diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
new file mode 100644
index 0000000..67311ab
--- /dev/null
+++ b/.github/workflows/ci.yaml
@@ -0,0 +1,43 @@
+name: CI / Build & Test
+
+on:
+  push:
+    branches: [master]
+  pull_request:
+    branches: [master]
+  workflow_dispatch: {}
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref_name != 'master' && github.ref || github.run_id }}
+  cancel-in-progress: true
+
+jobs:
+  ci:
+    name: Check, Lint & Test (Python ${{ matrix.python-version }})
+    runs-on: ubuntu-latest
+
+    strategy:
+      fail-fast: false
+      matrix:
+        python-version: ["3.11", "3.12", "3.13"]
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install uv
+        uses: astral-sh/setup-uv@v5
+
+      - name: Set up Python ${{ matrix.python-version }}
+        run: uv python install ${{ matrix.python-version }}
+
+      - name: Install dependencies
+        run: uv sync --all-extras
+
+      - name: Type check (pyrefly)
+        run: uv run pyrefly check
+
+      - name: Lint (ruff)
+        run: uv run ruff check .
+
+      - name: Test (pytest)
+        run: uv run pytest
diff --git a/.github/workflows/conventional-commit.yml b/.github/workflows/conventional-commit.yml
new file mode 100644
index 0000000..43253d0
--- /dev/null
+++ b/.github/workflows/conventional-commit.yml
@@ -0,0 +1,44 @@
+name: Conventional Commit Check
+
+on:
+  pull_request:
+    types: [opened, edited, synchronize]
+
+jobs:
+  validate_pr_title:
+    name: Validate PR Title
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Validate PR title
+        id: check_title
+        run: |
+          #!/bin/bash
+          set -euo pipefail
+
+          # Allowed prefixes
+          PREFIXES=("feat" "fix" "docs" "style" "refactor" "test" "chore" "ci" "perf")
+
+          # Get PR title
+          PR_TITLE=$(jq -r .pull_request.title "$GITHUB_EVENT_PATH")
+          echo "PR title: $PR_TITLE"
+
+          # Regex for conventional commit: prefix[optional scope][optional !]: description
+          PREFIX_PATTERN=$(IFS="|"; echo "${PREFIXES[*]}")
+          REGEX="^(${PREFIX_PATTERN})(\\([a-zA-Z0-9_-]+\\))?(!)?: .+"
+
+          if [[ "$PR_TITLE" =~ $REGEX ]]; then
+            echo "PR title follows Conventional Commits."
+          else
+            echo "PR title does NOT follow Conventional Commits."
+            echo "Expected format: <type>[optional scope][!]: description"
+            echo "Allowed types: ${PREFIXES[*]}"
+            echo "Examples:"
+            echo "  feat: add login endpoint"
+            echo "  fix(auth)!: fix critical bug"
+            exit 1
+          fi
+