diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 7c7b259ae..e9c4f0463 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -92,3 +92,49 @@ jobs:
       uses: codecov/codecov-action@d9f34f8cd5cb3b3eb79b3e4b5dae3a16df499a70 # v3.1.1
       with:
         files: lcov.info
+  # Lint shell scripts
+  shellcheck:
+    runs-on: ubuntu-latest
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v3
+    - name: Run shellcheck
+      uses: ludeeus/action-shellcheck@1.1.0
+  # Show WASM bundle size summary as a message in the pull request
+  bundle-size:
+    if: ${{ github.event_name == 'pull_request' }}
+    runs-on: ubuntu-latest
+    steps:
+    - name: Checking out
+      uses: actions/checkout@v3
+    - name: Install Rust toolchain
+      uses: ./.github/actions/rust-cargo-run
+      with:
+        command: version
+        github_token: ${{ secrets.GITHUB_TOKEN }}
+        save_cache: true
+    - name: Generate bundle delta summary
+      id: bundle-summary
+      run: |
+        echo 'bundle-summary<<EOF' >> $GITHUB_ENV
+        make bundle-size | tail -n3 >> $GITHUB_ENV
+        echo 'EOF' >> $GITHUB_ENV
+    # Find a relevant comment from GH bot to update if there is one
+    - name: Find Comment
+      uses: peter-evans/find-comment@v2
+      id: fc
+      with:
+        issue-number: ${{ github.event.pull_request.number }}
+        comment-author: 'github-actions[bot]'
+        body-regex: "^### WASM bundle summary"
+    - name: Create or update comment
+      uses: peter-evans/create-or-update-comment@v2
+      with:
+        comment-id: ${{ steps.fc.outputs.comment-id }}
+        issue-number: ${{ github.event.pull_request.number }}
+        body: |
+          ### WASM bundle summary 📦
+          ```
+          ${{ env.bundle-summary }}
+          ```
+        edit-mode: replace
diff --git a/.github/workflows/update-bundle-size.yml b/.github/workflows/update-bundle-size.yml
new file mode 100644
index 000000000..a776e7a68
--- /dev/null
+++ b/.github/workflows/update-bundle-size.yml
@@ -0,0 +1,36 @@
+name: Update WASM bundle size
+
+on:
+  push:
+    branches:
+      - master
+
+# Updates the `bundle-size` on the master branch, pushes a commit from the Github
+# bot (doesn't trigger the CI thanks to the magic message)
+jobs:
+  bundle-size:
+    runs-on: ubuntu-latest
+    steps:
+    - name: Checking out
+      uses: actions/checkout@v3
+      with:
+        ref: ${{ github.head_ref }}
+        fetch-depth: 0
+    - name: Install Rust toolchain
+      uses: ./.github/actions/rust-cargo-run
+      with:
+        command: version
+        github_token: ${{ secrets.GITHUB_TOKEN }}
+        save_cache: true
+    - name: Update bundle size
+      run: |
+        git config --local user.email "github-actions[bot]@users.noreply.github.com"
+        git config --local user.name "github-actions[bot]"
+        make bundle-size
+        git add bundle-size
+        git commit -m "[skip ci] update bundle-size" || true
+    - name: Push changes
+      uses: ad-m/github-push-action@master
+      with:
+        github_token: ${{ secrets.GITHUB_TOKEN }}
+        branch: ${{ github.head_ref }}
diff --git a/Makefile b/Makefile
index 181037b8b..7b39606e3 100644
--- a/Makefile
+++ b/Makefile
@@ -35,7 +35,10 @@ set-version: check-clean deps-release check
 publish:
 	cargo workspaces publish --from-git
 
-# Create a bundle in a deterministic location
+# Update the bundle size file, print the summary
+bundle-size: bundle
+	@bash scripts/update-bundle-size.sh $@ output/builtin-actors.car
+
 bundle:
 	cargo run -- -o output/builtin-actors.car
 
@@ -61,7 +64,8 @@ bundle-testing:
 	BUILD_FIL_NETWORK=testing cargo run -- -o output/builtin-actors-testing.car
 	BUILD_FIL_NETWORK=testing-fake-proofs cargo run -- -o output/builtin-actors-testing-fake-proofs.car
 
-.PHONY: all-bundles bundle-mainnet bundle-caterpillarnet bundle-butterflynet bundle-calibrationnet bundle-devnet bundle-testing
+
+.PHONY: all-bundles bundle-mainnet bundle-caterpillarnet bundle-butterflynet bundle-calibrationnet bundle-devnet bundle-testing bundle-size
 
 # Check if the working tree is clean.
 check-clean:
diff --git a/bundle-size b/bundle-size
new file mode 100644
index 000000000..d323ee146
--- /dev/null
+++ b/bundle-size
@@ -0,0 +1 @@
+6030519
diff --git a/scripts/publish-release.sh b/scripts/publish-release.sh
index 12f6a633a..c516baac1 100755
--- a/scripts/publish-release.sh
+++ b/scripts/publish-release.sh
@@ -33,8 +33,8 @@ release_tag="${GITHUB_REF:10}"
 
 # prepare artifacts
 pushd output
-mv $release_input $release_target
-shasum -a 256 $release_target > $release_target_hash
+mv $release_input "$release_target"
+shasum -a 256 "$release_target" > "$release_target_hash"
 popd
 
 # prepare release
@@ -42,18 +42,18 @@ ORG="filecoin-project"
 REPO="builtin-actors"
 
 # see if the release already exists by tag
-__release_response=`
+__release_response=$(
   curl \
    --header "Authorization: token $GITHUB_TOKEN" \
    "https://api.github.com/repos/$ORG/$REPO/releases/tags/$release_tag"
-`
-__release_id=`echo $__release_response | jq '.id'`
+)
+__release_id=$(echo "$__release_response" | jq '.id')
 if [ "$__release_id" = "null" ]; then
     echo "release $release_tag does not exist"
     exit 1
 fi
 
-__release_upload_url=`echo $__release_response | jq -r '.upload_url' | cut -d'{' -f1`
+__release_upload_url=$(echo "$__release_response" | jq -r '.upload_url' | cut -d'{' -f1)
 
 echo "uploading $release_target"
 curl \
diff --git a/scripts/update-bundle-size.sh b/scripts/update-bundle-size.sh
new file mode 100644
index 000000000..d5f087ebb
--- /dev/null
+++ b/scripts/update-bundle-size.sh
@@ -0,0 +1,34 @@
+#!/bin/bash
+# Checks and updates bundle size file, printing delta between the previous and current bundle size.
+
+# Check if the user provided both arguments
+if [ $# -ne 2 ]; then
+  echo "Usage: ./update-bundle-size.sh <bundle-size-path> <bundle-path>"
+  exit 1
+fi
+
+# Check if paths exist
+if [[ ! -f $1 || ! -f $2 ]]; then
+  echo "Invalid arguments. Please check that the files exist."
+  exit 1
+fi
+
+bundle_size_path=$1
+bundle_path=$2
+
+# Grab the current bundle size
+size_old=$(head -n 1 "$bundle_size_path")
+
+# Update bundle size
+wc -c < "$bundle_path" > "$bundle_size_path"
+
+# Grab the new bundle size
+size_new=$(head -n 1 "$bundle_size_path")
+
+# Calculate the difference
+diff=$((size_new - size_old))
+
+# Print stats
+echo "Old bundle size: $size_old"
+echo "New bundle size: $size_new"
+echo "Delta:           $diff byte(s)"