diff --git a/.github/workflows/docs.yml b/.github/workflows/docs.yml
new file mode 100644
index 0000000..3dec733
--- /dev/null
+++ b/.github/workflows/docs.yml
@@ -0,0 +1,52 @@
+# API reference: one DocC archive per module (the .docc catalogs under Sources/), merged into one static site and
+# published to GitHub Pages at https://mac4dstem.github.io/CuboKit/documentation/ on every tag.
+# On a pull request the site is built and uploaded as an artifact only, so a broken catalog fails before the tag.
+#
+# No swift-docc-plugin: the kit takes no package dependencies (CLAUDE.md). `xcodebuild docbuild` builds the archives
+# from the package's own schemes; `docc merge` (Xcode 16+) joins them. Needs Pages enabled with source "GitHub Actions"
+# (repository Settings > Pages). Pattern first proposed for CuboKit; the other kits copy it with their module list.
+name: Docs
+
+on:
+  push:
+    tags: ['*']
+  pull_request:
+    paths: ['Sources/**/*.docc/**', '.github/workflows/docs.yml', 'tools/build-docs.sh']
+  workflow_dispatch:
+
+permissions:
+  contents: read
+  pages: write
+  id-token: write
+
+concurrency:
+  group: docs-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  build:
+    runs-on: macos-latest
+    timeout-minutes: 60
+    steps:
+      - uses: actions/checkout@v4
+      - name: Select the newest Xcode
+        run: |
+          xcode=$(ls -d /Applications/Xcode*.app | sort -V | tail -1)
+          sudo xcode-select -s "$xcode"
+          xcodebuild -version
+      - name: Build the site
+        run: tools/build-docs.sh .docs-site /CuboKit
+      - uses: actions/upload-pages-artifact@v3
+        with:
+          path: .docs-site
+
+  deploy:
+    needs: build
+    if: startsWith(github.ref, 'refs/tags/')
+    runs-on: ubuntu-latest
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+    steps:
+      - id: deployment
+        uses: actions/deploy-pages@v4
diff --git a/.gitignore b/.gitignore
index d90c01e..0c14fcc 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,3 +4,4 @@
 .swiftpm/
 *.xcresult
 __pycache__/
+.docs-site/
diff --git a/README.md b/README.md
index f9412dc..c4dc984 100644
--- a/README.md
+++ b/README.md
@@ -158,6 +158,7 @@ swift build                         # no setup, no dependency; the Metal kernels
 swift test -c release               # the gate (tools/test.sh does the same and reports skipped real-data tests)
 tools/consumer-check/run.sh         # a separate package using the public API only
 tools/readme-consumer/run.sh    # the README's own code, compiled and run
+tools/build-docs.sh .docs-site  # the DocC site for every module (Xcode 16+); CI publishes it on a tag
 ```
 
 The tests need nothing outside the package: the synthetic pins are committed. To regenerate pins, install the reference
diff --git a/tools/build-docs.sh b/tools/build-docs.sh
new file mode 100755
index 0000000..72d2d99
--- /dev/null
+++ b/tools/build-docs.sh
@@ -0,0 +1,26 @@
+#!/bin/bash
+# Builds the DocC site for every module with a .docc catalog and merges it into one static site.
+#   tools/build-docs.sh <output-dir> [<hosting-base-path>]     e.g. tools/build-docs.sh .docs-site /CuboKit
+# macOS with Xcode 16 or later. Output is gitignored (.docs-site).
+set -euo pipefail
+cd "$(dirname "$0")/.."
+out="${1:?output dir}"
+base="${2:-}"
+derived="$(mktemp -d)"
+trap 'rm -rf "$derived"' EXIT
+
+modules=$(find Sources -maxdepth 2 -name '*.docc' -exec basename {} .docc \; | sort)
+archives=()
+for m in $modules; do
+  xcodebuild docbuild -scheme "$m" -destination 'generic/platform=macOS' -derivedDataPath "$derived" >"$derived/$m.log" 2>&1 \
+    || { tail -30 "$derived/$m.log"; echo "docbuild failed for $m"; exit 1; }
+  archives+=("$(find "$derived/Build/Products" -name "$m.doccarchive" -maxdepth 3 | head -1)")
+done
+
+merged="$derived/CuboKit.doccarchive"
+xcrun docc merge "${archives[@]}" --output-path "$merged"
+rm -rf "$out"
+xcrun docc process-archive transform-for-static-hosting "$merged" --output-path "$out" ${base:+--hosting-base-path "$base"}
+# the site root has no page of its own: send it to the merged documentation landing page
+printf '<!doctype html><meta charset="utf-8"><meta http-equiv="refresh" content="0; url=%s/documentation/">' "${base}" > "$out/index.html"
+echo "built $out ($(echo "$modules" | wc -l | tr -d ' ') modules)"