diff --git a/Cargo.lock b/Cargo.lock
index 6284a9e8c..4333604a5 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1274,6 +1274,13 @@ dependencies = [
  "syn 2.0.96",
 ]
 
+[[package]]
+name = "limbo_median"
+version = "0.0.12"
+dependencies = [
+ "limbo_ext",
+]
+
 [[package]]
 name = "limbo_regexp"
 version = "0.0.12"
diff --git a/Cargo.toml b/Cargo.toml
index 690d8feec..83db6dfa2 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -15,7 +15,7 @@ members = [
     "macros",
     "simulator",
     "sqlite3",
-    "test",
+    "test", "extensions/median",
 ]
 exclude = ["perf/latency/limbo"]
 
diff --git a/extensions/median/Cargo.toml b/extensions/median/Cargo.toml
new file mode 100644
index 000000000..615112628
--- /dev/null
+++ b/extensions/median/Cargo.toml
@@ -0,0 +1,13 @@
+[package]
+name = "limbo_median"
+version.workspace = true
+authors.workspace = true
+edition.workspace = true
+license.workspace = true
+repository.workspace = true
+
+[lib]
+crate-type = ["cdylib"]
+
+[dependencies]
+limbo_ext = { path = "../core" }
diff --git a/extensions/median/src/lib.rs b/extensions/median/src/lib.rs
new file mode 100644
index 000000000..4b123369d
--- /dev/null
+++ b/extensions/median/src/lib.rs
@@ -0,0 +1,44 @@
+use limbo_ext::{register_extension, AggFunc, AggregateDerive, Value};
+
+register_extension! {
+    aggregates: { MedianState },
+}
+
+#[derive(AggregateDerive)]
+struct MedianState;
+
+impl AggFunc for MedianState {
+    type State = Vec<f64>;
+
+    fn name(&self) -> &'static str {
+        "median"
+    }
+
+    fn args(&self) -> i32 {
+        1
+    }
+
+    fn step(state: &mut Self::State, args: &[Value]) {
+        if let Some(val) = args.first().and_then(Value::to_float) {
+            state.push(val);
+        }
+    }
+
+    fn finalize(state: Self::State) -> Value {
+        if state.is_empty() {
+            return Value::null();
+        }
+
+        let mut sorted = state;
+        sorted.sort_by(|a, b| a.partial_cmp(b).unwrap());
+
+        let len = sorted.len();
+        if len % 2 == 1 {
+            Value::from_float(sorted[len / 2])
+        } else {
+            let mid1 = sorted[len / 2 - 1];
+            let mid2 = sorted[len / 2];
+            Value::from_float((mid1 + mid2) / 2.0)
+        }
+    }
+}
diff --git a/testing/extensions.py b/testing/extensions.py
index 55c380f5b..ad87c65ca 100755
--- a/testing/extensions.py
+++ b/testing/extensions.py
@@ -7,6 +7,16 @@ import time
 sqlite_exec = "./target/debug/limbo"
 sqlite_flags = os.getenv("SQLITE_FLAGS", "-q").split(" ")
 
+test_data = """CREATE TABLE numbers ( id INTEGER PRIMARY KEY, value FLOAT NOT NULL);
+INSERT INTO numbers (value) VALUES (1.0);
+INSERT INTO numbers (value) VALUES (2.0);
+INSERT INTO numbers (value) VALUES (3.0);
+INSERT INTO numbers (value) VALUES (4.0);
+INSERT INTO numbers (value) VALUES (5.0);
+INSERT INTO numbers (value) VALUES (6.0);
+INSERT INTO numbers (value) VALUES (7.0);
+"""
+
 
 def init_limbo():
     pipe = subprocess.Popen(
@@ -16,6 +26,7 @@ def init_limbo():
         stderr=subprocess.PIPE,
         bufsize=0,
     )
+    write_to_pipe(pipe, test_data)
     return pipe
 
 
@@ -180,11 +191,39 @@ def test_regexp(pipe):
     )
 
 
+def validate_median(res):
+    return res == "4.0"
+
+
+def test_aggregates(pipe):
+    extension_path = "./target/debug/liblimbo_median.so"
+    # assert no function before extension loads
+    run_test(
+        pipe,
+        "SELECT median(1);",
+        returns_null,
+        "median agg function returns null when ext not loaded",
+    )
+    run_test(
+        pipe,
+        f".load {extension_path}",
+        returns_null,
+        "load extension command works properly",
+    )
+    run_test(
+        pipe,
+        "select median(value) from numbers;",
+        validate_median,
+        "median agg function works",
+    )
+
+
 def main():
     pipe = init_limbo()
     try:
         test_regexp(pipe)
         test_uuid(pipe)
+        test_aggregates(pipe)
     except Exception as e:
         print(f"Test FAILED: {e}")
         pipe.terminate()