diff --git a/sentry.c b/sentry.c
index e19a6d1..e9fdbb2 100644
--- a/sentry.c
+++ b/sentry.c
@@ -512,6 +512,15 @@ static void sentry_observer_end(zend_execute_data *execute_data, zval *return_va
         ZVAL_COPY(&metadata_zv, &state->metadata);
         add_assoc_zval(&event, "metadata", &metadata_zv);
 
+        zend_object *exception = EG(exception);
+        if (exception != NULL) {
+            zval exception_zv;
+            ZVAL_OBJ_COPY(&exception_zv, exception);
+            add_assoc_zval(&event, "exception", &exception_zv);
+        } else {
+            add_assoc_null(&event, "exception");
+        }
+
         ZVAL_COPY_VALUE(&params[0], &event);
 
         ZVAL_COPY_VALUE(&params[1], &state->user_state);
diff --git a/tests/test_cought_exceptions_do_not_leak.phpt b/tests/test_cought_exceptions_do_not_leak.phpt
new file mode 100644
index 0000000..55ec6f9
--- /dev/null
+++ b/tests/test_cought_exceptions_do_not_leak.phpt
@@ -0,0 +1,45 @@
+--TEST--
+Tests that re-throwing different exceptions properly populates the 'exception' key.
+--EXTENSIONS--
+sentry
+--FILE--
+<?php
+
+class CustomException extends Exception {}
+
+function test_throw() {
+    throw new CustomException("Oh no"); 
+}
+
+function test_rethrow() {
+    try {
+        test_throw();
+    } catch (Throwable $t) {
+        echo "Exception caught" . PHP_EOL;
+    }
+}
+
+\Sentry\setEndCallback(static function (array $data) {
+    $exception = $data['exception'];
+    if ($exception !== null) {
+        echo $exception->getMessage() . PHP_EOL;
+        echo get_class($exception) . PHP_EOL;
+    } else {
+        echo 'No exception here' . PHP_EOL;
+    }
+}); 
+
+\Sentry\instrument(null, 'test_throw');
+\Sentry\instrument(null, 'test_rethrow');
+try {
+test_rethrow();
+} catch (Throwable $t) {
+
+}
+
+?>
+--EXPECTF--
+Oh no
+CustomException
+Exception caught
+No exception here
\ No newline at end of file
diff --git a/tests/test_exception_set_in_end_callback.phpt b/tests/test_exception_set_in_end_callback.phpt
new file mode 100644
index 0000000..32ed6db
--- /dev/null
+++ b/tests/test_exception_set_in_end_callback.phpt
@@ -0,0 +1,32 @@
+--TEST--
+Tests that a thrown exception is captured and stored under the 'exception' key in the end callback
+--EXTENSIONS--
+sentry
+--FILE--
+<?php
+
+class CustomException extends Exception {
+
+}
+
+function test_throw() {
+    throw new CustomException("Oh no"); 
+}
+
+\Sentry\setEndCallback(static function (array $data) {
+    $exception = $data['exception'];
+    echo $exception->getMessage() . PHP_EOL;
+    echo get_class($exception) . PHP_EOL;
+}); 
+
+\Sentry\instrument(null, 'test_throw');
+try {
+test_throw();
+} catch (Throwable $t) {
+
+}
+
+?>
+--EXPECTF--
+Oh no
+CustomException
\ No newline at end of file
diff --git a/tests/test_fields_always_present.phpt b/tests/test_fields_always_present.phpt
new file mode 100644
index 0000000..21b5ac3
--- /dev/null
+++ b/tests/test_fields_always_present.phpt
@@ -0,0 +1,40 @@
+--TEST--
+Tests that some fields are always present in the start and end callback and also assert their type.
+--EXTENSIONS--
+sentry
+--FILE--
+<?php
+
+function test_instrumented() {
+    return 10;
+}
+
+\Sentry\setStartCallback(static function (array $data) {
+    echo 'Start callback' . PHP_EOL;
+    echo 'start_time: ' . get_debug_type($data['start_time'])  . PHP_EOL;
+    echo 'name: ' . get_debug_type($data['name']) . PHP_EOL;
+});
+
+\Sentry\setEndCallback(static function (array $data) {
+    echo 'End callback' . PHP_EOL;
+    echo 'start_time: ' . get_debug_type($data['start_time']) . PHP_EOL;
+    echo 'name: ' . get_debug_type($data['name']) . PHP_EOL;
+    echo 'duration: ' . get_debug_type($data['duration']) . PHP_EOL;
+    echo 'end_time: ' . get_debug_type($data['end_time']) . PHP_EOL;
+    echo 'metadata: ' . get_debug_type($data['metadata']) . PHP_EOL;
+}); 
+
+\Sentry\instrument(null, 'test_instrumented');
+test_instrumented();
+
+?>
+--EXPECTF--
+Start callback
+start_time: float
+name: string
+End callback
+start_time: float
+name: string
+duration: float
+end_time: float
+metadata: array
diff --git a/tests/test_metadata_key_always_exists.phpt b/tests/test_metadata_key_always_exists.phpt
new file mode 100644
index 0000000..2812077
--- /dev/null
+++ b/tests/test_metadata_key_always_exists.phpt
@@ -0,0 +1,27 @@
+--TEST--
+Tests that the 'metadata' key in data in the end callback is always populated and never null (Function)
+--EXTENSIONS--
+sentry
+--FILE--
+<?php
+
+function test_instrumented() {
+    return 10;
+}
+
+\Sentry\setEndCallback(static function (array $data) {
+    if (!isset($data['metadata'])) {
+        echo "metadata array is not set" . PHP_EOL;
+    } else if ($data['metadata'] === null) {
+        echo "metadata array is null" . PHP_EOL;
+    } else {
+        echo "[]" . PHP_EOL;
+    }
+}); 
+
+\Sentry\instrument(null, 'test_instrumented');
+test_instrumented();
+
+?>
+--EXPECTF--
+[]
\ No newline at end of file
diff --git a/tests/test_metadata_key_always_exists_attribute.phpt b/tests/test_metadata_key_always_exists_attribute.phpt
new file mode 100644
index 0000000..c61c671
--- /dev/null
+++ b/tests/test_metadata_key_always_exists_attribute.phpt
@@ -0,0 +1,27 @@
+--TEST--
+Tests that the 'metadata' key in data in the end callback is always populated and never null (Attribute)
+--EXTENSIONS--
+sentry
+--FILE--
+<?php
+
+#[\Sentry\Trace]
+function test_instrumented() {
+    return 10;
+}
+
+\Sentry\setEndCallback(static function (array $data) {
+    if (!isset($data['metadata'])) {
+        echo "metadata array is not set" . PHP_EOL;
+    } else if ($data['metadata'] === null) {
+        echo "metadata array is null" . PHP_EOL;
+    } else {
+        echo "[]" . PHP_EOL;
+    }
+}); 
+
+test_instrumented();
+
+?>
+--EXPECTF--
+[]
\ No newline at end of file
diff --git a/tests/test_nested_exceptions_properly_scoped.phpt b/tests/test_nested_exceptions_properly_scoped.phpt
new file mode 100644
index 0000000..08d6d76
--- /dev/null
+++ b/tests/test_nested_exceptions_properly_scoped.phpt
@@ -0,0 +1,43 @@
+--TEST--
+Tests that catching an exception in a function will make 'exception' be null in the end callback
+--EXTENSIONS--
+sentry
+--FILE--
+<?php
+
+class CustomException extends Exception {}
+
+class TestException extends Exception {}
+
+function test_throw() {
+    throw new CustomException("Oh no"); 
+}
+
+function test_rethrow() {
+    try {
+        test_throw();
+    } catch (Throwable $t) {
+        throw new TestException("throw different exception");
+    }
+}
+
+\Sentry\setEndCallback(static function (array $data) {
+    $exception = $data['exception'];
+    echo $exception->getMessage() . PHP_EOL;
+    echo get_class($exception) . PHP_EOL;
+}); 
+
+\Sentry\instrument(null, 'test_throw');
+\Sentry\instrument(null, 'test_rethrow');
+try {
+test_rethrow();
+} catch (Throwable $t) {
+
+}
+
+?>
+--EXPECTF--
+Oh no
+CustomException
+throw different exception
+TestException
\ No newline at end of file