diff --git a/.github/workflows/update-api-docs.yml b/.github/workflows/update-api-docs.yml
new file mode 100644
index 000000000..1c8ab4dcb
--- /dev/null
+++ b/.github/workflows/update-api-docs.yml
@@ -0,0 +1,101 @@
+name: Update API docs
+
+# Weekly (and on-demand) regeneration of the lynx-stack-derived API reference
+# docs, opened as a draft PR for review. Runs entirely in lynx-website and does
+# not touch the lynx-stack release pipeline or require cross-repo secrets.
+
+on:
+  schedule:
+    - cron: '0 18 * * 0' # Weekly, Sunday 18:00 UTC
+  workflow_dispatch:
+
+permissions: {}
+
+jobs:
+  update:
+    name: Regenerate API docs from lynx-stack
+    if: github.repository == 'lynx-family/lynx-website'
+    runs-on: ubuntu-latest
+    timeout-minutes: 40
+    # Serialize runs — both schedule and workflow_dispatch write to the same
+    # bot/update-api-docs branch, so overlapping runs would race.
+    concurrency:
+      group: ${{ github.workflow }}
+      cancel-in-progress: false
+    permissions:
+      contents: write
+      pull-requests: write
+    steps:
+      - name: Checkout lynx-website
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+        with:
+          # peter-evans/create-pull-request handles its own auth; don't leave
+          # GITHUB_TOKEN persisted in git config for later steps to reuse.
+          persist-credentials: false
+
+      - name: Checkout lynx-stack
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+        with:
+          repository: lynx-family/lynx-stack
+          ref: main
+          path: .lynx-stack
+          persist-credentials: false
+
+      - name: Setup Rust
+        # lynx-stack's build graph compiles wasm crates (e.g. react-transform,
+        # web-core). Match lynx-stack's rust-toolchain.toml (it lives in
+        # .lynx-stack/, so it isn't auto-detected from the repo root here).
+        uses: actions-rust-lang/setup-rust-toolchain@1780873c7b576612439a134613cc4cc74ce5538c # v1
+        with:
+          toolchain: '1.92.0'
+          target: wasm32-unknown-unknown,wasm32-wasip1
+          cache: false
+
+      - name: Setup PNPM
+        uses: pnpm/action-setup@fc06bc1257f339d1d5d8b3a19a8cae5388b55320 # v5
+
+      - name: Setup Node.js
+        uses: actions/setup-node@395ad3262231945c25e8478fd5baf05154b1d79f # v6
+        with:
+          # Satisfies both repos (lynx-stack engines: ^22 || ^24).
+          node-version: 24
+          cache: pnpm
+
+      - name: Install dependencies
+        run: pnpm install --frozen-lockfile
+
+      - name: Regenerate API docs
+        run: bash scripts/update-api-docs.sh .lynx-stack
+
+      - name: Validate build
+        id: build
+        continue-on-error: true
+        run: pnpm run build
+
+      - name: Create Pull Request
+        uses: peter-evans/create-pull-request@22a9089034f40e5a961c8808d113e2c98fb63676 # v7
+        with:
+          branch: bot/update-api-docs
+          delete-branch: true
+          draft: true
+          add-paths: |
+            docs/en/api
+            docs/zh/api
+          commit-message: 'docs(api): sync API reference from lynx-stack main'
+          title: 'docs(api): sync API reference from lynx-stack main'
+          body: |
+            Automated weekly regeneration of the lynx-stack-derived API docs.
+
+            **Build validation:** `${{ steps.build.outcome }}` (GITHUB_TOKEN PRs don't trigger CI, so the build is run inside this job).
+
+            Covered:
+            - `rspeedy/*` — API Extractor + API Documenter, from lynx-stack `main`.
+            - `reactlynx-testing-library`, `lynx-testing-environment` — TypeDoc.
+
+            **Reviewer checklist**
+            - [ ] Reconcile `docs/{en,zh}/api/_meta.json` sidebar nav if API members were added/removed (not automated).
+            - [ ] `docs/{en,zh}/api/react` is **not** auto-regenerated (bespoke: custom intro + projectDocuments whose sources don't ship). Update manually if its API changed.
+            - [ ] If **Build validation** above is `failure`, check the workflow run logs.
+
+            Generated by `.github/workflows/update-api-docs.yml` /
+            `scripts/update-api-docs.sh`.
diff --git a/.gitignore b/.gitignore
index 2ab6aa3dd..258a4185c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -11,6 +11,9 @@ node_modules
 dist/
 doc_build/
 
+# lynx-stack checkout used by the update-api-docs workflow
+.lynx-stack/
+
 # IDE
 .vscode/*
 !.vscode/extensions.json
diff --git a/scripts/update-api-docs.sh b/scripts/update-api-docs.sh
new file mode 100755
index 000000000..0481bedc6
--- /dev/null
+++ b/scripts/update-api-docs.sh
@@ -0,0 +1,101 @@
+#!/usr/bin/env bash
+#
+# Regenerate the lynx-stack-derived API reference docs in place, against a
+# lynx-stack checkout. Covers two pipelines:
+#
+#   1. rspeedy/*           – Microsoft API Extractor + API Documenter, run
+#                            inside the lynx-stack `website/` workspace.
+#   2. reactlynx-testing-library, lynx-testing-environment – TypeDoc, run here
+#                            in lynx-website (`pnpm run typedoc`), reading the
+#                            freshly built lynx-stack packages.
+#
+# NOT covered: docs/{en,zh}/api/react (bespoke: custom intro + projectDocuments
+# whose sources don't ship) and docs/{en,zh}/api/_meta.json (hand-curated
+# sidebar nav). Review the diff and reconcile nav when members are added/removed.
+#
+# Usage: scripts/update-api-docs.sh <path-to-lynx-stack-checkout>
+
+set -euo pipefail
+
+STACK_ARG="${1:?usage: scripts/update-api-docs.sh <lynx-stack-dir>}"
+STACK="$(cd "$STACK_ARG" && pwd)"
+WEBSITE="$(cd "$(dirname "$0")/.." && pwd)"
+
+# rspeedy-related packages mirrored under docs/api/rspeedy, with the package
+# directories that hold their api-extractor config.
+RSPEEDY_PKG_DIRS=(
+  packages/rspeedy/core
+  packages/rspeedy/plugin-react
+  packages/rspeedy/plugin-external-bundle
+  packages/rspeedy/plugin-qrcode
+  packages/rspeedy/lynx-bundle-rslib-config
+  packages/webpack/externals-loading-webpack-plugin
+)
+BUILD_FILTERS=(
+  --filter @lynx-js/rspeedy
+  --filter @lynx-js/react-rsbuild-plugin
+  --filter @lynx-js/external-bundle-rsbuild-plugin
+  --filter @lynx-js/qrcode-rsbuild-plugin
+  --filter @lynx-js/lynx-bundle-rslib-config
+  --filter @lynx-js/externals-loading-webpack-plugin
+  # Needed for the TypeDoc packages below.
+  --filter @lynx-js/react
+  --filter @lynx-js/testing-environment
+)
+
+echo "::group::Build lynx-stack packages"
+pushd "$STACK" >/dev/null
+corepack enable
+corepack pnpm install --frozen-lockfile
+corepack pnpm exec turbo run build "${BUILD_FILTERS[@]}"
+popd >/dev/null
+echo "::endgroup::"
+
+echo "::group::Generate rspeedy docs (API Extractor + API Documenter)"
+pushd "$STACK" >/dev/null
+rm -rf website/temp && mkdir -p website/temp
+for dir in "${RSPEEDY_PKG_DIRS[@]}"; do
+  (cd "$dir" && corepack pnpm run api-extractor)
+done
+(cd website && rm -rf docs/en/api docs/zh/api && corepack pnpm run docs)
+popd >/dev/null
+echo "::endgroup::"
+
+echo "::group::Sync rspeedy docs into lynx-website (preserving custom index.md)"
+for loc in en zh; do
+  gen="$STACK/website/docs/$loc/api"
+  web="$WEBSITE/docs/$loc/api/rspeedy"
+  # Drop docs whose API member no longer exists.
+  for f in "$web"/*.md; do
+    bn="$(basename "$f")"
+    [ "$bn" = "index.md" ] && continue
+    [ -f "$gen/$bn" ] || rm "$f"
+  done
+  # Copy current docs (index.md is the hand-written overview, leave it).
+  for f in "$gen"/*.md; do
+    bn="$(basename "$f")"
+    [ "$bn" = "index.md" ] && continue
+    cp "$f" "$web/$bn"
+  done
+done
+echo "::endgroup::"
+
+echo "::group::Overlay built packages into node_modules for TypeDoc"
+# TypeDoc reads node_modules. Overlay the freshly built source so the docs
+# reflect main — including the testing-library README the published
+# @lynx-js/react omits, and @lynx-js/testing-environment (unpublished).
+react_nm="$WEBSITE/node_modules/@lynx-js/react"
+te_nm="$WEBSITE/node_modules/@lynx-js/testing-environment"
+cp -R "$STACK/packages/react/types/." "$react_nm/types/"
+cp -R "$STACK/packages/react/testing-library/." "$react_nm/testing-library/"
+cp -R "$STACK/packages/testing-library/testing-environment/dist/." "$te_nm/dist/"
+cp -f "$STACK/packages/testing-library/testing-environment/README.md" "$te_nm/README.md"
+echo "::endgroup::"
+
+echo "::group::Generate TypeDoc docs"
+cd "$WEBSITE"
+pnpm run typedoc
+echo "::endgroup::"
+
+echo "API docs regenerated. Review the diff and update docs/{en,zh}/api/_meta.json"
+echo "if API members were added or removed."