diff --git a/legacy/pyproject.toml b/legacy/pyproject.toml
index f9cf5e2..ec1e27c 100644
--- a/legacy/pyproject.toml
+++ b/legacy/pyproject.toml
@@ -1,7 +1,20 @@
 [project]
 name = "lcr-connector"
-version = "0.1.0"
+version = "1.0.0"
 description = "Use as much 3 devices to reach target value for resistor, capacitor and inductor."
 readme = "README.md"
+authors = [
+    { name = "yyc12345", email = "yyc12321@outlook.com" }
+]
 requires-python = ">=3.11"
+classifiers = [
+    "Private :: Do Not Upload",
+]
 dependencies = []
+
+[project.scripts]
+lcr-connector = "lcr_connector:main"
+
+[build-system]
+requires = ["uv_build>=0.8.0,<0.9"]
+build-backend = "uv_build"
diff --git a/legacy/lcr_connector.py b/legacy/src/lcr_connector/__init__.py
similarity index 55%
rename from legacy/lcr_connector.py
rename to legacy/src/lcr_connector/__init__.py
index 3ff7f2a..66a37f0 100644
--- a/legacy/lcr_connector.py
+++ b/legacy/src/lcr_connector/__init__.py
@@ -2,17 +2,17 @@ import enum
 import argparse
 from dataclasses import dataclass
 from pathlib import Path
-from typing import TypeVar, cast
-from common import Circuit, CircuitDeviceScale, JointKind
-from dataset import (
+from typing import TypeVar, Callable
+from .common import Circuit, CircuitDeviceScale, JointKind, DeviceKind
+from .dataset import (
     DatasetCollection,
     to_human_readable_value,
     from_human_readable_value,
 )
-from query import Response
-from resolver import Resolver, LutResolver, AStarResolver
+from .query import Request, ResponsePriority, Response
+from .resolver import Resolver, LutResolver, AStarResolver
 
-_T = TypeVar("_T", bound=str)
+_TStrEnum = TypeVar("_TStrEnum", bound=enum.StrEnum)
 
 
 class AppResolver(enum.StrEnum):
@@ -74,13 +74,46 @@ class App:
         """
         print("LCR Connector")
         print('Type "help" for more info. Type "exit" to quit.')
-        print("query: do a query.")
-        print("help: show all command.")
-        print("exit: exit this app.")
+        self.__op_main()
 
+    class MainCmd(enum.StrEnum):
+        QUERY = "query"
+        HELP = "help"
+        EXIT = "exit"
+
+    class QueryDeviceChoice(enum.StrEnum):
+        RESISTOR = "r"
+        CAPACITOR = "c"
+        INDUCTOR = "l"
+
+        def to_device_kind(self) -> DeviceKind:
+            match self:
+                case App.QueryDeviceChoice.RESISTOR:
+                    return DeviceKind.RESISTOR
+                case App.QueryDeviceChoice.CAPACITOR:
+                    return DeviceKind.CAPACITOR
+                case App.QueryDeviceChoice.INDUCTOR:
+                    return DeviceKind.INDUCTOR
+
+    class QuerySortPriority(enum.StrEnum):
+        LESS_DEVICES = "l"
+        MORE_ACCURACY = "a"
+
+        def to_response_priority(self) -> ResponsePriority:
+            match self:
+                case App.QuerySortPriority.LESS_DEVICES:
+                    return ResponsePriority.LESS_DEVICES
+                case App.QuerySortPriority.MORE_ACCURACY:
+                    return ResponsePriority.MORE_ACCURACY
+
+    class PageViewerCmd(enum.StrEnum):
+        PREVIOUS_PAGE = "f"
+        NEXT_PAGE = "b"
+        QUIT = "q"
+
+    def __op_main(self) -> None:
         while True:
-            shit = self.__accept_command(("query", "help", "exit"))
-            match self.__accept_command(("query", "help", "exit")):
+            match self.__accept_command(App.MainCmd):
                 case "query":
                     self.__op_query()
                 case "help":
@@ -93,7 +126,35 @@ class App:
                     break
 
     def __op_query(self) -> None:
-        pass
+        # collecting request infos
+        print("What are you connecting?")
+        print("r: resistor")
+        print("l: inductor")
+        print("c: capacitor")
+        device_kind = self.__accept_command(App.QueryDeviceChoice).to_device_kind()
+
+        print("Your target value?")
+        print('Example: "2.1k", "0.75m", "3.2M" and etc.')
+        target_value = self.__accept_device_value()
+
+        print("Your tolerance?")
+        print('It can be absolute value like "2.1k".')
+        print('Or relative value to your target value like "19.5%".')
+        tolerance = self.__accept_device_value_tolerance(target_value)
+
+        print("How to sort result?")
+        print("l: less component")
+        print("a: more accuracy")
+        response_priority = self.__accept_command(
+            App.QuerySortPriority
+        ).to_response_priority()
+
+        # build request and ask resolver
+        request = Request(device_kind, target_value, tolerance, response_priority, 100)
+        response = self.__resolver.resolve(request)
+
+        # use page viewer to show result
+        self.__op_page_viewer(response)
 
     def __op_page_viewer(self, response: Response) -> None:
         cnt = len(response)
@@ -127,37 +188,95 @@ class App:
             print("Page {} of {}.".format(current_page + 1, all_page + 1))
             print("f: previous page. b: next page. q: quit this viewer.")
             # check command
-            match self.__accept_command(("f", "b", "q")):
-                case "f":
+            match self.__accept_command(App.PageViewerCmd):
+                case App.PageViewerCmd.PREVIOUS_PAGE:
                     current_page = max(0, current_page - 1)
-                case "b":
+                case App.PageViewerCmd.NEXT_PAGE:
                     current_page = min(all_page, current_page + 1)
-                case "q":
+                case App.PageViewerCmd.QUIT:
                     break
 
-    def __accept_command(self, valid_commands: tuple[_T, ...]) -> _T:
+    def __accept_command(self, cmd_enum: type[_TStrEnum]) -> _TStrEnum:
+        """
+        Accept a command from the user.
+
+        :param cmd_enum: The type of the command. It must be a subclass of `enum.StrEnum`.
+        :return: The command. It is an instance of `cmd_enum`.
+        """
         while True:
             print("> ", end=None)
             words = input()
             words = words.strip()
-            if words in valid_commands:
-                return cast(_T, words)
+            if words in cmd_enum:
+                return cmd_enum(words)
             print("Unknown command, please try again.")
 
-    def __accept_value_input(self) -> float:
+    def __accept_device_value(self) -> float:
+        while True:
+            words = input()
+            value = self.__parse_human_readable_value(words)
+            if value is None:
+                print("Wrong value, please try again.")
+            else:
+                return value
+
+    def __accept_device_value_tolerance(self, target_value: float) -> float:
         while True:
             words = input()
 
-            try:
-                pending = from_human_readable_value(words)
-            except ValueError:
-                print("Wrong value, please try again.")
-                continue
-
-            if pending > 0:
-                return pending
+            if words.endswith("%"):
+                value = self.__parse_plain_float(
+                    words[:-1], lambda x: x >= 0 and x <= 100
+                )
+                if value is not None:
+                    value = value / 100 * target_value
             else:
-                print("Value out of range, please try again.")
+                value = self.__parse_human_readable_value(words)
+
+            if value is None:
+                print("Wrong value, please try again.")
+            else:
+                return value
+
+    def __parse_plain_float(
+        self, user_value: str, checker: Callable[[float], bool]
+    ) -> float | None:
+        """
+        Parse a plain float value.
+
+        :param user_value: The value to parse.
+        :param checker: A function that checks if the input is valid.
+        It takes a float as input and returns a bool. True means the input is valid, otherwise False.
+        :return: The parsed value if it is valid, otherwise None.
+        """
+        # try parsing it first
+        try:
+            value = float(user_value)
+        except ValueError:
+            return None
+        # then check it by checker
+        if checker(value):
+            return value
+        else:
+            return None
+
+    def __parse_human_readable_value(self, user_value: str) -> float | None:
+        """
+        Parse a human-readable device value.
+
+        :param user_value: The value to parse.
+        :return: The parsed value if it is valid, otherwise None.
+        """
+        # parse it
+        try:
+            value = from_human_readable_value(user_value)
+        except ValueError:
+            return None
+        # then check its range
+        if value > 0:
+            return value
+        else:
+            return None
 
     def __get_joint_kind_symbol(self, joint_kind: JointKind) -> str:
         match joint_kind:
@@ -188,7 +307,7 @@ class App:
                 print(f"    └ {dev3}")
 
 
-if __name__ == "__main__":
+def main() -> None:
     parser = argparse.ArgumentParser(
         prog="LCR Connector",
         description="Get the resistor, capacitor, or inductor circuit which has the closest value for your given value within at most 3 devices.",
diff --git a/legacy/common.py b/legacy/src/lcr_connector/common.py
similarity index 100%
rename from legacy/common.py
rename to legacy/src/lcr_connector/common.py
diff --git a/legacy/dataset.py b/legacy/src/lcr_connector/dataset.py
similarity index 99%
rename from legacy/dataset.py
rename to legacy/src/lcr_connector/dataset.py
index 6d3b98b..726c20f 100644
--- a/legacy/dataset.py
+++ b/legacy/src/lcr_connector/dataset.py
@@ -1,6 +1,6 @@
 from typing import Iterable
 from pathlib import Path
-from common import LcrConnException
+from .common import LcrConnException
 
 
 class Dataset:
diff --git a/legacy/main.py b/legacy/src/lcr_connector/main.py
similarity index 100%
rename from legacy/main.py
rename to legacy/src/lcr_connector/main.py
diff --git a/legacy/query.py b/legacy/src/lcr_connector/query.py
similarity index 98%
rename from legacy/query.py
rename to legacy/src/lcr_connector/query.py
index 701e382..6baba5c 100644
--- a/legacy/query.py
+++ b/legacy/src/lcr_connector/query.py
@@ -2,7 +2,7 @@ import enum
 from functools import cached_property
 from dataclasses import dataclass
 from typing import Iterator
-from common import DeviceKind, Circuit
+from .common import DeviceKind, Circuit
 
 
 class ResponsePriority(enum.Enum):
diff --git a/legacy/resolver/__init__.py b/legacy/src/lcr_connector/resolver/__init__.py
similarity index 100%
rename from legacy/resolver/__init__.py
rename to legacy/src/lcr_connector/resolver/__init__.py
diff --git a/legacy/resolver/astar.py b/legacy/src/lcr_connector/resolver/astar.py
similarity index 84%
rename from legacy/resolver/astar.py
rename to legacy/src/lcr_connector/resolver/astar.py
index 35a569a..c4fe1e9 100644
--- a/legacy/resolver/astar.py
+++ b/legacy/src/lcr_connector/resolver/astar.py
@@ -1,7 +1,8 @@
 from typing import Iterator
-from .common import Resolver, Request, ResultPriority
+from .common import Resolver
 from ..dataset import DatasetCollection
 from ..common import Circuit
+from ..query import Request, Response
 
 class AStarResolver(Resolver):
     """
diff --git a/legacy/resolver/common.py b/legacy/src/lcr_connector/resolver/common.py
similarity index 100%
rename from legacy/resolver/common.py
rename to legacy/src/lcr_connector/resolver/common.py
diff --git a/legacy/resolver/lut.py b/legacy/src/lcr_connector/resolver/lut.py
similarity index 100%
rename from legacy/resolver/lut.py
rename to legacy/src/lcr_connector/resolver/lut.py
diff --git a/legacy/uv.lock b/legacy/uv.lock
index c774378..93837ed 100644
--- a/legacy/uv.lock
+++ b/legacy/uv.lock
@@ -4,5 +4,5 @@ requires-python = ">=3.11"
 
 [[package]]
 name = "lcr-connector"
-version = "0.1.0"
-source = { virtual = "." }
+version = "1.0.0"
+source = { editable = "." }