From 3306c7ac455a40a8625379019c4d0bb2f9934e85 Mon Sep 17 00:00:00 2001
From: Vlad Frangu <me@vladfrangu.dev>
Date: Sun, 14 Jun 2026 23:59:47 +0300
Subject: [PATCH 1/3] ci: report image size changes on image PRs
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On pull requests, each image build matrix now measures the new image's size
and compares it against the currently published rolling tag for the same
runtime version (e.g. apify/actor-node:22), uploading a per-image report.

A new size-report job aggregates those reports and posts/updates a single
sticky comment per workflow with a current/new/Δ table. The Markdown is
rendered by a TypeScript script run natively on Node.js 24 (type stripping,
no build step).

Applies to all six image workflows (node, node-playwright, node-puppeteer,
python, python-playwright, python-selenium).
---
 .github/scripts/format-image-size-report.ts   | 118 ++++++++++++++++++
 .../workflows/release-node-playwright.yaml    |  73 +++++++++++
 .github/workflows/release-node-puppeteer.yaml |  73 +++++++++++
 .github/workflows/release-node.yaml           |  73 +++++++++++
 .../workflows/release-python-playwright.yaml  |  73 +++++++++++
 .../workflows/release-python-selenium.yaml    |  73 +++++++++++
 .github/workflows/release-python.yaml         |  73 +++++++++++
 7 files changed, 556 insertions(+)
 create mode 100644 .github/scripts/format-image-size-report.ts

diff --git a/.github/scripts/format-image-size-report.ts b/.github/scripts/format-image-size-report.ts
new file mode 100644
index 00000000..fd199a1e
--- /dev/null
+++ b/.github/scripts/format-image-size-report.ts
@@ -0,0 +1,118 @@
+// Renders the Markdown body for the "image size" PR comment.
+//
+// Usage: node format-image-size-report.ts <reports-dir>
+// Runs natively on Node.js >=24 via built-in TypeScript type stripping (no build step).
+//
+// <reports-dir> contains one JSON file per built image (uploaded as artifacts by
+// the build matrix). Each file has the shape described by SizeReport below;
+// `currentBytes` is empty when there is no published baseline image to compare against.
+
+import { readdirSync, readFileSync } from 'node:fs';
+import { join } from 'node:path';
+
+interface SizeReport {
+    matrix?: Record<string, string>;
+    baseImage?: string;
+    currentBytes?: string;
+    newBytes?: string;
+}
+
+// Matrix keys we never want to surface as a "variant" in the table.
+const IGNORED_VERSION_KEYS = new Set<string>([
+    'node-version',
+    'python-version',
+    'apify-version',
+    'crawlee-version',
+    'latest-node-version',
+    'latest-python-version',
+]);
+
+const MiB = 1024 * 1024;
+
+function readReports(reportsDir: string): SizeReport[] {
+    let files: string[];
+    try {
+        files = readdirSync(reportsDir).filter((file) => file.endsWith('.json'));
+    } catch {
+        return [];
+    }
+
+    const reports: SizeReport[] = [];
+    for (const file of files) {
+        try {
+            reports.push(JSON.parse(readFileSync(join(reportsDir, file), 'utf8')) as SizeReport);
+        } catch {
+            // Skip unreadable/corrupt report files rather than failing the whole comment.
+        }
+    }
+    return reports;
+}
+
+function formatSize(bytes: string | undefined): string | null {
+    const n = Number(bytes);
+    if (!bytes || !Number.isFinite(n)) return null;
+    return `${(n / MiB).toFixed(1)} MiB`;
+}
+
+function formatDelta(currentBytes: string | undefined, newBytes: string | undefined): string {
+    const current = Number(currentBytes);
+    const next = Number(newBytes);
+    if (!currentBytes || !Number.isFinite(current) || !Number.isFinite(next)) {
+        return '🆕 _new image_';
+    }
+    const diff = next - current;
+    const pct = current === 0 ? 0 : (diff / current) * 100;
+    const sign = diff > 0 ? '+' : diff < 0 ? '−' : '';
+    const emoji = diff > 0 ? '🔺' : diff < 0 ? '🔻' : '➖';
+    const absMiB = (Math.abs(diff) / MiB).toFixed(1);
+    return `${emoji} ${sign}${absMiB} MiB (${sign}${Math.abs(pct).toFixed(1)}%)`;
+}
+
+function describeVariant(matrix: Record<string, string> = {}): string {
+    const variants: string[] = [];
+    for (const [key, value] of Object.entries(matrix)) {
+        if (!value || IGNORED_VERSION_KEYS.has(key) || !key.endsWith('-version')) continue;
+        variants.push(`${key.replace(/-version$/, '')} ${value}`);
+    }
+    return variants.join(', ');
+}
+
+function render(reports: SizeReport[]): string {
+    const lines: string[] = [];
+    lines.push('### 📦 Image size report');
+    lines.push('');
+
+    if (reports.length === 0) {
+        lines.push('No image size data was collected (no images were built in this run).');
+        lines.push('');
+        return lines.join('\n');
+    }
+
+    lines.push(
+        'Built images compared against the currently published rolling tag for the same runtime version '
+            + '(e.g. `apify/actor-node:22`). Sizes are the **uncompressed** on-disk size reported by '
+            + '`docker image inspect`, so they will be larger than the compressed download size shown on Docker Hub.',
+    );
+    lines.push('');
+    lines.push('| Image | Variant | Current | New | Δ |');
+    lines.push('| --- | --- | ---: | ---: | --- |');
+
+    const rows = reports
+        .map((report) => ({
+            image: report.baseImage || '(unknown)',
+            variant: describeVariant(report.matrix),
+            current: formatSize(report.currentBytes) ?? '_n/a_',
+            next: formatSize(report.newBytes) ?? '_n/a_',
+            delta: formatDelta(report.currentBytes, report.newBytes),
+        }))
+        .sort((a, b) => a.image.localeCompare(b.image) || a.variant.localeCompare(b.variant));
+
+    for (const row of rows) {
+        lines.push(`| \`${row.image}\` | ${row.variant || '—'} | ${row.current} | ${row.next} | ${row.delta} |`);
+    }
+
+    lines.push('');
+    return lines.join('\n');
+}
+
+process.stdout.write(render(readReports(process.argv[2] ?? '')));
diff --git a/.github/workflows/release-node-playwright.yaml b/.github/workflows/release-node-playwright.yaml
index 6c17eb19..6a453eb9 100644
--- a/.github/workflows/release-node-playwright.yaml
+++ b/.github/workflows/release-node-playwright.yaml
@@ -278,6 +278,41 @@ jobs:
       - name: Test slim image
         run: docker run ${{ fromJson(steps.prepare-slim-tags.outputs.result).firstImageName }}
 
+      - name: Measure image size
+        id: image-size
+        if: github.event_name == 'pull_request'
+        env:
+          MATRIX_JSON: ${{ toJSON(matrix) }}
+          NEW_IMAGE: ${{ fromJson(steps.prepare-tags.outputs.result).firstImageName }}
+          BASE_IMAGE: apify/actor-${{ matrix.image-name }}:${{ matrix.node-version }}
+        run: |
+          set -euo pipefail
+          mkdir -p size-report
+          id="$(printf '%s' "$MATRIX_JSON" | sha256sum | cut -c1-16)"
+          new_bytes="$(docker image inspect "$NEW_IMAGE" --format '{{.Size}}')"
+          if docker pull --platform linux/amd64 "$BASE_IMAGE" >/dev/null 2>&1; then
+            current_bytes="$(docker image inspect "$BASE_IMAGE" --format '{{.Size}}')"
+          else
+            current_bytes=""
+            echo "No published baseline image found for ${BASE_IMAGE}"
+          fi
+          jq -n \
+            --argjson matrix "$MATRIX_JSON" \
+            --arg base "$BASE_IMAGE" \
+            --arg current "$current_bytes" \
+            --arg new "$new_bytes" \
+            '{matrix: $matrix, baseImage: $base, currentBytes: $current, newBytes: $new}' \
+            > "size-report/${id}.json"
+          echo "id=${id}" >> "$GITHUB_OUTPUT"
+
+      - name: Upload image size report
+        if: github.event_name == 'pull_request'
+        uses: actions/upload-artifact@v7
+        with:
+          name: image-size-${{ steps.image-size.outputs.id }}
+          path: size-report/
+          retention-days: 1
+
       - name: Login to DockerHub
         if: github.event_name != 'pull_request'
         uses: docker/login-action@v4
@@ -319,3 +354,41 @@ jobs:
           cache-from: |
             type=gha,scope=${{ matrix.image-name }}-${{ matrix.node-version }}-${{ matrix.playwright-version }}-slim
             type=gha,scope=${{ matrix.image-name }}-${{ matrix.node-version }}-${{ matrix.playwright-version }}
+
+  # Aggregate the per-image size reports uploaded by the build matrix and post/update
+  # a single sticky PR comment comparing current vs new image sizes.
+  size-report:
+    name: Report image size changes
+    needs: [build-main]
+    if: ${{ always() && github.event_name == 'pull_request' }}
+    runs-on: ubuntu-latest
+    permissions:
+      pull-requests: write
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+
+      - name: Download image size reports
+        uses: actions/download-artifact@v8
+        continue-on-error: true
+        with:
+          pattern: image-size-*
+          path: size-reports
+          merge-multiple: true
+
+      - name: Set up Node.js
+        uses: actions/setup-node@v6
+        with:
+          node-version: 24
+
+      - name: Render comment body
+        run: |
+          mkdir -p size-reports
+          node .github/scripts/format-image-size-report.ts size-reports | tee image-size-comment.md
+
+      - name: Post or update image size comment
+        uses: marocchino/sticky-pull-request-comment@v3
+        with:
+          header: image-sizes-node-playwright
+          path: image-size-comment.md
diff --git a/.github/workflows/release-node-puppeteer.yaml b/.github/workflows/release-node-puppeteer.yaml
index 695527f9..824d8f6e 100644
--- a/.github/workflows/release-node-puppeteer.yaml
+++ b/.github/workflows/release-node-puppeteer.yaml
@@ -258,6 +258,41 @@ jobs:
       - name: Test slim image
         run: docker run ${{ fromJson(steps.prepare-slim-tags.outputs.result).firstImageName }}
 
+      - name: Measure image size
+        id: image-size
+        if: github.event_name == 'pull_request'
+        env:
+          MATRIX_JSON: ${{ toJSON(matrix) }}
+          NEW_IMAGE: ${{ fromJson(steps.prepare-tags.outputs.result).firstImageName }}
+          BASE_IMAGE: apify/actor-${{ matrix.image-name }}:${{ matrix.node-version }}
+        run: |
+          set -euo pipefail
+          mkdir -p size-report
+          id="$(printf '%s' "$MATRIX_JSON" | sha256sum | cut -c1-16)"
+          new_bytes="$(docker image inspect "$NEW_IMAGE" --format '{{.Size}}')"
+          if docker pull --platform linux/amd64 "$BASE_IMAGE" >/dev/null 2>&1; then
+            current_bytes="$(docker image inspect "$BASE_IMAGE" --format '{{.Size}}')"
+          else
+            current_bytes=""
+            echo "No published baseline image found for ${BASE_IMAGE}"
+          fi
+          jq -n \
+            --argjson matrix "$MATRIX_JSON" \
+            --arg base "$BASE_IMAGE" \
+            --arg current "$current_bytes" \
+            --arg new "$new_bytes" \
+            '{matrix: $matrix, baseImage: $base, currentBytes: $current, newBytes: $new}' \
+            > "size-report/${id}.json"
+          echo "id=${id}" >> "$GITHUB_OUTPUT"
+
+      - name: Upload image size report
+        if: github.event_name == 'pull_request'
+        uses: actions/upload-artifact@v7
+        with:
+          name: image-size-${{ steps.image-size.outputs.id }}
+          path: size-report/
+          retention-days: 1
+
       - name: Login to DockerHub
         if: github.event_name != 'pull_request'
         uses: docker/login-action@v4
@@ -299,3 +334,41 @@ jobs:
           cache-from: |
             type=gha,scope=${{ matrix.image-name }}-${{ matrix.node-version }}-${{ matrix.puppeteer-version }}-slim
             type=gha,scope=${{ matrix.image-name }}-${{ matrix.node-version }}-${{ matrix.puppeteer-version }}
+
+  # Aggregate the per-image size reports uploaded by the build matrix and post/update
+  # a single sticky PR comment comparing current vs new image sizes.
+  size-report:
+    name: Report image size changes
+    needs: [build-main]
+    if: ${{ always() && github.event_name == 'pull_request' }}
+    runs-on: ubuntu-latest
+    permissions:
+      pull-requests: write
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+
+      - name: Download image size reports
+        uses: actions/download-artifact@v8
+        continue-on-error: true
+        with:
+          pattern: image-size-*
+          path: size-reports
+          merge-multiple: true
+
+      - name: Set up Node.js
+        uses: actions/setup-node@v6
+        with:
+          node-version: 24
+
+      - name: Render comment body
+        run: |
+          mkdir -p size-reports
+          node .github/scripts/format-image-size-report.ts size-reports | tee image-size-comment.md
+
+      - name: Post or update image size comment
+        uses: marocchino/sticky-pull-request-comment@v3
+        with:
+          header: image-sizes-node-puppeteer
+          path: image-size-comment.md
diff --git a/.github/workflows/release-node.yaml b/.github/workflows/release-node.yaml
index 342008ea..9fde69e5 100644
--- a/.github/workflows/release-node.yaml
+++ b/.github/workflows/release-node.yaml
@@ -249,6 +249,41 @@ jobs:
       - name: Test slim image
         run: docker run ${{ fromJson(steps.prepare-slim-tags.outputs.result).firstImageName }}
 
+      - name: Measure image size
+        id: image-size
+        if: github.event_name == 'pull_request'
+        env:
+          MATRIX_JSON: ${{ toJSON(matrix) }}
+          NEW_IMAGE: ${{ fromJson(steps.prepare-tags.outputs.result).firstImageName }}
+          BASE_IMAGE: apify/actor-${{ matrix.image-name }}:${{ matrix.node-version }}
+        run: |
+          set -euo pipefail
+          mkdir -p size-report
+          id="$(printf '%s' "$MATRIX_JSON" | sha256sum | cut -c1-16)"
+          new_bytes="$(docker image inspect "$NEW_IMAGE" --format '{{.Size}}')"
+          if docker pull --platform linux/amd64 "$BASE_IMAGE" >/dev/null 2>&1; then
+            current_bytes="$(docker image inspect "$BASE_IMAGE" --format '{{.Size}}')"
+          else
+            current_bytes=""
+            echo "No published baseline image found for ${BASE_IMAGE}"
+          fi
+          jq -n \
+            --argjson matrix "$MATRIX_JSON" \
+            --arg base "$BASE_IMAGE" \
+            --arg current "$current_bytes" \
+            --arg new "$new_bytes" \
+            '{matrix: $matrix, baseImage: $base, currentBytes: $current, newBytes: $new}' \
+            > "size-report/${id}.json"
+          echo "id=${id}" >> "$GITHUB_OUTPUT"
+
+      - name: Upload image size report
+        if: github.event_name == 'pull_request'
+        uses: actions/upload-artifact@v7
+        with:
+          name: image-size-${{ steps.image-size.outputs.id }}
+          path: size-report/
+          retention-days: 1
+
       - name: Login to DockerHub
         if: github.event_name != 'pull_request'
         uses: docker/login-action@v4
@@ -287,3 +322,41 @@ jobs:
           cache-from: |
             type=gha,scope=${{ matrix.image-name }}-${{ matrix.node-version }}-slim
             type=gha,scope=${{ matrix.image-name }}-${{ matrix.node-version }}
+
+  # Aggregate the per-image size reports uploaded by the build matrix and post/update
+  # a single sticky PR comment comparing current vs new image sizes.
+  size-report:
+    name: Report image size changes
+    needs: [build-main]
+    if: ${{ always() && github.event_name == 'pull_request' }}
+    runs-on: ubuntu-latest
+    permissions:
+      pull-requests: write
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+
+      - name: Download image size reports
+        uses: actions/download-artifact@v8
+        continue-on-error: true
+        with:
+          pattern: image-size-*
+          path: size-reports
+          merge-multiple: true
+
+      - name: Set up Node.js
+        uses: actions/setup-node@v6
+        with:
+          node-version: 24
+
+      - name: Render comment body
+        run: |
+          mkdir -p size-reports
+          node .github/scripts/format-image-size-report.ts size-reports | tee image-size-comment.md
+
+      - name: Post or update image size comment
+        uses: marocchino/sticky-pull-request-comment@v3
+        with:
+          header: image-sizes-node
+          path: image-size-comment.md
diff --git a/.github/workflows/release-python-playwright.yaml b/.github/workflows/release-python-playwright.yaml
index cc057b3e..abe42cbb 100644
--- a/.github/workflows/release-python-playwright.yaml
+++ b/.github/workflows/release-python-playwright.yaml
@@ -187,6 +187,41 @@ jobs:
       - name: Test image
         run: docker run ${{ fromJson(steps.prepare-tags.outputs.result).firstImageName }}
 
+      - name: Measure image size
+        id: image-size
+        if: github.event_name == 'pull_request'
+        env:
+          MATRIX_JSON: ${{ toJSON(matrix) }}
+          NEW_IMAGE: ${{ fromJson(steps.prepare-tags.outputs.result).firstImageName }}
+          BASE_IMAGE: apify/actor-${{ matrix.image-name }}:${{ matrix.python-version }}
+        run: |
+          set -euo pipefail
+          mkdir -p size-report
+          id="$(printf '%s' "$MATRIX_JSON" | sha256sum | cut -c1-16)"
+          new_bytes="$(docker image inspect "$NEW_IMAGE" --format '{{.Size}}')"
+          if docker pull --platform linux/amd64 "$BASE_IMAGE" >/dev/null 2>&1; then
+            current_bytes="$(docker image inspect "$BASE_IMAGE" --format '{{.Size}}')"
+          else
+            current_bytes=""
+            echo "No published baseline image found for ${BASE_IMAGE}"
+          fi
+          jq -n \
+            --argjson matrix "$MATRIX_JSON" \
+            --arg base "$BASE_IMAGE" \
+            --arg current "$current_bytes" \
+            --arg new "$new_bytes" \
+            '{matrix: $matrix, baseImage: $base, currentBytes: $current, newBytes: $new}' \
+            > "size-report/${id}.json"
+          echo "id=${id}" >> "$GITHUB_OUTPUT"
+
+      - name: Upload image size report
+        if: github.event_name == 'pull_request'
+        uses: actions/upload-artifact@v7
+        with:
+          name: image-size-${{ steps.image-size.outputs.id }}
+          path: size-report/
+          retention-days: 1
+
       - name: Login to DockerHub
         if: github.event_name != 'pull_request'
         uses: docker/login-action@v4
@@ -210,3 +245,41 @@ jobs:
           tags: ${{ fromJson(steps.prepare-tags.outputs.result).allTags }}
           outputs: type=image,oci-mediatypes=true
           cache-from: type=gha,scope=${{ matrix.image-name }}-${{ matrix.python-version }}-${{ matrix.playwright-version }}-${{ matrix.camoufox-version }}
+
+  # Aggregate the per-image size reports uploaded by the build matrix and post/update
+  # a single sticky PR comment comparing current vs new image sizes.
+  size-report:
+    name: Report image size changes
+    needs: [build-main]
+    if: ${{ always() && github.event_name == 'pull_request' }}
+    runs-on: ubuntu-latest
+    permissions:
+      pull-requests: write
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+
+      - name: Download image size reports
+        uses: actions/download-artifact@v8
+        continue-on-error: true
+        with:
+          pattern: image-size-*
+          path: size-reports
+          merge-multiple: true
+
+      - name: Set up Node.js
+        uses: actions/setup-node@v6
+        with:
+          node-version: 24
+
+      - name: Render comment body
+        run: |
+          mkdir -p size-reports
+          node .github/scripts/format-image-size-report.ts size-reports | tee image-size-comment.md
+
+      - name: Post or update image size comment
+        uses: marocchino/sticky-pull-request-comment@v3
+        with:
+          header: image-sizes-python-playwright
+          path: image-size-comment.md
diff --git a/.github/workflows/release-python-selenium.yaml b/.github/workflows/release-python-selenium.yaml
index 25758b57..0fc09135 100644
--- a/.github/workflows/release-python-selenium.yaml
+++ b/.github/workflows/release-python-selenium.yaml
@@ -163,6 +163,41 @@ jobs:
       - name: Test image
         run: docker run ${{ fromJson(steps.prepare-tags.outputs.result).firstImageName }}
 
+      - name: Measure image size
+        id: image-size
+        if: github.event_name == 'pull_request'
+        env:
+          MATRIX_JSON: ${{ toJSON(matrix) }}
+          NEW_IMAGE: ${{ fromJson(steps.prepare-tags.outputs.result).firstImageName }}
+          BASE_IMAGE: apify/actor-${{ matrix.image-name }}:${{ matrix.python-version }}
+        run: |
+          set -euo pipefail
+          mkdir -p size-report
+          id="$(printf '%s' "$MATRIX_JSON" | sha256sum | cut -c1-16)"
+          new_bytes="$(docker image inspect "$NEW_IMAGE" --format '{{.Size}}')"
+          if docker pull --platform linux/amd64 "$BASE_IMAGE" >/dev/null 2>&1; then
+            current_bytes="$(docker image inspect "$BASE_IMAGE" --format '{{.Size}}')"
+          else
+            current_bytes=""
+            echo "No published baseline image found for ${BASE_IMAGE}"
+          fi
+          jq -n \
+            --argjson matrix "$MATRIX_JSON" \
+            --arg base "$BASE_IMAGE" \
+            --arg current "$current_bytes" \
+            --arg new "$new_bytes" \
+            '{matrix: $matrix, baseImage: $base, currentBytes: $current, newBytes: $new}' \
+            > "size-report/${id}.json"
+          echo "id=${id}" >> "$GITHUB_OUTPUT"
+
+      - name: Upload image size report
+        if: github.event_name == 'pull_request'
+        uses: actions/upload-artifact@v7
+        with:
+          name: image-size-${{ steps.image-size.outputs.id }}
+          path: size-report/
+          retention-days: 1
+
       - name: Login to DockerHub
         if: github.event_name != 'pull_request'
         uses: docker/login-action@v4
@@ -185,3 +220,41 @@ jobs:
           tags: ${{ fromJson(steps.prepare-tags.outputs.result).allTags }}
           outputs: type=image,oci-mediatypes=true
           cache-from: type=gha,scope=${{ matrix.image-name }}-${{ matrix.python-version }}-${{ matrix.selenium-version }}
+
+  # Aggregate the per-image size reports uploaded by the build matrix and post/update
+  # a single sticky PR comment comparing current vs new image sizes.
+  size-report:
+    name: Report image size changes
+    needs: [build-main]
+    if: ${{ always() && github.event_name == 'pull_request' }}
+    runs-on: ubuntu-latest
+    permissions:
+      pull-requests: write
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+
+      - name: Download image size reports
+        uses: actions/download-artifact@v8
+        continue-on-error: true
+        with:
+          pattern: image-size-*
+          path: size-reports
+          merge-multiple: true
+
+      - name: Set up Node.js
+        uses: actions/setup-node@v6
+        with:
+          node-version: 24
+
+      - name: Render comment body
+        run: |
+          mkdir -p size-reports
+          node .github/scripts/format-image-size-report.ts size-reports | tee image-size-comment.md
+
+      - name: Post or update image size comment
+        uses: marocchino/sticky-pull-request-comment@v3
+        with:
+          header: image-sizes-python-selenium
+          path: image-size-comment.md
diff --git a/.github/workflows/release-python.yaml b/.github/workflows/release-python.yaml
index b84e3fee..d4611cac 100644
--- a/.github/workflows/release-python.yaml
+++ b/.github/workflows/release-python.yaml
@@ -161,6 +161,41 @@ jobs:
       - name: Test image
         run: docker run ${{ fromJson(steps.prepare-tags.outputs.result).firstImageName }}
 
+      - name: Measure image size
+        id: image-size
+        if: github.event_name == 'pull_request'
+        env:
+          MATRIX_JSON: ${{ toJSON(matrix) }}
+          NEW_IMAGE: ${{ fromJson(steps.prepare-tags.outputs.result).firstImageName }}
+          BASE_IMAGE: apify/actor-${{ matrix.image-name }}:${{ matrix.python-version }}
+        run: |
+          set -euo pipefail
+          mkdir -p size-report
+          id="$(printf '%s' "$MATRIX_JSON" | sha256sum | cut -c1-16)"
+          new_bytes="$(docker image inspect "$NEW_IMAGE" --format '{{.Size}}')"
+          if docker pull --platform linux/amd64 "$BASE_IMAGE" >/dev/null 2>&1; then
+            current_bytes="$(docker image inspect "$BASE_IMAGE" --format '{{.Size}}')"
+          else
+            current_bytes=""
+            echo "No published baseline image found for ${BASE_IMAGE}"
+          fi
+          jq -n \
+            --argjson matrix "$MATRIX_JSON" \
+            --arg base "$BASE_IMAGE" \
+            --arg current "$current_bytes" \
+            --arg new "$new_bytes" \
+            '{matrix: $matrix, baseImage: $base, currentBytes: $current, newBytes: $new}' \
+            > "size-report/${id}.json"
+          echo "id=${id}" >> "$GITHUB_OUTPUT"
+
+      - name: Upload image size report
+        if: github.event_name == 'pull_request'
+        uses: actions/upload-artifact@v7
+        with:
+          name: image-size-${{ steps.image-size.outputs.id }}
+          path: size-report/
+          retention-days: 1
+
       - name: Login to DockerHub
         if: github.event_name != 'pull_request'
         uses: docker/login-action@v4
@@ -182,3 +217,41 @@ jobs:
           tags: ${{ fromJson(steps.prepare-tags.outputs.result).allTags }}
           outputs: type=image,oci-mediatypes=true
           cache-from: type=gha,scope=${{ matrix.image-name }}-${{ matrix.python-version }}
+
+  # Aggregate the per-image size reports uploaded by the build matrix and post/update
+  # a single sticky PR comment comparing current vs new image sizes.
+  size-report:
+    name: Report image size changes
+    needs: [build-main]
+    if: ${{ always() && github.event_name == 'pull_request' }}
+    runs-on: ubuntu-latest
+    permissions:
+      pull-requests: write
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+
+      - name: Download image size reports
+        uses: actions/download-artifact@v8
+        continue-on-error: true
+        with:
+          pattern: image-size-*
+          path: size-reports
+          merge-multiple: true
+
+      - name: Set up Node.js
+        uses: actions/setup-node@v6
+        with:
+          node-version: 24
+
+      - name: Render comment body
+        run: |
+          mkdir -p size-reports
+          node .github/scripts/format-image-size-report.ts size-reports | tee image-size-comment.md
+
+      - name: Post or update image size comment
+        uses: marocchino/sticky-pull-request-comment@v3
+        with:
+          header: image-sizes-python
+          path: image-size-comment.md

From db26898a7065acb5d057890ed90d686cfa856a9f Mon Sep 17 00:00:00 2001
From: Vlad Frangu <me@vladfrangu.dev>
Date: Mon, 31 Aug 2026 18:08:35 +0300
Subject: [PATCH 2/3] ci: include -slim variants in the image size report

The node workflows' measure step now records the slim image alongside the
regular one (baseline: the published rolling tag + -slim), and the report
renderer surfaces an explicit variant label next to the matrix-derived one.
Python workflows are unchanged as they have no slim variants.
---
 .github/scripts/format-image-size-report.ts   |  4 +-
 .../workflows/release-node-playwright.yaml    | 37 ++++++++++++-------
 .github/workflows/release-node-puppeteer.yaml | 37 ++++++++++++-------
 .github/workflows/release-node.yaml           | 37 ++++++++++++-------
 4 files changed, 72 insertions(+), 43 deletions(-)

diff --git a/.github/scripts/format-image-size-report.ts b/.github/scripts/format-image-size-report.ts
index fd199a1e..6342dcbc 100644
--- a/.github/scripts/format-image-size-report.ts
+++ b/.github/scripts/format-image-size-report.ts
@@ -13,6 +13,8 @@ import { join } from 'node:path';
 interface SizeReport {
     matrix?: Record<string, string>;
     baseImage?: string;
+    // Extra variant label not derivable from the matrix (e.g. "slim").
+    variant?: string;
     currentBytes?: string;
     newBytes?: string;
 }
@@ -100,7 +102,7 @@ function render(reports: SizeReport[]): string {
     const rows = reports
         .map((report) => ({
             image: report.baseImage || '(unknown)',
-            variant: describeVariant(report.matrix),
+            variant: [describeVariant(report.matrix), report.variant].filter(Boolean).join(', '),
             current: formatSize(report.currentBytes) ?? '_n/a_',
             next: formatSize(report.newBytes) ?? '_n/a_',
             delta: formatDelta(report.currentBytes, report.newBytes),
diff --git a/.github/workflows/release-node-playwright.yaml b/.github/workflows/release-node-playwright.yaml
index 6a453eb9..8412fc95 100644
--- a/.github/workflows/release-node-playwright.yaml
+++ b/.github/workflows/release-node-playwright.yaml
@@ -285,24 +285,33 @@ jobs:
           MATRIX_JSON: ${{ toJSON(matrix) }}
           NEW_IMAGE: ${{ fromJson(steps.prepare-tags.outputs.result).firstImageName }}
           BASE_IMAGE: apify/actor-${{ matrix.image-name }}:${{ matrix.node-version }}
+          NEW_SLIM_IMAGE: ${{ fromJson(steps.prepare-slim-tags.outputs.result).firstImageName }}
+          BASE_SLIM_IMAGE: apify/actor-${{ matrix.image-name }}:${{ matrix.node-version }}-slim
         run: |
           set -euo pipefail
           mkdir -p size-report
           id="$(printf '%s' "$MATRIX_JSON" | sha256sum | cut -c1-16)"
-          new_bytes="$(docker image inspect "$NEW_IMAGE" --format '{{.Size}}')"
-          if docker pull --platform linux/amd64 "$BASE_IMAGE" >/dev/null 2>&1; then
-            current_bytes="$(docker image inspect "$BASE_IMAGE" --format '{{.Size}}')"
-          else
-            current_bytes=""
-            echo "No published baseline image found for ${BASE_IMAGE}"
-          fi
-          jq -n \
-            --argjson matrix "$MATRIX_JSON" \
-            --arg base "$BASE_IMAGE" \
-            --arg current "$current_bytes" \
-            --arg new "$new_bytes" \
-            '{matrix: $matrix, baseImage: $base, currentBytes: $current, newBytes: $new}' \
-            > "size-report/${id}.json"
+          measure() {
+            local new_image="$1" base_image="$2" variant="$3" out="$4"
+            local new_bytes current_bytes
+            new_bytes="$(docker image inspect "$new_image" --format '{{.Size}}')"
+            if docker pull --platform linux/amd64 "$base_image" >/dev/null 2>&1; then
+              current_bytes="$(docker image inspect "$base_image" --format '{{.Size}}')"
+            else
+              current_bytes=""
+              echo "No published baseline image found for ${base_image}"
+            fi
+            jq -n \
+              --argjson matrix "$MATRIX_JSON" \
+              --arg base "$base_image" \
+              --arg variant "$variant" \
+              --arg current "$current_bytes" \
+              --arg new "$new_bytes" \
+              '{matrix: $matrix, baseImage: $base, variant: $variant, currentBytes: $current, newBytes: $new}' \
+              > "size-report/${out}.json"
+          }
+          measure "$NEW_IMAGE" "$BASE_IMAGE" "" "$id"
+          measure "$NEW_SLIM_IMAGE" "$BASE_SLIM_IMAGE" "slim" "${id}-slim"
           echo "id=${id}" >> "$GITHUB_OUTPUT"
 
       - name: Upload image size report
diff --git a/.github/workflows/release-node-puppeteer.yaml b/.github/workflows/release-node-puppeteer.yaml
index 824d8f6e..0987ed00 100644
--- a/.github/workflows/release-node-puppeteer.yaml
+++ b/.github/workflows/release-node-puppeteer.yaml
@@ -265,24 +265,33 @@ jobs:
           MATRIX_JSON: ${{ toJSON(matrix) }}
           NEW_IMAGE: ${{ fromJson(steps.prepare-tags.outputs.result).firstImageName }}
           BASE_IMAGE: apify/actor-${{ matrix.image-name }}:${{ matrix.node-version }}
+          NEW_SLIM_IMAGE: ${{ fromJson(steps.prepare-slim-tags.outputs.result).firstImageName }}
+          BASE_SLIM_IMAGE: apify/actor-${{ matrix.image-name }}:${{ matrix.node-version }}-slim
         run: |
           set -euo pipefail
           mkdir -p size-report
           id="$(printf '%s' "$MATRIX_JSON" | sha256sum | cut -c1-16)"
-          new_bytes="$(docker image inspect "$NEW_IMAGE" --format '{{.Size}}')"
-          if docker pull --platform linux/amd64 "$BASE_IMAGE" >/dev/null 2>&1; then
-            current_bytes="$(docker image inspect "$BASE_IMAGE" --format '{{.Size}}')"
-          else
-            current_bytes=""
-            echo "No published baseline image found for ${BASE_IMAGE}"
-          fi
-          jq -n \
-            --argjson matrix "$MATRIX_JSON" \
-            --arg base "$BASE_IMAGE" \
-            --arg current "$current_bytes" \
-            --arg new "$new_bytes" \
-            '{matrix: $matrix, baseImage: $base, currentBytes: $current, newBytes: $new}' \
-            > "size-report/${id}.json"
+          measure() {
+            local new_image="$1" base_image="$2" variant="$3" out="$4"
+            local new_bytes current_bytes
+            new_bytes="$(docker image inspect "$new_image" --format '{{.Size}}')"
+            if docker pull --platform linux/amd64 "$base_image" >/dev/null 2>&1; then
+              current_bytes="$(docker image inspect "$base_image" --format '{{.Size}}')"
+            else
+              current_bytes=""
+              echo "No published baseline image found for ${base_image}"
+            fi
+            jq -n \
+              --argjson matrix "$MATRIX_JSON" \
+              --arg base "$base_image" \
+              --arg variant "$variant" \
+              --arg current "$current_bytes" \
+              --arg new "$new_bytes" \
+              '{matrix: $matrix, baseImage: $base, variant: $variant, currentBytes: $current, newBytes: $new}' \
+              > "size-report/${out}.json"
+          }
+          measure "$NEW_IMAGE" "$BASE_IMAGE" "" "$id"
+          measure "$NEW_SLIM_IMAGE" "$BASE_SLIM_IMAGE" "slim" "${id}-slim"
           echo "id=${id}" >> "$GITHUB_OUTPUT"
 
       - name: Upload image size report
diff --git a/.github/workflows/release-node.yaml b/.github/workflows/release-node.yaml
index 9fde69e5..47edc6e7 100644
--- a/.github/workflows/release-node.yaml
+++ b/.github/workflows/release-node.yaml
@@ -256,24 +256,33 @@ jobs:
           MATRIX_JSON: ${{ toJSON(matrix) }}
           NEW_IMAGE: ${{ fromJson(steps.prepare-tags.outputs.result).firstImageName }}
           BASE_IMAGE: apify/actor-${{ matrix.image-name }}:${{ matrix.node-version }}
+          NEW_SLIM_IMAGE: ${{ fromJson(steps.prepare-slim-tags.outputs.result).firstImageName }}
+          BASE_SLIM_IMAGE: apify/actor-${{ matrix.image-name }}:${{ matrix.node-version }}-slim
         run: |
           set -euo pipefail
           mkdir -p size-report
           id="$(printf '%s' "$MATRIX_JSON" | sha256sum | cut -c1-16)"
-          new_bytes="$(docker image inspect "$NEW_IMAGE" --format '{{.Size}}')"
-          if docker pull --platform linux/amd64 "$BASE_IMAGE" >/dev/null 2>&1; then
-            current_bytes="$(docker image inspect "$BASE_IMAGE" --format '{{.Size}}')"
-          else
-            current_bytes=""
-            echo "No published baseline image found for ${BASE_IMAGE}"
-          fi
-          jq -n \
-            --argjson matrix "$MATRIX_JSON" \
-            --arg base "$BASE_IMAGE" \
-            --arg current "$current_bytes" \
-            --arg new "$new_bytes" \
-            '{matrix: $matrix, baseImage: $base, currentBytes: $current, newBytes: $new}' \
-            > "size-report/${id}.json"
+          measure() {
+            local new_image="$1" base_image="$2" variant="$3" out="$4"
+            local new_bytes current_bytes
+            new_bytes="$(docker image inspect "$new_image" --format '{{.Size}}')"
+            if docker pull --platform linux/amd64 "$base_image" >/dev/null 2>&1; then
+              current_bytes="$(docker image inspect "$base_image" --format '{{.Size}}')"
+            else
+              current_bytes=""
+              echo "No published baseline image found for ${base_image}"
+            fi
+            jq -n \
+              --argjson matrix "$MATRIX_JSON" \
+              --arg base "$base_image" \
+              --arg variant "$variant" \
+              --arg current "$current_bytes" \
+              --arg new "$new_bytes" \
+              '{matrix: $matrix, baseImage: $base, variant: $variant, currentBytes: $current, newBytes: $new}' \
+              > "size-report/${out}.json"
+          }
+          measure "$NEW_IMAGE" "$BASE_IMAGE" "" "$id"
+          measure "$NEW_SLIM_IMAGE" "$BASE_SLIM_IMAGE" "slim" "${id}-slim"
           echo "id=${id}" >> "$GITHUB_OUTPUT"
 
       - name: Upload image size report

From 1324b28c0f517f8b2fcb1ed297b31df4a3dcb0da Mon Sep 17 00:00:00 2001
From: Vlad Frangu <me@vladfrangu.dev>
Date: Mon, 31 Aug 2026 18:11:35 +0300
Subject: [PATCH 3/3] ci: merge image size reports into one PR comment with
 foldable sections

Instead of one sticky comment per workflow (up to 6 on a wide PR), all image
workflows now upsert their own marker-delimited <details> section into a
single shared comment. The size-report jobs share a repo-wide concurrency
group so concurrent read-modify-writes of the comment cannot drop sections.
Sections only appear for workflows the PR's changed paths actually triggered,
and each is stamped with the head SHA it measured.
---
 .github/scripts/format-image-size-report.ts   | 27 ++++++-----
 .github/scripts/upsert-image-size-comment.js  | 48 +++++++++++++++++++
 .../workflows/release-node-playwright.yaml    | 19 ++++++--
 .github/workflows/release-node-puppeteer.yaml | 19 ++++++--
 .github/workflows/release-node.yaml           | 19 ++++++--
 .../workflows/release-python-playwright.yaml  | 19 ++++++--
 .../workflows/release-python-selenium.yaml    | 19 ++++++--
 .github/workflows/release-python.yaml         | 19 ++++++--
 8 files changed, 147 insertions(+), 42 deletions(-)
 create mode 100644 .github/scripts/upsert-image-size-comment.js

diff --git a/.github/scripts/format-image-size-report.ts b/.github/scripts/format-image-size-report.ts
index 6342dcbc..6a124b18 100644
--- a/.github/scripts/format-image-size-report.ts
+++ b/.github/scripts/format-image-size-report.ts
@@ -1,6 +1,8 @@
-// Renders the Markdown body for the "image size" PR comment.
+// Renders one workflow's <details> section of the shared "image size" PR comment.
+// The section is upserted into a single sticky comment by upsert-image-size-comment.js,
+// so each image workflow only ever touches its own foldable block.
 //
-// Usage: node format-image-size-report.ts <reports-dir>
+// Usage: node format-image-size-report.ts <reports-dir> <section-title> [head-sha]
 // Runs natively on Node.js >=24 via built-in TypeScript type stripping (no build step).
 //
 // <reports-dir> contains one JSON file per built image (uploaded as artifacts by
@@ -79,22 +81,22 @@ function describeVariant(matrix: Record<string, string> = {}): string {
     return variants.join(', ');
 }
 
-function render(reports: SizeReport[]): string {
+function render(reports: SizeReport[], title: string, headSha: string): string {
     const lines: string[] = [];
-    lines.push('### 📦 Image size report');
-    lines.push('');
+    const measuredAt = headSha ? ` <sub>(at ${headSha.slice(0, 7)})</sub>` : '';
 
     if (reports.length === 0) {
-        lines.push('No image size data was collected (no images were built in this run).');
+        lines.push('<details>');
+        lines.push(`<summary><b>${title}</b> — no image size data collected${measuredAt}</summary>`);
+        lines.push('');
+        lines.push('No images were built in this run.');
+        lines.push('</details>');
         lines.push('');
         return lines.join('\n');
     }
 
-    lines.push(
-        'Built images compared against the currently published rolling tag for the same runtime version '
-            + '(e.g. `apify/actor-node:22`). Sizes are the **uncompressed** on-disk size reported by '
-            + '`docker image inspect`, so they will be larger than the compressed download size shown on Docker Hub.',
-    );
+    lines.push('<details>');
+    lines.push(`<summary><b>${title}</b> — ${reports.length} image${reports.length === 1 ? '' : 's'}${measuredAt}</summary>`);
     lines.push('');
     lines.push('| Image | Variant | Current | New | Δ |');
     lines.push('| --- | --- | ---: | ---: | --- |');
@@ -113,8 +115,9 @@ function render(reports: SizeReport[]): string {
         lines.push(`| \`${row.image}\` | ${row.variant || '—'} | ${row.current} | ${row.next} | ${row.delta} |`);
     }
 
+    lines.push('</details>');
     lines.push('');
     return lines.join('\n');
 }
 
-process.stdout.write(render(readReports(process.argv[2] ?? '')));
+process.stdout.write(render(readReports(process.argv[2] ?? ''), process.argv[3] ?? 'Image sizes', process.argv[4] ?? ''));
diff --git a/.github/scripts/upsert-image-size-comment.js b/.github/scripts/upsert-image-size-comment.js
new file mode 100644
index 00000000..109fa488
--- /dev/null
+++ b/.github/scripts/upsert-image-size-comment.js
@@ -0,0 +1,48 @@
+// Upserts one workflow's section into the single shared "image size" PR comment.
+//
+// Every image workflow renders its own <details> block (format-image-size-report.ts) and
+// calls this from actions/github-script. The comment is identified by MARKER; each section
+// is delimited by per-workflow markers so a workflow only ever rewrites its own block.
+// Concurrent writers are serialized by the size-report jobs sharing a repo-wide
+// `concurrency` group, so the read-modify-write below cannot lose sections.
+
+const MARKER = '<!-- image-size-report -->';
+const PREAMBLE = `${MARKER}
+### 📦 Image size report
+
+Built images compared against the currently published rolling tag for the same runtime \
+version (e.g. \`apify/actor-node:22\`; \`-slim\` variants against the \`-slim\` tag). Sizes \
+are the **uncompressed** on-disk size reported by \`docker image inspect\`, so they will be \
+larger than the compressed download size shown on Docker Hub. Only workflows triggered by \
+this PR's changes report a section.
+`;
+
+module.exports = async ({ github, context }, sectionKey, sectionBody) => {
+    if (!/^[a-z][a-z0-9-]*$/.test(sectionKey)) throw new Error(`Invalid section key: ${sectionKey}`);
+
+    const { owner, repo } = context.repo;
+    const issue_number = context.issue.number;
+    const begin = `<!-- section:${sectionKey} -->`;
+    const end = `<!-- /section:${sectionKey} -->`;
+    const section = `${begin}\n${sectionBody.trim()}\n${end}`;
+
+    const comments = await github.paginate(github.rest.issues.listComments, {
+        owner,
+        repo,
+        issue_number,
+        per_page: 100,
+    });
+    const existing = comments.find((comment) => comment.body?.includes(MARKER));
+
+    if (!existing) {
+        await github.rest.issues.createComment({ owner, repo, issue_number, body: `${PREAMBLE}\n${section}\n` });
+        return;
+    }
+
+    const sectionPattern = new RegExp(`${begin}[\\s\\S]*?${end}`);
+    const body = sectionPattern.test(existing.body)
+        ? existing.body.replace(sectionPattern, section)
+        : `${existing.body.trimEnd()}\n\n${section}\n`;
+
+    await github.rest.issues.updateComment({ owner, repo, comment_id: existing.id, body });
+};
diff --git a/.github/workflows/release-node-playwright.yaml b/.github/workflows/release-node-playwright.yaml
index 8412fc95..26bbaeec 100644
--- a/.github/workflows/release-node-playwright.yaml
+++ b/.github/workflows/release-node-playwright.yaml
@@ -373,6 +373,11 @@ jobs:
     runs-on: ubuntu-latest
     permissions:
       pull-requests: write
+    # All image workflows update sections of ONE shared PR comment; the repo-wide
+    # concurrency group serializes their read-modify-write so no section is lost.
+    concurrency:
+      group: image-size-comment-${{ github.event.pull_request.number }}
+      cancel-in-progress: false
 
     steps:
       - name: Checkout
@@ -391,13 +396,17 @@ jobs:
         with:
           node-version: 24
 
-      - name: Render comment body
+      - name: Render comment section
         run: |
           mkdir -p size-reports
-          node .github/scripts/format-image-size-report.ts size-reports | tee image-size-comment.md
+          node .github/scripts/format-image-size-report.ts size-reports "Node + Playwright images" "${{ github.event.pull_request.head.sha }}" | tee image-size-comment.md
 
       - name: Post or update image size comment
-        uses: marocchino/sticky-pull-request-comment@v3
+        uses: actions/github-script@v8
+        env:
+          SECTION_KEY: node-playwright
         with:
-          header: image-sizes-node-playwright
-          path: image-size-comment.md
+          script: |
+            const { readFileSync } = require('node:fs');
+            const upsertSection = require('./.github/scripts/upsert-image-size-comment.js');
+            await upsertSection({ github, context }, process.env.SECTION_KEY, readFileSync('image-size-comment.md', 'utf8'));
diff --git a/.github/workflows/release-node-puppeteer.yaml b/.github/workflows/release-node-puppeteer.yaml
index 0987ed00..c905ab53 100644
--- a/.github/workflows/release-node-puppeteer.yaml
+++ b/.github/workflows/release-node-puppeteer.yaml
@@ -353,6 +353,11 @@ jobs:
     runs-on: ubuntu-latest
     permissions:
       pull-requests: write
+    # All image workflows update sections of ONE shared PR comment; the repo-wide
+    # concurrency group serializes their read-modify-write so no section is lost.
+    concurrency:
+      group: image-size-comment-${{ github.event.pull_request.number }}
+      cancel-in-progress: false
 
     steps:
       - name: Checkout
@@ -371,13 +376,17 @@ jobs:
         with:
           node-version: 24
 
-      - name: Render comment body
+      - name: Render comment section
         run: |
           mkdir -p size-reports
-          node .github/scripts/format-image-size-report.ts size-reports | tee image-size-comment.md
+          node .github/scripts/format-image-size-report.ts size-reports "Node + Puppeteer images" "${{ github.event.pull_request.head.sha }}" | tee image-size-comment.md
 
       - name: Post or update image size comment
-        uses: marocchino/sticky-pull-request-comment@v3
+        uses: actions/github-script@v8
+        env:
+          SECTION_KEY: node-puppeteer
         with:
-          header: image-sizes-node-puppeteer
-          path: image-size-comment.md
+          script: |
+            const { readFileSync } = require('node:fs');
+            const upsertSection = require('./.github/scripts/upsert-image-size-comment.js');
+            await upsertSection({ github, context }, process.env.SECTION_KEY, readFileSync('image-size-comment.md', 'utf8'));
diff --git a/.github/workflows/release-node.yaml b/.github/workflows/release-node.yaml
index 47edc6e7..40ea779c 100644
--- a/.github/workflows/release-node.yaml
+++ b/.github/workflows/release-node.yaml
@@ -341,6 +341,11 @@ jobs:
     runs-on: ubuntu-latest
     permissions:
       pull-requests: write
+    # All image workflows update sections of ONE shared PR comment; the repo-wide
+    # concurrency group serializes their read-modify-write so no section is lost.
+    concurrency:
+      group: image-size-comment-${{ github.event.pull_request.number }}
+      cancel-in-progress: false
 
     steps:
       - name: Checkout
@@ -359,13 +364,17 @@ jobs:
         with:
           node-version: 24
 
-      - name: Render comment body
+      - name: Render comment section
         run: |
           mkdir -p size-reports
-          node .github/scripts/format-image-size-report.ts size-reports | tee image-size-comment.md
+          node .github/scripts/format-image-size-report.ts size-reports "Node basic images" "${{ github.event.pull_request.head.sha }}" | tee image-size-comment.md
 
       - name: Post or update image size comment
-        uses: marocchino/sticky-pull-request-comment@v3
+        uses: actions/github-script@v8
+        env:
+          SECTION_KEY: node
         with:
-          header: image-sizes-node
-          path: image-size-comment.md
+          script: |
+            const { readFileSync } = require('node:fs');
+            const upsertSection = require('./.github/scripts/upsert-image-size-comment.js');
+            await upsertSection({ github, context }, process.env.SECTION_KEY, readFileSync('image-size-comment.md', 'utf8'));
diff --git a/.github/workflows/release-python-playwright.yaml b/.github/workflows/release-python-playwright.yaml
index abe42cbb..18f7ec74 100644
--- a/.github/workflows/release-python-playwright.yaml
+++ b/.github/workflows/release-python-playwright.yaml
@@ -255,6 +255,11 @@ jobs:
     runs-on: ubuntu-latest
     permissions:
       pull-requests: write
+    # All image workflows update sections of ONE shared PR comment; the repo-wide
+    # concurrency group serializes their read-modify-write so no section is lost.
+    concurrency:
+      group: image-size-comment-${{ github.event.pull_request.number }}
+      cancel-in-progress: false
 
     steps:
       - name: Checkout
@@ -273,13 +278,17 @@ jobs:
         with:
           node-version: 24
 
-      - name: Render comment body
+      - name: Render comment section
         run: |
           mkdir -p size-reports
-          node .github/scripts/format-image-size-report.ts size-reports | tee image-size-comment.md
+          node .github/scripts/format-image-size-report.ts size-reports "Python + Playwright images" "${{ github.event.pull_request.head.sha }}" | tee image-size-comment.md
 
       - name: Post or update image size comment
-        uses: marocchino/sticky-pull-request-comment@v3
+        uses: actions/github-script@v8
+        env:
+          SECTION_KEY: python-playwright
         with:
-          header: image-sizes-python-playwright
-          path: image-size-comment.md
+          script: |
+            const { readFileSync } = require('node:fs');
+            const upsertSection = require('./.github/scripts/upsert-image-size-comment.js');
+            await upsertSection({ github, context }, process.env.SECTION_KEY, readFileSync('image-size-comment.md', 'utf8'));
diff --git a/.github/workflows/release-python-selenium.yaml b/.github/workflows/release-python-selenium.yaml
index 0fc09135..3a253975 100644
--- a/.github/workflows/release-python-selenium.yaml
+++ b/.github/workflows/release-python-selenium.yaml
@@ -230,6 +230,11 @@ jobs:
     runs-on: ubuntu-latest
     permissions:
       pull-requests: write
+    # All image workflows update sections of ONE shared PR comment; the repo-wide
+    # concurrency group serializes their read-modify-write so no section is lost.
+    concurrency:
+      group: image-size-comment-${{ github.event.pull_request.number }}
+      cancel-in-progress: false
 
     steps:
       - name: Checkout
@@ -248,13 +253,17 @@ jobs:
         with:
           node-version: 24
 
-      - name: Render comment body
+      - name: Render comment section
         run: |
           mkdir -p size-reports
-          node .github/scripts/format-image-size-report.ts size-reports | tee image-size-comment.md
+          node .github/scripts/format-image-size-report.ts size-reports "Python + Selenium images" "${{ github.event.pull_request.head.sha }}" | tee image-size-comment.md
 
       - name: Post or update image size comment
-        uses: marocchino/sticky-pull-request-comment@v3
+        uses: actions/github-script@v8
+        env:
+          SECTION_KEY: python-selenium
         with:
-          header: image-sizes-python-selenium
-          path: image-size-comment.md
+          script: |
+            const { readFileSync } = require('node:fs');
+            const upsertSection = require('./.github/scripts/upsert-image-size-comment.js');
+            await upsertSection({ github, context }, process.env.SECTION_KEY, readFileSync('image-size-comment.md', 'utf8'));
diff --git a/.github/workflows/release-python.yaml b/.github/workflows/release-python.yaml
index d4611cac..ba9f8d80 100644
--- a/.github/workflows/release-python.yaml
+++ b/.github/workflows/release-python.yaml
@@ -227,6 +227,11 @@ jobs:
     runs-on: ubuntu-latest
     permissions:
       pull-requests: write
+    # All image workflows update sections of ONE shared PR comment; the repo-wide
+    # concurrency group serializes their read-modify-write so no section is lost.
+    concurrency:
+      group: image-size-comment-${{ github.event.pull_request.number }}
+      cancel-in-progress: false
 
     steps:
       - name: Checkout
@@ -245,13 +250,17 @@ jobs:
         with:
           node-version: 24
 
-      - name: Render comment body
+      - name: Render comment section
         run: |
           mkdir -p size-reports
-          node .github/scripts/format-image-size-report.ts size-reports | tee image-size-comment.md
+          node .github/scripts/format-image-size-report.ts size-reports "Python basic images" "${{ github.event.pull_request.head.sha }}" | tee image-size-comment.md
 
       - name: Post or update image size comment
-        uses: marocchino/sticky-pull-request-comment@v3
+        uses: actions/github-script@v8
+        env:
+          SECTION_KEY: python
         with:
-          header: image-sizes-python
-          path: image-size-comment.md
+          script: |
+            const { readFileSync } = require('node:fs');
+            const upsertSection = require('./.github/scripts/upsert-image-size-comment.js');
+            await upsertSection({ github, context }, process.env.SECTION_KEY, readFileSync('image-size-comment.md', 'utf8'));