test Depot runners for team commits (#6394)

Co-authored-by: ConnorYoh <[email protected]>

.github/config/.files.yaml

@@ -8,7 +8,6 @@ openapi: &openapi
 
 docker-base: &docker-base
   - docker/base/Dockerfile
-  - ".github/workflows/push-docker-base.yml"
 
 docker: &docker
   - docker/embedded/Dockerfile

.github/workflows/PR-Auto-Deploy-V2.yml

@@ -23,9 +23,13 @@ permissions:
   pull-requests: write
 
 jobs:
+  pick:
+    uses: ./.github/workflows/_runner-pick.yml
+
   check-pr:
     if: (github.event_name == 'pull_request' && github.event.action != 'closed') || github.event_name == 'workflow_dispatch'
-    runs-on: ubuntu-latest
+    needs: pick
+    runs-on: ${{ needs.pick.outputs.is_fork == 'true' && 'ubuntu-latest' || 'depot-ubuntu-24.04-4' }}
     outputs:
       should_deploy: ${{ steps.decide.outputs.should_deploy }}
       is_fork: ${{ steps.resolve.outputs.is_fork }}
@@ -97,8 +101,8 @@ jobs:
           echo "allow_fork=${allow_fork:-false}" >> $GITHUB_OUTPUT
 
   deploy-v2-pr:
-    needs: check-pr
-    runs-on: ubuntu-latest
+    needs: [pick, check-pr]
+    runs-on: ${{ needs.pick.outputs.is_fork == 'true' && 'ubuntu-latest' || 'depot-ubuntu-24.04-4' }}
     if: needs.check-pr.outputs.should_deploy == 'true' && (needs.check-pr.outputs.is_fork == 'false' || needs.check-pr.outputs.allow_fork == 'true')
     # Concurrency control - only one deployment per PR at a time
     concurrency:
@@ -108,6 +112,10 @@ jobs:
       contents: read
       issues: write
       pull-requests: write
+      id-token: write
+    env:
+      USE_DEPOT: ${{ needs.pick.outputs.is_fork != 'true' }}
+      DEPOT_TOKEN: ${{ secrets.DEPOT_TOKEN }}
 
     steps:
       - name: Harden Runner
@@ -179,7 +187,12 @@ jobs:
           token: ${{ secrets.GITHUB_TOKEN }}
           fetch-depth: 0 # Fetch full history for commit hash detection
 
+      - name: Set up Depot CLI
+        if: env.USE_DEPOT == 'true'
+        uses: depot/setup-action@15c09a5f77a0840ad4bce955686522a257853461 # v1.0.0
+
       - name: Set up Docker Buildx
+        if: env.USE_DEPOT != 'true'
         uses: docker/setup-buildx-action@4d04d5d9486b7bd6fa91e7baf45bbb4f8b9deedd # v4.0.0
 
       - name: Get version number
@@ -224,8 +237,20 @@ jobs:
             echo "Image needs to be built"
           fi
 
-      - name: Build and push V2 image
-        if: steps.check-image.outputs.exists == 'false'
+      - name: Build and push V2 image (Depot)
+        if: env.USE_DEPOT == 'true' && steps.check-image.outputs.exists == 'false'
+        uses: depot/build-push-action@5f3b3c2e5a00f0093de47f657aeaefcedff27d18 # v1.16.0
+        with:
+          project: ${{ vars.DEPOT_PROJECT_ID }}
+          context: .
+          file: ./docker/embedded/Dockerfile
+          push: true
+          tags: ${{ secrets.DOCKER_HUB_USERNAME }}/test:v2-${{ steps.commit-hash.outputs.app_short }}
+          build-args: VERSION_TAG=v2-alpha
+          platforms: linux/amd64
+
+      - name: Build and push V2 image (Docker fork fallback)
+        if: env.USE_DEPOT != 'true' && steps.check-image.outputs.exists == 'false'
         uses: docker/build-push-action@bcafcacb16a39f128d818304e6c9c0c18556b85f # v7.1.0
         with:
           context: .
@@ -351,7 +376,8 @@ jobs:
 
   cleanup-v2-deployment:
     if: github.event.action == 'closed'
-    runs-on: ubuntu-latest
+    needs: pick
+    runs-on: ${{ needs.pick.outputs.is_fork == 'true' && 'ubuntu-latest' || 'depot-ubuntu-24.04-4' }}
     permissions:
       contents: read
       issues: write

.github/workflows/PR-Demo-Comment-with-react.yml

@@ -34,8 +34,12 @@ permissions:
   pull-requests: read
 
 jobs:
+  pick:
+    uses: ./.github/workflows/_runner-pick.yml
+
   check-comment:
-    runs-on: ubuntu-latest
+    needs: pick
+    runs-on: ${{ needs.pick.outputs.is_fork == 'true' && 'ubuntu-latest' || 'depot-ubuntu-24.04-4' }}
     permissions:
       issues: write
     if: |
@@ -175,11 +179,15 @@ jobs:
             }
 
   deploy-pr:
-    needs: check-comment
-    runs-on: ubuntu-latest
+    needs: [pick, check-comment]
+    runs-on: ${{ needs.pick.outputs.is_fork == 'true' && 'ubuntu-latest' || 'depot-ubuntu-24.04-4' }}
     permissions:
       issues: write
       pull-requests: write
+      id-token: write
+    env:
+      USE_DEPOT: ${{ needs.pick.outputs.is_fork != 'true' }}
+      DEPOT_TOKEN: ${{ secrets.DEPOT_TOKEN }}
 
     steps:
       - name: Harden Runner
@@ -232,7 +240,12 @@ jobs:
           MAVEN_PUBLIC_URL: ${{ secrets.MAVEN_PUBLIC_URL }}
           STIRLING_PDF_DESKTOP_UI: false
 
+      - name: Set up Depot CLI
+        if: env.USE_DEPOT == 'true'
+        uses: depot/setup-action@15c09a5f77a0840ad4bce955686522a257853461 # v1.0.0
+
       - name: Set up Docker Buildx
+        if: env.USE_DEPOT != 'true'
         uses: docker/setup-buildx-action@4d04d5d9486b7bd6fa91e7baf45bbb4f8b9deedd # v4.0.0
 
       - name: Login to Docker Hub
@@ -241,7 +254,22 @@ jobs:
           username: ${{ secrets.DOCKER_HUB_USERNAME }}
           password: ${{ secrets.DOCKER_HUB_API }}
 
-      - name: Build and push PR-specific image
+      - name: Build and push PR-specific image (Depot)
+        if: env.USE_DEPOT == 'true'
+        uses: depot/build-push-action@5f3b3c2e5a00f0093de47f657aeaefcedff27d18 # v1.16.0
+        with:
+          project: ${{ vars.DEPOT_PROJECT_ID }}
+          context: .
+          file: ./docker/embedded/Dockerfile
+          push: true
+          tags: ${{ secrets.DOCKER_HUB_USERNAME }}/test:pr-${{ needs.check-comment.outputs.pr_number }}
+          build-args: |
+            VERSION_TAG=alpha
+            PROTOTYPES_BUILD=${{ needs.check-comment.outputs.enable_prototypes }}
+          platforms: linux/amd64
+
+      - name: Build and push PR-specific image (Docker fork fallback)
+        if: env.USE_DEPOT != 'true'
         uses: docker/build-push-action@bcafcacb16a39f128d818304e6c9c0c18556b85f # v7.1.0
         with:
           context: .
@@ -255,8 +283,19 @@ jobs:
             PROTOTYPES_BUILD=${{ needs.check-comment.outputs.enable_prototypes }}
           platforms: linux/amd64
 
-      - name: Build and push engine image
-        if: needs.check-comment.outputs.enable_prototypes == 'true'
+      - name: Build and push engine image (Depot)
+        if: env.USE_DEPOT == 'true' && needs.check-comment.outputs.enable_prototypes == 'true'
+        uses: depot/build-push-action@5f3b3c2e5a00f0093de47f657aeaefcedff27d18 # v1.16.0
+        with:
+          project: ${{ vars.DEPOT_PROJECT_ID }}
+          context: ./engine
+          file: ./engine/Dockerfile
+          push: true
+          tags: ${{ secrets.DOCKER_HUB_USERNAME }}/test:engine-pr-${{ needs.check-comment.outputs.pr_number }}
+          platforms: linux/amd64
+
+      - name: Build and push engine image (Docker fork fallback)
+        if: env.USE_DEPOT != 'true' && needs.check-comment.outputs.enable_prototypes == 'true'
         uses: docker/build-push-action@bcafcacb16a39f128d818304e6c9c0c18556b85f # v7.1.0
         with:
           context: ./engine
@@ -471,7 +510,8 @@ jobs:
 
   handle-label-commands:
     if: ${{ github.event.issue.pull_request != null }}
-    runs-on: ubuntu-latest
+    needs: pick
+    runs-on: ${{ needs.pick.outputs.is_fork == 'true' && 'ubuntu-latest' || 'depot-ubuntu-24.04-4' }}
     steps:
       - name: Harden Runner
         uses: step-security/harden-runner@a5ad31d6a139d249332a2605b85202e8c0b78450 # v2.19.1

.github/workflows/_runner-pick.yml

@@ -0,0 +1,65 @@
+name: _runner-pick
+
+# Tiny reusable workflow that classifies the trigger as either a "fork PR
+# from an untrusted contributor" or a "trusted commit" so downstream jobs
+# can pick a runner class without each one duplicating the 200-char gate
+# expression in their own `runs-on:`.
+#
+# Caller pattern:
+#
+#   jobs:
+#     pick:
+#       uses: ./.github/workflows/_runner-pick.yml
+#
+#     real-work:
+#       needs: pick
+#       runs-on: ${{ needs.pick.outputs.is_fork == 'true' && 'ubuntu-latest' || 'depot-ubuntu-24.04-8' }}
+#       steps: [...]
+#
+# Output:
+#   is_fork: "true" when the trigger is a pull_request from a fork or an
+#            untrusted author_association, "false" otherwise.
+
+on:
+  workflow_call:
+    outputs:
+      is_fork:
+        description: '"true" if the trigger is an untrusted fork PR.'
+        value: ${{ jobs.pick.outputs.is_fork }}
+
+permissions:
+  contents: read
+
+jobs:
+  pick:
+    runs-on: ubuntu-latest
+    timeout-minutes: 1
+    outputs:
+      is_fork: ${{ steps.decide.outputs.is_fork }}
+    steps:
+      - name: Classify the trigger
+        id: decide
+        env:
+          PR_NUMBER: ${{ github.event.pull_request.number }}
+          HEAD_REPO_FORK: ${{ github.event.pull_request.head.repo.fork }}
+          AUTHOR_ASSOC: ${{ github.event.pull_request.author_association }}
+        run: |
+          set -eu
+          if [ -z "${PR_NUMBER:-}" ]; then
+            # Not a pull_request event at all (push, schedule, workflow_dispatch,
+            # workflow_call from a non-PR trigger) -> trusted by default.
+            echo "is_fork=false" >> "$GITHUB_OUTPUT"
+            exit 0
+          fi
+          if [ "${HEAD_REPO_FORK}" = "true" ]; then
+            echo "is_fork=true" >> "$GITHUB_OUTPUT"
+            exit 0
+          fi
+          case "${AUTHOR_ASSOC}" in
+            OWNER|MEMBER|COLLABORATOR)
+              echo "is_fork=false" >> "$GITHUB_OUTPUT"
+              ;;
+            *)
+              echo "is_fork=true" >> "$GITHUB_OUTPUT"
+              ;;
+          esac

.github/workflows/ai-engine.yml

@@ -17,6 +17,8 @@ jobs:
     permissions:
       contents: read
       pull-requests: write
+    env:
+      DEPOT_TOKEN: ${{ secrets.DEPOT_TOKEN }}
     steps:
       - name: Harden the runner (Audit all outbound calls)
         uses: step-security/harden-runner@a5ad31d6a139d249332a2605b85202e8c0b78450 # v2.19.1

.github/workflows/aur-publish.yml

@@ -106,7 +106,7 @@ jobs:
 
       - name: Publish stirling-pdf-desktop to AUR
         if: ${{ github.event_name == 'release' || inputs.dry_run == false }}
-        uses: KSXGitHub/[email protected]
+        uses: KSXGitHub/github-actions-deploy-aur@da03e160361ce01bf087e790b6ffd196d7dccff7 # v4.1.3
         with:
           pkgname: stirling-pdf-desktop
           pkgbuild: .github/aur/stirling-pdf-desktop/PKGBUILD

.github/workflows/backend-build.yml

@@ -13,8 +13,14 @@ permissions:
   pull-requests: write
 
 jobs:
+  pick:
+    uses: ./.github/workflows/_runner-pick.yml
+
   build:
-    runs-on: ubuntu-latest
+    needs: pick
+    runs-on: ${{ needs.pick.outputs.is_fork == 'true' && 'ubuntu-latest' || 'depot-ubuntu-24.04-8' }}
+    env:
+      DEPOT_TOKEN: ${{ secrets.DEPOT_TOKEN }}
     strategy:
       fail-fast: false
       matrix:

.github/workflows/build-enterprise.yml

@@ -17,11 +17,23 @@ name: Enterprise E2E (Playwright)
 
 on:
   workflow_call:
+    inputs:
+      depot_cores:
+        description: "Depot runner vCPU count (used in runs-on). Override for benchmarking."
+        required: false
+        type: string
+        default: "8"
   push:
     branches: ["main"]
   schedule:
     - cron: "0 4 * * *"
   workflow_dispatch:
+    inputs:
+      depot_cores:
+        description: "Depot runner vCPU count (used in runs-on). Override for benchmarking."
+        required: false
+        type: string
+        default: "8"
 
 # No `concurrency:` block here on purpose. When this workflow is called via
 # workflow_call from build.yml, ${{ github.workflow }}/event_name/pr_number
@@ -35,13 +47,18 @@ permissions:
   contents: read
 
 jobs:
+  pick:
+    uses: ./.github/workflows/_runner-pick.yml
+
   playwright-e2e-enterprise:
-    runs-on: ubuntu-latest
+    needs: pick
+    runs-on: ${{ needs.pick.outputs.is_fork == 'true' && 'ubuntu-latest' || format('depot-ubuntu-24.04-{0}', inputs.depot_cores || '8') }}
     timeout-minutes: 45
     env:
       PREMIUM_KEY: ${{ secrets.PREMIUM_KEY_ENTERPRISE }}
       PREMIUM_ENABLED: "true"
       SYSTEM_ENABLEANALYTICS: "false"
+      DEPOT_TOKEN: ${{ secrets.DEPOT_TOKEN }}
     steps:
       - name: Harden Runner
         uses: step-security/harden-runner@a5ad31d6a139d249332a2605b85202e8c0b78450 # v2.19.1

.github/workflows/build.yml

@@ -135,6 +135,7 @@ jobs:
     permissions:
       contents: read
       packages: read
+      id-token: write
     uses: ./.github/workflows/test-build-docker.yml
     secrets: inherit
     with:

.github/workflows/check-licence.yml

@@ -11,6 +11,8 @@ permissions:
 jobs:
   check-licence:
     runs-on: ubuntu-latest
+    env:
+      DEPOT_TOKEN: ${{ secrets.DEPOT_TOKEN }}
     steps:
       - name: Harden Runner
         uses: step-security/harden-runner@a5ad31d6a139d249332a2605b85202e8c0b78450 # v2.19.1

.github/workflows/check-openapi.yml

@@ -10,8 +10,14 @@ permissions:
   contents: read
 
 jobs:
+  pick:
+    uses: ./.github/workflows/_runner-pick.yml
+
   check-generate-openapi-docs:
-    runs-on: ubuntu-latest
+    needs: pick
+    runs-on: ${{ needs.pick.outputs.is_fork == 'true' && 'ubuntu-latest' || 'depot-ubuntu-24.04-4' }}
+    env:
+      DEPOT_TOKEN: ${{ secrets.DEPOT_TOKEN }}
     steps:
       - name: Harden Runner
         uses: step-security/harden-runner@a5ad31d6a139d249332a2605b85202e8c0b78450 # v2.19.1

.github/workflows/deploy-on-v2-commit.yml

@@ -10,11 +10,21 @@ permissions:
   contents: read
 
 jobs:
+  pick:
+    uses: ./.github/workflows/_runner-pick.yml
+
   deploy-v2-on-push:
-    runs-on: ubuntu-latest
+    needs: pick
+    runs-on: ${{ needs.pick.outputs.is_fork == 'true' && 'ubuntu-latest' || 'depot-ubuntu-24.04-4' }}
     concurrency:
       group: deploy-v2-push-V2
       cancel-in-progress: true
+    permissions:
+      contents: read
+      id-token: write
+    env:
+      USE_DEPOT: ${{ needs.pick.outputs.is_fork != 'true' }}
+      DEPOT_TOKEN: ${{ secrets.DEPOT_TOKEN }}
 
     steps:
       - name: Harden Runner
@@ -25,7 +35,12 @@ jobs:
       - name: Checkout code
         uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
 
+      - name: Set up Depot CLI
+        if: env.USE_DEPOT == 'true'
+        uses: depot/setup-action@15c09a5f77a0840ad4bce955686522a257853461 # v1.0.0
+
       - name: Set up Docker Buildx
+        if: env.USE_DEPOT != 'true'
         uses: docker/setup-buildx-action@4d04d5d9486b7bd6fa91e7baf45bbb4f8b9deedd # v4.0.0
 
       - name: Get commit hashes for frontend and backend
@@ -90,8 +105,22 @@ jobs:
           username: ${{ secrets.DOCKER_HUB_USERNAME }}
           password: ${{ secrets.DOCKER_HUB_API }}
 
-      - name: Build and push frontend image
-        if: steps.check-frontend.outputs.exists == 'false'
+      - name: Build and push frontend image (Depot)
+        if: env.USE_DEPOT == 'true' && steps.check-frontend.outputs.exists == 'false'
+        uses: depot/build-push-action@5f3b3c2e5a00f0093de47f657aeaefcedff27d18 # v1.16.0
+        with:
+          project: ${{ vars.DEPOT_PROJECT_ID }}
+          context: .
+          file: ./docker/frontend/Dockerfile
+          push: true
+          tags: |
+            ${{ secrets.DOCKER_HUB_USERNAME }}/test:v2-frontend-${{ steps.commit-hashes.outputs.frontend_short }}
+            ${{ secrets.DOCKER_HUB_USERNAME }}/test:v2-frontend-latest
+          build-args: VERSION_TAG=v2-alpha
+          platforms: linux/amd64
+
+      - name: Build and push frontend image (Docker fork fallback)
+        if: env.USE_DEPOT != 'true' && steps.check-frontend.outputs.exists == 'false'
         uses: docker/build-push-action@bcafcacb16a39f128d818304e6c9c0c18556b85f # v7.1.0
         with:
           context: .
@@ -105,8 +134,22 @@ jobs:
           build-args: VERSION_TAG=v2-alpha
           platforms: linux/amd64
 
-      - name: Build and push backend image
-        if: steps.check-backend.outputs.exists == 'false'
+      - name: Build and push backend image (Depot)
+        if: env.USE_DEPOT == 'true' && steps.check-backend.outputs.exists == 'false'
+        uses: depot/build-push-action@5f3b3c2e5a00f0093de47f657aeaefcedff27d18 # v1.16.0
+        with:
+          project: ${{ vars.DEPOT_PROJECT_ID }}
+          context: .
+          file: ./docker/backend/Dockerfile
+          push: true
+          tags: |
+            ${{ secrets.DOCKER_HUB_USERNAME }}/test:v2-backend-${{ steps.commit-hashes.outputs.backend_short }}
+            ${{ secrets.DOCKER_HUB_USERNAME }}/test:v2-backend-latest
+          build-args: VERSION_TAG=v2-alpha
+          platforms: linux/amd64
+
+      - name: Build and push backend image (Docker fork fallback)
+        if: env.USE_DEPOT != 'true' && steps.check-backend.outputs.exists == 'false'
         uses: docker/build-push-action@bcafcacb16a39f128d818304e6c9c0c18556b85f # v7.1.0
         with:
           context: .

.github/workflows/docker-compose-tests.yml

@@ -11,17 +11,28 @@ on:
         required: false
         type: string
         default: "false"
+      depot_cores:
+        description: "Depot runner vCPU count (used in runs-on). Override for benchmarking. Tuned to 4 because bench showed 16 was within noise of 4."
+        required: false
+        type: string
+        default: "4"
 
 permissions:
   contents: read
 
 jobs:
+  pick:
+    uses: ./.github/workflows/_runner-pick.yml
+
   docker-compose-tests:
-    runs-on: ubuntu-latest
+    needs: pick
+    runs-on: ${{ needs.pick.outputs.is_fork == 'true' && 'ubuntu-latest' || format('depot-ubuntu-24.04-{0}', inputs.depot_cores || '4') }}
     permissions:
       actions: write
       contents: read
       checks: write
+    env:
+      DEPOT_TOKEN: ${{ secrets.DEPOT_TOKEN }}
 
     steps:
       - name: Harden Runner

.github/workflows/e2e-live.yml

@@ -5,13 +5,23 @@ name: Playwright E2E (live backend)
 # server.
 on:
   workflow_call:
+    inputs:
+      depot_cores:
+        description: "Depot runner vCPU count (used in runs-on). Override for benchmarking."
+        required: false
+        type: string
+        default: "8"
 
 permissions:
   contents: read
 
 jobs:
+  pick:
+    uses: ./.github/workflows/_runner-pick.yml
+
   playwright-e2e-live:
-    runs-on: ubuntu-latest
+    needs: pick
+    runs-on: ${{ needs.pick.outputs.is_fork == 'true' && 'ubuntu-latest' || format('depot-ubuntu-24.04-{0}', inputs.depot_cores || '8') }}
     timeout-minutes: 30
     steps:
       - name: Harden Runner

.github/workflows/e2e-stubbed.yml

@@ -5,13 +5,23 @@ name: Playwright E2E (stubbed)
 # mocks API responses in the browser.
 on:
   workflow_call:
+    inputs:
+      depot_cores:
+        description: "Depot runner vCPU count (used in runs-on). Override for benchmarking. Tuned to 8 to match the other playwright workflows; bench showed flat scaling above 8."
+        required: false
+        type: string
+        default: "8"
 
 permissions:
   contents: read
 
 jobs:
+  pick:
+    uses: ./.github/workflows/_runner-pick.yml
+
   playwright-e2e:
-    runs-on: ubuntu-latest
+    needs: pick
+    runs-on: ${{ needs.pick.outputs.is_fork == 'true' && 'ubuntu-latest' || format('depot-ubuntu-24.04-{0}', inputs.depot_cores || '8') }}
     steps:
       - name: Harden Runner
         uses: step-security/harden-runner@a5ad31d6a139d249332a2605b85202e8c0b78450 # v2.19.1

.github/workflows/frontend-backend-licenses-update.yml

@@ -19,9 +19,13 @@ permissions:
   contents: read
 
 jobs:
+  pick:
+    uses: ./.github/workflows/_runner-pick.yml
+
   files-changed:
     name: detect what files changed
-    runs-on: ubuntu-latest
+    needs: pick
+    runs-on: ${{ needs.pick.outputs.is_fork == 'true' && 'ubuntu-latest' || 'depot-ubuntu-24.04-4' }}
     timeout-minutes: 3
     outputs:
       licenses-frontend: ${{ steps.changes.outputs.licenses-frontend }}
@@ -44,8 +48,8 @@ jobs:
   generate-frontend-license-report:
     if: needs.files-changed.outputs.licenses-frontend == 'true'
     name: Generate Frontend License Report
-    needs: files-changed
-    runs-on: ubuntu-latest
+    needs: [pick, files-changed]
+    runs-on: ${{ needs.pick.outputs.is_fork == 'true' && 'ubuntu-latest' || 'depot-ubuntu-24.04-4' }}
     permissions:
       contents: write
       pull-requests: write
@@ -307,13 +311,15 @@ jobs:
 
   generate-backend-license-report:
     if: needs.files-changed.outputs.licenses-backend == 'true'
-    needs: files-changed
+    needs: [pick, files-changed]
     name: Generate Backend License Report
-    runs-on: ubuntu-latest
+    runs-on: ${{ needs.pick.outputs.is_fork == 'true' && 'ubuntu-latest' || 'depot-ubuntu-24.04-4' }}
     permissions:
       contents: write
       pull-requests: write
       repository-projects: write # Required for enabling automerge
+    env:
+      DEPOT_TOKEN: ${{ secrets.DEPOT_TOKEN }}
     steps:
       - name: Harden Runner
         uses: step-security/harden-runner@a5ad31d6a139d249332a2605b85202e8c0b78450 # v2.19.1

.github/workflows/frontend-validation.yml

@@ -11,8 +11,12 @@ permissions:
   pull-requests: write
 
 jobs:
+  pick:
+    uses: ./.github/workflows/_runner-pick.yml
+
   frontend-validation:
-    runs-on: ubuntu-latest
+    needs: pick
+    runs-on: ${{ needs.pick.outputs.is_fork == 'true' && 'ubuntu-latest' || 'depot-ubuntu-24.04-4' }}
     steps:
       - name: Harden Runner
         uses: step-security/harden-runner@a5ad31d6a139d249332a2605b85202e8c0b78450 # v2.19.1

.github/workflows/multiOSReleases.yml

@@ -36,9 +36,13 @@ permissions:
   contents: read
 
 jobs:
+  pick:
+    uses: ./.github/workflows/_runner-pick.yml
+
   determine-matrix:
     if: ${{ vars.CI_PROFILE != 'lite' }}
-    runs-on: ubuntu-latest
+    needs: pick
+    runs-on: ${{ needs.pick.outputs.is_fork == 'true' && 'ubuntu-latest' || 'depot-ubuntu-24.04-4' }}
     outputs:
       matrix: ${{ steps.set-matrix.outputs.matrix }}
       version: ${{ steps.versionNumber.outputs.versionNumber }}
@@ -108,8 +112,10 @@ jobs:
           fi
 
   build-jars:
-    needs: determine-matrix
-    runs-on: ubuntu-latest
+    needs: [pick, determine-matrix]
+    runs-on: ${{ needs.pick.outputs.is_fork == 'true' && 'ubuntu-latest' || 'depot-ubuntu-24.04-4' }}
+    env:
+      DEPOT_TOKEN: ${{ secrets.DEPOT_TOKEN }}
     strategy:
       matrix:
         variant:
@@ -189,6 +195,7 @@ jobs:
       SM_API_KEY: ${{ secrets.SM_API_KEY }}
       WINDOWS_CERTIFICATE: ${{ secrets.WINDOWS_CERTIFICATE }}
       RELEASE_GPG_PRIVATE_KEY: ${{ secrets.RELEASE_GPG_PRIVATE_KEY }}
+      DEPOT_TOKEN: ${{ secrets.DEPOT_TOKEN }}
     steps:
       - name: Harden Runner
         uses: step-security/harden-runner@a5ad31d6a139d249332a2605b85202e8c0b78450 # v2.19.1
@@ -600,8 +607,8 @@ jobs:
 
   create-release:
     if: (github.event_name == 'workflow_dispatch' && github.event.inputs.test_mode != 'true') || github.event_name == 'release' || github.ref == 'refs/heads/V2-master'
-    needs: [determine-matrix, build, build-jars]
-    runs-on: ubuntu-latest
+    needs: [pick, determine-matrix, build, build-jars]
+    runs-on: ${{ needs.pick.outputs.is_fork == 'true' && 'ubuntu-latest' || 'depot-ubuntu-24.04-4' }}
     permissions:
       contents: write
     steps:

.github/workflows/nightly.yml

@@ -13,9 +13,13 @@ permissions:
   contents: read
 
 jobs:
+  pick:
+    uses: ./.github/workflows/_runner-pick.yml
+
   playwright-all-browsers:
     name: Playwright (chromium + firefox + webkit)
-    runs-on: ubuntu-latest
+    needs: pick
+    runs-on: ${{ needs.pick.outputs.is_fork == 'true' && 'ubuntu-latest' || 'depot-ubuntu-24.04-4' }}
     steps:
       - name: Harden the runner (Audit all outbound calls)
         uses: step-security/harden-runner@a5ad31d6a139d249332a2605b85202e8c0b78450 # v2.19.1

.github/workflows/swagger.yml

@@ -22,9 +22,15 @@ permissions:
   contents: read
 
 jobs:
+  pick:
+    uses: ./.github/workflows/_runner-pick.yml
+
   push:
     if: ${{ vars.CI_PROFILE != 'lite' }}
-    runs-on: ubuntu-latest
+    needs: pick
+    runs-on: ${{ needs.pick.outputs.is_fork == 'true' && 'ubuntu-latest' || 'depot-ubuntu-24.04-4' }}
+    env:
+      DEPOT_TOKEN: ${{ secrets.DEPOT_TOKEN }}
     steps:
       - name: Harden Runner
         uses: step-security/harden-runner@a5ad31d6a139d249332a2605b85202e8c0b78450 # v2.19.1

.github/workflows/tauri-build.yml

@@ -84,6 +84,7 @@ jobs:
       WINDOWS_CERTIFICATE: ${{ secrets.WINDOWS_CERTIFICATE }}
       APPLE_CERTIFICATE: ${{ secrets.APPLE_CERTIFICATE }}
       RELEASE_GPG_PRIVATE_KEY: ${{ secrets.RELEASE_GPG_PRIVATE_KEY }}
+      DEPOT_TOKEN: ${{ secrets.DEPOT_TOKEN }}
     steps:
       - name: Harden Runner
         uses: step-security/harden-runner@a5ad31d6a139d249332a2605b85202e8c0b78450 # v2.19.1

.github/workflows/test-build-docker.yml

@@ -12,11 +12,19 @@ on:
         required: false
         type: string
         default: "false"
+      depot_cores:
+        description: "Depot runner vCPU count (used in runs-on). Override for benchmarking."
+        required: false
+        type: string
+        default: "8"
 
 permissions:
   contents: read
 
 jobs:
+  pick:
+    uses: ./.github/workflows/_runner-pick.yml
+
   # TODO: extract a pre-matrix `prepare` job that runs once and produces
   # shared artifacts for the three matrix entries below to consume:
   #   1. `task backend:build` — currently runs 3× in parallel with
@@ -32,7 +40,14 @@ jobs:
   # spring-security=true matrix entry if `task backend:build` and
   # `task backend:build:ci` produce equivalent JARs (verify before wiring).
   test-build-docker-images:
-    runs-on: ubuntu-latest
+    needs: pick
+    runs-on: ${{ needs.pick.outputs.is_fork == 'true' && 'ubuntu-latest' || format('depot-ubuntu-24.04-{0}', inputs.depot_cores || '8') }}
+    permissions:
+      contents: read
+      id-token: write
+    env:
+      USE_DEPOT: ${{ needs.pick.outputs.is_fork != 'true' && inputs.docker-base-changed != 'true' }}
+      DEPOT_TOKEN: ${{ secrets.DEPOT_TOKEN }}
     strategy:
       fail-fast: false
       matrix:
@@ -105,10 +120,16 @@ jobs:
           DISABLE_ADDITIONAL_FEATURES: true
           STIRLING_PDF_DESKTOP_UI: false
 
+      - name: Set up Depot CLI
+        if: env.USE_DEPOT == 'true'
+        uses: depot/setup-action@15c09a5f77a0840ad4bce955686522a257853461 # v1.0.0
+
       - name: Set up QEMU
+        if: env.USE_DEPOT != 'true'
         uses: docker/setup-qemu-action@ce360397dd3f832beb865e1373c09c0e9f86d70a # v4.0.0
 
       - name: Set up Docker Buildx
+        if: env.USE_DEPOT != 'true'
         id: buildx
         uses: docker/setup-buildx-action@4d04d5d9486b7bd6fa91e7baf45bbb4f8b9deedd # v4.0.0
 
@@ -134,7 +155,22 @@ jobs:
             echo "platforms=linux/amd64,linux/arm64/v8" >> "$GITHUB_OUTPUT"
           fi
 
-      - name: Build ${{ matrix.docker-rev }}
+      - name: Build ${{ matrix.docker-rev }} (Depot)
+        if: env.USE_DEPOT == 'true'
+        uses: depot/build-push-action@5f3b3c2e5a00f0093de47f657aeaefcedff27d18 # v1.16.0
+        with:
+          project: ${{ vars.DEPOT_PROJECT_ID }}
+          context: .
+          file: ./${{ matrix.docker-rev }}
+          push: false
+          platforms: ${{ steps.build-params.outputs.platforms }}
+          build-args: |
+            BASE_IMAGE=${{ steps.build-params.outputs.base_image }}
+          provenance: true
+          sbom: true
+
+      - name: Build ${{ matrix.docker-rev }} (Docker fork fallback)
+        if: env.USE_DEPOT != 'true'
         uses: docker/build-push-action@bcafcacb16a39f128d818304e6c9c0c18556b85f # v7.1.0
         with:
           builder: ${{ steps.buildx.outputs.name }}
@@ -162,7 +198,14 @@ jobs:
           if-no-files-found: warn
 
   test-build-unoserver-image:
-    runs-on: ubuntu-latest
+    needs: pick
+    runs-on: ${{ needs.pick.outputs.is_fork == 'true' && 'ubuntu-latest' || format('depot-ubuntu-24.04-{0}', inputs.depot_cores || '8') }}
+    permissions:
+      contents: read
+      id-token: write
+    env:
+      USE_DEPOT: ${{ needs.pick.outputs.is_fork != 'true' && inputs.docker-base-changed != 'true' }}
+      DEPOT_TOKEN: ${{ secrets.DEPOT_TOKEN }}
     steps:
       - name: Harden Runner
         uses: step-security/harden-runner@a5ad31d6a139d249332a2605b85202e8c0b78450 # v2.19.1
@@ -172,14 +215,35 @@ jobs:
       - name: Checkout Repository
         uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
 
+      - name: Set up Depot CLI
+        if: env.USE_DEPOT == 'true'
+        uses: depot/setup-action@15c09a5f77a0840ad4bce955686522a257853461 # v1.0.0
+
       - name: Set up QEMU
+        if: env.USE_DEPOT != 'true'
         uses: docker/setup-qemu-action@ce360397dd3f832beb865e1373c09c0e9f86d70a # v4.0.0
 
       - name: Set up Docker Buildx
+        if: env.USE_DEPOT != 'true'
         id: buildx
         uses: docker/setup-buildx-action@4d04d5d9486b7bd6fa91e7baf45bbb4f8b9deedd # v4.0.0
 
-      - name: Build docker/unoserver/Dockerfile
+      - name: Build docker/unoserver/Dockerfile (Depot)
+        if: env.USE_DEPOT == 'true'
+        uses: depot/build-push-action@5f3b3c2e5a00f0093de47f657aeaefcedff27d18 # v1.16.0
+        with:
+          project: ${{ vars.DEPOT_PROJECT_ID }}
+          context: .
+          file: ./docker/unoserver/Dockerfile
+          push: false
+          load: true
+          platforms: linux/amd64
+          tags: stirling-unoserver:pr-test
+          provenance: false
+          sbom: false
+
+      - name: Build docker/unoserver/Dockerfile (Docker fork fallback)
+        if: env.USE_DEPOT != 'true'
         uses: docker/build-push-action@bcafcacb16a39f128d818304e6c9c0c18556b85f # v7.1.0
         with:
           builder: ${{ steps.buildx.outputs.name }}

.github/workflows/testdriver.yml

@@ -20,9 +20,19 @@ permissions:
   contents: read
 
 jobs:
+  pick:
+    uses: ./.github/workflows/_runner-pick.yml
+
   deploy:
     if: ${{ vars.CI_PROFILE != 'lite' }}
-    runs-on: ubuntu-latest
+    needs: pick
+    runs-on: ${{ needs.pick.outputs.is_fork == 'true' && 'ubuntu-latest' || 'depot-ubuntu-24.04-4' }}
+    permissions:
+      contents: read
+      id-token: write
+    env:
+      USE_DEPOT: ${{ needs.pick.outputs.is_fork != 'true' }}
+      DEPOT_TOKEN: ${{ secrets.DEPOT_TOKEN }}
     steps:
       - name: Harden Runner
         uses: step-security/harden-runner@a5ad31d6a139d249332a2605b85202e8c0b78450 # v2.19.1
@@ -51,7 +61,12 @@ jobs:
           MAVEN_PUBLIC_URL: ${{ secrets.MAVEN_PUBLIC_URL }}
           DISABLE_ADDITIONAL_FEATURES: true
 
+      - name: Set up Depot CLI
+        if: env.USE_DEPOT == 'true'
+        uses: depot/setup-action@15c09a5f77a0840ad4bce955686522a257853461 # v1.0.0
+
       - name: Set up Docker Buildx
+        if: env.USE_DEPOT != 'true'
         uses: docker/setup-buildx-action@4d04d5d9486b7bd6fa91e7baf45bbb4f8b9deedd # v4.0.0
 
       - name: Get version number
@@ -66,7 +81,20 @@ jobs:
           username: ${{ secrets.DOCKER_HUB_USERNAME }}
           password: ${{ secrets.DOCKER_HUB_API }}
 
-      - name: Build and push test image
+      - name: Build and push test image (Depot)
+        if: env.USE_DEPOT == 'true'
+        uses: depot/build-push-action@5f3b3c2e5a00f0093de47f657aeaefcedff27d18 # v1.16.0
+        with:
+          project: ${{ vars.DEPOT_PROJECT_ID }}
+          context: .
+          file: ./docker/embedded/Dockerfile
+          push: true
+          tags: ${{ secrets.DOCKER_HUB_USERNAME }}/test:test-${{ github.sha }}
+          build-args: VERSION_TAG=${{ steps.versionNumber.outputs.versionNumber }}
+          platforms: linux/amd64
+
+      - name: Build and push test image (Docker fork fallback)
+        if: env.USE_DEPOT != 'true'
         uses: docker/build-push-action@bcafcacb16a39f128d818304e6c9c0c18556b85f # v7.1.0
         with:
           context: .
@@ -125,7 +153,8 @@ jobs:
   files-changed:
     if: always()
     name: detect what files changed
-    runs-on: ubuntu-latest
+    needs: pick
+    runs-on: ${{ needs.pick.outputs.is_fork == 'true' && 'ubuntu-latest' || 'depot-ubuntu-24.04-4' }}
     timeout-minutes: 3
     outputs:
       frontend: ${{ steps.changes.outputs.frontend }}
@@ -145,9 +174,8 @@ jobs:
 
   test:
     if: needs.files-changed.outputs.frontend == 'true'
-    needs: [deploy, files-changed]
-    runs-on: ubuntu-latest
-
+    needs: [pick, deploy, files-changed]
+    runs-on: ${{ needs.pick.outputs.is_fork == 'true' && 'ubuntu-latest' || 'depot-ubuntu-24.04-4' }}
     steps:
       - name: Harden Runner
         uses: step-security/harden-runner@a5ad31d6a139d249332a2605b85202e8c0b78450 # v2.19.1
@@ -180,8 +208,8 @@ jobs:
           FORCE_COLOR: "3"
 
   cleanup:
-    needs: [deploy, test]
-    runs-on: ubuntu-latest
+    needs: [pick, deploy, test]
+    runs-on: ${{ needs.pick.outputs.is_fork == 'true' && 'ubuntu-latest' || 'depot-ubuntu-24.04-4' }}
     if: always()
 
     steps:

AGENTS.md

@@ -458,3 +458,26 @@ The frontend is organized with a clear separation of concerns:
 - Confirm approach before making structural changes
 - Request guidance on preferences (cross-platform vs specific tools, etc.)
 - Verify understanding of requirements before proceeding
+
+
+## Stack reality check (don't trust LLM training data) <!-- bleeding-edge-stack-note -->
+
+This codebase is on bleeding-edge versions of its core JVM stack: **Spring Boot 4.0.6**,
+**Jackson 3 (`tools.jackson`)**, **JDK 21/25 source/target with JDK 25 toolchain**.
+All three are *post*-2024 releases and your training corpus is overwhelmingly Spring Boot 2/3 and
+Jackson 2 patterns — those patterns will compile, run differently, or hallucinate APIs that no
+longer exist.
+
+Before writing or editing Spring / Jackson / JDK code:
+
+1. Open an existing module in `app/core/` or `app/common/` and grep for the actual imports being
+   used — `import tools.jackson...` not `import com.fasterxml.jackson...`, and the new
+   `org.springframework.boot` 4.x package layout.
+2. If you're not sure whether an API exists in this stack version, **check the source on disk
+   first** (the dependency JARs are downloaded under `~/.gradle/caches/modules-2/`).
+3. Do not silently downgrade a Spring Boot 4 pattern to a Spring Boot 3 equivalent. If something
+   doesn't work, surface it to the human — don't guess.
+
+Same goes for Jackson 3's API surface (renamed `ObjectMapper` builder methods, new
+`tools.jackson.databind` namespace) and JDK 25 preview features. Ground your code in this repo's
+actual imports, not what worked three years ago.

build.gradle

@@ -619,3 +619,10 @@ tasks.register('buildRestartHelper', Jar) {
         println "restart-helper.jar created at: ${destinationDirectory.get()}/restart-helper.jar"
     }
 }
+
+
+tasks.withType(Test).configureEach {
+    // maxParallelForks: parallelise JUnit across cores
+    // Half of available CPUs is a safe default; bump if your tests are I/O-bound.
+    maxParallelForks = Math.max(1, (Runtime.runtime.availableProcessors().intdiv(2)) as int)
+}

settings.gradle

@@ -23,6 +23,29 @@ plugins {
     id 'org.gradle.toolchains.foojay-resolver-convention' version '1.0.0'
 }
 
+// Depot remote build cache. Silently no-ops when DEPOT_TOKEN is absent
+// (local dev without depot login, and fork PRs where GitHub hides secrets),
+// so contributors without Depot access still build fine on local cache only.
+buildCache {
+    def depotToken = System.getenv('DEPOT_TOKEN')
+    local {
+        enabled = true
+    }
+    if (depotToken) {
+        remote(HttpBuildCache) {
+            url = 'https://cache.depot.dev'
+            enabled = true
+            // Only CI runs push to the shared cache; dev laptops pull-only
+            // so a misconfigured local task can't poison everyone else.
+            push = System.getenv('CI') == 'true'
+            credentials {
+                username = ''
+                password = depotToken
+            }
+        }
+    }
+}
+
 rootProject.name = 'Stirling PDF'
 
 // Flavors: core | proprietary (default) | saas.