diff --git a/cascade/base/__init__.py b/cascade/base/__init__.py
index 0b4a2b7c..4248412a 100644
--- a/cascade/base/__init__.py
+++ b/cascade/base/__init__.py
@@ -1,2 +1,3 @@
 from .meta_handler import MetaHandler
 from .traceable import Traceable
+from .meta_handler import CustomEncoder as JSONEncoder
diff --git a/cascade/base/meta_handler.py b/cascade/base/meta_handler.py
index 521d3503..a1222148 100644
--- a/cascade/base/meta_handler.py
+++ b/cascade/base/meta_handler.py
@@ -16,9 +16,12 @@
 
 import os
 import json
+from typing import Union, Dict, List
 import datetime
+from typing import List, Dict
 from json import JSONEncoder
 
+import yaml
 import numpy as np
 
 
@@ -28,13 +31,13 @@ def default(self, obj):
             return str(obj)
         if isinstance(obj, (datetime.datetime, datetime.date, datetime.time)):
             return obj.isoformat()
+
         elif isinstance(obj, datetime.timedelta):
             return (datetime.datetime.min + obj).time().isoformat()
 
         elif isinstance(obj, (np.int_, np.intc, np.intp, np.int8,
                               np.int16, np.int32, np.int64, np.uint8,
                               np.uint16, np.uint32, np.uint64)):
-
             return int(obj)
 
         elif isinstance(obj, (np.float_, np.float16, np.float32, np.float64)):
@@ -46,29 +49,39 @@ def default(self, obj):
         elif isinstance(obj, (np.ndarray,)):
             return obj.tolist()
 
-        elif isinstance(obj, (np.bool_)):
+        elif isinstance(obj, np.bool_):
             return bool(obj)
 
-        elif isinstance(obj, (np.void)):
+        elif isinstance(obj, np.void):
             return None
 
         return super(CustomEncoder, self).default(obj)
 
+    def obj_to_dict(self, obj):
+        return json.loads(self.encode(obj))
 
-class MetaHandler:
+
+class BaseHandler:
+    def read(self, path) -> List[Dict]:
+        raise NotImplementedError()
+
+    def write(self, path, obj, overwrite=True) -> None:
+        raise NotImplementedError()
+
+
+class JSONHandler(BaseHandler):
     """
     Handles the logic of dumping and loading json files
     """
-    def read(self, path) -> dict:
+    def read(self, path) -> Union[Dict, List[Dict]]:
         """
         Reads json from path
 
         Parameters
         ----------
         path:
-            Path to the file. If no extension provided, then .json assumed
+            Path to the file. If no extension provided, then .json will be added
         """
-        assert os.path.exists(path)
         _, ext = os.path.splitext(path)
         if ext == '':
             path += '.json'
@@ -79,16 +92,77 @@ def read(self, path) -> dict:
                 meta = json.loads(meta)
             return meta
 
-    def write(self, name, obj, overwrite=True) -> None:
+    def write(self, name, obj:List[Dict], overwrite=True) -> None:
         """
         Writes json to path using custom encoder
         """
-
         if not overwrite and os.path.exists(name):
             return
 
-        with open(name, 'w') as json_meta:
-            json.dump(obj, json_meta, cls=CustomEncoder, indent=4)
+        with open(name, 'w') as f:
+            json.dump(obj, f, cls=CustomEncoder, indent=4)
+
+
+class YAMLHandler(BaseHandler):
+    def read(self, path) -> Union[Dict, List[Dict]]:
+        """
+        Reads yaml from path
+
+        Parameters
+        ----------
+        path:
+            Path to the file. If no extension provided, then .yml will be added
+        """
+        _, ext = os.path.splitext(path)
+        if ext == '':
+            path += '.yml'
+
+        with open(path, 'r') as meta_file:
+            meta = yaml.safe_load(meta_file)
+            return meta
+
+    def write(self, path, obj, overwrite=True) -> None:
+        if not overwrite and os.path.exists(path):
+            return
+
+        obj = CustomEncoder().obj_to_dict(obj)
+        with open(path, 'w') as f:
+            yaml.safe_dump(obj, f)
 
-    def encode(self, obj):
-        return CustomEncoder().encode(obj)
+
+class TextHandler(BaseHandler):
+    def read(self, path) -> Dict:
+        """
+        Reads text file from path and returns dict in the form {path: 'text from file'}
+
+        Parameters
+        ----------
+        path:
+            Path to the file
+        """
+
+        with open(path, 'r') as meta_file:
+            meta = {path: ''.join(meta_file.readlines())}
+            return meta
+
+    def write(self, path, obj, overwrite=True) -> None:
+        raise NotImplementedError('MetaHandler does not write text files, only reads')       
+
+
+class MetaHandler:
+    def read(self, path) -> List[Dict]:
+        handler = self._get_handler(path)
+        return handler.read(path)
+
+    def write(self, path, obj, overwrite=True) -> None:
+        handler = self._get_handler(path)
+        return handler.write(path, obj, overwrite=overwrite)
+
+    def _get_handler(self, path) -> BaseHandler:
+        ext = os.path.splitext(path)[-1]
+        if ext == '.json':
+            return JSONHandler()
+        elif ext == '.yml':
+            return YAMLHandler()
+        else:
+            return TextHandler()
diff --git a/cascade/meta/meta_viewer.py b/cascade/meta/meta_viewer.py
index de623d6b..507d87c1 100644
--- a/cascade/meta/meta_viewer.py
+++ b/cascade/meta/meta_viewer.py
@@ -15,8 +15,8 @@
 """
 
 import os
-import json
-from ..base import MetaHandler
+from typing import List, Dict, Union
+from ..base import MetaHandler, JSONEncoder
 
 
 class MetaViewer:
@@ -50,11 +50,11 @@ def __init__(self, root, filt=None) -> None:
         if filt is not None:
             self.metas = list(filter(self._filter, self.metas))
 
-    def __getitem__(self, index) -> dict:
+    def __getitem__(self, index) -> List[Dict]:
         """
         Returns
         -------
-        meta: dict
+        meta: List[Dict]
             object containing meta
         """
         return self.metas[index]
@@ -86,14 +86,14 @@ def pretty(d, indent=0, sep=' '):
             out += pretty(meta, 4)
         return out
 
-    def write(self, name, obj: dict) -> None:
-        """
-        Dumps obj to name
+    def write(self, name, obj: List[Dict]) -> None:
         """
+       Dumps obj to name
+       """
         self.metas.append(obj)
         self.mh.write(name, obj)
 
-    def read(self, path) -> dict:
+    def read(self, path) -> List[Dict]:
         """
         Loads object from path
         """
@@ -110,4 +110,4 @@ def _filter(self, meta):
         return True
 
     def obj_to_dict(self, obj):
-        return json.loads(self.mh.encode(obj))
+        return JSONEncoder().obj_to_dict(obj)
diff --git a/cascade/models/model_line.py b/cascade/models/model_line.py
index 6a16d010..88d8feeb 100644
--- a/cascade/models/model_line.py
+++ b/cascade/models/model_line.py
@@ -31,7 +31,7 @@ class ModelLine(Traceable):
     A line of models is typically a models with the same hyperparameters and architecture,
     but different epochs or using different data.
     """
-    def __init__(self, folder, model_cls=Model, **kwargs) -> None:
+    def __init__(self, folder, model_cls=Model, meta_fmt='.json', **kwargs) -> None:
         """
         All models in line should be instances of the same class.
 
@@ -42,12 +42,16 @@ def __init__(self, folder, model_cls=Model, **kwargs) -> None:
             if folder does not exist, creates it
         model_cls:
             A class of models in repo. ModelLine uses this class to reconstruct a model
+        meta_fmt:
+            Format in which to store meta data. '.json', '.yml' are supported. .json is default.
         See also
         --------
         cascade.models.ModelRepo
         """
         super().__init__(**kwargs)
 
+        assert meta_fmt in ['.json', '.yml'], 'Only .json or .yml are supported formats'
+        self.meta_fmt = meta_fmt
         self.model_cls = model_cls
         self.root = folder
         self.model_names = []
@@ -122,10 +126,10 @@ def save(self, model: Model) -> None:
         meta[-1]['saved_at'] = pendulum.now(tz='UTC')
 
         # Save model's meta
-        self.meta_viewer.write(os.path.join(self.root, folder_name, 'meta.json'), meta)
+        self.meta_viewer.write(os.path.join(self.root, folder_name, 'meta' + self.meta_fmt), meta)
 
         # Save updated line's meta
-        self.meta_viewer.write(os.path.join(self.root, 'meta.json'), self.get_meta())
+        self.meta_viewer.write(os.path.join(self.root, 'meta' + self.meta_fmt), self.get_meta())
 
     def __repr__(self) -> str:
         return f'ModelLine of {len(self)} models of {self.model_cls}'
diff --git a/cascade/models/model_repo.py b/cascade/models/model_repo.py
index f920a520..dd873893 100644
--- a/cascade/models/model_repo.py
+++ b/cascade/models/model_repo.py
@@ -95,7 +95,7 @@ def __init__(self, folder, lines=None, overwrite=False, **kwargs):
 
         self._update_meta()
 
-    def add_line(self, name, model_cls):
+    def add_line(self, name, model_cls, **kwargs):
         """
         Adds new line to repo if it doesn't exist and returns it
         If line exists, defines it in repo
@@ -111,7 +111,7 @@ def add_line(self, name, model_cls):
         assert type(model_cls) == type, f'You should pass model\'s class, not {type(model_cls)}'
 
         folder = os.path.join(self.root, name)
-        line = ModelLine(folder, model_cls=model_cls, meta_prefix=self.meta_prefix)
+        line = ModelLine(folder, model_cls=model_cls, meta_prefix=self.meta_prefix, **kwargs)
         self.lines[name] = line
 
         self._update_meta()
diff --git a/cascade/tests/conftest.py b/cascade/tests/conftest.py
index 5ec4f862..9de78fd0 100644
--- a/cascade/tests/conftest.py
+++ b/cascade/tests/conftest.py
@@ -17,8 +17,9 @@
 
 import os
 import sys
-import random
-import shutil
+import datetime
+import pendulum
+from dateutil import tz
 import numpy as np
 import pytest
 
@@ -26,7 +27,7 @@
 sys.path.append(os.path.dirname(MODULE_PATH))
 
 from cascade.data import Wrapper, Iterator
-from cascade.models import Model, ModelRepo, BasicModel
+from cascade.models import Model, ModelLine, ModelRepo, BasicModel
 
 
 class DummyModel(Model):
@@ -99,14 +100,30 @@ def number_iterator(request):
    {'a': 0},
    {'b': 1},
    {'a': 0, 'b': 'alala'},
-   {'c': np.array([1, 2]), 'd': {'a': 0}}])
+   {'c': np.array([1, 2]), 'd': {'a': 0}},
+   {'e': datetime.datetime(2022, 7, 8, 16, 4, 3, 5, tz.gettz('Europe / Moscow'))},
+   {'f': pendulum.datetime(2022, 7, 8, 16, 4, 3, 5, 'Europe/Moscow')}])
 def dummy_model(request):
-   return DummyModel(**request.param)
+    return DummyModel(**request.param)
 
 
 @pytest.fixture
 def empty_model():
-   return EmptyModel()
+    return EmptyModel()
+
+
+@pytest.fixture(params=[
+    {
+        'model_cls': DummyModel,
+        'meta_fmt': '.json'
+    },
+    {
+        'model_cls': DummyModel,
+        'meta_fmt': '.yml'
+    }])
+def model_line(request, tmp_path):
+    line = ModelLine(str(tmp_path), **request.param)
+    return line
 
 
 @pytest.fixture
diff --git a/cascade/tests/test_bruteforce_cacher.py b/cascade/tests/test_bruteforce_cacher.py
index e9d50380..cfd7596a 100644
--- a/cascade/tests/test_bruteforce_cacher.py
+++ b/cascade/tests/test_bruteforce_cacher.py
@@ -25,14 +25,12 @@
 
 def test_ds(number_dataset):
     ds = BruteforceCacher(number_dataset)
-    assert([number_dataset[i] for i in range(len(number_dataset))] \
-        == [item for item in ds])
+    assert([number_dataset[i] for i in range(len(number_dataset))] == [item for item in ds])
 
 
 def test_it(number_iterator):
     ds = BruteforceCacher(number_iterator)
-    assert([item for item in number_iterator] \
-        == [item for item in ds])
+    assert([item for item in number_iterator] == [item for item in ds])
 
 
 def test_meta():
diff --git a/cascade/tests/test_meta_handler.py b/cascade/tests/test_meta_handler.py
index f86a417d..eb759126 100644
--- a/cascade/tests/test_meta_handler.py
+++ b/cascade/tests/test_meta_handler.py
@@ -18,6 +18,7 @@
 import sys
 import pendulum
 import numpy as np
+import pytest
 
 MODULE_PATH = os.path.dirname(os.path.abspath(os.path.dirname(__file__)))
 sys.path.append(os.path.dirname(MODULE_PATH))
@@ -25,10 +26,16 @@
 from cascade.base import MetaHandler
 
 
-def test(tmp_path):
+@pytest.mark.parametrize(
+    'ext', [
+        '.json',
+        '.yml'
+    ]
+)
+def test(tmp_path, ext):
     tmp_path = str(tmp_path)
     mh = MetaHandler()
-    mh.write(os.path.join(tmp_path, 'meta.json'), 
+    mh.write(os.path.join(tmp_path, 'meta' + ext),
     {
         'name': 'test_mh',
         'array': np.zeros(4),
@@ -36,22 +43,28 @@ def test(tmp_path):
         'date': pendulum.now(tz='UTC')
     })
 
-    obj = mh.read(os.path.join(tmp_path, 'meta.json'))
+    obj = mh.read(os.path.join(tmp_path, 'meta' + ext))
 
     assert(obj['name'] == 'test_mh')
-    assert(all(obj['array'] == np.zeros(4)))
+    assert(obj['array'] == [0, 0, 0, 0])
     assert(obj['none'] is None)
 
 
-def test_overwrite(tmp_path):
-    tmp_path = os.path.join(str(tmp_path), 'test_mh_ow.json')
+@pytest.mark.parametrize(
+    'ext', [
+        '.json',
+        '.yml'
+    ]
+)
+def test_overwrite(tmp_path, ext):
+    tmp_path = os.path.join(str(tmp_path), 'test_mh_ow' + ext)
 
     mh = MetaHandler()
     mh.write(
         tmp_path, 
         {'name': 'first'},
         overwrite=False)
-    
+
     mh.write(
         tmp_path, 
         {'name': 'second'},
@@ -59,3 +72,22 @@ def test_overwrite(tmp_path):
 
     obj = mh.read(tmp_path)
     assert(obj['name'] == 'first')
+
+
+@pytest.mark.parametrize(
+    'ext', [
+        '.txt',
+        '.md'
+    ]
+)
+def test_text(tmp_path, ext):
+    tmp_path = str(os.path.join(tmp_path, 'meta' + ext))
+    mh = MetaHandler()
+
+    info = '#Meta\n\n\n this is object for testing text files'
+    with open(tmp_path, 'w') as f:
+        f.write(info)
+
+    obj = mh.read(tmp_path)
+
+    assert(obj[tmp_path] == info)
diff --git a/cascade/tests/test_meta_viewer.py b/cascade/tests/test_meta_viewer.py
index f179fe06..de1654d7 100644
--- a/cascade/tests/test_meta_viewer.py
+++ b/cascade/tests/test_meta_viewer.py
@@ -32,7 +32,7 @@ def test(tmp_path):
         json.dump({'name': 'test0'}, f)
 
     # Write also using mv
-    mv = MetaViewer()
+    mv = MetaViewer(tmp_path)
     mv.write(os.path.join(tmp_path, 'model', 'test.json'), {'name': 'test1'})    
 
     mv = MetaViewer(tmp_path)
diff --git a/cascade/tests/test_model_line.py b/cascade/tests/test_model_line.py
index 158b5f80..ff8d0a15 100644
--- a/cascade/tests/test_model_line.py
+++ b/cascade/tests/test_model_line.py
@@ -24,23 +24,17 @@
 from cascade.models.model_repo import ModelLine
 
 
-def test_save_load(tmp_path):
-    tmp_path = str(tmp_path)
-    line = ModelLine(tmp_path, DummyModel)
-    m = DummyModel()
-    line.save(m)
-    model = line[0]
-
-    assert(len(line) == 1)
+def test_save_load(model_line, dummy_model):
+    model_line.save(dummy_model)
+    model = model_line[0]
+
+    assert(len(model_line) == 1)
     assert(model.model == "b'model'")
 
 
-def test_meta(tmp_path):
-    tmp_path = str(tmp_path)
-    line = ModelLine(tmp_path, DummyModel)
-    m = DummyModel()
-    line.save(m)
-    meta = line.get_meta()
+def test_meta(model_line, dummy_model):
+    model_line.save(dummy_model)
+    meta = model_line.get_meta()
 
     assert(meta[0]['model_cls'] == repr(DummyModel))
     assert(meta[0]['len'] == 1)
diff --git a/requirements.txt b/requirements.txt
index 179ffa70..0aaed753 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -5,3 +5,4 @@ deepdiff
 pendulum
 plotly
 flatten_json
+pyyaml
diff --git a/setup.py b/setup.py
index 8f098894..011b3089 100644
--- a/setup.py
+++ b/setup.py
@@ -32,6 +32,7 @@
         'deepdiff',
         'pendulum',
         'plotly',
-        'flatten_json'
+        'flatten_json',
+        'pyyaml'
     ]
 )