diff --git a/.github/workflows/alpha-release.yml b/.github/workflows/alpha-release.yml
new file mode 100644
index 000000000..6f61fa864
--- /dev/null
+++ b/.github/workflows/alpha-release.yml
@@ -0,0 +1,195 @@
+name: Alpha Release
+
+# Publishes a worker from a feature branch for integration testing without
+# touching the branch or main. The tag points at an ephemeral commit whose
+# manifest is bumped to an alpha version; only the tag is pushed.
+#
+# The regular release workflow handles this tag normally, producing a GitHub
+# prerelease and publishing the worker to the isolated `experimental` channel.
+# Run this workflow from main and provide the feature branch or pull-request
+# ref to release. That lets it test PRs created before this workflow existed.
+
+on:
+  workflow_dispatch:
+    inputs:
+      source_ref:
+        description: 'Feature branch or pull-request ref (e.g. feat/my-worker or refs/pull/123/head)'
+        required: true
+        type: string
+      worker:
+        description: 'Worker module to publish from this branch'
+        required: true
+        type: choice
+        options:
+          - acp
+          - approval-gate
+          - bridge
+          - browser
+          - claude-code
+          - codex
+          - devin
+          - console
+          - grok
+          - context-manager
+          - cron
+          - database
+          - email
+          - eval
+          - harness
+          - hermes
+          - http
+          - iii-directory
+          - lsp
+          - image-resize
+          - llm-router
+          - fp
+          - github
+          - mcp
+          - memory
+          - memory-consolidate
+          - opencode
+          - pi
+          - provider-anthropic
+          - provider-claude-code
+          - provider-kimi
+          - provider-llamacpp
+          - provider-openai
+          - provider-openai-codex
+          - provider-xai
+          - provider-zai
+          - pubsub
+          - queue
+          - rbac-proxy
+          - session-manager
+          - slack
+          - telegram-bot
+          - shell
+          - state
+          - storage
+          - scrapling
+          - web
+          - worktree
+      bump:
+        description: 'Base version for the alpha (none = use the manifest version as its base)'
+        required: true
+        type: choice
+        options:
+          - patch
+          - minor
+          - major
+          - none
+        default: patch
+
+permissions:
+  contents: write
+
+concurrency:
+  group: alpha-release-${{ inputs.worker }}
+  cancel-in-progress: false
+
+jobs:
+  prepare:
+    name: Bump and tag alpha
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+
+    steps:
+      - name: Checkout source ref
+        uses: actions/checkout@v5
+        with:
+          fetch-depth: 0
+          ref: ${{ inputs.source_ref }}
+
+      - name: Refuse to release main
+        env:
+          SOURCE_REF: ${{ inputs.source_ref }}
+        run: |
+          set -euo pipefail
+          git fetch origin main
+          source_sha=$(git rev-parse HEAD)
+          main_sha=$(git rev-parse origin/main)
+          if [[ "$source_sha" == "$main_sha" ]]; then
+            echo "::error::Alpha Release is for feature branches; use Create Tag for main releases"
+            exit 1
+          fi
+          echo "::notice::Preparing alpha release from $SOURCE_REF at $source_sha"
+
+      - name: Discover manifest
+        id: meta
+        env:
+          WORKER: ${{ inputs.worker }}
+        run: |
+          set -euo pipefail
+          if [[ ! -f "$WORKER/iii.worker.yaml" ]]; then
+            echo "::error::$WORKER/iii.worker.yaml is missing"
+            exit 1
+          fi
+          manifest=$(grep '^manifest:' "$WORKER/iii.worker.yaml" | head -n1 | awk '{print $2}')
+          if [[ -z "$manifest" ]]; then
+            echo "::error::$WORKER/iii.worker.yaml has no 'manifest' key"
+            exit 1
+          fi
+          echo "manifest=$manifest" >> "$GITHUB_OUTPUT"
+
+      - name: Calculate and write alpha version
+        id: version
+        env:
+          WORKER: ${{ inputs.worker }}
+          BUMP: ${{ inputs.bump }}
+          MANIFEST: ${{ steps.meta.outputs.manifest }}
+        run: |
+          set -euo pipefail
+          version=$(python3 .github/scripts/manifest_version.py bump "$WORKER/$MANIFEST" \
+            --kind "$BUMP" --suffix alpha --worker "$WORKER")
+          echo "version=$version" >> "$GITHUB_OUTPUT"
+          echo "tag=${WORKER}/v${version}" >> "$GITHUB_OUTPUT"
+          echo "::notice::${WORKER}: alpha ${version}@experimental"
+
+      - name: Validate manifest update
+        env:
+          WORKER: ${{ inputs.worker }}
+          MANIFEST: ${{ steps.meta.outputs.manifest }}
+          VERSION: ${{ steps.version.outputs.version }}
+        run: |
+          set -euo pipefail
+          python3 .github/scripts/manifest_version.py verify \
+            "$WORKER/$MANIFEST" --expected "$VERSION"
+
+      - name: Sync Cargo.lock to alpha version
+        env:
+          WORKER: ${{ inputs.worker }}
+          MANIFEST: ${{ steps.meta.outputs.manifest }}
+        run: |
+          set -euo pipefail
+          python3 .github/scripts/manifest_version.py sync-lock "$WORKER/$MANIFEST"
+
+      - name: Check tag does not exist
+        env:
+          TAG: ${{ steps.version.outputs.tag }}
+        run: |
+          if git rev-parse "$TAG" >/dev/null 2>&1; then
+            echo "::error::Tag $TAG already exists"
+            exit 1
+          fi
+
+      - name: Commit alpha version and push only its tag
+        env:
+          TAG: ${{ steps.version.outputs.tag }}
+          WORKER: ${{ inputs.worker }}
+          VERSION: ${{ steps.version.outputs.version }}
+        run: |
+          set -euo pipefail
+          git config user.name "workers-ci[bot]"
+          git config user.email "workers-ci[bot]@users.noreply.github.com"
+          git add -A
+          git commit -m "chore(${WORKER}): alpha v${VERSION} [skip ci]"
+          git tag -a "$TAG" -m "Alpha release $TAG
+
+          worker: $WORKER
+          version: $VERSION
+          registry-tag: experimental
+          "
+          # The ephemeral commit is reachable only through this tag. Never
+          # push the selected feature branch or main from this workflow.
+          git push origin "$TAG"
+          echo "::notice::Published $TAG@experimental"
diff --git a/docs/sops/release.md b/docs/sops/release.md
index 037ec323a..e4a45c4e8 100644
--- a/docs/sops/release.md
+++ b/docs/sops/release.md
@@ -173,6 +173,23 @@ way the GitHub Release is marked prerelease and still builds and publishes
 (unless `interface_smoke: false`). A hand-pushed tag must carry the `.N`
 counter — `parse_release_tag.py` detects prereleases as `-<word>.<number>`.
 
+### Alpha release from a pull request branch
+
+To publish a worker from an unmerged pull request for integration testing, use
+**Actions → Alpha Release** from `main`. Set **Source ref** to the pull request
+branch (or `refs/pull/<number>/head`), then choose the worker and the intended
+base-version bump. The workflow creates an ephemeral commit with an
+`-alpha.N` manifest version, then pushes only its annotated tag, for example
+`browser/v1.4.0-alpha.1`.
+
+The release pipeline publishes that tag as a GitHub prerelease and assigns it
+the `experimental` registry channel (`browser@experimental`). Neither the
+selected branch nor `main` is pushed or changed. The channel is shared: a new
+alpha release for the same worker moves `experimental` to that version.
+
+**Source ref** must not resolve to `main`; use **Create Tag** for a release
+that should move `latest` or `next`.
+
 ### Dry run
 
 Tag shape: `<worker>/vX.Y.Z-dry-run.1` (parsed by `parse_release_tag.py`).