diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..46693b4
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,33 @@
+name: CI
+
+on:
+  push:
+    branches: [ master, feature/** ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  build-and-test:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: Setup .NET
+      uses: actions/setup-dotnet@v4
+      with:
+        dotnet-version: |
+          9.0.x
+          10.0.x
+
+    - name: Restore dependencies
+      run: dotnet restore
+
+    - name: Build
+      run: dotnet build src/MaskedUUID.AspNetCore/MaskedUUID.AspNetCore.csproj --configuration Release --no-restore
+
+    - name: Build Tests
+      run: dotnet build tests/MaskedUUID.AspNetCore.Tests/MaskedUUID.AspNetCore.Tests.csproj --configuration Release --no-restore
+
+    - name: Test
+      run: dotnet test tests/MaskedUUID.AspNetCore.Tests/MaskedUUID.AspNetCore.Tests.csproj --configuration Release --no-build --verbosity normal
diff --git a/.github/workflows/nuget-publish.yml b/.github/workflows/nuget-publish.yml
new file mode 100644
index 0000000..3b3b051
--- /dev/null
+++ b/.github/workflows/nuget-publish.yml
@@ -0,0 +1,84 @@
+name: Publish to NuGet
+
+on:
+  push:
+    branches: [ release ]
+  workflow_dispatch:
+
+jobs:
+  build-and-publish:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v4
+      with:
+        fetch-depth: 0  # タグ取得用
+
+    - name: Setup .NET
+      uses: actions/setup-dotnet@v4
+      with:
+        dotnet-version: |
+          9.0.x
+          10.0.x
+
+    - name: Restore dependencies
+      run: dotnet restore
+
+    - name: Build
+      run: dotnet build src/MaskedUUID.AspNetCore/MaskedUUID.AspNetCore.csproj --configuration Release --no-restore
+
+    - name: Build Tests
+      run: dotnet build tests/MaskedUUID.AspNetCore.Tests/MaskedUUID.AspNetCore.Tests.csproj --configuration Release --no-restore
+
+    - name: Test
+      run: dotnet test tests/MaskedUUID.AspNetCore.Tests/MaskedUUID.AspNetCore.Tests.csproj --configuration Release --no-build --verbosity normal
+
+    - name: Calculate Version
+      id: version
+      run: |
+        # csprojからVersionPrefixを取得
+        VERSION_PREFIX=$(grep -oP '(?<=<VersionPrefix>)[^<]+' src/MaskedUUID.AspNetCore/MaskedUUID.AspNetCore.csproj)
+        echo "VersionPrefix: $VERSION_PREFIX"
+
+        # 前回のタグを取得
+        PREV_TAG=$(git describe --tags --abbrev=0 2>/dev/null || echo "")
+
+        if [ -z "$PREV_TAG" ]; then
+          # タグがない場合は初回リリース
+          VERSION="${VERSION_PREFIX}.0"
+        else
+          # 前回タグからx.yを抽出
+          PREV_XY=$(echo $PREV_TAG | sed 's/^v//' | cut -d. -f1,2)
+          PREV_Z=$(echo $PREV_TAG | sed 's/^v//' | cut -d. -f3)
+
+          if [ "$PREV_XY" = "$VERSION_PREFIX" ]; then
+            # 同じx.yならzをインクリメント
+            NEW_Z=$((PREV_Z + 1))
+            VERSION="${VERSION_PREFIX}.${NEW_Z}"
+          else
+            # 異なるx.yならz=0
+            VERSION="${VERSION_PREFIX}.0"
+          fi
+        fi
+
+        echo "version=$VERSION" >> $GITHUB_OUTPUT
+        echo "Package Version: $VERSION"
+
+    - name: Pack
+      run: dotnet pack src/MaskedUUID.AspNetCore/MaskedUUID.AspNetCore.csproj
+        --configuration Release
+        --output ./nupkg
+        /p:PackageVersion=${{ steps.version.outputs.version }}
+
+    - name: Publish to NuGet
+      run: dotnet nuget push ./nupkg/*.nupkg
+        --api-key ${{ secrets.NUGET_API_KEY }}
+        --source https://api.nuget.org/v3/index.json
+        --skip-duplicate
+
+    - name: Create Git Tag
+      run: |
+        git config user.name "github-actions[bot]"
+        git config user.email "github-actions[bot]@users.noreply.github.com"
+        git tag v${{ steps.version.outputs.version }}
+        git push origin v${{ steps.version.outputs.version }}
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..c869c8b
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2025 actbit
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/src/MaskedUUID.AspNetCore/MaskedUUID.AspNetCore.csproj b/src/MaskedUUID.AspNetCore/MaskedUUID.AspNetCore.csproj
index e824bd3..a69a6ca 100644
--- a/src/MaskedUUID.AspNetCore/MaskedUUID.AspNetCore.csproj
+++ b/src/MaskedUUID.AspNetCore/MaskedUUID.AspNetCore.csproj
@@ -17,6 +17,22 @@
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
     <OutputType>Library</OutputType>
+    <IsPackable>true</IsPackable>
+
+    <!-- NuGet Package Settings -->
+    <PackageId>MaskedUUID.AspNetCore</PackageId>
+    <VersionPrefix>1.0</VersionPrefix>
+    <Authors>actbit</Authors>
+    <Description>ASP.NET Core で UUIDv7 のタイムスタンプ部を UUIDv47 アルゴリズムでマスクし、可逆的に変換するライブラリ</Description>
+    <PackageTags>uuid;uuidv7;uuidv47;aspnetcore;masking</PackageTags>
+    <PackageLicenseExpression>MIT</PackageLicenseExpression>
+    <PackageReadmeFile>README.md</PackageReadmeFile>
+    <RepositoryUrl>https://github.com/actbit/MaskedUUID</RepositoryUrl>
+    <RepositoryType>git</RepositoryType>
   </PropertyGroup>
 
+  <ItemGroup>
+    <None Include="..\..\README.md" Pack="true" PackagePath="\" />
+  </ItemGroup>
+
 </Project>