diff --git a/fugue_tune/trial.py b/fugue_tune/trial.py
new file mode 100644
index 0000000..38e87e8
--- /dev/null
+++ b/fugue_tune/trial.py
@@ -0,0 +1,49 @@
+import copy
+from threading import RLock
+from typing import Any, Callable, Dict, List
+from uuid import uuid4
+
+from fugue.rpc import RPCHandler
+
+
+class TrialsTracker(RPCHandler):
+    def __init__(self):
+        super().__init__()
+        self._tt_lock = RLock()
+        self._raw_data: Dict[str, List[Dict[str, Any]]] = {}
+
+    def get_raw_data(self) -> Dict[str, List[Dict[str, Any]]]:
+        with self._tt_lock:
+            return copy.deepcopy(self._raw_data)
+
+    def __call__(self, method: str, **kwargs: Any) -> Any:
+        return getattr(self, method)(**kwargs)
+
+    def log_trial(self, trial_id: str, **kwargs: Any) -> None:
+        with self._tt_lock:
+            if trial_id not in self._raw_data:
+                self._raw_data[trial_id] = [dict(kwargs)]
+            else:
+                self._raw_data[trial_id].append(dict(kwargs))
+
+    def prune(self, trial_id: str) -> bool:
+        return False
+
+
+class TrialCallback(object):
+    def __init__(self, callback: Callable):
+        self._trial_id = str(uuid4())
+        self._callback = callback
+
+    @property
+    def trial_id(self) -> str:
+        return self._trial_id
+
+    def log_trial(self, **kwargs: Any) -> None:
+        self._callback(method="log_trial", trial_id=self.trial_id, **kwargs)
+
+    def __getattr__(self, method: str) -> Callable:
+        def _wrapper(**kwargs: Any) -> Any:
+            return self._callback(method=method, trial_id=self.trial_id, **kwargs)
+
+        return _wrapper
diff --git a/fugue_tune/tune.py b/fugue_tune/tune.py
index 5fd558c..998d75f 100644
--- a/fugue_tune/tune.py
+++ b/fugue_tune/tune.py
@@ -6,6 +6,7 @@
 from typing import Any, Callable, Dict, Iterable, List, Optional, Set, no_type_check
 from uuid import uuid4
 
+import matplotlib.pyplot as plt
 import pandas as pd
 from fugue import (
     ArrayDataFrame,
@@ -30,7 +31,7 @@
 
 from fugue_tune.exceptions import FugueTuneCompileError, FugueTuneRuntimeError
 from fugue_tune.space import Space, decode
-import matplotlib.pyplot as plt
+from fugue_tune.trial import TrialCallback, TrialsTracker
 
 
 class Tunable(object):
@@ -301,6 +302,7 @@ def tune(  # noqa: C901
     tunable: Any,
     distributable: Optional[bool] = None,
     objective_runner: Optional[ObjectiveRunner] = None,
+    tracker: Optional[TrialsTracker] = None,
 ) -> WorkflowDataFrame:
     t = _to_tunable(  # type: ignore
         tunable, *get_caller_global_local_vars(), distributable
@@ -313,7 +315,9 @@ def tune(  # noqa: C901
 
     # input_has: __fmin_params__:str
     # schema: *,__fmin_value__:double,__fmin_metadata__:str
-    def compute_transformer(df: Iterable[Dict[str, Any]]) -> Iterable[Dict[str, Any]]:
+    def compute_transformer(
+        df: Iterable[Dict[str, Any]], cb: Optional[Callable] = None
+    ) -> Iterable[Dict[str, Any]]:
         for row in df:
             dfs: Dict[str, Any] = {}
             dfs_keys: Set[str] = set()
diff --git a/setup.py b/setup.py
index 724e980..0e68ef9 100644
--- a/setup.py
+++ b/setup.py
@@ -27,7 +27,7 @@ def get_version() -> str:
     author_email="goodwanghan@gmail.com",
     keywords="fugue incubator experiment",
     url="http://github.com/fugue-project/fugue-incubator",
-    install_requires=["fugue>=0.5.0", "scikit-learn", "matplotlib"],
+    install_requires=["fugue==0.5.1.dev0", "scikit-learn", "matplotlib", "flask"],
     extras_require={"hyperopt": ["hyperopt"], "all": ["hyperopt"]},
     classifiers=[
         # "3 - Alpha", "4 - Beta" or "5 - Production/Stable"
diff --git a/tests/fugue_tune/test_trial.py b/tests/fugue_tune/test_trial.py
new file mode 100644
index 0000000..a246986
--- /dev/null
+++ b/tests/fugue_tune/test_trial.py
@@ -0,0 +1,11 @@
+from fugue_tune.trial import TrialCallback, TrialsTracker
+
+
+def test_callback():
+    tt = TrialsTracker()
+    tb = TrialCallback(tt)
+    tb.log_trial(a=1, b=2)
+    tb.log_trial(a=2, b=3)
+    key = tb.trial_id
+    assert [{"a": 1, "b": 2}, {"a": 2, "b": 3}] == tt.get_raw_data()[key]
+    assert not tb.prune()