diff --git a/careless/README.md b/careless/README.md
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+# careless
+
+Scaling and merging of X-ray diffraction data with approximate Bayesian
+inference (variational merging), built on TensorFlow.
+
+- Upstream: https://github.com/rs-station/careless
+- License: MIT
+
+## How it is built
+
+The build installs a private miniconda into `$PREFIX/miniconda`, creates a
+`careless_<version>` env with Python 3.12 (upstream supports >=3.9,<3.13),
+and runs `pip install careless[cuda]==<version>` inside it. The `[cuda]`
+extra pulls the NVIDIA libraries as pip wheels, so the same install works
+on GPU and CPU-only Ra nodes.
+
+Loading the module puts the env's `bin/` on `PATH` (the `careless` command
+is directly available, no `conda activate` needed) and sets `CARELESS_ENV`
+to the conda env path.
+
+## Adding a new version
+
+Add the version under `versions:` in `files/config.yaml`, then on a Ra
+login node: `./build <version>`.
diff --git a/careless/build b/careless/build
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+#!/usr/bin/env modbuild
+
+pbuild::prep() {
+    :
+}
+
+pbuild::configure() {
+    # careless is pip-installed, but upstream recommends a fresh conda env
+    # (TensorFlow dependency conflicts), so install a private miniconda in PREFIX
+    mkdir -p "$PREFIX/miniconda"
+    wget https://repo.anaconda.com/miniconda/Miniconda3-latest-Linux-x86_64.sh -O "$PREFIX/miniconda/miniconda.sh"
+    bash "$PREFIX/miniconda/miniconda.sh" -b -u -p "$PREFIX/miniconda/"
+    "$PREFIX/miniconda/condabin/conda" create -y -n "careless_$V" python=3.12
+}
+
+pbuild::compile() {
+    :
+}
+
+pbuild::install() {
+    source "$PREFIX/miniconda/etc/profile.d/conda.sh"
+    conda activate "careless_$V"
+    pip install --upgrade pip
+    # [cuda] extra ships the NVIDIA libs via pip wheels; works on CPU-only nodes too
+    pip install --no-cache-dir "careless[cuda]==${V_PKG}"
+    conda deactivate
+}
diff --git a/careless/files/config.yaml b/careless/files/config.yaml
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+++ b/careless/files/config.yaml
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+---
+format: 1
+careless:
+  defaults:
+    group: MX
+    overlay: base
+    relstage: unstable
+  versions:
+    0.5.4:
+      config:
+        relstage: unstable
diff --git a/careless/modulefile b/careless/modulefile
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+#%Module1.0
+
+module-whatis       "careless - merging crystallography data with variational inference"
+module-url          "https://github.com/rs-station/careless"
+module-license      "MIT"
+module-maintainer   "MX Data <jiaxin.duan@psi.ch>"
+
+module-help     "
+careless: scaling and merging of X-ray diffraction data using
+approximate Bayesian inference (TensorFlow). Installed with the
+[cuda] extra, so it uses NVIDIA GPUs when available and falls
+back to CPU otherwise.
+"
+
+setenv          CARELESS_ENV    $PREFIX/miniconda/envs/careless_$V
+prepend-path    PATH            $PREFIX/miniconda/envs/careless_$V/bin