diff --git a/lib/main.js b/lib/main.js
new file mode 100644
index 0000000..e879858
--- /dev/null
+++ b/lib/main.js
@@ -0,0 +1,39 @@
+"use strict";
+var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    return new (P || (P = Promise))(function (resolve, reject) {
+        function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
+        function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
+        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        step((generator = generator.apply(thisArg, _arguments || [])).next());
+    });
+};
+var __importStar = (this && this.__importStar) || function (mod) {
+    if (mod && mod.__esModule) return mod;
+    var result = {};
+    if (mod != null) for (var k in mod) if (Object.hasOwnProperty.call(mod, k)) result[k] = mod[k];
+    result["default"] = mod;
+    return result;
+};
+Object.defineProperty(exports, "__esModule", { value: true });
+const core = __importStar(require("@actions/core"));
+const github = __importStar(require("@actions/github"));
+function run() {
+    return __awaiter(this, void 0, void 0, function* () {
+        try {
+            const description_regex = core.getInput('description-regex');
+            core.debug(`Applying ${description_regex} to description string.`);
+            const description = github.context.payload.pull_request.body;
+            console.log('PR Description: ${description}');
+            if (!description.match(new RegExp(description_regex))) {
+                core.setFailed('Please fix your PR SUMMARY line to match ${description_regex}');
+            }
+            else {
+                console.log('PR description contains valid SUMMARY line.');
+            }
+        }
+        catch (error) {
+            core.setFailed(error.message);
+        }
+    });
+}
+run();