diff --git a/pylon/plugins/test_api/api/v1/metadata.py b/pylon/plugins/test_api/api/v1/metadata.py
index 1d92478..920f020 100644
--- a/pylon/plugins/test_api/api/v1/metadata.py
+++ b/pylon/plugins/test_api/api/v1/metadata.py
@@ -1,8 +1,20 @@
 from flask_restful import Resource
+from flask import request
+from pydantic import ValidationError
 
 from pylon.core.tools import log
+from ...models.metadata import MetadataEntry
+from ...models.pd.metadata import MetadataKeyResponse, MetadataDataResponse, MetadataValidatorModel
 
-# from ...models.metadata import MetadataEntry
+
+def check_key_param(func):
+    def wrap(*args, **kwargs):
+        if not kwargs.get("key"):
+            msg = "key is required."
+            log.error(msg)
+            return {"error": msg}, 400
+        return func(*args, **kwargs)
+    return wrap
 
 
 class API(Resource):
@@ -16,9 +28,50 @@ class API(Resource):
     def __init__(self, module):
         self.module = module
 
-    def get(self, key=None):
+    def get(self, key: str | None = None):
         """ List all metadata keys or get metadata vales for specific key """
         if key is None:
-            return []  # TODO: list present keys
-        # TODO: get data for key
-        return {"error": "not implemented yet"}, 418
+            items = MetadataEntry.get_all()
+            return [MetadataKeyResponse.from_orm(item).dict() for item in items], 200
+
+        item = MetadataEntry.get_or_404(key)
+        return MetadataDataResponse.from_orm(item).dict(), 200
+
+    @check_key_param
+    def post(self, key: str | None = None):
+        """ Create metadata"""
+        payload = request.get_json()
+        payload["key"] = key
+
+        try:
+            MetadataValidatorModel.validate(payload)
+        except ValidationError as e:
+            return {'error': 'validation error', 'detail': e.errors()}, 400
+
+        if MetadataEntry.get_by_key(key):
+            return {"error": "key already exists."}, 400
+
+        item = MetadataEntry(**payload)
+        item.insert()
+        return MetadataDataResponse.from_orm(item).dict(), 201
+
+    @check_key_param
+    def put(self, key: str | None = None):
+        """ Update metadata"""
+        payload = request.get_json()
+        payload["key"] = key
+
+        try:
+            MetadataValidatorModel.validate(payload)
+        except ValidationError as e:
+            return {'error': 'validation error', 'detail': e.errors()}, 400
+
+        item = MetadataEntry.put(key, payload["data"])
+        return MetadataDataResponse.from_orm(item).dict(), 200
+
+    @check_key_param
+    def delete(self, key: str | None = None):
+        """ Delete metadata"""
+        if item := MetadataEntry.get_or_404(key):
+            item.delete()
+            return {"message": "successfully deleted"}, 204
diff --git a/pylon/plugins/test_api/models/metadata.py b/pylon/plugins/test_api/models/metadata.py
index cbfeeb1..77e87da 100644
--- a/pylon/plugins/test_api/models/metadata.py
+++ b/pylon/plugins/test_api/models/metadata.py
@@ -18,13 +18,53 @@
 """ Secrets DB model """
 
 # from sqlalchemy import Something  # pylint: disable=E0401
+from sqlalchemy.orm import relationship, Mapped, mapped_column
+from sqlalchemy import Integer, String
+from flask import abort
 
 from tools import db, db_tools
+from pylon.core.tools import log
 
 
-# class MetadataEntry(db_tools.AbstractBaseMixin, db.Base):  # pylint: disable=C0111
-#
-#     # TODO: add something here
+class MetadataEntry(db_tools.AbstractBaseMixin, db.Base):  # pylint: disable=C0111
+    __tablename__ = "metadata_entry"
+
+    id: Mapped[int] = mapped_column(Integer, primary_key=True)
+    key: Mapped[str] = mapped_column(String(20), unique=True)
+    data: Mapped[str] = mapped_column(String(90))
+
+    @staticmethod
+    def get_all():
+        return MetadataEntry.query.all()
+
+    @staticmethod
+    def get_by_key(key: str):
+        return MetadataEntry.query.filter(MetadataEntry.key == key).first()
+
+    @staticmethod
+    def get_or_404(key: str):
+        metadata_entry = MetadataEntry.query.filter(MetadataEntry.key == key).first()
+        if not metadata_entry:
+            abort(404, description="not found.")
+        return metadata_entry
+
+    @staticmethod
+    def put(key: str, data: str):
+        item = MetadataEntry.get_or_404(key)
+        item.data = data
+        item.commit()
+        return item
+
+    def commit(self) -> None:
+        try:
+            self._session.commit()
+        except Exception as e:
+            self.rollback()
+            log.error(e)
+            abort(422, description="rollback transaction on error.")
+
+    def __repr__(self) -> str:
+        return f"<metadata_entry(id={self.id}, key={self.key})>"
 #
 #     @property
 #     def serialized(self):
diff --git a/pylon/plugins/test_api/models/pd/metadata.py b/pylon/plugins/test_api/models/pd/metadata.py
index 6cdee01..91dbeb5 100644
--- a/pylon/plugins/test_api/models/pd/metadata.py
+++ b/pylon/plugins/test_api/models/pd/metadata.py
@@ -1,5 +1,20 @@
-from pydantic import BaseModel
+from pydantic import BaseModel, constr
 
 
-# class MetadataValidatorModel(BaseModel):
-#     # FIXME: can add something here for input schema validation
+class MetadataValidatorModel(BaseModel):
+    key: constr(min_length=1, max_length=20)
+    data: constr(min_length=1, max_length=90)
+
+
+class MetadataKeyResponse(BaseModel):
+    key: str
+
+    class Config:
+        orm_mode = True
+
+
+class MetadataDataResponse(BaseModel):
+    data: str
+
+    class Config:
+        orm_mode = True