diff --git a/.claude/settings.json b/.claude/settings.json
index d8f7e469..b525aebb 100644
--- a/.claude/settings.json
+++ b/.claude/settings.json
@@ -9,6 +9,7 @@
       "Bash(gh pr status:*)",
       "Bash(gh pr update-branch:*)",
       "Bash(gh pr view:*)",
+      "Bash(gh release list:*)",
       "Bash(gh search code:*)",
       "Bash(git diff:*)",
       "Bash(git fetch:*)",
diff --git a/.github/workflows/delete-pr-build-on-close.yml b/.github/workflows/delete-pr-build-on-close.yml
deleted file mode 100644
index 0834ad35..00000000
--- a/.github/workflows/delete-pr-build-on-close.yml
+++ /dev/null
@@ -1,84 +0,0 @@
-name: Delete pre-release when a branch is deleted
-# This workflow action deletes pre-releases when a PR is merged or closed.
-#
-# The CircleCI configuration builds CLI binaries when a PR is opened.
-# These are uploaded to the upstream project as GitHub (pre-)releases.
-#
-# The release tag matches one of the following patterns:
-#  - v1.2.3-example-branch-placeholder  # Branches on upstream
-#  - v1.2.3-pull-12-head                # Branches from forks
-#
-# A "pull_request_target" event is used to delete pre-releases upstream.
-#
-# See https://docs.github.com/en/actions/using-workflows/events-that-trigger-workflows#running-your-pull_request-workflow-when-a-pull-request-merges
-# See https://docs.github.com/en/actions/writing-workflows/choosing-when-your-workflow-runs/events-that-trigger-workflows#pull_request_target
-on:
-  pull_request_target: # zizmor: ignore[dangerous-triggers]
-    types:
-      - closed
-
-jobs:
-  delete-pre-release:
-    name: Delete pre-release if exists
-    runs-on: ubuntu-latest
-    permissions:
-      contents: write
-    steps:
-      - name: Delete pre-release and tag named after branch
-        env:
-          GH_TOKEN: ${{ github.token }}
-          PR_BRANCH: ${{ github.event.pull_request.head.ref }}
-          PR_NUMBER: ${{ github.event.pull_request.number }}
-          PR_REPO: ${{ github.event.pull_request.head.repo.full_name }}
-        shell: bash
-        run: |
-          # Use either an upstream or fork PR branch
-          if [[ "$PR_REPO" != "slackapi/slack-cli" ]]; then
-            BRANCH="pull/$PR_NUMBER/head"
-          else
-            BRANCH="$PR_BRANCH"
-          fi
-
-          # Escape tags to create a semantic version
-          REF=$(echo "${BRANCH}" | sed 's/\//-/g')
-          RELEASE_FOUND=1
-
-          # Delete tags matching the pull request branch from forks
-          if GH_DEBUG=1 gh release --repo="slackapi/slack-cli" delete "${REF}" -y --cleanup-tag; then
-            echo "Successfully deleted ${REF}"
-            RELEASE_FOUND=0
-          else
-            echo "Did not find ${REF} tag, trying version prefixes..."
-          fi
-
-          # Figure out tag name from branch name. This is coupled to the tag name generation that exists in .circleci/config.yml's `create-github-release` job.
-          RELEASES=$(gh release list --repo="slackapi/slack-cli" --order="desc" --json="tagName" --exclude-drafts --exclude-pre-releases --limit=24 --jq ".[] | .tagName")
-          for TAGS in $RELEASES; do
-            TAG_NAME="${TAGS}-${REF}"
-            echo "Identified pre-release tagname to 🔪: $TAG_NAME"
-
-            # Delete the pre-release
-            if GH_DEBUG=1 gh release --repo="slackapi/slack-cli" delete "$TAG_NAME" -y --cleanup-tag; then
-              echo "Successfully deleted $TAG_NAME"
-              RELEASE_FOUND=0
-            else
-              echo "Failed to find $TAG_NAME, trying next..."
-            fi
-            sleep 1
-
-            FEATURE_TAG_NAME="${TAGS}-${REF}-feature"
-            echo "Identified feature-release tagname as 🔪: $FEATURE_TAG_NAME"
-
-            # Delete a feature-release
-            if GH_DEBUG=1 gh release --repo="slackapi/slack-cli" delete "$FEATURE_TAG_NAME" -y --cleanup-tag; then
-              echo "Successfully deleted $FEATURE_TAG_NAME"
-              RELEASE_FOUND=0
-            else
-              echo "Failed to find $FEATURE_TAG_NAME, trying next..."
-            fi
-            sleep 1
-          done
-          if [ "$RELEASE_FOUND" -ne 0 ]; then
-            echo "No matching pre-releases tag was found for the branch $TAG_NAME in recent versions"
-          fi
-          exit "$RELEASE_FOUND"
diff --git a/.github/workflows/delete-stale-pre-releases.yml b/.github/workflows/delete-stale-pre-releases.yml
new file mode 100644
index 00000000..b7f57d52
--- /dev/null
+++ b/.github/workflows/delete-stale-pre-releases.yml
@@ -0,0 +1,84 @@
+name: Delete stale pre-releases
+# This workflow deletes pre-releases whose source branch no longer exists.
+#
+# The CircleCI configuration builds CLI binaries when a PR is opened.
+# These are uploaded to the upstream project as GitHub (pre-)releases.
+#
+# The release tag matches one of the following patterns:
+#  - v1.2.3-example-branch-placeholder  # Branches on upstream
+#  - v1.2.3-pull-12-head                # Branches from forks
+#
+# Runs on push to main (catches merges) and on a daily schedule
+# (catches closed-without-merge PRs and any other missed cleanups).
+#
+# Only pre-releases are considered. Production releases (v1.2.3) and
+# the long-running dev-build pre-release are never touched.
+on:
+  push:
+    branches:
+      - main
+  schedule:
+    - cron: "0 0 * * *"
+  workflow_dispatch:
+
+jobs:
+  delete-stale-pre-releases:
+    name: Delete stale pre-releases
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+    steps:
+      - name: Delete pre-releases for branches that no longer exist
+        env:
+          GH_TOKEN: ${{ github.token }}
+        shell: bash
+        run: |
+          REPO="slackapi/slack-cli"
+          DELETED=0
+
+          # Gather all pre-release tag names
+          PRE_RELEASES=$(gh release list --repo="$REPO" --json="tagName,isPrerelease" --limit=100 --jq '.[] | select(.isPrerelease) | .tagName')
+
+          for TAG in $PRE_RELEASES; do
+            # Skip the long-running dev-build pre-release
+            if [ "$TAG" = "dev-build" ]; then
+              continue
+            fi
+
+            echo "Checking pre-release: $TAG"
+
+            # Extract branch name from the tag. Tags follow the pattern:
+            #   v1.2.3-branch-name         (standard PR builds)
+            #   v1.2.3-branch-name-feature  (feature builds)
+            # Strip the leading semver prefix to recover the branch name.
+            BRANCH=$(echo "$TAG" | sed 's/^v[0-9]*\.[0-9]*\.[0-9]*-//')
+
+            # Feature builds have a "-feature" suffix that is not part of the branch name
+            BRANCH_WITHOUT_FEATURE=$(echo "$BRANCH" | sed 's/-feature$//')
+
+            # Check if the branch still exists on the remote
+            BRANCH_EXISTS=false
+            for CANDIDATE in "$BRANCH" "$BRANCH_WITHOUT_FEATURE"; do
+              if gh api "repos/$REPO/branches/$CANDIDATE" --silent 2>/dev/null; then
+                BRANCH_EXISTS=true
+                break
+              fi
+            done
+
+            if [ "$BRANCH_EXISTS" = "true" ]; then
+              echo "  Branch still exists, skipping"
+              continue
+            fi
+
+            # Branch is gone — delete the stale pre-release and its tag
+            echo "  Branch no longer exists, deleting pre-release: $TAG"
+            if gh release --repo="$REPO" delete "$TAG" -y --cleanup-tag; then
+              echo "  Successfully deleted $TAG"
+              DELETED=$((DELETED + 1))
+            else
+              echo "  Failed to delete $TAG"
+            fi
+            sleep 1
+          done
+
+          echo "Deleted $DELETED stale pre-release(s)"