diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
new file mode 100644
index 0000000..5c01e48
--- /dev/null
+++ b/.github/workflows/build.yml
@@ -0,0 +1,45 @@
+name: Build
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - main
+
+permissions:
+  contents: read
+
+jobs:
+  swift:
+    name: Swift build and test
+    runs-on: macos-15
+    timeout-minutes: 20
+
+    steps:
+      - name: Check out repository
+        uses: actions/checkout@v6
+
+      - name: Select Xcode 26
+        shell: bash
+        run: |
+          set -euo pipefail
+          xcode_app="$(find /Applications -maxdepth 1 -name 'Xcode_26*.app' -print | sort | tail -n 1)"
+          if [[ -z "$xcode_app" ]]; then
+            echo "Xcode 26 is required for Swift tools 6.2 but was not found." >&2
+            exit 1
+          fi
+          echo "DEVELOPER_DIR=$xcode_app/Contents/Developer" >> "$GITHUB_ENV"
+          echo "Selected $xcode_app"
+
+      - name: Print tool versions
+        run: |
+          xcodebuild -version
+          swift --version
+
+      - name: Build
+        run: swift build
+
+      - name: Test
+        run: swift test
diff --git a/README.md b/README.md
index 25420ae..9b0c5cb 100644
--- a/README.md
+++ b/README.md
@@ -61,6 +61,12 @@ When launching a test build that someone might manually test, pass `CATCH_GLOBAL
 
 ## Verification And Debugging
 
+### Continuous Integration
+
+`.github/workflows/build.yml` runs on pushes to `main` and pull requests to `main`. It selects an installed Xcode 26 toolchain for Swift tools 6.2, then runs `swift build` and `swift test`.
+
+The release packaging workflow stays separate in `.github/workflows/release.yml` and only runs for `v*` tags or manual dispatch. To make the per-commit build block merges, a repository admin still needs to add the `Swift build and test` check to the `main` branch protection rule in GitHub settings.
+
 ### SwiftUI Previews
 
 Open the package in Xcode and select the `CatchKit` scheme before refreshing SwiftUI previews. `CatchKit` is exposed as a dynamic library product so previews can build through a framework scheme; using the `Catch` executable scheme can produce Xcode's `ENABLE_DEBUG_DYLIB` preview error.