diff --git a/.github/workflows/build-jellyfish.yml b/.github/workflows/build-jellyfish.yml
new file mode 100644
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+++ b/.github/workflows/build-jellyfish.yml
@@ -0,0 +1,108 @@
+# SPDX-FileCopyrightText: 2026 The RISE Project
+# SPDX-License-Identifier: MIT
+---
+# This workflow is based on the `linux` job of
+# https://github.com/jamesturk/jellyfish/blob/v1.2.1/.github/workflows/CI.yml
+name: Build jellyfish wheels (riscv64)
+
+on:
+  workflow_dispatch:
+    inputs:
+      version:
+        description: 'jellyfish version to build (git tag without leading v, e.g. 1.2.1)'
+        required: true
+        default: '1.2.1'
+  pull_request:
+    paths:
+      - '.github/workflows/build-jellyfish.yml'
+
+concurrency:
+  group: ${{ github.workflow }}-${{ inputs.version || '1.2.1' }}-${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
+permissions:
+  contents: read  # to fetch code (actions/checkout)
+
+env:
+  JELLYFISH_VERSION: ${{ inputs.version || '1.2.1' }}
+  MANYLINUX_RISCV64_IMAGE: quay.io/pypa/manylinux_2_39_riscv64
+
+jobs:
+  build_wheels:
+    name: Build jellyfish ${{ inputs.version || '1.2.1' }} ${{ matrix.python }}-manylinux_riscv64
+    runs-on: ubuntu-24.04-riscv
+    timeout-minutes: 90
+    strategy:
+      fail-fast: false
+      matrix:
+        # PyO3 extension built per interpreter (upstream ships cp3x-cp3x wheels,
+        # no abi3). cp314t is excluded: upstream publishes no free-threaded wheel
+        # and the module does not declare `gil_used(false)`, so it would re-enable
+        # the GIL on import.
+        python: ["cp312", "cp313", "cp314"]
+
+    steps:
+      # PyPI records the Codeberg repository, but upstream's releases and CI live
+      # on this GitHub mirror; the v1.2.1 tree matches the released sdist.
+      - name: Checkout jellyfish ${{ env.JELLYFISH_VERSION }}
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0  # v7.0.0
+        with:
+          repository: jamesturk/jellyfish
+          ref: v${{ env.JELLYFISH_VERSION }}
+          persist-credentials: false
+
+      - name: Build wheels
+        uses: pypa/cibuildwheel@1828c10ab37f080699c7b81cea34097c684a7074  # v4.2.0
+        with:
+          output-dir: wheelhouse/
+          # musllinux is out of reach: rustup publishes rust-std but no rustc/cargo
+          # host toolchain for riscv64gc-unknown-linux-musl.
+          only: ${{ matrix.python }}-manylinux_riscv64
+        env:
+          CIBW_MANYLINUX_RISCV64_IMAGE: ${{ env.MANYLINUX_RISCV64_IMAGE }}
+          # jellyfish ships no [tool.cibuildwheel], so the Rust toolchain its
+          # maturin backend needs is installed in-container here.
+          CIBW_BEFORE_ALL_LINUX: >-
+            curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs |
+            sh -s -- -y --profile minimal
+          CIBW_ENVIRONMENT: 'PATH="$PATH:$HOME/.cargo/bin"'
+          CIBW_TEST_REQUIRES: pytest
+          # The suite opens testdata/*.csv relative to the working directory, so
+          # stage it beside tests/ at its original path.
+          CIBW_TEST_SOURCES: tests testdata
+          CIBW_TEST_COMMAND: python -m pytest tests
+
+      - name: Check the extension module made it into the wheel
+        run: |
+          python3 - wheelhouse/*.whl <<'EOF'
+          import sys, zipfile
+          for whl in sys.argv[1:]:
+              names = zipfile.ZipFile(whl).namelist()
+              assert any(n.startswith("jellyfish/_rustyfish.") and n.endswith(".so")
+                         for n in names), names
+              print(whl, "ok")
+          EOF
+
+      - uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a  # v7.0.1
+        with:
+          name: jellyfish-${{ env.JELLYFISH_VERSION }}-${{ matrix.python }}-manylinux_riscv64
+          path: wheelhouse/*.whl
+          if-no-files-found: error
+
+  publish:
+    name: Publish jellyfish ${{ inputs.version || '1.2.1' }} to GitLab
+    needs: [build_wheels]
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+      pull-requests: write
+
+    steps:
+      - name: Publish wheels and open docs PR
+        uses: riseproject-dev/python-wheels/actions/publish-wheels@main
+        with:
+          artifact-pattern: jellyfish-${{ env.JELLYFISH_VERSION }}-*-manylinux_riscv64
+          gitlab-username: ${{ vars.GITLAB_DEPLOY_USER }}
+          gitlab-token: ${{ secrets.GITLAB_DEPLOY_TOKEN }}
+          gitlab-project-id: ${{ vars.GITLAB_PROJECT_ID }}
+          gh-token: ${{ secrets.GITHUB_TOKEN }}