diff --git a/.github/workflows/build-vapoursynth.yml b/.github/workflows/build-vapoursynth.yml
new file mode 100644
index 000000000000..1c149d88b1e1
--- /dev/null
+++ b/.github/workflows/build-vapoursynth.yml
@@ -0,0 +1,174 @@
+# SPDX-FileCopyrightText: 2026 The RISE Project
+# SPDX-License-Identifier: MIT
+---
+# This workflow is based on the `build-wheel` job (linux_x86_64/linux_aarch64
+# legs) of https://github.com/vapoursynth/vapoursynth/blob/R81/.github/workflows/build.yml
+name: Build vapoursynth wheels (riscv64)
+
+on:
+  workflow_dispatch:
+    inputs:
+      version:
+        description: 'Version glob to (re)build; empty builds every version of docs/packages/vapoursynth.yaml not released yet'
+        required: false
+        default: ''
+  pull_request:
+    branches: [main]
+    paths:
+      - '.github/workflows/build-vapoursynth.yml'
+      - 'docs/packages/vapoursynth.yaml'
+      - 'patches/vapoursynth/**'
+  push:
+    branches: [main]
+    paths:
+      - '.github/workflows/build-vapoursynth.yml'
+      - 'docs/packages/vapoursynth.yaml'
+      - 'patches/vapoursynth/**'
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
+permissions:
+  contents: read  # to fetch code (actions/checkout)
+
+env:
+  MANYLINUX_RISCV64_IMAGE: quay.io/pypa/manylinux_2_39_riscv64
+
+jobs:
+  setup:
+    uses: $/.github/workflows/_setup.yml
+    with:
+      package: vapoursynth
+      version: ${{ inputs.version }}
+
+  # One cp312-abi3 wheel: meson-python's limited-api=true builds it once and
+  # cibuildwheel reuses+tests it on cp313/cp314 (find_compatible_wheel).
+  build_abi3:
+    needs: [setup]
+    if: needs.setup.outputs.versions != '[]'
+    name: Build vapoursynth ${{ matrix.version }} cp312-abi3-manylinux_riscv64
+    runs-on: ubuntu-24.04-riscv
+    timeout-minutes: 180
+    strategy:
+      fail-fast: false
+      matrix:
+        version: ${{ fromJSON(needs.setup.outputs.versions) }}
+
+    env:
+      VAPOURSYNTH_VERSION: ${{ matrix.version }}
+
+    steps:
+      - name: Checkout vapoursynth R${{ env.VAPOURSYNTH_VERSION }}
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1  # v7.0.1
+        with:
+          repository: vapoursynth/vapoursynth
+          ref: R${{ env.VAPOURSYNTH_VERSION }}
+          persist-credentials: false
+
+      - name: Checkout python-wheels
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1  # v7.0.1
+        with:
+          path: python-wheels
+          persist-credentials: false
+
+      # glslang, Vulkan-Headers, libp2p and zimg are meson-wrap subprojects
+      # fetched and statically linked in at build time; none of their
+      # licences are in this checkout. glslang/Vulkan-Headers pin a tag
+      # (subprojects/*.wrap); libp2p/zimg pin revision = HEAD, so their
+      # notice is staged from the default branch, same lack of pinning as
+      # upstream's own build.
+      - name: Stage the vendored subprojects' licences
+        run: |
+          set -euo pipefail
+          curl -fsSL --retry 5 "https://raw.githubusercontent.com/KhronosGroup/glslang/vulkan-sdk-1.4.357.0/LICENSE.txt" -o LICENSE.glslang
+          curl -fsSL --retry 5 "https://raw.githubusercontent.com/KhronosGroup/Vulkan-Headers/vulkan-sdk-1.4.357.0/LICENSE.md" -o LICENSE.vulkan-headers
+          curl -fsSL --retry 5 "https://raw.githubusercontent.com/sekrit-twc/libp2p/master/COPYING" -o COPYING.libp2p
+          curl -fsSL --retry 5 "https://raw.githubusercontent.com/sekrit-twc/zimg/master/COPYING" -o COPYING.zimg
+
+      - name: Apply patches
+        run: git apply python-wheels/patches/vapoursynth/${{ env.VAPOURSYNTH_VERSION }}/*.patch
+
+      - uses: pypa/cibuildwheel@1828c10ab37f080699c7b81cea34097c684a7074  # v4.2.0
+        env:
+          CIBW_ARCHS: riscv64
+          CIBW_BUILD: 'cp312-* cp313-* cp314-*'
+          CIBW_MANYLINUX_RISCV64_IMAGE: ${{ env.MANYLINUX_RISCV64_IMAGE }}
+
+      - uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a  # v7.0.1
+        with:
+          name: vapoursynth-${{ env.VAPOURSYNTH_VERSION }}-cp312-abi3-manylinux_riscv64
+          path: ./wheelhouse/*.whl
+          if-no-files-found: error
+
+  # Free-threaded wheel: upstream's own `cp3??t-*` override disables
+  # meson-python's limited-api, so cp314t needs its own per-interpreter
+  # build. Upstream's own build list names cp315t; our riscv64 image has
+  # cp314t but no cp315t (gotcha 11).
+  build_freethreaded:
+    needs: [setup]
+    if: needs.setup.outputs.versions != '[]'
+    name: Build vapoursynth ${{ matrix.version }} cp314t-manylinux_riscv64
+    runs-on: ubuntu-24.04-riscv
+    timeout-minutes: 180
+    strategy:
+      fail-fast: false
+      matrix:
+        version: ${{ fromJSON(needs.setup.outputs.versions) }}
+
+    env:
+      VAPOURSYNTH_VERSION: ${{ matrix.version }}
+
+    steps:
+      - name: Checkout vapoursynth R${{ env.VAPOURSYNTH_VERSION }}
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1  # v7.0.1
+        with:
+          repository: vapoursynth/vapoursynth
+          ref: R${{ env.VAPOURSYNTH_VERSION }}
+          persist-credentials: false
+
+      - name: Checkout python-wheels
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1  # v7.0.1
+        with:
+          path: python-wheels
+          persist-credentials: false
+
+      - name: Stage the vendored subprojects' licences
+        run: |
+          set -euo pipefail
+          curl -fsSL --retry 5 "https://raw.githubusercontent.com/KhronosGroup/glslang/vulkan-sdk-1.4.357.0/LICENSE.txt" -o LICENSE.glslang
+          curl -fsSL --retry 5 "https://raw.githubusercontent.com/KhronosGroup/Vulkan-Headers/vulkan-sdk-1.4.357.0/LICENSE.md" -o LICENSE.vulkan-headers
+          curl -fsSL --retry 5 "https://raw.githubusercontent.com/sekrit-twc/libp2p/master/COPYING" -o COPYING.libp2p
+          curl -fsSL --retry 5 "https://raw.githubusercontent.com/sekrit-twc/zimg/master/COPYING" -o COPYING.zimg
+
+      - name: Apply patches
+        run: git apply python-wheels/patches/vapoursynth/${{ env.VAPOURSYNTH_VERSION }}/*.patch
+
+      - uses: pypa/cibuildwheel@1828c10ab37f080699c7b81cea34097c684a7074  # v4.2.0
+        env:
+          CIBW_ARCHS: riscv64
+          CIBW_BUILD: 'cp314t-*'
+          CIBW_MANYLINUX_RISCV64_IMAGE: ${{ env.MANYLINUX_RISCV64_IMAGE }}
+
+      - uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a  # v7.0.1
+        with:
+          name: vapoursynth-${{ env.VAPOURSYNTH_VERSION }}-cp314t-manylinux_riscv64
+          path: ./wheelhouse/*.whl
+          if-no-files-found: error
+
+  publish:
+    name: Publish vapoursynth ${{ matrix.version }}
+    needs: [setup, build_abi3, build_freethreaded]
+    if: needs.setup.outputs.versions != '[]'
+    strategy:
+      fail-fast: false
+      matrix:
+        version: ${{ fromJSON(needs.setup.outputs.versions) }}
+    permissions:
+      contents: write
+      pull-requests: write
+    uses: $/.github/workflows/_publish-wheel.yml
+    secrets:
+      app-private-key: ${{ secrets.RISEPROJECT_APP_PRIVATE_KEY }}
+    with:
+      artifact-pattern: vapoursynth-${{ matrix.version }}-*-manylinux_riscv64
diff --git a/docs/packages/vapoursynth.yaml b/docs/packages/vapoursynth.yaml
new file mode 100644
index 000000000000..36864b3e1b59
--- /dev/null
+++ b/docs/packages/vapoursynth.yaml
@@ -0,0 +1,5 @@
+package-name: vapoursynth
+source-code: https://github.com/vapoursynth/vapoursynth
+license: LGPL-2.1-or-later
+versions:
+- version: '81'
diff --git a/patches/vapoursynth/81/0001-Ship-the-statically-embedded-subprojects-licences-in.patch b/patches/vapoursynth/81/0001-Ship-the-statically-embedded-subprojects-licences-in.patch
new file mode 100644
index 000000000000..c6aa232ff38a
--- /dev/null
+++ b/patches/vapoursynth/81/0001-Ship-the-statically-embedded-subprojects-licences-in.patch
@@ -0,0 +1,36 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Ludovic Henry <git@ludovic.dev>
+Date: Thu, 15 Oct 2026 23:54:36 +0000
+Subject: [PATCH] Ship the statically-embedded subprojects' licences in wheel
+ metadata
+
+glslang, Vulkan-Headers, libp2p and zimg are meson-wrap subprojects
+fetched and compiled in at build time (glslang "embedded statically
+and always present" per meson.build; libp2p/zimg linked into the core
+unconditionally); none of their licences are in this checkout or in
+the wheel. license-files is an explicit list here, so there is no
+default glob to extend it with - widen the list directly to add
+LICENSE.glslang, LICENSE.vulkan-headers, COPYING.libp2p and
+COPYING.zimg, staged at the project root by the workflow from each
+subproject's own release tag (pinned for glslang/Vulkan-Headers;
+libp2p/zimg's wraps pin revision = HEAD, so their notice is fetched
+from the default branch, same lack of pinning as upstream's own build).
+
+Upstream-Status: To upstream [not submitted from this automated port run]
+---
+ pyproject.toml | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/pyproject.toml b/pyproject.toml
+index 46700e2..6049406 100644
+--- a/pyproject.toml
++++ b/pyproject.toml
+@@ -8,7 +8,7 @@ description = "A frameserver for the 21st century"
+ readme = "README.md"
+ requires-python = ">=3.12"
+ license = "LGPL-2.1-or-later"
+-license-files = ["COPYING.LESSER"]
++license-files = ["COPYING.LESSER", "LICENSE.glslang", "LICENSE.vulkan-headers", "COPYING.libp2p", "COPYING.zimg"]
+ authors = [{ name = "Fredrik Mellbin", email = "fredrik.mellbin@gmail.com" }]
+ keywords = ["frameserver", "video", "audio"]
+ classifiers = [