diff --git a/.github/workflows/release-ruby.yml b/.github/workflows/release-ruby.yml
index b157201..0ce2cb4 100644
--- a/.github/workflows/release-ruby.yml
+++ b/.github/workflows/release-ruby.yml
@@ -123,6 +123,7 @@ jobs:
           sha: ${{ inputs.sha || github.event.pull_request.head.sha }}
           dry_run: ${{ inputs.dry_run || github.event_name == 'pull_request' }}
           working_directory: test/release/ruby
+          package_name: bt-publishing-test # exercises the RubyGems-availability fail-fast check
 
   prepare:
     needs: validate
diff --git a/actions/release/lang/js/publish/action.yml b/actions/release/lang/js/publish/action.yml
index c0ab986..568ede4 100644
--- a/actions/release/lang/js/publish/action.yml
+++ b/actions/release/lang/js/publish/action.yml
@@ -421,7 +421,7 @@ runs:
         echo "=== pnpm ==="
         pnpm --version || echo "(unavailable)"
         echo "=== Registry ==="
-        npm config get registry
+        pnpm config get registry
         echo "=== package.json version ==="
         node -p "require('./package.json').version" 2>/dev/null || echo "(unavailable)"
 
diff --git a/actions/release/lang/js/validate/action.yml b/actions/release/lang/js/validate/action.yml
index c76c4a2..cb9737e 100644
--- a/actions/release/lang/js/validate/action.yml
+++ b/actions/release/lang/js/validate/action.yml
@@ -159,11 +159,24 @@ runs:
           echo "No package_name provided; skipping npm availability check."
           exit 0
         fi
-        if npm view "$PACKAGE_NAME@$VERSION" version --registry "$REGISTRY" >/dev/null 2>&1; then
-          echo "Error: $PACKAGE_NAME@$VERSION already exists on npm — has the version been bumped?"
-          exit 1
-        fi
-        echo "$PACKAGE_NAME@$VERSION is available on npm."
+        REGISTRY="${REGISTRY%/}"
+        CODE=$(curl -sS -o /dev/null -w '%{http_code}' \
+          --retry 3 --retry-connrefused --max-time 30 \
+          "$REGISTRY/$PACKAGE_NAME/$VERSION")
+        case "$CODE" in
+          200)
+            echo "Error: $PACKAGE_NAME@$VERSION already exists on npm — has the version been bumped?"
+            exit 1
+            ;;
+          404)
+            echo "$PACKAGE_NAME@$VERSION is available on npm."
+            ;;
+          *)
+            echo "Error: unexpected response from the npm registry (HTTP $CODE) checking $PACKAGE_NAME@$VERSION;"
+            echo "cannot confirm the version is unpublished — aborting rather than risk a bad release."
+            exit 1
+            ;;
+        esac
 
     - name: Validate release channel
       shell: bash
@@ -251,6 +264,6 @@ runs:
         echo "=== pnpm ==="
         pnpm --version || echo "(unavailable)"
         echo "=== Registry ==="
-        npm config get registry
+        pnpm config get registry
         echo "=== package.json version ==="
         node -p "require('./package.json').version" 2>/dev/null || echo "(unavailable)"
diff --git a/actions/release/lang/ruby/validate/action.yml b/actions/release/lang/ruby/validate/action.yml
index b2e77e1..7f887b6 100644
--- a/actions/release/lang/ruby/validate/action.yml
+++ b/actions/release/lang/ruby/validate/action.yml
@@ -2,8 +2,8 @@
 name: Validate Ruby Release
 description: >
   Checks out the release SHA, sets up Ruby, reads the gem version, validates
-  the release (tag existence, branch, commit metadata), and runs lint + build
-  to confirm the gem is publishable before the approval gate.
+  the release (RubyGems availability, tag existence, branch, commit metadata),
+  and runs lint + build to confirm the gem is publishable before the approval gate.
 
 inputs:
   sha:
@@ -32,6 +32,13 @@ inputs:
     description: "Path to the gem root (where Gemfile and gemspec live)"
     required: false
     default: '.'
+  package_name:
+    description: >
+      RubyGems gem name. When set, validate fails fast if this version is already
+      published — the registry, not the git tag, is the source of truth (covers
+      prereleases and force-deleted tags). Leave empty to skip.
+    required: false
+    default: ''
   ruby_version:
     description: "Ruby version to use, or a version file path (.tool-versions, .ruby-version)"
     required: false
@@ -83,6 +90,34 @@ runs:
           echo "version=$VERSION" >> $GITHUB_OUTPUT
         fi
 
+    - name: Check RubyGems version availability
+      shell: bash
+      env:
+        PACKAGE_NAME: ${{ inputs.package_name }}
+        VERSION: ${{ steps.read-version.outputs.version }}
+      run: |
+        if [ -z "$PACKAGE_NAME" ]; then
+          echo "No package_name provided; skipping RubyGems availability check."
+          exit 0
+        fi
+        CODE=$(curl -sS -o /dev/null -w '%{http_code}' \
+          --retry 3 --retry-connrefused --max-time 30 \
+          "https://rubygems.org/api/v2/rubygems/$PACKAGE_NAME/versions/$VERSION.json")
+        case "$CODE" in
+          200)
+            echo "Error: $PACKAGE_NAME $VERSION already exists on RubyGems — has the version been bumped?"
+            exit 1
+            ;;
+          404)
+            echo "$PACKAGE_NAME $VERSION is available on RubyGems."
+            ;;
+          *)
+            echo "Error: unexpected response from RubyGems (HTTP $CODE) checking $PACKAGE_NAME $VERSION;"
+            echo "cannot confirm the version is unpublished — aborting rather than risk a bad release."
+            exit 1
+            ;;
+        esac
+
     - name: Validate SHA format
       shell: bash
       env:
diff --git a/templates/actions/release/lang/ruby/validate.yml.erb b/templates/actions/release/lang/ruby/validate.yml.erb
index 4b918d7..f5e5967 100644
--- a/templates/actions/release/lang/ruby/validate.yml.erb
+++ b/templates/actions/release/lang/ruby/validate.yml.erb
@@ -1,8 +1,8 @@
 name: Validate Ruby Release
 description: >
   Checks out the release SHA, sets up Ruby, reads the gem version, validates
-  the release (tag existence, branch, commit metadata), and runs lint + build
-  to confirm the gem is publishable before the approval gate.
+  the release (RubyGems availability, tag existence, branch, commit metadata),
+  and runs lint + build to confirm the gem is publishable before the approval gate.
 
 inputs:
   sha:
@@ -31,6 +31,13 @@ inputs:
     description: "Path to the gem root (where Gemfile and gemspec live)"
     required: false
     default: '.'
+  package_name:
+    description: >
+      RubyGems gem name. When set, validate fails fast if this version is already
+      published — the registry, not the git tag, is the source of truth (covers
+      prereleases and force-deleted tags). Leave empty to skip.
+    required: false
+    default: ''
   ruby_version:
     description: "Ruby version to use, or a version file path (.tool-versions, .ruby-version)"
     required: false
@@ -64,6 +71,8 @@ runs:
 
 <%= render_step('lang/ruby/read-version') %>
 
+<%= render_step('release/lang/ruby/rubygems-availability') %>
+
 <%= render_step('release/validate', version: "${{ steps.read-version.outputs.version }}") %>
 
     - name: Lint and build
diff --git a/templates/steps/lang/js/env-dump.yml.erb b/templates/steps/lang/js/env-dump.yml.erb
index 3319b4c..920fe52 100644
--- a/templates/steps/lang/js/env-dump.yml.erb
+++ b/templates/steps/lang/js/env-dump.yml.erb
@@ -15,6 +15,6 @@
     echo "=== pnpm ==="
     pnpm --version || echo "(unavailable)"
     echo "=== Registry ==="
-    npm config get registry
+    pnpm config get registry
     echo "=== package.json version ==="
     node -p "require('./package.json').version" 2>/dev/null || echo "(unavailable)"
diff --git a/templates/steps/release/lang/js/npm-availability.yml.erb b/templates/steps/release/lang/js/npm-availability.yml.erb
index 63b078d..e5ac1a8 100644
--- a/templates/steps/release/lang/js/npm-availability.yml.erb
+++ b/templates/steps/release/lang/js/npm-availability.yml.erb
@@ -1,8 +1,11 @@
 <%#
   Fails fast if the package version is already published to the npm registry.
-  Read-only registry query (no auth). Self-guards: skips when package_name is
-  empty. Complements release/validate's git-tag check by covering prereleases,
-  which aren't tagged. Assumes the read-version step (id: read-version) has run.
+  Read-only registry HTTP query — no auth, and no package-manager CLI, so it works
+  in pnpm-strict repos (a `npm view` here trips devEngines/engines with
+  EBADDEVENGINES, and swallowing that error silently passes the check). Self-guards:
+  skips when package_name is empty. Complements release/validate's git-tag check by
+  covering prereleases, which aren't tagged. Assumes the read-version step
+  (id: read-version) has run.
 
   @param package_name [String] expr for the npm package name. Default: ${{ inputs.package_name }}
   @param registry     [String] expr for the npm registry URL. Default: ${{ inputs.registry }}
@@ -18,8 +21,21 @@
       echo "No package_name provided; skipping npm availability check."
       exit 0
     fi
-    if npm view "$PACKAGE_NAME@$VERSION" version --registry "$REGISTRY" >/dev/null 2>&1; then
-      echo "Error: $PACKAGE_NAME@$VERSION already exists on npm — has the version been bumped?"
-      exit 1
-    fi
-    echo "$PACKAGE_NAME@$VERSION is available on npm."
+    REGISTRY="${REGISTRY%/}"
+    CODE=$(curl -sS -o /dev/null -w '%{http_code}' \
+      --retry 3 --retry-connrefused --max-time 30 \
+      "$REGISTRY/$PACKAGE_NAME/$VERSION")
+    case "$CODE" in
+      200)
+        echo "Error: $PACKAGE_NAME@$VERSION already exists on npm — has the version been bumped?"
+        exit 1
+        ;;
+      404)
+        echo "$PACKAGE_NAME@$VERSION is available on npm."
+        ;;
+      *)
+        echo "Error: unexpected response from the npm registry (HTTP $CODE) checking $PACKAGE_NAME@$VERSION;"
+        echo "cannot confirm the version is unpublished — aborting rather than risk a bad release."
+        exit 1
+        ;;
+    esac
diff --git a/templates/steps/release/lang/ruby/rubygems-availability.yml.erb b/templates/steps/release/lang/ruby/rubygems-availability.yml.erb
new file mode 100644
index 0000000..178d8f9
--- /dev/null
+++ b/templates/steps/release/lang/ruby/rubygems-availability.yml.erb
@@ -0,0 +1,36 @@
+<%#
+  Fails fast if the gem version is already published to RubyGems. Read-only
+  registry HTTP query (no auth). The registry — not the git tag — is the source of
+  truth, so this catches a duplicate even if the tag was force-deleted or never
+  pushed, and it covers prereleases (which aren't tagged). Self-guards: skips when
+  package_name is empty. Assumes the read-version step (id: read-version) has run.
+
+  @param package_name [String] expr for the RubyGems gem name. Default: ${{ inputs.package_name }}
+-%>
+- name: Check RubyGems version availability
+  shell: bash
+  env:
+    PACKAGE_NAME: <%= locals.fetch(:package_name) { "${{ inputs.package_name }}" } %>
+    VERSION: ${{ steps.read-version.outputs.version }}
+  run: |
+    if [ -z "$PACKAGE_NAME" ]; then
+      echo "No package_name provided; skipping RubyGems availability check."
+      exit 0
+    fi
+    CODE=$(curl -sS -o /dev/null -w '%{http_code}' \
+      --retry 3 --retry-connrefused --max-time 30 \
+      "https://rubygems.org/api/v2/rubygems/$PACKAGE_NAME/versions/$VERSION.json")
+    case "$CODE" in
+      200)
+        echo "Error: $PACKAGE_NAME $VERSION already exists on RubyGems — has the version been bumped?"
+        exit 1
+        ;;
+      404)
+        echo "$PACKAGE_NAME $VERSION is available on RubyGems."
+        ;;
+      *)
+        echo "Error: unexpected response from RubyGems (HTTP $CODE) checking $PACKAGE_NAME $VERSION;"
+        echo "cannot confirm the version is unpublished — aborting rather than risk a bad release."
+        exit 1
+        ;;
+    esac