diff --git a/.github/actions/build-test/action.yml b/.github/actions/build-test/action.yml
new file mode 100644
index 0000000..9b9bf0b
--- /dev/null
+++ b/.github/actions/build-test/action.yml
@@ -0,0 +1,42 @@
+name: "Build and Test"
+description: "Install deps, build and test the Chat SDK (shared by CI and publish workflows)"
+inputs:
+  node-version:
+    description: "Node.js version"
+    required: false
+    default: "22.14.0" # pinned >= the OIDC minimum (Node 22.14); major-only "22" can resolve below it
+  run-checks:
+    description: "Run lint + format checks before build+test (enable for PR CI)"
+    required: false
+    default: "false"
+runs:
+  using: "composite"
+  steps:
+    - uses: actions/setup-node@v4
+      with:
+        node-version: ${{ inputs.node-version }}
+        registry-url: "https://registry.npmjs.org" # writes .npmrc; harmless on PR, used by OIDC on publish
+        cache: "npm"
+    - name: Upgrade npm (trusted publishing needs >= 11.5.1)
+      shell: bash
+      # Pinned for deterministic builds; bump intentionally (must stay >= 11.5.1 for OIDC).
+      run: npm install -g npm@11.5.1
+    - name: Install dependencies
+      shell: bash
+      run: npm ci
+    # Run lint + format as non-mutating gates BEFORE build/test, so build/test exercise the actual
+    # committed code rather than code an `eslint --fix` / `prettier --write` may have rewritten
+    # afterwards. prettier:check is scoped to first-party src/tests (a repo-wide check fails on
+    # pre-existing unrelated files such as the semantic-release-managed CHANGELOG.md).
+    - name: Lint and check formatting
+      if: ${{ inputs.run-checks == 'true' }}
+      shell: bash
+      run: |
+        npm run lint
+        npm run prettier:check
+    - name: Build
+      shell: bash
+      run: npm run build
+    - name: Test
+      shell: bash
+      run: npm run test
diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 09b36f5..0b7856f 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -1,23 +1,10 @@
-name: Call reusable workflow - Chat SDK
+name: CI - Chat SDK
 
 on:
-  push:
-    branches:
-      - main
   pull_request:
     branches:
       - main
 
 jobs:
-  call-reusable-workflow-PR:
-    uses: ./.github/workflows/ci_reusable.yaml
-    if: github.event_name == 'pull_request'
-    with:
-      PUBLISH_NPM: false
-    secrets: inherit
-  call-reusable-workflow-testing:
+  build-test:
     uses: ./.github/workflows/ci_reusable.yaml
-    if: github.event_name == 'push'
-    with:
-      PUBLISH_NPM: true
-    secrets: inherit
diff --git a/.github/workflows/ci_reusable.yaml b/.github/workflows/ci_reusable.yaml
index 6654dc4..522d221 100644
--- a/.github/workflows/ci_reusable.yaml
+++ b/.github/workflows/ci_reusable.yaml
@@ -1,60 +1,14 @@
-name: Build, Test and Publish - Chat SDK
+name: Build and Test - Chat SDK
 
 on:
   workflow_call:
-    inputs:
-      PUBLISH_NPM:
-        required: true
-        type: boolean
-    secrets:
-      NPM_TOKEN:
-        required: true
 
 jobs:
-  build-test-publish:
-    name: Build, Test and Publish
+  build-test:
+    name: Build and Test
     runs-on: ubuntu-latest
-    env:
-      NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}
-      PUBLISH_NPM: ${{ inputs.PUBLISH_NPM }}
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4 # defaults to github.sha (the PR merge commit); works in workflow_call and for fork PRs
+      - uses: ./.github/actions/build-test # same shared composite as publish.yaml
         with:
-          ref: ${{ github.event.pull_request.head.ref }}
-      - uses: actions/setup-node@v3
-        with:
-          node-version: "20"
-          registry-url: "https://registry.npmjs.org"
-          cache: "npm"
-      - name: Cache dependencies
-        uses: actions/cache@v3
-        with:
-          path: ~/.npm
-          key: npm-${{ hashFiles('package-lock.json') }}
-          restore-keys: npm-
-      - run: npm ci
-      - run: npm run prettier
-      - run: npm run lint:fix
-      - run: npm run build
-      - run: npm run test
-      - name: Set github bot
-        run: |
-          git config user.name 'github-actions[bot]'
-          git config user.email 'github-actions[bot]@users.noreply.github.com'
-      - name: "Update to alpha version"
-        if: inputs.PUBLISH_NPM
-        env:
-          NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}
-        run: |
-          git reset --hard
-          npm version prerelease --preid alpha
-          OLD_MSG=$(git log --format=%B -n1)
-          git commit --amend -m "$OLD_MSG" -m "[skip ci]"
-          git push
-          git push --tags
-      - name: "Publish to npm"
-        if: inputs.PUBLISH_NPM
-        run: |
-          npm publish --tag alpha
-        env:
-          NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}
+          run-checks: "true" # lint runs (non-mutating) before build+test on PRs; skipped on publish
diff --git a/.github/workflows/publish-latest.yaml b/.github/workflows/publish-latest.yaml
deleted file mode 100644
index ff92517..0000000
--- a/.github/workflows/publish-latest.yaml
+++ /dev/null
@@ -1,59 +0,0 @@
-name: Publish latest
-
-on:
-  workflow_dispatch:
-
-permissions:
-  contents: write # for GitHub releases
-  issues: write # for release comments
-  pull-requests: write # for PR comments
-  id-token: write # for npm provenance if needed
-
-jobs:
-  release:
-    name: Build and release latest
-    if: ${{ github.ref == 'refs/heads/main' }}
-    runs-on: ubuntu-latest
-    env:
-      GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-      NPM_TOKEN: ${{ secrets.NPM_TOKEN }}
-
-    steps:
-      # 1. Checkout latest main
-      - uses: actions/checkout@v3
-        with:
-          persist-credentials: false
-          fetch-depth: 0
-
-      - run: |
-          git fetch origin main
-          git checkout main
-          git reset --hard origin/main
-
-      # 2. Setup Node and npm auth
-      - uses: actions/setup-node@v3
-        with:
-          node-version: "20"
-          registry-url: "https://registry.npmjs.org"
-          cache: "npm"
-        env:
-          NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}
-
-      # 3. Install dependencies and build
-      - run: npm ci
-      - run: npm run build
-
-      - name: Semantic Release Publish
-        uses: cycjimmy/semantic-release-action@v4
-        with:
-          semantic_version: 24
-          extra_plugins: |
-            @semantic-release/changelog@6
-            @semantic-release/git@10
-          branches: |
-            [
-              'main'
-            ]
-        env:
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-          NPM_TOKEN: ${{ secrets.NPM_TOKEN }}
diff --git a/.github/workflows/publish.yaml b/.github/workflows/publish.yaml
new file mode 100644
index 0000000..122f9a9
--- /dev/null
+++ b/.github/workflows/publish.yaml
@@ -0,0 +1,75 @@
+name: Publish - Chat SDK
+
+on:
+  push:
+    branches:
+      - main
+  workflow_dispatch:
+
+# Serialize publish runs: this job bumps + pushes main and publishes to npm, so overlapping runs
+# (back-to-back pushes, or a manual dispatch during a push publish) would race on the main push and
+# the prerelease sequence. Never cancel a run mid-publish.
+concurrency:
+  group: publish-${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: false
+
+permissions:
+  contents: write # push alpha version commit/tag + create GitHub release
+  id-token: write # OIDC trusted publishing + provenance
+  issues: write # semantic-release release comments
+  pull-requests: write # semantic-release release comments
+
+jobs:
+  publish:
+    name: Build, Test and Publish
+    if: ${{ github.ref == 'refs/heads/main' }}
+    runs-on: ubuntu-latest
+    env:
+      GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          ref: ${{ github.sha }} # tie the run to the triggering commit, not the latest main
+          fetch-depth: 0 # semantic-release needs full history
+          # persist-credentials defaults true -> alpha `git push` uses GITHUB_TOKEN
+      - name: Create local main branch at the triggering commit
+        run: |
+          git checkout -B main # non-detached HEAD (needed for the alpha git push) tied to github.sha
+          # -B leaves the branch untracked; set its upstream to origin/main so semantic-release's
+          # own `git push` (workflow_dispatch / latest path) and any bare `git push` resolve a target.
+          git config branch.main.remote origin
+          git config branch.main.merge refs/heads/main
+      - uses: ./.github/actions/build-test # shared composite: setup-node + npm upgrade + ci + build + test
+      # Needed by both paths: the alpha bump commit and semantic-release's @semantic-release/git commits.
+      - name: Configure git author
+        run: |
+          git config user.name 'github-actions[bot]'
+          git config user.email 'github-actions[bot]@users.noreply.github.com'
+
+      # ---- alpha: every push to main ----
+      - name: Publish alpha to npm
+        if: github.event_name == 'push'
+        run: |
+          git reset --hard
+          # Bake [skip ci] into the commit message so the version bump commit+tag are created in
+          # one step (no --amend, which would leave the tag pointing at the pre-amend commit) and
+          # the pushed commit to main does not re-trigger this workflow.
+          npm version prerelease --preid alpha -m "%s [skip ci]"
+          git push --follow-tags origin main # push the bump commit + its tag explicitly (upstream is set above)
+          npm publish --tag alpha # tokenless OIDC, provenance automatic
+
+      # ---- latest: on demand (workflow_dispatch) ----
+      - name: Publish latest + GitHub release (semantic-release)
+        if: github.event_name == 'workflow_dispatch'
+        uses: cycjimmy/semantic-release-action@v4
+        with:
+          semantic_version: 25 # bundles @semantic-release/npm >= 13.1 (OIDC)
+          extra_plugins: |
+            @semantic-release/changelog@6
+            @semantic-release/git@10
+          branches: |
+            [
+              'main'
+            ]
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }} # no NPM_TOKEN — OIDC handles npm auth
diff --git a/package.json b/package.json
index 9d7d690..d9360ed 100644
--- a/package.json
+++ b/package.json
@@ -43,6 +43,7 @@
     "lint": "eslint --ignore-path .gitignore --ext .js,.ts . --config .eslintrc.tests.cjs",
     "lint:fix": "npm run lint -- --fix",
     "prettier": "prettier --write .",
+    "prettier:check": "prettier --check \"src/**/*\" \"tests/**/*\"",
     "test": "run-p test:browser test:node",
     "test:browser": "vitest --config vite.config.mts",
     "test:node": "vitest --config vite.config.node.mts",
@@ -119,7 +120,7 @@
     "vitest": "^3.1.1"
   },
   "volta": {
-    "node": "20.19.0",
-    "npm": "8.11.0"
+    "node": "22.14.0",
+    "npm": "11.5.1"
   }
 }