diff --git a/.github/workflows/build-eckitlib.yml b/.github/workflows/build-eckitlib.yml
new file mode 100644
index 00000000000..02b762726a2
--- /dev/null
+++ b/.github/workflows/build-eckitlib.yml
@@ -0,0 +1,335 @@
+# SPDX-FileCopyrightText: 2026 The RISE Project
+# SPDX-License-Identifier: MIT
+---
+# Upstream builds eckitlib via a private tool (ecmwf/reusable-workflows'
+# python-wrapper-wheel.yml + the "wheelmaker" image), not a public workflow, so this
+# replays ecmwf/eckit's own python/eckitlib/buildconfig CMAKE_PARAMS and
+# post-build.sh directly. The built libraries use no Python C API, so this builds
+# one py3-none wheel instead of upstream's byte-identical cp310..cp314 matrix.
+# ENABLE_PYTHON is off: the Cython extension it adds is installed into the separate
+# `eckit` distribution's source tree, never into this wheel.
+name: Build eckitlib wheels (riscv64)
+
+on:
+  workflow_dispatch:
+    inputs:
+      version:
+        description: 'Version glob to (re)build; empty builds every version of docs/packages/eckitlib.yaml not released yet'
+        required: false
+        default: ''
+  pull_request:
+    branches: [main]
+    paths:
+      - '.github/workflows/build-eckitlib.yml'
+      - 'docs/packages/eckitlib.yaml'
+  push:
+    branches: [main]
+    paths:
+      - '.github/workflows/build-eckitlib.yml'
+      - 'docs/packages/eckitlib.yaml'
+
+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
+  ECBUILD_VERSION: '3.14.2'
+
+jobs:
+  setup:
+    uses: $/.github/workflows/_setup.yml
+    with:
+      package: eckitlib
+      version: ${{ inputs.version }}
+
+  build_wheels:
+    needs: [setup]
+    if: needs.setup.outputs.versions != '[]'
+    strategy:
+      fail-fast: false
+      matrix:
+        version: ${{ fromJSON(needs.setup.outputs.versions) }}
+    name: Build eckitlib ${{ matrix.version }} py3-none-manylinux_riscv64
+    runs-on: ubuntu-24.04-riscv
+    timeout-minutes: 720
+    env:
+      PACKAGE_VERSION: ${{ matrix.version }}
+
+    steps:
+      - name: Derive the eckit git tag from the package version
+        run: echo "ECKIT_VERSION=$(echo "$PACKAGE_VERSION" | sed -E 's/\.[0-9]+$//')" >> "$GITHUB_ENV"
+
+      - name: Checkout eckit ${{ env.ECKIT_VERSION }}
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1  # v7.0.1
+        with:
+          repository: ecmwf/eckit
+          ref: ${{ env.ECKIT_VERSION }}
+          persist-credentials: false
+
+      - name: Record the resolved commit
+        run: echo "ECKIT_COMMIT=$(git rev-parse HEAD)" >> "$GITHUB_ENV"
+
+      - name: Write the wheel packaging scripts
+        run: |
+          cat > collect_licences.py <<'PY'
+          import glob
+          import json
+          import os
+          import re
+          import shutil
+          import subprocess
+          import sys
+
+          WHEEL_DIR = sys.argv[1]
+          dist_info = glob.glob(f"{WHEEL_DIR}/*.dist-info")[0]
+          sbom = json.load(open(f"{dist_info}/sboms/auditwheel.cdx.json"))
+
+
+          def rpm(*args):
+              return subprocess.run(["rpm", *args], capture_output=True, text=True).stdout
+
+
+          def licences_of(package):
+              return [
+                  path
+                  for path in rpm("-ql", package).splitlines()
+                  if path.startswith("/usr/share/licenses/") and os.path.isfile(path)
+              ]
+
+
+          by_source = [line.split() for line in rpm("-qa", "--qf", "%{SOURCERPM} %{NAME}\n").splitlines()]
+
+          for name in sorted({c["name"] for c in sbom["components"] if c["purl"].startswith("pkg:rpm/")}):
+              source = rpm("-q", "--qf", "%{SOURCERPM}", name)
+              files = [
+                  path
+                  for sibling_source, sibling in by_source
+                  if sibling_source == source
+                  for path in licences_of(sibling)
+              ]
+              if not files:
+                  # lz4-libs is a runtime subpackage with no %license file and no installed
+                  # sibling that has one, so its source package has to be pulled in.
+                  base = re.sub(r"-[^-]+-[^-]+\.src\.rpm$", "", source)
+                  subprocess.run(["dnf", "-y", "-q", "install", base], check=True)
+                  files = licences_of(base)
+              if not files:
+                  raise SystemExit(f"no licence file found for {name}")
+              dest = f"{dist_info}/licenses/{name}"
+              os.makedirs(dest, exist_ok=True)
+              for path in files:
+                  shutil.copy(path, dest)
+          PY
+
+          cat > pack_wheel.py <<'PY'
+          import hashlib
+          import os
+          import sys
+          import zipfile
+          from base64 import urlsafe_b64encode
+
+          STAGE, OUT_DIR = sys.argv[1:3]
+
+          dist_info = next(n for n in sorted(os.listdir(STAGE)) if n.endswith(".dist-info"))
+          name, version = dist_info[: -len(".dist-info")].split("-")
+          tags = [
+              line.split(":", 1)[1].strip()
+              for line in open(os.path.join(STAGE, dist_info, "WHEEL"))
+              if line.startswith("Tag:")
+          ]
+          interpreter, abi = tags[0].split("-")[:2]
+          tag = f"{interpreter}-{abi}-{'.'.join(t.split('-', 2)[2] for t in tags)}"
+
+          os.makedirs(OUT_DIR, exist_ok=True)
+          wheel_path = os.path.join(OUT_DIR, f"{name}-{version}-{tag}.whl")
+          record_name = f"{dist_info}/RECORD"
+          records = []
+
+          with zipfile.ZipFile(wheel_path, "w", zipfile.ZIP_DEFLATED) as zf:
+              for root, _dirs, files in os.walk(STAGE):
+                  for filename in sorted(files):
+                      path = os.path.join(root, filename)
+                      arcname = os.path.relpath(path, STAGE)
+                      if arcname == record_name:
+                          continue
+                      with open(path, "rb") as f:
+                          data = f.read()
+                      info = zipfile.ZipInfo(arcname)
+                      info.external_attr = (os.stat(path).st_mode & 0xFFFF) << 16
+                      zf.writestr(info, data, zipfile.ZIP_DEFLATED)
+                      digest = urlsafe_b64encode(hashlib.sha256(data).digest()).rstrip(b"=").decode()
+                      records.append(f"{arcname},sha256={digest},{len(data)}")
+
+              zf.writestr(record_name, "\n".join(records + [f"{record_name},,"]) + "\n")
+
+          print(wheel_path)
+          PY
+
+      - name: Build eckit, then package and repair the wheel
+        run: |
+          docker run --rm \
+            -v "$(pwd)":/workspace \
+            --workdir /workspace \
+            -e PACKAGE_VERSION="$PACKAGE_VERSION" \
+            -e ECKIT_COMMIT="$ECKIT_COMMIT" \
+            -e ECBUILD_VERSION="$ECBUILD_VERSION" \
+            "$MANYLINUX_RISCV64_IMAGE" \
+            bash -c '
+              set -euo pipefail
+              dnf -y -q install libcurl-devel lz4-devel flex
+              DIST_INFO=/tmp/stage/eckitlib-$PACKAGE_VERSION.dist-info
+              mkdir -p /tmp/deps /tmp/build $DIST_INFO/licenses
+
+              curl -fsSL "https://github.com/ecmwf/ecbuild/archive/refs/tags/$ECBUILD_VERSION.tar.gz" | tar xz -C /tmp/build
+              cmake -S "/tmp/build/ecbuild-$ECBUILD_VERSION" -B /tmp/build/ecbuild-build -D CMAKE_INSTALL_PREFIX=/tmp/deps
+              cmake --build /tmp/build/ecbuild-build -j "$(nproc)"
+              cmake --install /tmp/build/ecbuild-build
+
+              cmake -S . -B /tmp/build/eckit-build \
+                -D CMAKE_BUILD_TYPE=MinSizeRel \
+                -D CMAKE_PREFIX_PATH=/tmp/deps \
+                -D CMAKE_INSTALL_PREFIX=/tmp/stage/eckitlib \
+                -D CMAKE_INSTALL_LIBDIR=lib64 \
+                -D ENABLE_MPI=0 \
+                -D ENABLE_ECKIT_GEO=1 \
+                -D ENABLE_BUILD_TOOLS=OFF \
+                -D ENABLE_AEC=0 \
+                -D ENABLE_EIGEN=0 \
+                -D ENABLE_LZ4=1 \
+                -D ENABLE_PYTHON=0
+              cmake --build /tmp/build/eckit-build -j "$(nproc)"
+              cmake --install /tmp/build/eckit-build
+
+              printf "__version__ = \"%s\"\n__commit_hash__ = \"%s\"\nfindlibs_dependencies = []\n" \
+                "$PACKAGE_VERSION" "$ECKIT_COMMIT" > /tmp/stage/eckitlib/__init__.py
+
+              cp LICENSE AUTHORS $DIST_INFO/licenses/
+              printf "eckitlib\n" > $DIST_INFO/top_level.txt
+              printf "Wheel-Version: 1.0\nGenerator: python-wheels-riscv64-port\nRoot-Is-Purelib: false\nTag: py3-none-linux_riscv64\n" > $DIST_INFO/WHEEL
+              printf "Metadata-Version: 2.4\nName: eckitlib\nVersion: %s\nSummary: Compiled eckit C++ toolkit libraries (ECMWF), no Python bindings\nHome-page: https://github.com/ecmwf/eckit\nLicense-Expression: Apache-2.0\n" \
+                "$PACKAGE_VERSION" > $DIST_INFO/METADATA
+
+              python3 pack_wheel.py /tmp/stage /tmp/unrepaired
+              auditwheel repair --plat manylinux_2_39_riscv64 -w /tmp/repaired /tmp/unrepaired/*.whl
+
+              mkdir -p /tmp/final
+              cd /tmp/final && unzip -q /tmp/repaired/*.whl && cd /workspace
+              python3 collect_licences.py /tmp/final
+              # Rocky ships only the GPLv2 text covering the lz4 CLI tools, while the
+              # bundled liblz4 is BSD-2-Clause and no RPM carries that text; upstream
+              # pre-compile.sh fetches it from the lz4 repository for the same reason.
+              LZ4_LICENSES=/tmp/final/eckitlib-$PACKAGE_VERSION.dist-info/licenses/lz4-libs
+              LZ4_VERSION=$(rpm -q --qf "%{VERSION}" lz4-libs)
+              curl -fsSL "https://raw.githubusercontent.com/lz4/lz4/v$LZ4_VERSION/LICENSE" -o "$LZ4_LICENSES/LICENSE"
+              curl -fsSL "https://raw.githubusercontent.com/lz4/lz4/v$LZ4_VERSION/lib/LICENSE" -o "$LZ4_LICENSES/lib-LICENSE"
+
+              python3 pack_wheel.py /tmp/final wheelhouse
+            '
+
+      - name: Check the wheel ships the libraries and every bundled licence
+        run: |
+          python3 - wheelhouse/*.whl <<'EOF'
+          import json, sys, zipfile
+
+          zf = zipfile.ZipFile(sys.argv[1])
+          names = zf.namelist()
+          for lib in ("libeckit.so", "libeckit_geo.so", "libeckit_sql.so", "libeckit_codec.so"):
+              assert any(n.endswith(f"lib64/{lib}") for n in names), (lib, names)
+          for licence in ("LICENSE", "AUTHORS"):
+              assert any(n.endswith(f".dist-info/licenses/{licence}") for n in names), licence
+
+          sbom = json.loads(zf.read(next(n for n in names if n.endswith("auditwheel.cdx.json"))))
+          for component in sbom["components"]:
+              if component["purl"].startswith("pkg:rpm/"):
+                  prefix = f".dist-info/licenses/{component['name']}/"
+                  assert any(prefix in n for n in names), component["name"]
+          EOF
+
+      - name: Smoke-test the built libraries
+        run: |
+          sudo apt-get update -qq
+          sudo apt-get install -y -qq --no-install-recommends python3-venv
+          python3 -m venv .venv
+          . .venv/bin/activate
+          # gotcha 234: stock Ubuntu 24.04 apt pip (24.0) has zero manylinux_*_riscv64
+          # tags, so it rejects the riscv64 wheel outright without upgrading first.
+          pip install -q --upgrade pip
+          pip install -q findlibs wheelhouse/*.whl
+          python3 -c "
+          import ctypes, glob, os
+          import eckitlib, findlibs
+
+          for lib in sorted(glob.glob(os.path.join(os.path.dirname(eckitlib.__file__), 'lib64', '*.so'))):
+              ctypes.CDLL(lib)
+              print('loaded', os.path.basename(lib))
+
+          eckit = findlibs.load('eckit')
+          for name in ('eckit_version', 'eckit_version_str', 'eckit_git_sha1'):
+              getattr(eckit, name).restype = ctypes.c_char_p
+          eckit.eckit_version_int.restype = ctypes.c_uint
+          print(eckit.eckit_version().decode(), eckit.eckit_version_int(), eckit.eckit_git_sha1().decode())
+          assert eckit.eckit_version_str().decode() == eckitlib.__version__.rsplit('.', 1)[0]
+          assert eckit.eckit_git_sha1().decode() == eckitlib.__commit_hash__
+          "
+
+      - uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a  # v7.0.1
+        with:
+          name: eckitlib-${{ matrix.version }}-py3-none-manylinux_riscv64
+          path: wheelhouse/*.whl
+          if-no-files-found: error
+
+  gpl_sources:
+    needs: [setup]
+    if: needs.setup.outputs.versions != '[]'
+    strategy:
+      fail-fast: false
+      matrix:
+        version: ${{ fromJSON(needs.setup.outputs.versions) }}
+    name: Collect GPL sources for eckitlib ${{ matrix.version }}
+    runs-on: ubuntu-24.04-riscv
+
+    env:
+      PACKAGE_VERSION: ${{ matrix.version }}
+
+    steps:
+      - name: Checkout python-wheels
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1  # v7.0.1
+        with:
+          persist-credentials: false
+
+      # The copyleft (GPL/LGPL) libraries auditwheel vendors out of the build image
+      # along libcurl's dependency closure.
+      - uses: ./actions/collect-gpl-sources
+        with:
+          image: ${{ env.MANYLINUX_RISCV64_IMAGE }}
+          packages: gcc keyutils-libs libssh libidn2 libunistring libxcrypt systemd-libs libcap pcre2
+          output: gpl-sources.tar
+
+      - uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a  # v7.0.1
+        with:
+          name: eckitlib-${{ env.PACKAGE_VERSION }}-gpl-sources
+          path: gpl-sources.tar
+          if-no-files-found: error
+
+  publish:
+    name: Publish eckitlib ${{ matrix.version }}
+    needs: [setup, build_wheels, gpl_sources]
+    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: ${{ secrets.RISEPROJECT_APP_PRIVATE_KEY }}
+    with:
+      artifact-pattern: eckitlib-${{ matrix.version }}-*-manylinux_riscv64
+      gpl-sources-artifact: eckitlib-${{ matrix.version }}-gpl-sources
+      gpl-sources-description: gcc and the copyleft libraries bundled in the wheel
diff --git a/docs/packages/eckitlib.yaml b/docs/packages/eckitlib.yaml
new file mode 100644
index 00000000000..bf25596f5dc
--- /dev/null
+++ b/docs/packages/eckitlib.yaml
@@ -0,0 +1,5 @@
+package-name: eckitlib
+source-code: https://github.com/ecmwf/eckit
+license: Apache-2.0
+versions:
+- version: 2.1.1.26