diff --git a/ccp4/README.md b/ccp4/README.md
index e69de29..7baa009 100644
--- a/ccp4/README.md
+++ b/ccp4/README.md
@@ -0,0 +1,53 @@
+# ccp4
+
+CCP4 suite (binary distribution, bundled with SHELX and ARP/wARP) for
+macromolecular crystallography. https://www.ccp4.ac.uk/
+
+- Vendor tarball install: default `prep` downloads the ~5 GB tarball
+  (cached in `$PMODULES_DISTFILESDIR`), `install` untars it into `$PREFIX`
+  and runs `BINARY.setup`.
+- Non-interactive: the CCP4 licence is pre-agreed via `.agree2ccp4v6`
+  before `BINARY.setup` runs, so the build never prompts.
+- No `shasums:`: the download link is session-gated (`sid=` expires), so
+  the checksum cannot be pinned ahead of the first fetch. After the first
+  successful build, `sha256sum` the cached tarball and add it if wanted.
+- Module version is the series (`9.0`); minor updates (9.0.xxx) come via
+  the CCP4 update manager inside the installation.
+
+## Build on Ra
+
+One-time per user: put the Pmodules build tmp and download cache on
+/das instead of /var/tmp and $HOME (the tarball alone would blow the
+home quota):
+
+```bash
+mkdir -p /das/work/p21/p21515/.cache/Pmodules/distfiles ~/.Pmodules
+cat > ~/.Pmodules/Pmodules.yaml <<'EOF'
+tmp_dir: /das/work/p21/p21515/.cache/Pmodules
+download_dir: /das/work/p21/p21515/.cache/Pmodules/distfiles
+EOF
+```
+
+Then:
+
+```bash
+module use unstable && module load modbuild/2.1.2
+cd ccp4
+modbuild build --check-mode 9.0     # yamllint the config first
+modbuild build 9.0
+```
+
+If the download fails (expired sid), fetch a fresh link from
+https://www.ccp4.ac.uk/download/ and update `files/config.yaml`, or drop a
+hand-downloaded tarball into the distfiles dir under the `name:` given in
+`files/config.yaml`.
+
+## Verify
+
+```bash
+module use MX unstable && module load ccp4/9.0
+which refmac5 ccp4i2
+echo $CCP4          # should point into /opt/psi/MX/ccp4/9.0/ccp4
+```
+
+Bundled SHELX and ARP/wARP still need their own academic registrations.
diff --git a/ccp4/build b/ccp4/build
new file mode 100755
index 0000000..f82090b
--- /dev/null
+++ b/ccp4/build
@@ -0,0 +1,27 @@
+#!/usr/bin/env modbuild
+
+# Download happens in the default prep via urls: in files/config.yaml.
+# unpacker: none because BINARY.setup patches paths relative to its final
+# location — we untar once, directly into $PREFIX, instead of unpacking
+# ~20 GB into the build tmp and copying it over.
+
+pbuild::configure() {
+    :
+}
+
+pbuild::compile() {
+    :
+}
+
+pbuild::install() {
+    cd "${PREFIX}"
+    tar -xzf "${SRC_DIR}/ccp4-${V}-shelx-arp-x86_64.tar.gz"
+    # Pre-agree the CCP4 licence so BINARY.setup skips its interactive prompt
+    # (downloading from ccp4.ac.uk already required accepting it). The printf
+    # answers any prompt a newer BINARY.setup might still ask; printf instead
+    # of `yes` because modbuild runs with pipefail and yes dies by SIGPIPE.
+    touch "${PREFIX}/.agree2ccp4v6" "${HOME}/.agree2ccp4v6"
+    printf 'y\ny\ny\n' | "./ccp4-${V_MAJOR}.${V_MINOR}/BINARY.setup"
+    # version-independent symlink so the modulefile survives 9.0.xxx updates
+    ln -sfn "ccp4-${V_MAJOR}.${V_MINOR}" ccp4
+}
diff --git a/ccp4/files/config.yaml b/ccp4/files/config.yaml
new file mode 100644
index 0000000..c2af7de
--- /dev/null
+++ b/ccp4/files/config.yaml
@@ -0,0 +1,19 @@
+---
+format: 1
+ccp4:
+  defaults:
+    group: MX
+    overlay: base
+    relstage: unstable
+    urls:
+      # sid= is session-generated on ccp4.ac.uk and expires; if the download
+      # fails, get a fresh link from https://www.ccp4.ac.uk/download/
+      # (package "CCP4 + SHELX + ARP/wARP", Linux x86_64) or pre-stage the
+      # tarball as $PMODULES_DISTFILESDIR/ccp4-<version>-shelx-arp-x86_64.tar.gz
+      - url: "https://www.ccp4.ac.uk/download/download_file.php?os=linux&pkg=ccp4-shelx-arp-x86_64&sid=09b78d1369f605f517efa393f88d2bae713ad0b6"
+        name: ccp4-${V}-shelx-arp-x86_64.tar.gz
+        unpacker: none
+  versions:
+    9.0:
+      config:
+        relstage: unstable
diff --git a/ccp4/modulefile b/ccp4/modulefile
new file mode 100644
index 0000000..4984cdc
--- /dev/null
+++ b/ccp4/modulefile
@@ -0,0 +1,19 @@
+#%Module1.0
+
+module-whatis       "CCP4: software suite for macromolecular X-ray crystallography"
+module-url          "https://www.ccp4.ac.uk/"
+module-license      "CCP4 licence; bundled SHELX and ARP/wARP need their own academic registration"
+module-maintainer   "Jiaxin Duan <jiaxin.duan@psi.ch>"
+
+module-help "
+CCP4 suite (binary distribution bundled with SHELX and ARP/wARP) for
+macromolecular crystallography: data processing, phasing, model building
+and refinement (refmac5, ccp4i2, coot, shelx, arp/warp, ...).
+
+Loading this module sources ccp4.setup-sh, which sets CCP4, CBIN,
+CCP4_SCR and PATH.
+"
+
+# build's install() leaves a version-independent 'ccp4' symlink next to
+# ccp4-<major.minor>, so this line survives 9.0.xxx updates
+puts stdout "source $PREFIX/ccp4/bin/ccp4.setup-sh;"