@@ -12,11 +12,17 @@ prerelease and changes since the previous stable release. Present the candidate
 to the maintainer. Once approved, dispatch Release from that branch:
 
 ```shell
-gh workflow run release.yml --ref main -f tag=vX.Y.Z
+gh workflow run release.yml --ref main
 ```
 
-Use the support branch instead of `main` for a previous minor version. Release
-selects the highest-numbered `vX.Y.Z-pre.N` reachable from that branch with a
+Without `tag`, Release detects the highest prerelease version reachable from the
+selected branch, then selects its highest-numbered passing candidate. It stops
+if that version has no qualified candidate or already has a stable tag. Supply
+`-f tag=vX.Y.Z` to select a version explicitly or retry a stable release.
+
+Use the support branch instead of `main` for a previous minor version. That
+branch must contain the updated release workflows. Release selects the
+highest-numbered `vX.Y.Z-pre.N` reachable from that branch with a
 successful Pre-release run triggered by that tag or dispatched on the same branch,
 and matching passing `release-tag-v1` qualification evidence. Missing or expired evidence blocks
 promotion. Inspect the selected candidate in the promotion job summary.
@@ -39,6 +45,31 @@ created using `GITHUB_TOKEN`, dispatch Pre-release explicitly on the intended br
 gh workflow run release-prerelease.yml --ref main -f tag=vX.Y.Z-pre.1
 ```
 
+Once the first tag seeds a series, omit `tag` to create the next candidate at
+the selected branch's dispatch commit:
+
+```shell
+gh workflow run release-prerelease.yml --ref main
+```
+
+This selects the highest release series reachable from that branch and requires
+its `-pre.1` seed there. It stops if that version is already stable. New version
+series always need an explicit seed. Manual runs create a new candidate even
+without new commits; pass an existing tag explicitly to retry that candidate.
+Candidate creation is serialized with Release Auto-Tag, which still skips
+unchanged commits and inactive series on `main`.
+
+For example, start a support patch series by tagging its intended branch commit
+as `v0.4.4-pre.1`. Subsequent candidates and promotion use the support branch:
+
+```shell
+gh workflow run release-prerelease.yml --ref release/0.4
+gh workflow run release.yml --ref release/0.4
+```
+
+Replace `release/0.4` with the actual support branch. Use explicit tag inputs if
+its history also contains a higher version series.
+
 Wait for the entire Pre-release run to pass before promoting it. Stable tag pushes do not
 start Release. Release Auto-Tag creates and dispatches prereleases on `main`.
 
 
@@ -176,6 +176,13 @@ selects the latest passing prerelease for the requested version and branch,
 verifies its qualification evidence, creates the stable tag at its exact commit,
 then rebuilds and publishes without rerunning qualification. The promotion job
 summary and `stable-promotion-*` artifact record the candidate and evidence.
+Both workflows accept optional tags. Tagless Pre-release creates the next
+candidate in the selected branch's seeded series; inspect Resolve Prerelease Tag
+for the actual tag and commit. Tagless Release infers the highest reachable
+prerelease version and stops if it is already stable. Explicit tags select an
+existing candidate or stable version for retries. Release Auto-Tag and manual
+candidate creation share a concurrency group; pending tag-resolution jobs can
+be waiting for that lock.
 Failed, cancelled, or skipped required suites fail
 qualification; stable publication is blocked, while published pre-release
 artifacts remain available. The Pre-release failure notification includes the
 
@@ -21,69 +21,43 @@ jobs:
   create-tag:
     runs-on: ubuntu-latest
     timeout-minutes: 5
+    concurrency:
+      group: release-prerelease-tags
+      cancel-in-progress: false
+      queue: max
     steps:
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
         with:
           ref: main
           fetch-depth: 0
+          persist-credentials: false
+
+      - uses: astral-sh/setup-uv@20cfd1bf945f4377ade1205e4dbc17946fc9a30d # v10.0.1
+        with:
+          version: "0.10.12"
+          python-version: "3.13"
+          enable-cache: false
 
       - name: Determine next pre-release version
         id: version
         run: |
           set -euo pipefail
-          tags=$(git tag -l)
-          latest=$(printf '%s\n' "$tags" | \
-            { grep -E '^v[0-9]+\.[0-9]+\.[0-9]+(-pre\.[1-9][0-9]*)?$' || true; } | \
-            sort -V | tail -1)
-          if [[ ! "$latest" =~ ^(v[0-9]+\.[0-9]+\.[0-9]+)-pre\.([1-9][0-9]*)$ ]]; then
-            echo "No active pre-release series — skipping tag creation"
-            echo "skip=true" >> "$GITHUB_OUTPUT"
-            exit 0
-          fi
-          base=${BASH_REMATCH[1]}
-          number=${BASH_REMATCH[2]}
-          if ! git show-ref --verify --quiet "refs/tags/${base}-pre.1"; then
-            echo "No ${base}-pre.1 seed — skipping tag creation"
+          next=$(uv run --no-project python tasks/scripts/next-prerelease-tag.py --scheduled)
+          if [[ -z "${next}" ]]; then
             echo "skip=true" >> "$GITHUB_OUTPUT"
             exit 0
           fi
-          if git show-ref --verify --quiet "refs/tags/${base}"; then
-            echo "$base is already stable — skipping tag creation"
-            echo "skip=true" >> "$GITHUB_OUTPUT"
-            exit 0
-          fi
-          if ! git merge-base --is-ancestor "$latest" HEAD; then
-            echo "::error::Latest pre-release $latest is not an ancestor of main"
-            exit 1
-          fi
-          echo "Latest tag: $latest"
-
-          # Skip if no new commits since the latest tag
-          commit_count=$(git rev-list "${latest}..HEAD" --count)
-          echo "Commits since $latest: $commit_count"
-          if [ "$commit_count" -eq 0 ]; then
-            echo "No new commits since $latest — skipping tag creation"
-            echo "skip=true" >> "$GITHUB_OUTPUT"
-            exit 0
-          fi
-
-          next="${base}-pre.$((number + 1))"
-
-          if git tag -l "$next" | grep -q .; then
-            echo "::error::Tag $next already exists"
-            exit 1
-          fi
-
           echo "next=$next" >> "$GITHUB_OUTPUT"
           echo "Next tag: $next"
 
-      - name: Create and push tag
+      - name: Create tag
         if: steps.version.outputs.skip != 'true'
         env:
+          GH_TOKEN: ${{ github.token }}
           NEXT_TAG: ${{ steps.version.outputs.next }}
         run: |
-          git tag "$NEXT_TAG"
-          git push origin "refs/tags/$NEXT_TAG"
+          gh api --method POST "repos/${GITHUB_REPOSITORY}/git/refs" \
+            -f "ref=refs/tags/${NEXT_TAG}" -f "sha=$(git rev-parse HEAD)"
 
       - name: Trigger Pre-release workflow
         if: steps.version.outputs.skip != 'true'
 
@@ -11,7 +11,7 @@ on:
         required: true
         type: string
       expected-source-sha:
-        description: Qualified source commit that the release tag must resolve to
+        description: Expected source commit that the release tag must resolve to
         required: false
         default: ""
         type: string
@@ -89,7 +89,7 @@ jobs:
         run: |
           set -euo pipefail
           if [[ -n "${EXPECTED_SOURCE_SHA}" && "$(git rev-parse HEAD)" != "${EXPECTED_SOURCE_SHA}" ]]; then
-            echo "Release tag ${RELEASE_TAG} does not match the qualified commit ${EXPECTED_SOURCE_SHA}." >&2
+            echo "Release tag ${RELEASE_TAG} does not match the expected commit ${EXPECTED_SOURCE_SHA}." >&2
             exit 1
           fi
           if [[ "${RELEASE_TAG}" =~ ^v[0-9]+\.[0-9]+\.[0-9]+-pre\.[1-9][0-9]*$ ]]; then
 
@@ -10,43 +10,107 @@ on:
   workflow_dispatch:
     inputs:
       tag:
-        description: "Pre-release tag to publish and qualify (e.g. v0.0.4-pre.1)"
-        required: true
+        description: "Existing prerelease tag (e.g. v0.0.4-pre.1); omit to create the next candidate on this branch"
+        required: false
         type: string
 
 permissions:
   contents: read
 
 jobs:
+  resolve:
+    name: Resolve Prerelease Tag
+    runs-on: ubuntu-latest
+    timeout-minutes: 5
+    permissions:
+      contents: write
+    concurrency:
+      group: release-prerelease-tags
+      cancel-in-progress: false
+      queue: max
+    outputs:
+      tag: ${{ steps.tag.outputs.tag }}
+      source-sha: ${{ steps.tag.outputs.source_sha }}
+    steps:
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        with:
+          fetch-depth: 0
+          persist-credentials: false
+
+      - uses: astral-sh/setup-uv@20cfd1bf945f4377ade1205e4dbc17946fc9a30d # v10.0.1
+        with:
+          version: "0.10.12"
+          python-version: "3.13"
+          enable-cache: false
+
+      - name: Resolve or create candidate tag
+        id: tag
+        env:
+          GH_TOKEN: ${{ github.token }}
+          RELEASE_TAG: ${{ inputs.tag }}
+          EVENT_NAME: ${{ github.event_name }}
+          REF_TYPE: ${{ github.ref_type }}
+          REF_NAME: ${{ github.ref_name }}
+        run: |
+          set -euo pipefail
+          tag="${RELEASE_TAG}"
+          if [[ "${EVENT_NAME}" == "push" ]]; then
+            tag="${REF_NAME}"
+          fi
+          if [[ -z "${tag}" ]]; then
+            test "${REF_TYPE}" = branch
+            tag=$(uv run --no-project python tasks/scripts/next-prerelease-tag.py)
+            source_sha=$(git rev-parse HEAD)
+            gh api --method POST "repos/${GITHUB_REPOSITORY}/git/refs" \
+              -f "ref=refs/tags/${tag}" -f "sha=${source_sha}"
+          else
+            if [[ ! "${tag}" =~ ^v[0-9]+\.[0-9]+\.[0-9]+-pre\.[1-9][0-9]*$ ]]; then
+              echo "Unsupported prerelease tag: ${tag}" >&2
+              exit 1
+            fi
+            source_sha=$(git rev-parse "refs/tags/${tag}^{commit}")
+          fi
+          {
+            echo "tag=${tag}"
+            echo "source_sha=${source_sha}"
+          } >> "${GITHUB_OUTPUT}"
+          {
+            echo "## Prerelease candidate"
+            echo "- Tag: \`${tag}\`"
+            echo "- Source commit: \`${source_sha}\`"
+          } >> "${GITHUB_STEP_SUMMARY}"
+
   build:
     name: Build
+    needs: resolve
     permissions:
       actions: read
       contents: read
       packages: write
     uses: ./.github/workflows/release-build.yml
     with:
-      release-tag: ${{ inputs.tag || github.ref_name }}
+      release-tag: ${{ needs.resolve.outputs.tag }}
+      expected-source-sha: ${{ needs.resolve.outputs.source-sha }}
       is-prerelease: true
     secrets:
       CACHIX_AUTH_TOKEN: ${{ secrets.CACHIX_AUTH_TOKEN }}
 
   release-notes:
     name: Preview Release Notes
-    needs: build
+    needs: [resolve, build]
     permissions:
       contents: read
       pull-requests: read
     uses: ./.github/workflows/release-notes.yml
     with:
-      release-tag: ${{ inputs.tag || github.ref_name }}
+      release-tag: ${{ needs.resolve.outputs.tag }}
       advisory: true
     secrets:
       LLM_INFERENCE_API_KEY: ${{ secrets.LLM_INFERENCE_API_KEY }}
 
   publish:
     name: Publish
-    needs: build
+    needs: [resolve, build]
     permissions:
       actions: read
       contents: write
@@ -57,7 +121,7 @@ jobs:
       artifact-metadata: write
     uses: ./.github/workflows/release-publish.yml
     with:
-      release-tag: ${{ inputs.tag || github.ref_name }}
+      release-tag: ${{ needs.resolve.outputs.tag }}
       source-sha: ${{ needs.build.outputs.source_sha }}
       semver: ${{ needs.build.outputs.semver }}
       python-version: ${{ needs.build.outputs.python_version }}
@@ -68,7 +132,7 @@ jobs:
 
   qualify:
     name: Qualify
-    needs: build
+    needs: [resolve, build]
     permissions:
       actions: read
       contents: read
@@ -77,7 +141,7 @@ jobs:
       pull-requests: read
     uses: ./.github/workflows/release-qualification.yml
     with:
-      release-tag: ${{ inputs.tag || github.ref_name }}
+      release-tag: ${{ needs.resolve.outputs.tag }}
       source-sha: ${{ needs.build.outputs.source_sha }}
       is-prerelease: true
     secrets:
@@ -86,7 +150,7 @@ jobs:
 
   notify-prerelease-success:
     name: Notify Prerelease Success
-    needs: [build, publish, qualify]
+    needs: [resolve, build, publish, qualify]
     if: success()
     runs-on: ubuntu-latest
     timeout-minutes: 2
@@ -95,10 +159,10 @@ jobs:
       - name: Send Slack notification
         continue-on-error: true
         env:
-          RELEASE_TAG: ${{ inputs.tag || github.ref_name }}
+          RELEASE_TAG: ${{ needs.resolve.outputs.tag }}
           SLACK_WEBHOOK_URL: ${{ secrets.SLACK_OPENSHELL_TRIAGE_WEBHOOK_URL }}
           RUN_URL: ${{ format('{0}/{1}/actions/runs/{2}/attempts/{3}', github.server_url, github.repository, github.run_id, github.run_attempt) }}
-          TAG_URL: ${{ format('{0}/{1}/tree/{2}', github.server_url, github.repository, inputs.tag || github.ref_name) }}
+          TAG_URL: ${{ format('{0}/{1}/tree/{2}', github.server_url, github.repository, needs.resolve.outputs.tag) }}
         run: |
           set -euo pipefail
           if [[ -z "${SLACK_WEBHOOK_URL}" ]]; then
@@ -114,7 +178,7 @@ jobs:
 
   notify-prerelease-failure:
     name: Notify Prerelease Failure
-    needs: [build, publish, qualify]
+    needs: [resolve, build, publish, qualify]
     if: failure()
     runs-on: ubuntu-latest
     timeout-minutes: 2
@@ -127,7 +191,7 @@ jobs:
       - name: Send Slack notification
         continue-on-error: true
         env:
-          RELEASE_TAG: ${{ inputs.tag || github.ref_name }}
+          RELEASE_TAG: ${{ needs.resolve.outputs.tag || inputs.tag || github.ref_name }}
           PUBLICATION_RESULT: ${{ needs.publish.result }}
           SLACK_WEBHOOK_URL: ${{ secrets.SLACK_OPENSHELL_TRIAGE_WEBHOOK_URL }}
           SLACK_MENTION: ${{ secrets.SLACK_OPENSHELL_TRIAGE_MENTION }}
 
@@ -7,8 +7,8 @@ on:
   workflow_dispatch:
     inputs:
       tag:
-        description: "Stable version to promote from its latest passing prerelease (e.g. v0.0.4)"
-        required: true
+        description: "Stable version (e.g. v0.0.4); omit to detect the highest prerelease version on this branch"
+        required: false
         type: string
       notes-only:
         description: "Generate a release notes artifact without promoting or publishing"
@@ -87,7 +87,7 @@ jobs:
       - name: Retain promotion record
         uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7
         with:
-          name: stable-promotion-${{ inputs.tag }}-${{ github.run_id }}-${{ github.run_attempt }}
+          name: stable-promotion-${{ steps.candidate.outputs.tag }}-${{ github.run_id }}-${{ github.run_attempt }}
           path: promotion.json
           retention-days: 90
           if-no-files-found: error