diff --git a/test/core.test.ts b/test/core.test.ts
new file mode 100644
index 0000000..20acfed
--- /dev/null
+++ b/test/core.test.ts
@@ -0,0 +1,217 @@
+import Flare, {
+    FlareFirePriority,
+    FlareFireStrategy,
+} from '../src';
+
+type Events = {
+    add: { value: number };
+    remove: { value: number };
+};
+
+describe('Base features', () => {
+    let flare: Flare<Events>;
+
+    beforeEach(() => {
+        flare = new Flare<Events>();
+    });
+
+    describe('handler registration and execution', () => {
+        it('should register and execute a handler via catch()', async () => {
+            const handler = jest.fn();
+            flare.catch('add', handler);
+
+            await flare.fire('add', { value: 1 });
+
+            expect(handler).toHaveBeenCalledWith({ value: 1 });
+        });
+
+        it('should return warning message if no handler is found for event', async () => {
+            const result = await flare.fire('remove', { value: 10 });
+
+            expect(typeof result).toBe('string');
+            expect(result).toContain('No handlers found for event "remove"');
+        });
+
+        it('should allow multiple handlers for same event', async () => {
+            const h1 = jest.fn();
+            const h2 = jest.fn();
+
+            flare.catch('add', h1);
+            flare.catch('add', h2);
+
+            await flare.fire('add', { value: 10 });
+
+            expect(h1).toHaveBeenCalled();
+            expect(h2).toHaveBeenCalled();
+        });
+
+        it('should respect handler priority (high first)', async () => {
+            const callOrder: string[] = [];
+
+            flare.catch('add', () => { callOrder.push('low') }, { priority: FlareFirePriority.Low });
+            flare.catch('add', () => { callOrder.push('high') }, { priority: FlareFirePriority.High });
+
+            await flare.fire('add', { value: 10 });
+
+            expect(callOrder).toEqual(['high', 'low']);
+        });
+
+        it('should skip handler when "when" condition returns false', async () => {
+            const handler = jest.fn();
+
+            flare.catch('add', handler, {
+                when: (payload) => payload.value > 10,
+            });
+
+            await flare.fire('add', { value: 5 });
+
+            expect(handler).not.toHaveBeenCalled();
+        });
+
+        it('should remove "once" handlers automatically after first run', async () => {
+            const handler = jest.fn();
+
+            flare.catch('add', handler, { once: true });
+
+            await flare.fire('add', { value: 1 });
+            await flare.fire('add', { value: 2 });
+
+            expect(handler).toHaveBeenCalledTimes(1);
+        });
+    });
+
+    describe('handler release and releaseAll', () => {
+        it('should remove a specific handler with release()', async () => {
+            const handler = jest.fn();
+            flare.catch('add', handler);
+
+            flare.release('add', handler);
+            await flare.fire('add', { value: 1 });
+
+            expect(handler).not.toHaveBeenCalled();
+        });
+
+        it('should remove all handlers via releaseAll()', async () => {
+            const h1 = jest.fn();
+            const h2 = jest.fn();
+
+            flare.catch('add', h1);
+            flare.catch('remove', h2);
+
+            flare.releaseAll();
+
+            await flare.fire('add', { value: 1 });
+            await flare.fire('remove', { value: 1 });
+
+            expect(h1).not.toHaveBeenCalled();
+            expect(h2).not.toHaveBeenCalled();
+        });
+
+        it('should not throw if release() is called for non-existing handler', () => {
+            expect(() => flare.release('add', jest.fn())).not.toThrow();
+        });
+    });
+
+    describe('handler execution strategies', () => {
+        it('should execute handlers in parallel by default', async () => {
+            const order: string[] = [];
+
+            flare.catch('add', async () => {
+                await new Promise(r => setTimeout(r, 20));
+                order.push('first');
+            });
+
+            flare.catch('add', async () => {
+                order.push('second');
+            });
+
+            await flare.fire('add', { value: 5 });
+            expect(order).toContain('second');
+            expect(order).toContain('first');
+        });
+
+        it('should execute handlers sequentially when strategy=Serial', async () => {
+            const order: string[] = [];
+
+            flare.catch('add', async () => {
+                order.push('first');
+            }, { priority: 1 });
+
+            flare.catch('add', async () => {
+                order.push('second');
+            }, { priority: 0 });
+
+            await flare.fire('add', { value: 1 }, { strategy: FlareFireStrategy.Serial });
+
+            expect(order).toEqual(['first', 'second']);
+        });
+
+        it('should respect haltOnError when true (Serial strategy)', async () => {
+            const order: string[] = [];
+
+            flare.catch('add', async () => {
+                order.push('first');
+                throw new Error('fail');
+            });
+
+            flare.catch('add', async () => {
+                order.push('second');
+            });
+
+            await flare.fire('add', { value: 5 }, {
+                strategy: FlareFireStrategy.Serial,
+                haltOnError: true,
+            });
+
+            expect(order).toEqual(['first']); // second should not execute
+        });
+
+        it('should continue when haltOnError=false (Serial strategy)', async () => {
+            const order: string[] = [];
+
+            flare.catch('add', async () => {
+                order.push('first');
+                throw new Error('fail');
+            });
+
+            flare.catch('add', async () => {
+                order.push('second');
+            });
+
+            await flare.fire('add', { value: 5 }, {
+                strategy: FlareFireStrategy.Serial,
+                haltOnError: false,
+            });
+
+            expect(order).toEqual(['first', 'second']);
+        });
+
+        it('should timeout handlers that exceed given timeout', async () => {
+            const slowHandler = jest.fn(async () => {
+                await new Promise(r => setTimeout(r, 50));
+            });
+
+            flare.catch('add', slowHandler);
+
+            await expect(
+                flare.fire('add', { value: 2 }, { timeout: 10 })
+            ).resolves.not.toThrow();
+
+            expect(slowHandler).toHaveBeenCalled();
+        });
+    });
+
+    describe('return values and message correctness', () => {
+        it('should resolve to undefined when event runs successfully', async () => {
+            flare.catch('add', jest.fn());
+            const result = await flare.fire('add', { value: 1 });
+
+            expect(result).toBeUndefined();
+        });
+
+        it('should resolve with descriptive message when stopped by no handler', async () => {
+            const result = await flare.fire('remove', { value: 0 });
+            expect(result).toContain('No handlers found');
+        });
+    });
+});