diff --git a/.github/dependabot.yml b/.github/dependabot.yml
new file mode 100644
index 00000000..afa0f4d8
--- /dev/null
+++ b/.github/dependabot.yml
@@ -0,0 +1,38 @@
+version: 2
+
+# All third-party GitHub Actions are SHA-pinned (Codex W2 supply-chain
+# hardening). Dependabot does NOT convert tag pins to SHA pins on its
+# own, so pinning must be done by hand at commit time; Dependabot then
+# keeps the existing SHA pins fresh.
+
+updates:
+  - package-ecosystem: github-actions
+    directory: /
+    schedule:
+      interval: weekly
+      day: monday
+      time: '09:00'
+      timezone: 'Asia/Tokyo'
+    open-pull-requests-limit: 5
+    labels:
+      - dependencies
+      - github-actions
+    commit-message:
+      prefix: 'Update'
+      include: scope
+
+  - package-ecosystem: npm
+    directory: /
+    schedule:
+      interval: weekly
+      day: monday
+      time: '09:00'
+      timezone: 'Asia/Tokyo'
+    open-pull-requests-limit: 5
+    labels:
+      - dependencies
+      - npm
+    commit-message:
+      prefix: 'Update'
+      include: scope
+    versioning-strategy: increase
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
new file mode 100644
index 00000000..2b36357d
--- /dev/null
+++ b/.github/workflows/release.yml
@@ -0,0 +1,171 @@
+name: Release
+
+# vX.Y.Z tag push triggers the full release. workflow_dispatch only
+# permits dry-runs so that the OIDC handshake can be smoke-tested
+# without publishing.
+
+on:
+  push:
+    tags:
+      - 'v*.*.*'
+  workflow_dispatch:
+    inputs:
+      dry_run:
+        description: 'Skip the actual publish / release-create. Use to smoke-test the workflow on a non-tag run.'
+        type: boolean
+        default: true
+
+# Minimum-required default; each job tightens or expands as needed
+# (Codex W2 / supply-chain hardening).
+permissions:
+  contents: read
+
+env:
+  FORCE_JAVASCRIPT_ACTIONS_TO_NODE24: 'true'
+  NODE_OPTIONS: '--max-old-space-size=4096'
+
+jobs:
+  # ==========================================================
+  # 1. verify — confirm the tagged tree is typecheck / lint /
+  #    test green before any publish step runs.
+  # ==========================================================
+  verify:
+    name: Verify (typecheck / lint / test)
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+      - name: Install pnpm
+        uses: pnpm/action-setup@ac6db6d3c1f721f886538a378a2d73e85697340a # v6
+      - uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6
+        with:
+          # `.nvmrc` is pinned to Node 24, which ships npm v11.5+ —
+          # required for OIDC trusted publishing.
+          node-version-file: '.nvmrc'
+          cache: 'pnpm'
+      - name: Install dependencies
+        run: pnpm install --frozen-lockfile
+      - name: Build all workspace packages
+        run: pnpm -r run build
+      - name: Typecheck
+        run: pnpm -r typecheck
+      - name: Lint
+        run: pnpm run lint
+      - name: Test
+        run: pnpm -r --if-present test
+
+  # ==========================================================
+  # 2. publish-npm — publish each package through npm's OIDC
+  #    trusted publisher path, with SLSA provenance v1 attestation.
+  # ==========================================================
+  publish-npm:
+    name: Publish ${{ matrix.pkg }} to npm
+    needs: verify
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      # Required so the runner can fetch an OIDC token to exchange
+      # with the npm registry and Sigstore Fulcio.
+      id-token: write
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - pkg: '@basou/core'
+            dir: core
+          - pkg: '@basou/cli'
+            dir: cli
+          - pkg: '@basou/sdk'
+            dir: sdk
+    steps:
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+
+      - name: Install pnpm
+        uses: pnpm/action-setup@ac6db6d3c1f721f886538a378a2d73e85697340a # v6
+
+      # `registry-url` is intentionally omitted: when it is set,
+      # `actions/setup-node` writes a `_authToken=${NODE_AUTH_TOKEN}`
+      # line into ~/.npmrc that the npm CLI then sends as an empty
+      # bearer token, bypassing the OIDC trusted-publisher path and
+      # producing a 404. The separate step below rewrites ~/.npmrc to
+      # contain only the registry line.
+      - uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6
+        with:
+          node-version-file: '.nvmrc'
+          cache: 'pnpm'
+
+      - name: Configure npm registry without a token line (so OIDC takes over)
+        run: |
+          echo "registry=https://registry.npmjs.org/" > ~/.npmrc
+          cat ~/.npmrc
+
+      - name: Install dependencies
+        run: pnpm install --frozen-lockfile
+
+      - name: Build all workspace packages so workspace:* refs resolve
+        run: pnpm -r run build
+
+      - name: pnpm pack + npm publish (provenance via OIDC)
+        working-directory: packages/${{ matrix.dir }}
+        run: |
+          # Real publish runs only on tag push. workflow_dispatch
+          # always exercises the dry-run branch — the dry_run input
+          # is informational only.
+          if [ "$GITHUB_EVENT_NAME" = "push" ]; then
+            echo "Publishing ${{ matrix.pkg }} via npm CLI (pnpm pack handles the workspace:* rewrite)"
+            pnpm pack
+            TGZ=$(ls *.tgz | head -1)
+            echo "Packed tarball: $TGZ"
+            npm publish "$TGZ" --access public --provenance
+          else
+            echo "Dry-run mode (event=$GITHUB_EVENT_NAME, dry_run=${{ inputs.dry_run }}): pnpm publish --dry-run for ${{ matrix.pkg }}"
+            pnpm publish --access public --provenance --no-git-checks --dry-run
+          fi
+
+  # ==========================================================
+  # 3. github-release — attach pnpm-packed tarballs plus cosign
+  #    sign-blob bundles as release assets, with auto-generated
+  #    release notes.
+  # ==========================================================
+  github-release:
+    name: Create GitHub Release with signed npm tarballs
+    needs: [publish-npm]
+    if: ${{ inputs.dry_run != true && github.event_name == 'push' }}
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+      id-token: write
+    steps:
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+      - name: Install pnpm
+        uses: pnpm/action-setup@ac6db6d3c1f721f886538a378a2d73e85697340a # v6
+      - uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6
+        with:
+          node-version-file: '.nvmrc'
+          cache: 'pnpm'
+      - name: Install dependencies
+        run: pnpm install --frozen-lockfile
+      - name: Build all workspace packages
+        run: pnpm -r run build
+      - name: Pack tarballs (using pnpm to rewrite workspace:*, matching publish-npm)
+        run: |
+          mkdir -p artifacts
+          for d in core cli sdk; do
+            (cd "packages/$d" && pnpm pack --pack-destination ../../artifacts)
+          done
+          ls -la artifacts/
+      - name: Install cosign
+        uses: sigstore/cosign-installer@f713795cb21599bc4e5c4b58cbad1da852d7eeb9 # v3
+      - name: Sign each tarball with cosign sign-blob
+        run: |
+          for f in artifacts/*.tgz; do
+            cosign sign-blob --yes --bundle "$f.bundle" "$f"
+          done
+      - name: Create GitHub Release
+        uses: softprops/action-gh-release@3bb12739c298aeb8a4eeaf626c5b8d85266b0e65 # v2
+        with:
+          tag_name: ${{ github.ref_name }}
+          name: Basou ${{ github.ref_name }}
+          generate_release_notes: true
+          files: |
+            artifacts/*.tgz
+            artifacts/*.bundle
diff --git a/.nvmrc b/.nvmrc
new file mode 100644
index 00000000..a45fd52c
--- /dev/null
+++ b/.nvmrc
@@ -0,0 +1 @@
+24
diff --git a/packages/basou/package.json b/packages/basou/package.json
index e9a4d853..d8e0952d 100644
--- a/packages/basou/package.json
+++ b/packages/basou/package.json
@@ -21,7 +21,14 @@
     "url": "git+https://github.com/basou-dev/basou.git",
     "directory": "packages/basou"
   },
-  "publishConfig": { "access": "public" },
+  "homepage": "https://basou.dev",
+  "bugs": {
+    "url": "https://github.com/basou-dev/basou/issues"
+  },
+  "publishConfig": {
+    "access": "public",
+    "provenance": true
+  },
   "bin": {
     "basou": "./bin.mjs"
   },
@@ -29,6 +36,9 @@
   "engines": {
     "node": ">=20.10.0"
   },
+  "scripts": {
+    "prepublishOnly": "pnpm -w run build"
+  },
   "dependencies": {
     "@basou/cli": "workspace:*"
   }
diff --git a/packages/cli/package.json b/packages/cli/package.json
index 1cab2029..6ca871cd 100644
--- a/packages/cli/package.json
+++ b/packages/cli/package.json
@@ -11,7 +11,14 @@
     "url": "git+https://github.com/basou-dev/basou.git",
     "directory": "packages/cli"
   },
-  "publishConfig": { "access": "public" },
+  "homepage": "https://basou.dev",
+  "bugs": {
+    "url": "https://github.com/basou-dev/basou/issues"
+  },
+  "publishConfig": {
+    "access": "public",
+    "provenance": true
+  },
   "main": "./dist/index.js",
   "module": "./dist/index.js",
   "types": "./dist/index.d.ts",
@@ -34,7 +41,8 @@
     "typecheck": "tsc --noEmit",
     "test": "vitest run",
     "test:watch": "vitest",
-    "clean": "rm -rf dist .tsup *.tsbuildinfo"
+    "clean": "rm -rf dist .tsup *.tsbuildinfo",
+    "prepublishOnly": "pnpm -w run build"
   },
   "dependencies": {
     "@basou/core": "workspace:*",
diff --git a/packages/core/package.json b/packages/core/package.json
index 1c0eec08..cf8bc753 100644
--- a/packages/core/package.json
+++ b/packages/core/package.json
@@ -11,8 +11,13 @@
     "url": "git+https://github.com/basou-dev/basou.git",
     "directory": "packages/core"
   },
+  "homepage": "https://basou.dev",
+  "bugs": {
+    "url": "https://github.com/basou-dev/basou/issues"
+  },
   "publishConfig": {
-    "access": "public"
+    "access": "public",
+    "provenance": true
   },
   "sideEffects": false,
   "main": "./dist/index.js",
@@ -34,7 +39,8 @@
     "typecheck": "tsc --noEmit",
     "test": "vitest run",
     "test:watch": "vitest",
-    "clean": "rm -rf dist .tsup *.tsbuildinfo"
+    "clean": "rm -rf dist .tsup *.tsbuildinfo",
+    "prepublishOnly": "pnpm -w run build"
   },
   "dependencies": {
     "simple-git": "^3.36.0",
diff --git a/packages/sdk/package.json b/packages/sdk/package.json
index bfec9c6b..210a43ad 100644
--- a/packages/sdk/package.json
+++ b/packages/sdk/package.json
@@ -11,7 +11,14 @@
     "url": "git+https://github.com/basou-dev/basou.git",
     "directory": "packages/sdk"
   },
-  "publishConfig": { "access": "public" },
+  "homepage": "https://basou.dev",
+  "bugs": {
+    "url": "https://github.com/basou-dev/basou/issues"
+  },
+  "publishConfig": {
+    "access": "public",
+    "provenance": true
+  },
   "sideEffects": false,
   "main": "./dist/index.js",
   "module": "./dist/index.js",
@@ -32,6 +39,7 @@
     "typecheck": "tsc --noEmit",
     "test": "vitest run",
     "test:watch": "vitest",
-    "clean": "rm -rf dist .tsup *.tsbuildinfo"
+    "clean": "rm -rf dist .tsup *.tsbuildinfo",
+    "prepublishOnly": "pnpm -w run build"
   }
 }