diff --git a/.github/workflows/codex-pr-review.yml b/.github/workflows/codex-pr-review.yml
index 354e8a60ca..55036776c6 100644
--- a/.github/workflows/codex-pr-review.yml
+++ b/.github/workflows/codex-pr-review.yml
@@ -40,11 +40,14 @@ jobs:
     # an author_association gate: the pull_request webhook payload reports private org
     # members as CONTRIBUTOR/NONE (only public members show as MEMBER), which silently
     # skips auto-review for every private member.
+    # Dependabot-triggered runs get a separate secret scope, so this job has no API
+    # key and cannot review. workflow_call stays open for an explicit request.
     if: |
       github.event_name == 'workflow_call' ||
       (
         github.event.pull_request.draft == false &&
-        github.event.pull_request.head.repo.fork == false
+        github.event.pull_request.head.repo.fork == false &&
+        github.event.pull_request.user.login != 'dependabot[bot]'
       )
     permissions:
       contents: read
diff --git a/.github/workflows/discord-notification.yml b/.github/workflows/discord-notification.yml
index d731faafd9..c83cbc90d3 100644
--- a/.github/workflows/discord-notification.yml
+++ b/.github/workflows/discord-notification.yml
@@ -13,7 +13,8 @@ on:
 
 jobs:
   notify_discord_when_pr_opened:
-    if: (github.event.pull_request.draft == false) && (github.event.action == 'opened' || github.event.action == 'ready_for_review')
+    # No thread is opened for Dependabot PRs, so nothing downstream may assume one.
+    if: (github.event.pull_request.draft == false) && (github.event.action == 'opened' || github.event.action == 'ready_for_review') && (github.event.pull_request.user.login != 'dependabot[bot]')
     uses: ./.github/workflows/shareable-discord-notification.yml
     with:
       PR_TITLE: ${{ github.event.pull_request.title }}
@@ -28,7 +29,8 @@ jobs:
       DISCORD_BOT_TOKEN: ${{ secrets.DISCORD_AI_BOT_TOKEN }}
 
   merge_success_emoji:
-    if: github.event.action == 'closed'
+    # Must match open_thread's exclusion: this reacts to a thread that was never created.
+    if: github.event.action == 'closed' && github.event.pull_request.user.login != 'dependabot[bot]'
     uses: ./.github/workflows/shareable-discord-notification.yml
     with:
       PR_STATUS: "merged"
diff --git a/.github/workflows/pi-pr-review.yml b/.github/workflows/pi-pr-review.yml
index a89275cfb5..a18dc28ff2 100644
--- a/.github/workflows/pi-pr-review.yml
+++ b/.github/workflows/pi-pr-review.yml
@@ -38,11 +38,14 @@ jobs:
     # an author_association gate: the pull_request webhook payload reports private org
     # members as CONTRIBUTOR/NONE (only public members show as MEMBER), which silently
     # skips auto-review for every private member.
+    # Dependabot-triggered runs get a separate secret scope, so this job has no API
+    # key and cannot review. workflow_call stays open for an explicit request.
     if: |
       github.event_name == 'workflow_call' ||
       (
         github.event.pull_request.draft == false &&
-        github.event.pull_request.head.repo.fork == false
+        github.event.pull_request.head.repo.fork == false &&
+        github.event.pull_request.user.login != 'dependabot[bot]'
       )
     permissions:
       contents: read
diff --git a/.github/workflows/pr-ready-review.yml b/.github/workflows/pr-ready-review.yml
index 4bfb5b4147..5e5c6a8c61 100644
--- a/.github/workflows/pr-ready-review.yml
+++ b/.github/workflows/pr-ready-review.yml
@@ -37,11 +37,14 @@ jobs:
     # an author_association gate: the pull_request webhook payload reports private org
     # members as CONTRIBUTOR/NONE (only public members show as MEMBER), which silently
     # skips auto-review for every private member.
+    # Dependabot-triggered runs get a separate secret scope, so this job has no API
+    # key and cannot review. workflow_call stays open for an explicit request.
     if: |
       github.event_name == 'workflow_call' ||
       (
         (github.event.pull_request.draft == false || github.event.pull_request.ready_for_review == true) &&
-        github.event.pull_request.head.repo.fork == false
+        github.event.pull_request.head.repo.fork == false &&
+        github.event.pull_request.user.login != 'dependabot[bot]'
       )
     permissions:
       contents: read