diff --git a/stdlib/src/parallel.rs b/stdlib/src/parallel.rs
index e5f4eaeb..c4d9784c 100644
--- a/stdlib/src/parallel.rs
+++ b/stdlib/src/parallel.rs
@@ -62,3 +62,79 @@ impl StdlibRegistry {
         );
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use techscript_runtime::context::{RuntimeConfig, RuntimeContext};
+
+    #[test]
+    fn test_register_parallel() {
+        let mut registry = StdlibRegistry {
+            modules: HashMap::new(),
+        };
+        registry.register_parallel();
+
+        assert!(registry.has_module("std.parallel"));
+        let module = registry.get_module("std.parallel").unwrap();
+        assert_eq!(module.name, "std.parallel");
+        assert_eq!(module.version, "1.0.0");
+        assert!(module.exports.contains_key("run"));
+        assert!(module.exports.contains_key("sleep"));
+        assert!(module.exports.contains_key("num_cpus"));
+    }
+
+    #[test]
+    fn test_parallel_num_cpus() {
+        let mut registry = StdlibRegistry {
+            modules: HashMap::new(),
+        };
+        registry.register_parallel();
+
+        let module = registry.get_module("std.parallel").unwrap();
+        let num_cpus_fn = module.exports.get("num_cpus").unwrap();
+
+        let mut ctx = RuntimeContext::new(RuntimeConfig::default());
+        let result = num_cpus_fn.call(&mut ctx, vec![]).unwrap();
+
+        if let RuntimeValue::Int(cpus) = result {
+            assert!(cpus >= 1);
+        } else {
+            panic!("Expected RuntimeValue::Int for num_cpus");
+        }
+    }
+
+    #[test]
+    fn test_parallel_run() {
+        let mut registry = StdlibRegistry {
+            modules: HashMap::new(),
+        };
+        registry.register_parallel();
+
+        let module = registry.get_module("std.parallel").unwrap();
+        let run_fn = module.exports.get("run").unwrap();
+
+        let mut ctx = RuntimeContext::new(RuntimeConfig::default());
+        let result = run_fn
+            .call(&mut ctx, vec![RuntimeValue::Str("task1".to_string())])
+            .unwrap();
+
+        assert_eq!(result, RuntimeValue::Null);
+    }
+
+    #[test]
+    fn test_parallel_sleep() {
+        let mut registry = StdlibRegistry {
+            modules: HashMap::new(),
+        };
+        registry.register_parallel();
+
+        let module = registry.get_module("std.parallel").unwrap();
+        let sleep_fn = module.exports.get("sleep").unwrap();
+
+        let mut ctx = RuntimeContext::new(RuntimeConfig::default());
+        let result = sleep_fn.call(&mut ctx, vec![RuntimeValue::Int(0)]).unwrap();
+
+        assert_eq!(result, RuntimeValue::Null);
+    }
+}