diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..9b81cd4
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,45 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+permissions:
+  contents: read
+
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+      - name: Run actionlint
+        run: |
+          bash <(curl https://raw.githubusercontent.com/rhysd/actionlint/main/scripts/download-actionlint.bash)
+          ./actionlint -color
+      - name: Run markdownlint
+        run: |
+          npm install -g markdownlint-cli2
+
+          markdownlint-cli2 "**/*.md"
+
+      - name: Run yamllint
+        run: |
+          pip install yamllint
+          yamllint .
+
+  secrets:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Run gitleaks
+        uses: gitleaks/gitleaks-action@v2
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
diff --git a/.markdownlint.yaml b/.markdownlint.yaml
new file mode 100644
index 0000000..89bd30b
--- /dev/null
+++ b/.markdownlint.yaml
@@ -0,0 +1,3 @@
+# Markdownlint config issue — keeps default rules except line-length.
+default: true
+MD013: false
diff --git a/.yamllint b/.yamllint
new file mode 100644
index 0000000..44644ab
--- /dev/null
+++ b/.yamllint
@@ -0,0 +1,8 @@
+# .yamllint — sensible defaults for GitHub Actions workflows
+extends: default
+rules:
+  truthy:
+    allowed-values: ['true', 'false', 'on', 'off']
+  line-length:
+    max: 120
+  document-start: disable
diff --git a/LICENSE b/LICENSE
index 1ae54ba..223e1bd 100644
--- a/LICENSE
+++ b/LICENSE
@@ -1,3 +1,4 @@
+
 MIT License
 
 Copyright (c) 2026 Cristina Borges
@@ -18,4 +19,4 @@ 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.
\ No newline at end of file
+SOFTWARE.
diff --git a/README.md b/README.md
index 28e13aa..7063691 100644
--- a/README.md
+++ b/README.md
@@ -47,4 +47,4 @@ See `docs/ARCHITECTURE.md` once it lands.
 
 ## License
 
-MIT. See `LICENSE`.
\ No newline at end of file
+MIT. See `LICENSE`.