diff --git a/.github/workflows/e2e-tests.yml b/.github/workflows/e2e-tests.yml
index 208f635d8..9a8c4b70d 100644
--- a/.github/workflows/e2e-tests.yml
+++ b/.github/workflows/e2e-tests.yml
@@ -1,5 +1,5 @@
 name: End-to-End Tests
-run-name: e2e Test - ${{ inputs.test-name || github.event.inputs.generate-cli-command }}
+run-name: e2e Test - ${{ inputs.test-name || inputs.generate-cli-command || github.event.inputs.generate-cli-command }}
 
 on:
     workflow_dispatch:
@@ -12,6 +12,24 @@ on:
                 description: "Name for this test run"
                 required: false
                 type: string
+            ref:
+                description: "Ref (branch/sha) to checkout for generating configs"
+                required: false
+                type: string
+    workflow_call:
+        inputs:
+            generate-cli-command:
+                description: "Command passed to generate matrix script"
+                required: true
+                type: string
+            test-name:
+                description: "Name for this test run"
+                required: false
+                type: string
+            ref:
+                description: "Ref (branch/sha) to checkout for generating configs"
+                required: false
+                type: string
 
 jobs:
     get-jobs:
@@ -19,14 +37,21 @@ jobs:
         outputs:
             search-space-config: ${{ steps.get-jobs.outputs.search-space-config }}
         steps:
-            - name: Checkout code
+            - name: Checkout code (ref)
+              if: ${{ inputs.ref && inputs.ref != '' }}
+              uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
+              with:
+                ref: ${{ inputs.ref }}
+
+            - name: Checkout code (default)
+              if: ${{ !inputs.ref || inputs.ref == '' }}
               uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
 
             - id: get-jobs
               run: |
                   pip install pydantic
                   CONFIG_JSON=$(python3 ${GITHUB_WORKSPACE}/utils/matrix_logic/generate_sweep_configs.py \
-                    ${{ inputs.generate-cli-command }} \
+                    ${{ inputs.generate-cli-command || github.event.inputs.generate-cli-command }} \
                     --runner-config .github/configs/runners.yaml \
                     --config-files .github/configs/nvidia-master.yaml .github/configs/amd-master.yaml)
                   echo "search-space-config=$CONFIG_JSON" >> $GITHUB_OUTPUT
diff --git a/.github/workflows/pr-comment-sweep.yml b/.github/workflows/pr-comment-sweep.yml
new file mode 100644
index 000000000..a66b4dc7a
--- /dev/null
+++ b/.github/workflows/pr-comment-sweep.yml
@@ -0,0 +1,146 @@
+name: Slash Command Sweep
+run-name: "Validate PR #${{ github.event.issue.number }}"
+
+on:
+  issue_comment:
+    types: [created]
+
+concurrency:
+  group: "PR#${{ github.event.issue.number || github.ref_name }}"
+  cancel-in-progress: true
+
+permissions:
+  contents: read
+  issues: write
+  pull-requests: write
+
+jobs:
+  get-jobs:
+    # Only run for PR comments that start with /sweep
+    if: ${{ github.event.issue.pull_request && startsWith(github.event.comment.body, '/sweep') }}
+    runs-on: ubuntu-latest
+    outputs:
+      pr-number: ${{ steps.parse.outputs.pr-number }}
+      generator-args: ${{ steps.parse.outputs.generator-args }}
+      author-can-bypass: ${{ steps.auth.outputs.can-bypass }}
+      # Immutable ref (commit SHA) to prevent TOCTOU on refs/pull/<n>/head
+      ref: ${{ steps.ref_comment.outputs.ref }}
+    steps:
+      - name: Parse PR comment (/sweep ...)
+        id: parse
+        if: ${{ github.event_name == 'issue_comment' && github.event.issue.pull_request && startsWith(github.event.comment.body, '/sweep') }}
+        shell: bash
+        env:
+          BODY: ${{ github.event.comment.body }}
+          PR_NUMBER: ${{ github.event.issue.number }}
+        run: |
+          set -euo pipefail
+          # Require /sweep at the start of the line
+          cmd_line=$(printf "%s" "$BODY" | awk '/^\/sweep/{print; exit}')
+          if [[ -z "$cmd_line" ]]; then
+            echo "No /sweep command found at comment start" >&2
+            exit 1
+          fi
+          if [[ "$cmd_line" == "/sweep" ]]; then
+            cmd_args=""
+          else
+            cmd_args=${cmd_line#/sweep}
+          fi
+          cmd_args=$(echo "$cmd_args" | xargs || true)
+
+          echo "generator-args=$cmd_args" >> "$GITHUB_OUTPUT"
+          echo "pr-number=$PR_NUMBER" >> "$GITHUB_OUTPUT"
+
+      - name: Check author permissions
+        id: auth
+        if: ${{ github.event_name == 'issue_comment' && github.event.issue.pull_request }}
+        uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7.0.1
+        with:
+          script: |
+            const owner = context.repo.owner;
+            const repo = context.repo.repo;
+            const username = context.payload.comment?.user?.login;
+            let permission = 'none';
+            try {
+              const res = await github.rest.repos.getCollaboratorPermissionLevel({ owner, repo, username });
+              permission = res.data?.permission || 'none';
+            } catch (e) {
+              permission = 'none';
+            }
+            const canBypass = ['admin','maintain','write'].includes(permission);
+            core.info(`Author ${username} permission: ${permission}; bypass=${canBypass}`);
+            core.setOutput('can-bypass', canBypass ? 'true' : 'false');
+
+      # ---- PR SHA pinning ----
+      - name: Resolve immutable PR ref (pin to head SHA)
+        id: ref_comment
+        if: ${{ github.event_name == 'issue_comment' && github.event.issue.pull_request && startsWith(github.event.comment.body, '/sweep') }}
+        uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7.0.1
+        with:
+          script: |
+            const owner = context.repo.owner;
+            const repo = context.repo.repo;
+            const pr = context.issue.number;
+            const res = await github.rest.pulls.get({ owner, repo, pull_number: pr });
+            const sha = res.data.head.sha;
+            core.info(`Resolved PR #${pr} head SHA: ${sha}`);
+            core.setOutput('ref', sha);
+
+      - name: Reply with run link
+        if: ${{ github.event_name == 'issue_comment' && startsWith(github.event.comment.body, '/sweep') && github.repository_owner == 'InferenceMAX' }}
+        uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7.0.1
+        continue-on-error: true
+        env:
+          RUN_URL: ${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}
+          AUTHOR: ${{ github.event.comment.user.login }}
+          GEN_CMD: ${{ steps.parse.outputs.generator-args }}
+          CAN_BYPASS: ${{ steps.auth.outputs.can-bypass }}
+          PINNED_REF: ${{ steps.ref_comment.outputs.ref }}
+        with:
+          github-token: ${{ github.token }}
+          script: |
+            const owner = context.repo.owner;
+            const repo = context.repo.repo;
+            const issue_number = context.issue.number;
+            const runUrl = process.env.RUN_URL;
+            const author = process.env.AUTHOR;
+            const genCmd = process.env.GEN_CMD || '';
+            const canBypass = (process.env.CAN_BYPASS || '').toLowerCase() === 'true';
+            const pinned = process.env.PINNED_REF || '';
+            const shortSha = pinned ? pinned.slice(0, 7) : '';
+            const approvalMsg = canBypass ? 'Approval: not required (trusted collaborator).' : "Approval: required in environment 'Outside Collaborator E2E Test'.";
+            const body = `@${author} Kicking off a sweep.\n\nRun: ${runUrl}\nCommand: \`${genCmd}\`\nPinned ref: \`${shortSha}\`\n${approvalMsg}`;
+            await github.rest.issues.createComment({ owner, repo, issue_number, body });
+
+  approval:
+    needs: get-jobs
+    if: ${{ github.event_name == 'issue_comment' && needs.get-jobs.outputs.pr-number != '' && needs.get-jobs.outputs.generator-args != '' && needs.get-jobs.outputs.author-can-bypass != 'true' }}
+    runs-on: ubuntu-latest
+    name: approval
+    environment: Outside Collaborator E2E Test
+    steps:
+      - run: echo "approved"
+
+  validate-trusted:
+    needs: [get-jobs]
+    if: ${{ github.event_name == 'issue_comment' && needs.get-jobs.outputs.pr-number != '' && needs.get-jobs.outputs.generator-args != '' && needs.get-jobs.outputs.author-can-bypass == 'true' }}
+    uses: ./.github/workflows/e2e-tests.yml
+    name: validate (trusted author)
+    secrets: inherit
+    with:
+      generate-cli-command: ${{ needs.get-jobs.outputs.generator-args }}
+      test-name: PR #${{ needs.get-jobs.outputs.pr-number }} sweep
+      # Use pinned SHA to prevent TOCTOU on refs/pull/<n>/head
+      ref: ${{ needs.get-jobs.outputs.ref }}
+
+  validate:
+    needs: [get-jobs, approval]
+    if: ${{ github.event_name == 'issue_comment' && needs.get-jobs.outputs.pr-number != '' && needs.get-jobs.outputs.generator-args != '' && needs.get-jobs.outputs.author-can-bypass != 'true' && needs.approval.result == 'success' }}
+    uses: ./.github/workflows/e2e-tests.yml
+    name: validate
+    secrets: inherit
+    with:
+      generate-cli-command: ${{ needs.get-jobs.outputs.generator-args }}
+      test-name: PR #${{ needs.get-jobs.outputs.pr-number }} sweep
+      # Use pinned SHA to prevent TOCTOU on refs/pull/<n>/head
+      ref: ${{ needs.get-jobs.outputs.ref }}