diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
new file mode 100644
index 0000000..8cc419b
--- /dev/null
+++ b/.github/workflows/test.yml
@@ -0,0 +1,21 @@
+name: test
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 22
+      - run: npm install
+      - run: npm run test:all
+      # the built artifacts are committed (the demo pages load them) — fail if a
+      # change to src/ or tools/ was pushed without rebuilding dist/
+      - run: npm run build
+      - run: git diff --exit-code -- dist
diff --git a/README.md b/README.md
index 5d2811d..98519f2 100644
--- a/README.md
+++ b/README.md
@@ -290,7 +290,7 @@ each facet derives its own normal so the shading is flat.
 
 ## Minified build
 
-`dist/tinywebgpu.min.js` — **15.7 KB** (7.7 KB gzipped), versus 91 KB for the source. Rebuild it with
+`dist/tinywebgpu.min.js` — **15.5 KB** (7.4 KB gzipped), versus 91 KB for the source. Rebuild it with
 `npm run build:min` (esbuild is the only dev dependency; consumers still install nothing).
 
 It is a **production artifact and it is silent**: every `console` warning is stripped, and so are
@@ -306,10 +306,10 @@ accident.
 ## Tiny build (inline / on-chain embedding)
 
 When the library has to be *inlined* — a single self-contained HTML file, an on-chain generative
-artwork with a hard byte budget — 15.7 KB of it is still mostly features you are not using. A
+artwork with a hard byte budget — 15.5 KB of it is still mostly features you are not using. A
 procedural piece renders from a shader and never touches image loading, readback, or PNG export.
 
-`npm run build:tiny` produces **`dist/tinywebgpu.tiny.js` — 8.8 KB** (4.6 KB gzipped) by dropping
+`npm run build:tiny` produces **`dist/tinywebgpu.tiny.js` — 8.5 KB** (4.5 KB gzipped) by dropping
 every optional entry point, and adding `--iife --no-banner` gets a classic
 `<script>` that assigns `globalThis.WEBGPU` for the same size. Two of the dropped switches trade
 *behavior* rather than entry points, so know what you are giving up:
@@ -352,7 +352,7 @@ node tools/build-min.mjs tiny --iife --no-banner --out=twg.js
 node tools/build-min.mjs --config=my.config.mjs           a config of your own
 ```
 
-What each switch is worth, measured against the 15.7 KB build:
+What each switch is worth, measured against the 15.5 KB build:
 
 | `--without=` | Removes | Saves |
 |---|---|---|
diff --git a/docs/API.md b/docs/API.md
index 6870690..791bd87 100644
--- a/docs/API.md
+++ b/docs/API.md
@@ -339,8 +339,8 @@ the longer spellings above.
 | File | Size | What it is |
 |---|---|---|
 | `src/tinywebgpu.js` | 91 KB | the source, with comments and every diagnostic. `main`/`exports` point here. |
-| `dist/tinywebgpu.min.js` | 15.7 KB (7.7 gz) | `npm run build:min`. Silent: no console output, no compile-error window, no resource validator, no debug labels. Errors still throw with their messages. |
-| `dist/tinywebgpu.tiny.js` | 8.8 KB (4.6 gz) | `npm run build:tiny`. The above, plus every optional entry point removed and error text folded to numbers. For inlining into a single file. |
+| `dist/tinywebgpu.min.js` | 15.5 KB (7.4 gz) | `npm run build:min`. Silent: no console output, no compile-error window, no resource validator, no debug labels. Errors still throw with their messages. |
+| `dist/tinywebgpu.tiny.js` | 8.5 KB (4.5 gz) | `npm run build:tiny`. The above, plus every optional entry point removed and error text folded to numbers. For inlining into a single file. |
 
 `build:tiny` drops `writeTexture`, `loadTexture`, `readTexture`, buffer `.r()`, `save`, `show`,
 the ping-pong helpers, `resizeCanvas`, depth support, mipmaps, the staging ring (in-frame writes become plain queue writes — last value per frame wins), the long aliases, and the named blend presets. Tiny builds also pack repeated WebGPU member names into a string table (`--no-pack` to skip). Keep any of them with