diff --git a/.github/workflows/ci-routing-probe.yml b/.github/workflows/ci-routing-probe.yml
new file mode 100644
index 0000000000..d78ebfae36
--- /dev/null
+++ b/.github/workflows/ci-routing-probe.yml
@@ -0,0 +1,252 @@
+name: CI non-browser routing probe
+on:
+  push:
+    branches:
+      - investigate-ci-throughput
+    paths:
+      - .github/workflows/ci-routing-probe.yml
+  workflow_dispatch: {}
+permissions:
+  contents: read
+env:
+  ONNXRUNTIME_NODE_INSTALL: skip
+jobs:
+  changes:
+    runs-on: ubuntu-latest
+    outputs:
+      full: ${{ steps.route.outputs.full }}
+      browser: ${{ steps.route.outputs.browser }}
+      format: ${{ steps.route.outputs.format }}
+      quality: ${{ steps.route.outputs.quality }}
+      relay: ${{ steps.route.outputs.relay }}
+      sdk: ${{ steps.route.outputs.sdk }}
+    steps:
+      - id: route
+        run: >-
+          for contract in full browser quality relay sdk; do echo "$contract=false" >>
+          "$GITHUB_OUTPUT"; done
+
+          echo "format=true" >> "$GITHUB_OUTPUT"
+  quality:
+    name: quality
+    needs: changes
+    if:
+      ${{ !cancelled() && (needs.changes.outputs.full != 'false' || needs.changes.outputs.format !=
+      'false' || needs.changes.outputs.quality != 'false' || needs.changes.outputs.relay != 'false'
+      || needs.changes.outputs.sdk != 'false') }}
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: "22"
+          cache: npm
+      - name: Install dependencies
+        id: install
+        run: node scripts/npm-retry.mjs ci
+      - name: Check formatting
+        if:
+          ${{ !cancelled() && steps.install.outcome == 'success' && (needs.changes.outputs.full != 'false'
+          || needs.changes.outputs.format != 'false') }}
+        run: npm run format:check
+      - name: Lint lockfile
+        if:
+          ${{ !cancelled() && steps.install.outcome == 'success' && (needs.changes.outputs.full != 'false'
+          || needs.changes.outputs.quality != 'false') }}
+        run: npx --yes lockfile-lint --path package-lock.json --type npm --allowed-hosts npm
+          --validate-https --validate-integrity
+      - name: Verify dependency signatures
+        if:
+          ${{ !cancelled() && steps.install.outcome == 'success' && (needs.changes.outputs.full != 'false'
+          || needs.changes.outputs.quality != 'false') }}
+        run: npm audit signatures
+      - name: Lint
+        if:
+          ${{ !cancelled() && steps.install.outcome == 'success' && (needs.changes.outputs.full != 'false'
+          || needs.changes.outputs.quality != 'false') }}
+        run: npm run lint
+      - name: Build relay
+        if:
+          ${{ !cancelled() && steps.install.outcome == 'success' && (needs.changes.outputs.full != 'false'
+          || needs.changes.outputs.relay != 'false') }}
+        run: npm run build:relay
+      - name: Run relay tests
+        if:
+          ${{ !cancelled() && steps.install.outcome == 'success' && (needs.changes.outputs.full != 'false'
+          || needs.changes.outputs.relay != 'false') }}
+        run: npm run test --workspace=@getpaseo/relay
+      - name: Build client dependencies
+        if:
+          ${{ !cancelled() && steps.install.outcome == 'success' && (needs.changes.outputs.full != 'false'
+          || needs.changes.outputs.sdk != 'false') }}
+        run: npm run build:relay && npm run build:client
+      - name: Build plugin SDK
+        if:
+          ${{ !cancelled() && steps.install.outcome == 'success' && (needs.changes.outputs.full != 'false'
+          || needs.changes.outputs.sdk != 'false') }}
+        run: npm run build:plugin
+      - name: Run plugin SDK tests
+        if:
+          ${{ !cancelled() && steps.install.outcome == 'success' && (needs.changes.outputs.full != 'false'
+          || needs.changes.outputs.sdk != 'false') }}
+        run: npm run test --workspace=@getpaseo/plugin
+      - name: Run protocol tests
+        if:
+          ${{ !cancelled() && steps.install.outcome == 'success' && (needs.changes.outputs.full != 'false'
+          || needs.changes.outputs.sdk != 'false') }}
+        run: npm run test --workspace=@getpaseo/protocol
+      - name: Run client tests
+        if:
+          ${{ !cancelled() && steps.install.outcome == 'success' && (needs.changes.outputs.full != 'false'
+          || needs.changes.outputs.sdk != 'false') }}
+        run: npm run test --workspace=@getpaseo/client
+      - name: Run highlight tests
+        if:
+          ${{ !cancelled() && steps.install.outcome == 'success' && (needs.changes.outputs.full != 'false'
+          || needs.changes.outputs.sdk != 'false') }}
+        run: npm run test --workspace=@getpaseo/highlight
+      - name: Typecheck client examples
+        if:
+          ${{ !cancelled() && steps.install.outcome == 'success' && (needs.changes.outputs.full != 'false'
+          || needs.changes.outputs.sdk != 'false') }}
+        run: npm run typecheck:examples --workspace=@getpaseo/client
+  playwright-1:
+    name: playwright (shard 1/8)
+    needs: changes
+    if:
+      ${{ !cancelled() && (needs.changes.outputs.full != 'false' || needs.changes.outputs.browser !=
+      'false') }}
+    runs-on: ubuntu-latest
+    steps:
+      - run: echo "Browser coverage was intentionally unrouted; this must not execute"; exit 99
+  playwright-2:
+    name: playwright (shard 2/8)
+    needs: changes
+    if:
+      ${{ !cancelled() && (needs.changes.outputs.full != 'false' || needs.changes.outputs.browser !=
+      'false') }}
+    runs-on: ubuntu-latest
+    steps:
+      - run: echo "Browser coverage was intentionally unrouted; this must not execute"; exit 99
+  playwright-3:
+    name: playwright (shard 3/8)
+    needs: changes
+    if:
+      ${{ !cancelled() && (needs.changes.outputs.full != 'false' || needs.changes.outputs.browser !=
+      'false') }}
+    runs-on: ubuntu-latest
+    steps:
+      - run: echo "Browser coverage was intentionally unrouted; this must not execute"; exit 99
+  playwright-4:
+    name: playwright (shard 4/8)
+    needs: changes
+    if:
+      ${{ !cancelled() && (needs.changes.outputs.full != 'false' || needs.changes.outputs.browser !=
+      'false') }}
+    runs-on: ubuntu-latest
+    steps:
+      - run: echo "Browser coverage was intentionally unrouted; this must not execute"; exit 99
+  playwright-5:
+    name: playwright (shard 5/8)
+    needs: changes
+    if:
+      ${{ !cancelled() && (needs.changes.outputs.full != 'false' || needs.changes.outputs.browser !=
+      'false') }}
+    runs-on: ubuntu-latest
+    steps:
+      - run: echo "Browser coverage was intentionally unrouted; this must not execute"; exit 99
+  playwright-6:
+    name: playwright (shard 6/8)
+    needs: changes
+    if:
+      ${{ !cancelled() && (needs.changes.outputs.full != 'false' || needs.changes.outputs.browser !=
+      'false') }}
+    runs-on: ubuntu-latest
+    steps:
+      - run: echo "Browser coverage was intentionally unrouted; this must not execute"; exit 99
+  playwright-7:
+    name: playwright (shard 7/8)
+    needs: changes
+    if:
+      ${{ !cancelled() && (needs.changes.outputs.full != 'false' || needs.changes.outputs.browser !=
+      'false') }}
+    runs-on: ubuntu-latest
+    steps:
+      - run: echo "Browser coverage was intentionally unrouted; this must not execute"; exit 99
+  playwright-8:
+    name: playwright (shard 8/8)
+    needs: changes
+    if:
+      ${{ !cancelled() && (needs.changes.outputs.full != 'false' || needs.changes.outputs.browser !=
+      'false') }}
+    runs-on: ubuntu-latest
+    steps:
+      - run: echo "Browser coverage was intentionally unrouted; this must not execute"; exit 99
+  playwright:
+    name: playwright
+    needs:
+      - changes
+      - playwright-1
+      - playwright-2
+      - playwright-3
+      - playwright-4
+      - playwright-5
+      - playwright-6
+      - playwright-7
+      - playwright-8
+    if: ${{ !cancelled() }}
+    runs-on: ubuntu-latest
+    steps:
+      - name: Require all routed Playwright shards
+        env:
+          NEEDS_JSON: ${{ toJSON(needs) }}
+        run: >
+          node --input-type=module <<'NODE'
+
+          const needs = JSON.parse(process.env.NEEDS_JSON);
+
+          const routed = needs.changes.outputs.full !== 'false' || needs.changes.outputs.browser !==
+          'false';
+
+          const failures = Object.entries(needs).filter(([name, job]) =>
+            job.result !== (name === 'changes' || routed ? 'success' : 'skipped'));
+          for (const [name, job] of failures) console.error(`${name}: ${job.result}`);
+
+          process.exitCode = failures.length ? 1 : 0;
+
+          NODE
+  verify:
+    needs:
+      - changes
+      - quality
+      - playwright
+      - playwright-1
+      - playwright-2
+      - playwright-3
+      - playwright-4
+      - playwright-5
+      - playwright-6
+      - playwright-7
+      - playwright-8
+    if: ${{ !cancelled() }}
+    runs-on: ubuntu-latest
+    steps:
+      - env:
+          NEEDS_JSON: ${{ toJSON(needs) }}
+        run: >-
+          node --input-type=module <<'NODE'
+
+          import assert from 'node:assert/strict';
+
+          const needs=JSON.parse(process.env.NEEDS_JSON);
+
+          for(const name of ['changes','quality','playwright'])
+          assert.equal(needs[name].result,'success',name);
+
+          for(let i=1;i<=8;i++)
+          assert.equal(needs['playwright-'+i].result,'skipped','playwright-'+i);
+
+          console.log('PASS: real quality ran formatting only; all eight real browser job conditions
+          skipped; the actual result gate succeeded');
+
+          NODE