diff --git a/.editorconfig b/.editorconfig
new file mode 100644
index 0000000..74d64a5
--- /dev/null
+++ b/.editorconfig
@@ -0,0 +1,8 @@
+[*]
+end_of_line = lf
+charset = utf-8
+
+[*.{nix,json,sh}]
+indent_style = space
+indent_size = 2
+trim_trailing_whitespace = true
diff --git a/.forgejo/workflows/check.yml b/.forgejo/workflows/check.yml
new file mode 100644
index 0000000..9e2a6ce
--- /dev/null
+++ b/.forgejo/workflows/check.yml
@@ -0,0 +1,41 @@
+on:
+  push:
+jobs:
+  check:
+    runs-on: nixos
+    strategy:
+      matrix:
+        check:
+          - treefmt
+    steps:
+      - uses: "https://git.salame.cl/actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683" # v4
+      - name: Run checks
+        run: |
+          nix --version
+          # shellcheck disable=SC2016
+          nix build --print-build-logs '.#checks.x86_64-linux.${{ matrix.check }}'
+  check-renovaterc:
+    runs-on: nixos
+    steps:
+      - uses: "https://git.salame.cl/actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683" # v4
+      - name: Validate renovaterc.json
+        run: |
+          nix --version
+          nix shell nixpkgs#renovate --command renovate-config-validator
+  report-size:
+    runs-on: nixos
+    needs: check
+    steps:
+      - uses: "https://git.salame.cl/actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683" # v4
+      - run: nix --version
+      - name: Create Size Report
+        uses: ./action.yml
+        with:
+          # Create a comment on the associated PR
+          comment-on-pr: ${{ github.ref_name != 'main' }}
+          # Generate artifacts on main (to speed up comparisons)
+          generate-artifact: ${{ github.ref_name == 'main' }}
+          # Generate comparisons to main
+          do-comparison: 'true'
+          # This job's name (so we can find the artifacts)
+          job-name: report-size
diff --git a/README.md b/README.md
index 7e50c4a..d3bceb9 100644
--- a/README.md
+++ b/README.md
@@ -51,6 +51,7 @@ For more details see the [action.yaml](./action.yml) file.
   - Reduce the `NAR Size` by reducing the size of the build outputs, e.g. don't copy unnecessary data to the $out dir, optimize binaries for size, etc.
   - Reduce the `Size` by reducing the dependencies (e.g. `buildInputs`).
   - Don't worry too much about size, some dependencies are deduplicated, e.g. `glibc` adds ~40MiB to the `Size`, but is generally shared by ~every binary on the system, so, chances are, you are already including it from somewhere else and statically linking with e.g. `musl` is not gonna improve things.
+
 # NixOS Configurations
 
 | Name | Size | Size Change | NAR Size | NAR Size Change |
diff --git a/comment_on_pr.sh b/comment_on_pr.sh
index e3feb0a..e7a7487 100755
--- a/comment_on_pr.sh
+++ b/comment_on_pr.sh
@@ -11,34 +11,34 @@ util_path="${GITHUB_ACTION_PATH:-.}/utils.sh"
 #
 # JSON_FILE can be piped from stdin
 json_to_md_rows() {
-	jq --raw-output \
-		".$1[]"' | "| `\(.name)` | \(.size) | \(.narSize) |"' "$2" |
-		numfmt --suffix=B --to=iec-i --field=4,6
+  jq --raw-output \
+    ".$1[]"' | "| `\(.name)` | \(.size) | \(.narSize) |"' "$2" |
+    numfmt --suffix=B --to=iec-i --field=4,6
 }
 
 # USAGE: json_to_md_rows <FIELD> [JSON_FILE]
 #
 # JSON_FILE can be piped from stdin
 json_to_md_rows_and_change() {
-	jq --raw-output \
-		".$1[]"' | "| `\(.name)` | \(.size) | \(.sizeChange) | \(.narSize) | \(.narSizeChange) |"' |
-		numfmt --suffix=B --to=iec-i --field=4,6,8,10
+  jq --raw-output \
+    ".$1[]"' | "| `\(.name)` | \(.size) | \(.sizeChange) | \(.narSize) | \(.narSizeChange) |"' |
+    numfmt --suffix=B --to=iec-i --field=4,6,8,10
 }
 
 # USAGE: has_elements <FIELD> <JSON_FILE>
 has_elements() {
-	if [ "${2+set}" = 'set' ]; then
-		[ "$(jq ".$1 != []" "$2")" = 'true' ]
-	else
-		[ "$(jq ".$1 != []")" = 'true' ]
-	fi
+  if [ "${2+set}" = 'set' ]; then
+    [ "$(jq ".$1 != []" "$2")" = 'true' ]
+  else
+    [ "$(jq ".$1 != []")" = 'true' ]
+  fi
 }
 
 # USAGE: markdown_from_report <REPORT> [BASE_REPORT]
 #
 # If BASE_REPORT is provided, a comparison will be made
 markdown_from_report() {
-	cat <<-"EOF"
+  cat <<-"EOF"
 		<!-- AUTOGENERATED by nix-flake-outputs-size action -->
 
 		# Flake output sizes
@@ -49,12 +49,12 @@ markdown_from_report() {
 		- `Size`: the closure size (size on disk/NAR size + all transitive dependencies).
 		- `NAR Size`: the size of the build output (package without the dependencies).
 	EOF
-	if [ "${2+set}" = "set" ]; then
-		cat <<-"EOF"
+  if [ "${2+set}" = "set" ]; then
+    cat <<-"EOF"
 			- `[NAR] Size Change`: the amount changed compared to the main branch.
 		EOF
-	fi
-	cat <<-"EOF"
+  fi
+  cat <<-"EOF"
 
 		**Tips on reading this data:**
 
@@ -66,62 +66,62 @@ markdown_from_report() {
 		  - Don't worry too much about size, some dependencies are deduplicated, e.g. `glibc` adds ~40MiB to the `Size`, but is generally shared by ~every binary on the system, so, chances are, you are already including it from somewhere else and statically linking with e.g. `musl` is not gonna improve things.
 	EOF
 
-	if [ "${2+set}" = "set" ]; then
-		compare=$(jq --slurp --from-file "${GITHUB_ACTION_PATH:-.}/compare.jq" "$1" "$2")
-		if echo "$compare" | has_elements 'nixosConfigurations'; then
-			cat <<-"EOF"
+  if [ "${2+set}" = "set" ]; then
+    compare=$(jq --slurp --from-file "${GITHUB_ACTION_PATH:-.}/compare.jq" "$1" "$2")
+    if echo "$compare" | has_elements 'nixosConfigurations'; then
+      cat <<-"EOF"
 				# NixOS Configurations
 
 				| Name | Size | Size Change | NAR Size | NAR Size Change |
 				|------|-----:|------------:|---------:|----------------:|
 			EOF
-			echo "$compare" | json_to_md_rows_and_change "nixosConfigurations"
-			echo
-		fi
-		if echo "$compare" | has_elements 'packages'; then
-			cat <<-"EOF"
+      echo "$compare" | json_to_md_rows_and_change "nixosConfigurations"
+      echo
+    fi
+    if echo "$compare" | has_elements 'packages'; then
+      cat <<-"EOF"
 				# Packages
 
 				| Name | Size | Size Change | NAR Size | NAR Size Change |
 				|------|-----:|------------:|---------:|----------------:|
 			EOF
-			echo "$compare" | json_to_md_rows_and_change "packages"
-			echo
-		fi
-	else
-		if has_elements 'nixosConfigurations' "$1"; then
-			cat <<-"EOF"
+      echo "$compare" | json_to_md_rows_and_change "packages"
+      echo
+    fi
+  else
+    if has_elements 'nixosConfigurations' "$1"; then
+      cat <<-"EOF"
 				# NixOS Configurations
 
 				| Name | Size | NAR Size |
 				|------|-----:|---------:|
 			EOF
-			json_to_md_rows "nixosConfigurations" "$1"
-			echo
-		fi
-		if has_elements 'packages' "$1"; then
-			cat <<-"EOF"
+      json_to_md_rows "nixosConfigurations" "$1"
+      echo
+    fi
+    if has_elements 'packages' "$1"; then
+      cat <<-"EOF"
 				# Packages
 
 				| Name | Size | NAR Size |
 				|------|-----:|---------:|
 			EOF
-			json_to_md_rows "packages" "$1"
-			echo
-		fi
-	fi
+      json_to_md_rows "packages" "$1"
+      echo
+    fi
+  fi
 }
 
 # Test outside CI
 if [ "${CI:-false}" != 'true' ]; then
-	markdown_from_report "$@"
-	exit 0
+  markdown_from_report "$@"
+  exit 0
 fi
 
 # Protect against running before a PR is made or if it is triggered on the main branch
 if [ -z "$PR_ID" ]; then
-	warn "No PR created for this commit"
-	exit 0
+  warn "No PR created for this commit"
+  exit 0
 fi
 
 log 'Generating comment body'
@@ -137,19 +137,19 @@ log "$data"
 endgroup
 
 if [ -z "$COMMENT_ID" ]; then
-	log 'Posting new comment'
-	curl -o - -X 'POST' \
-		"$GITHUB_API_URL/repos/$GITHUB_REPOSITORY/issues/$PR_ID/comments" \
-		-H 'accept: application/json' \
-		-H "Authorization: token $GITHUB_TOKEN" \
-		-H 'Content-Type: application/json' \
-		-d "$data"
+  log 'Posting new comment'
+  curl -o - -X 'POST' \
+    "$GITHUB_API_URL/repos/$GITHUB_REPOSITORY/issues/$PR_ID/comments" \
+    -H 'accept: application/json' \
+    -H "Authorization: token $GITHUB_TOKEN" \
+    -H 'Content-Type: application/json' \
+    -d "$data"
 else
-	log "Editing comment $COMMENT_ID"
-	curl -o - -X 'PATCH' \
-		"$GITHUB_API_URL/repos/$GITHUB_REPOSITORY/issues/$PR_ID/comments/$COMMENT_ID" \
-		-H 'accept: application/json' \
-		-H "Authorization: token $GITHUB_TOKEN" \
-		-H 'Content-Type: application/json' \
-		-d "$data"
+  log "Editing comment $COMMENT_ID"
+  curl -o - -X 'PATCH' \
+    "$GITHUB_API_URL/repos/$GITHUB_REPOSITORY/issues/$PR_ID/comments/$COMMENT_ID" \
+    -H 'accept: application/json' \
+    -H "Authorization: token $GITHUB_TOKEN" \
+    -H 'Content-Type: application/json' \
+    -d "$data"
 fi
diff --git a/create-report.sh b/create-report.sh
index 1a8a15d..bd478aa 100755
--- a/create-report.sh
+++ b/create-report.sh
@@ -13,7 +13,7 @@ endgroup
 
 group 'Show Packages'
 packages=$(
-	jq --raw-output '.packages."x86_64-linux" | select(. != null) | keys[]' <<-EOF
+  jq --raw-output '.packages."x86_64-linux" | select(. != null) | keys[]' <<-EOF
 		$flake_info
 	EOF
 )
@@ -22,7 +22,7 @@ endgroup
 
 group 'Show NixOS Configurations'
 configurations=$(
-	jq --raw-output '.nixosConfigurations | select(. != null) | keys[]' <<-EOF
+  jq --raw-output '.nixosConfigurations | select(. != null) | keys[]' <<-EOF
 		$flake_info
 	EOF
 )
@@ -30,34 +30,34 @@ log "$configurations"
 endgroup
 
 pkgs_json() {
-	group 'Building packages'
-	trap endgroup RETURN 
-	for package in $packages; do
-		log "Building $package"
-		path=$(nix build --print-out-paths ".#$package")
-		log "Calculating size of $package"
-		nix path-info --closure-size --json "$path" |
-			jq --compact-output --arg pkg "$package" '.[] | {"name": $pkg, "size": .closureSize, "narSize": .narSize}'
-	done
-	endgroup
+  group 'Building packages'
+  trap endgroup RETURN
+  for package in $packages; do
+    log "Building $package"
+    path=$(nix build --print-out-paths ".#$package")
+    log "Calculating size of $package"
+    nix path-info --closure-size --json "$path" |
+      jq --compact-output --arg pkg "$package" '.[] | {"name": $pkg, "size": .closureSize, "narSize": .narSize}'
+  done
+  endgroup
 }
 
 configs_json() {
-	group 'Building NixOS configurations'
-	trap endgroup RETURN 
-	for config in $configurations; do
-		log "Building $config"
-		path=$(nix build --print-out-paths ".#nixosConfigurations.$config.config.system.build.toplevel")
-		log "Calculating size of $config"
-		nix path-info --closure-size --json "$path" |
-			jq --compact-output --arg pkg "$config" '.[] | {"name": $pkg, "size": .closureSize, "narSize": .narSize}'
-	done
+  group 'Building NixOS configurations'
+  trap endgroup RETURN
+  for config in $configurations; do
+    log "Building $config"
+    path=$(nix build --print-out-paths ".#nixosConfigurations.$config.config.system.build.toplevel")
+    log "Calculating size of $config"
+    nix path-info --closure-size --json "$path" |
+      jq --compact-output --arg pkg "$config" '.[] | {"name": $pkg, "size": .closureSize, "narSize": .narSize}'
+  done
 }
 
 pkgs=$(pkgs_json | jq --slurp '.')
 configs=$(configs_json | jq --slurp '.')
 
 echo "{}" | jq \
-	--argjson pkgs "$pkgs" \
-	--argjson configs "$configs" \
-	'{"packages": $pkgs, "nixosConfigurations": $configs}'
+  --argjson pkgs "$pkgs" \
+  --argjson configs "$configs" \
+  '{"packages": $pkgs, "nixosConfigurations": $configs}'
diff --git a/flake.lock b/flake.lock
new file mode 100644
index 0000000..7e05325
--- /dev/null
+++ b/flake.lock
@@ -0,0 +1,98 @@
+{
+  "nodes": {
+    "flake-parts": {
+      "inputs": {
+        "nixpkgs-lib": "nixpkgs-lib"
+      },
+      "locked": {
+        "lastModified": 1741352980,
+        "narHash": "sha256-+u2UunDA4Cl5Fci3m7S643HzKmIDAe+fiXrLqYsR2fs=",
+        "owner": "hercules-ci",
+        "repo": "flake-parts",
+        "rev": "f4330d22f1c5d2ba72d3d22df5597d123fdb60a9",
+        "type": "github"
+      },
+      "original": {
+        "owner": "hercules-ci",
+        "repo": "flake-parts",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1741513245,
+        "narHash": "sha256-7rTAMNTY1xoBwz0h7ZMtEcd8LELk9R5TzBPoHuhNSCk=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "e3e32b642a31e6714ec1b712de8c91a3352ce7e1",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "nixpkgs-lib": {
+      "locked": {
+        "lastModified": 1740877520,
+        "narHash": "sha256-oiwv/ZK/2FhGxrCkQkB83i7GnWXPPLzoqFHpDD3uYpk=",
+        "owner": "nix-community",
+        "repo": "nixpkgs.lib",
+        "rev": "147dee35aab2193b174e4c0868bd80ead5ce755c",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-community",
+        "repo": "nixpkgs.lib",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "flake-parts": "flake-parts",
+        "nixpkgs": "nixpkgs",
+        "systems": "systems",
+        "treefmt-nix": "treefmt-nix"
+      }
+    },
+    "systems": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    },
+    "treefmt-nix": {
+      "inputs": {
+        "nixpkgs": [
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1739829690,
+        "narHash": "sha256-mL1szCeIsjh6Khn3nH2cYtwO5YXG6gBiTw1A30iGeDU=",
+        "owner": "numtide",
+        "repo": "treefmt-nix",
+        "rev": "3d0579f5cc93436052d94b73925b48973a104204",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "treefmt-nix",
+        "type": "github"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/flake.nix b/flake.nix
new file mode 100644
index 0000000..46e3e7b
--- /dev/null
+++ b/flake.nix
@@ -0,0 +1,43 @@
+{
+  description = "Description for the project";
+
+  inputs = {
+    flake-parts.url = "github:hercules-ci/flake-parts";
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+    treefmt-nix = {
+      url = "github:numtide/treefmt-nix";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+    systems.url = "github:nix-systems/default";
+  };
+
+  outputs =
+    inputs@{ flake-parts, ... }:
+    flake-parts.lib.mkFlake { inherit inputs; } {
+      imports = [ inputs.treefmt-nix.flakeModule ];
+      systems = import inputs.systems;
+
+      perSystem =
+        { pkgs, ... }:
+        {
+          # Export pkgs.hello so we can test this action
+          packages = { inherit (pkgs) hello; };
+
+          # Setup formatters
+          treefmt = {
+            # Ignore images
+            settings.global.excludes = [ "*.png" ];
+            projectRootFile = "flake.nix";
+            programs = {
+              mdformat.enable = true;
+              nixfmt.enable = true;
+              shfmt.enable = true;
+              shellcheck.enable = true;
+              statix.enable = true;
+              typos.enable = true;
+              yamlfmt.enable = true;
+            };
+          };
+        };
+    };
+}
diff --git a/retrieve-old-report.sh b/retrieve-old-report.sh
index 0d748b1..e7c8de6 100755
--- a/retrieve-old-report.sh
+++ b/retrieve-old-report.sh
@@ -3,59 +3,59 @@
 . "${GITHUB_ACTION_PATH}/utils.sh"
 
 repo_info() {
-	curl -X GET \
-		-H "Authorization: token $GITHUB_TOKEN" \
-		-H 'accept: application/json' \
-		"$GITHUB_API_URL/repos/$GITHUB_REPOSITORY"
+  curl -X GET \
+    -H "Authorization: token $GITHUB_TOKEN" \
+    -H 'accept: application/json' \
+    "$GITHUB_API_URL/repos/$GITHUB_REPOSITORY"
 }
 
 in_private_repo() {
-	test "$(repo_info | jq --raw-output '.private')" = 'true'
+  test "$(repo_info | jq --raw-output '.private')" = 'true'
 }
 
 default_branch() {
-	repo_info | jq --raw-output '.default_branch'
+  repo_info | jq --raw-output '.default_branch'
 }
 
 # USAGE: base_report_url <BASE_BRANCH>
 base_report_url() {
-	curl -X 'GET' \
-		"$GITHUB_API_URL/repos/$GITHUB_REPOSITORY/actions/tasks" \
-		-H "Authorization: token $GITHUB_TOKEN" \
-		-H 'accept: application/json' |
-		jq --raw-output \
-			--arg name "$JOB_NAME" \
-			--arg head_branch "$1" \
-			'[.workflow_runs[] | select(.name == $name and .head_branch == $head_branch)] | first | .url'
+  curl -X 'GET' \
+    "$GITHUB_API_URL/repos/$GITHUB_REPOSITORY/actions/tasks" \
+    -H "Authorization: token $GITHUB_TOKEN" \
+    -H 'accept: application/json' |
+    jq --raw-output \
+      --arg name "$JOB_NAME" \
+      --arg head_branch "$1" \
+      '[.workflow_runs[] | select(.name == $name and .head_branch == $head_branch)] | first | .url'
 }
 
 # USAGE: has_report <REPORT_URL>
 has_report() {
-	http_code=$(curl -X 'GET' -o /dev/null --silent -Iw '%{http_code}' \
-		"$1" -H "Authorization: token $GITHUB_TOKEN")
-	log "Got code $http_code for $1"
-	test "$http_code" = '200'
+  http_code=$(curl -X 'GET' -o /dev/null --silent -Iw '%{http_code}' \
+    "$1" -H "Authorization: token $GITHUB_TOKEN")
+  log "Got code $http_code for $1"
+  test "$http_code" = '200'
 }
 
 # If a base branch is not provided, use the default branch
 base_branch=${BASE_BRANCH:-$(default_branch)}
 
 if [ "$(in_private_repo)" != 'true' ] && [ "$JOB_NAME" ]; then
-	url=$(base_report_url "$base_branch")
+  url=$(base_report_url "$base_branch")
 
-	log "Found previous run at: $url"
-	report_url="$url/artifacts/$ARTIFACT_NAME"
+  log "Found previous run at: $url"
+  report_url="$url/artifacts/$ARTIFACT_NAME"
 
-	if has_report "$report_url"; then
-		log 'Found previous report, downloading...'
-		curl -X 'GET' \
-			"$report_url" \
-			-H "Authorization: token $GITHUB_TOKEN" |
-			gunzip >old-report.json
-		log "Reporting on sizes and comparing to sizes in $base_branch"
-		exit 0
-	fi
-	error "Failed to find previous report, expected at: $report_url"
+  if has_report "$report_url"; then
+    log 'Found previous report, downloading...'
+    curl -X 'GET' \
+      "$report_url" \
+      -H "Authorization: token $GITHUB_TOKEN" |
+      gunzip >old-report.json
+    log "Reporting on sizes and comparing to sizes in $base_branch"
+    exit 0
+  fi
+  error "Failed to find previous report, expected at: $report_url"
 fi
 
 warn "Couldn't retrieve old report:"
@@ -69,9 +69,9 @@ error "Falling back to slow method (checkout $base_branch and generate the repor
 old=$(mktemp -d)
 group "Download files from $base_branch"
 curl -X 'GET' \
-	"$GITHUB_API_URL/repos/$GITHUB_REPOSITORY/archive/$base_branch.tar.gz" \
-	-H "Authorization: token $GITHUB_TOKEN" |
-	tar -zvx --strip-components=1 -C "$old"
+  "$GITHUB_API_URL/repos/$GITHUB_REPOSITORY/archive/$base_branch.tar.gz" \
+  -H "Authorization: token $GITHUB_TOKEN" |
+  tar -zvx --strip-components=1 -C "$old"
 endgroup
 
 (cd "$old" && "$GITHUB_ACTION_PATH/create-report.sh") >old-report.json
diff --git a/utils.sh b/utils.sh
index 9cba1aa..e61c2a3 100755
--- a/utils.sh
+++ b/utils.sh
@@ -1,19 +1,21 @@
+#!/bin/sh
+
 log() {
-	echo "$@" >&2
+  echo "$@" >&2
 }
 
 warn() {
-	log "\e[0;33m[ERROR]:" "$@" "\e[0m"
+  log "\e[0;33m[ERROR]:" "$@" "\e[0m"
 }
 
 error() {
-	log "\e[0;31m[WARN]:" "$@" "\e[0m"
+  log "\e[0;31m[WARN]:" "$@" "\e[0m"
 }
 
 group() {
-	log "::group::$1"
+  log "::group::$1"
 }
 
 endgroup() {
-	log '::endgroup::'
+  log '::endgroup::'
 }