latest (coverage on 22), Playwright browsers, Bun (latest), Deno (v2.x); uploads to Codecov
 
 ## Publishing
 
@@ -154,16 +155,16 @@ src/
 
 ## Key Conventions
 
-- Node.js 20+ required (`package.json` `engines`); ES2022 target
+- Node.js 22+ required (`package.json` `engines`); ES2022 target
 - npm only (engine-strict in `.npmrc`)
 - Zero runtime dependencies
-- TypeScript 7 (tsgo) strict mode throughout; ESM-only
+- TypeScript 7 (`tsc` from `typescript` 7) strict mode throughout; ESM-only
 - Tests are numbered by feature area (e.g., `1_json_loglevel`, `5_pretty_Log_Types`)
 - Browser-specific code isolated in `index.browser.ts` and `tests/support/`
 
 ## Quality Standards
 
-- **100% test coverage** on statements, branches, functions and lines — enforced by `coverage.thresholds` in `vitest.config.ts` (`npm run coverage`, CI's Node 20 job, fails below it) — but only with meaningful tests, no padding. Vitest 4 counts the implicit `else` of every `if` as a branch and binds `/* v8 ignore next */` to a single AST node (`next N` counts are ignored; use `/* v8 ignore else */` before an `if` for a truly unreachable else path)
+- **100% test coverage** on statements, branches, functions and lines — enforced by `coverage.thresholds` in `vitest.config.ts` (`npm run coverage`, CI's Node 22 job, fails below it) — but only with meaningful tests, no padding. Vitest 4+ counts the implicit `else` of every `if` as a branch and binds `/* v8 ignore next */` to a single AST node (`next N` counts are ignored; use `/* v8 ignore else */` before an `if` for a truly unreachable else path)
 - Every new feature **must** have corresponding tests
 - Every new feature **must** be reflected in the docs (`docs/`)
 - Don't write tests just to hit coverage numbers; each test should verify real behavior

diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -5,6 +5,8 @@ All notable changes to this project are documented here. This project adheres to
 ## [5.2.0] - 2026-09-11
 
 ### Changed
+- **Node.js 22 or newer is required** — Node 20 reached end-of-life in April 2026, so `engines.node` is now `>=22` and CI no longer tests it. Stay on `tslog@5.1.0` if you still run Node 20. Nothing in the runtime code relied on dropping it; Bun, Deno and browsers are unaffected.
+- **Built with stable TypeScript 7.0** — the ESM output and declarations are emitted by `tsc` from `typescript@7` instead of the `@typescript/native-preview` dev builds.
 - **Logged errors are cloned** — with `mask` configured, an `Error` argument is replaced by a masked clone like every other argument, and that clone is what transports receive as `nativeError`. It is a real `Error` with the source's prototype (no subclass constructor runs), so `instanceof`, JSON error detection and Sentry-style transports keep working, and the caller's instance is never modified. Without `mask`, errors pass through untouched as before.
 
 ### Fixed

diff --git a/MIGRATION_v4_to_v5.md b/MIGRATION_v4_to_v5.md
@@ -74,7 +74,7 @@ You should upgrade to v5 when you want one or more of these. None of them exist
 | | v4 | v5 |
 |---|---|---|
 | Module system | ESM **and** CJS (`require` worked) | **ESM-only** — no CJS, no `require` |
-| Node.js | 16+ | **20+** |
+| Node.js | 16+ | **22+** (20+ up to 5.1) |
 | TS target | es2020 | **es2022** |
 | Runtime deps | none | none |
 
@@ -709,7 +709,7 @@ silently degrading. Develop against `tslog`, ship `tslog/slim`.
 
 ## Migration checklist
 
-- [ ] Move the app (or the file importing tslog) to **ESM**; bump Node to **20+**, TS target to **es2022**.
+- [ ] Move the app (or the file importing tslog) to **ESM**; bump Node to **22+** (20+ for tslog 5.0–5.1), TS target to **es2022**.
 - [ ] Replace `require("tslog")` with `import`.
 - [ ] Translate every flat setting key to its **grouped path** (table in §2).
 - [ ] Replace `hideLogPositionForProduction` with `stack.capture: "off"` (or drop it for `type: "json"`).

diff --git a/README.md b/README.md
@@ -82,7 +82,7 @@ Donations help me allocate more time for my open source work.
 The per-runtime details are below.
 
 > [!IMPORTANT]
-> **tslog v5 is ESM-only and requires Node.js ≥ 20.** There is no CommonJS build and no `require("tslog")`. If you cannot move to ESM or off Node 16/18 yet, stay on **`tslog@4.11.0`** — it keeps CJS, Node 16+ and the v4 JSON shape. See **[Upgrading from v4?](#upgrading-from-v4)**.
+> **tslog v5 is ESM-only and requires Node.js ≥ 22** (5.0–5.1 also ran on Node 20; stay on **`tslog@5.1.0`** if you are still on it). There is no CommonJS build and no `require("tslog")`. If you cannot move to ESM or off Node 16/18 yet, stay on **`tslog@4.11.0`** — it keeps CJS, Node 16+ and the v4 JSON shape. See **[Upgrading from v4?](#upgrading-from-v4)**.
 
 ### Node.js
 
@@ -1061,7 +1061,7 @@ Whichever logger you come from, `createTestLogger` from `tslog/testing` captures
 > [!IMPORTANT]
 > **`tslog@4.11.0` is the safe staying point.** Most of the v5 performance wins (faster lazy stack capture, transport isolation, masking fixes) were back-ported to **4.11.0 with zero breaking changes**. If you are on the 4.x line and just want the wins, `npm install tslog@4.11.0` keeps your existing settings, CJS `require`, Node 16+, and the v4 JSON shape exactly as they are. There is no deprecation pressure.
 
-Move to **v5** when you actually want its new capabilities: opt-in structured JSON output, the flat fields-first JSON shape, grouped settings, `use()` middleware, per-transport level/format, the presets, and the AI/agent DX. v5 is ESM-only and requires Node ≥ 20.
+Move to **v5** when you actually want its new capabilities: opt-in structured JSON output, the flat fields-first JSON shape, grouped settings, `use()` middleware, per-transport level/format, the presets, and the AI/agent DX. v5 is ESM-only and requires Node ≥ 22 (≥ 20 up to 5.1).
 
 👉 **Full guide: [MIGRATION_v4_to_v5.md](./MIGRATION_v4_to_v5.md)** — it maps every removed v4 setting (`stylePrettyLogs`, `prettyLogTemplate`, `maskValuesOfKeys`, `metaProperty`, `hideLogPositionForProduction`, the whole `overwrite.*` family, …) to its v5 replacement.
 

diff --git a/biome.json b/biome.json
@@ -1,5 +1,5 @@
 {
-  "$schema": "https://biomejs.dev/schemas/2.3.14/schema.json",
+  "$schema": "https://biomejs.dev/schemas/2.5.13/schema.json",
   "vcs": {
     "enabled": true,
     "clientKind": "git",
@@ -24,7 +24,7 @@
   "linter": {
     "enabled": true,
     "rules": {
-      "recommended": true
+      "preset": "recommended"
     }
   },
   "assist": {