diff --git a/.forgejo/workflows/size-report.yml b/.forgejo/workflows/size-report.yml
new file mode 100644
index 0000000..1bf2a41
--- /dev/null
+++ b/.forgejo/workflows/size-report.yml
@@ -0,0 +1,10 @@
+on:
+  pull_request:
+jobs:
+  report-size:
+    runs-on: nixos
+    steps:
+      - uses: "https://git.salame.cl/actions/checkout@v4"
+      - run: nix --version
+      - name: Report Size
+        run: ci-scripts/report-size.sh
diff --git a/.gitignore b/.gitignore
index 880066b..040b2e1 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,5 @@
 result
+result-*
 .direnv/
 .pre-commit-config.yaml
 # ignore vm images
diff --git a/ci-scripts/report-size.sh b/ci-scripts/report-size.sh
new file mode 100755
index 0000000..778cb55
--- /dev/null
+++ b/ci-scripts/report-size.sh
@@ -0,0 +1,40 @@
+#!/bin/sh
+
+package_size_table() {
+	packages=$(nix flake show --json 2>/dev/null | jq --raw-output '.packages."x86_64-linux" | ".#" + keys[]')
+	# we want to split the words as each of them is a different installable
+	# shellcheck disable=SC2086
+	nix build $packages
+	# shellcheck disable=SC2086
+	table=$(nix path-info --size --closure-size --human-readable \
+		$packages |
+		sed 's/^\(\S\+\)\(\s\+\)\(\S\+\)\(\s\+\)\(\S\+\)$/| \1\2| \3 | \4\5 |/')
+
+	cat <<-EOF
+		| Nix Store Path | NAR Size | Closure Size |
+		|----------------|---------:|-------------:|
+		$table
+	EOF
+}
+
+if [ "$CI" = "true" ]; then
+	echo "Logging in to $GITHUB_SERVER_URL with default token"
+	tea login add --url "$GITHUB_SERVER_URL" --token "$GITHUB_TOKEN"
+	echo "Retrieving PR index for $GITHUB_HEAD_REF"
+	pr_index=$(tea pulls -f index,head -o simple | grep "$GITHUB_HEAD_REF" | head -n1 | cut -d' ' -f 1)
+	echo "Retrieved index: $pr_index"
+	echo "Expected PR URL: $GITHUB_SERVER_URL/$GITHUB_REPOSITORY/pulls/$pr_index"
+	tea comment "$pr_index" "$(
+		cat <<-EOF
+			### NixOS Configurations sizes
+
+			TODO
+
+			### Package sizes
+
+			$(package_size_table)
+		EOF
+	)"
+else
+	package_size_table
+fi
diff --git a/flake.lock b/flake.lock
index 2b0a22c..fbf262a 100644
--- a/flake.lock
+++ b/flake.lock
@@ -212,11 +212,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1733808091,
-        "narHash": "sha256-KWwINTQelKOoQgrXftxoqxmKFZb9pLVfnRvK270nkVk=",
+        "lastModified": 1734083684,
+        "narHash": "sha256-5fNndbndxSx5d+C/D0p/VF32xDiJCJzyOqorOYW4JEo=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "a0f3e10d94359665dba45b71b4227b0aeb851f8e",
+        "rev": "314e12ba369ccdb9b352a4db26ff419f7c49fa84",
         "type": "github"
       },
       "original": {
@@ -246,11 +246,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1734103614,
-        "narHash": "sha256-H5JN0fajkKZLir/GN6QHmLsR3cW+/EIOR+W/VmwHKfI=",
+        "lastModified": 1734223742,
+        "narHash": "sha256-vp3wSbCVU/4y5W+YI6H9PSix3WD7XbcIyesmB7W0ZWo=",
         "owner": "nix-community",
         "repo": "nixvim",
-        "rev": "c181014422fa9261db06fc9b5ecbf67f42c30ec3",
+        "rev": "58d2a5ac9cc4ff987e6edb77f2b55d1dec05ce50",
         "type": "github"
       },
       "original": {