diff --git a/flake.lock b/flake.lock
index d9d94f390..425678d4d 100644
--- a/flake.lock
+++ b/flake.lock
@@ -89,6 +89,21 @@
         "type": "github"
       }
     },
+    "nix-select": {
+      "locked": {
+        "lastModified": 1745005516,
+        "narHash": "sha256-IVaoOGDIvAa/8I0sdiiZuKptDldrkDWUNf/+ezIRhyc=",
+        "ref": "refs/heads/main",
+        "rev": "69d8bf596194c5c35a4e90dd02c52aa530caddf8",
+        "revCount": 40,
+        "type": "git",
+        "url": "https://git.clan.lol/clan/nix-select"
+      },
+      "original": {
+        "type": "git",
+        "url": "https://git.clan.lol/clan/nix-select"
+      }
+    },
     "nixos-facter-modules": {
       "locked": {
         "lastModified": 1743671943,
@@ -123,6 +138,7 @@
         "disko": "disko",
         "flake-parts": "flake-parts",
         "nix-darwin": "nix-darwin",
+        "nix-select": "nix-select",
         "nixos-facter-modules": "nixos-facter-modules",
         "nixpkgs": "nixpkgs",
         "sops-nix": "sops-nix",
diff --git a/flake.nix b/flake.nix
index cc79aad5e..43169c9a0 100644
--- a/flake.nix
+++ b/flake.nix
@@ -23,6 +23,8 @@
     treefmt-nix.url = "github:numtide/treefmt-nix";
     treefmt-nix.inputs.nixpkgs.follows = "nixpkgs";
 
+    nix-select.url = "git+https://git.clan.lol/clan/nix-select";
+
     data-mesher = {
       url = "git+https://git.clan.lol/clan/data-mesher";
       inputs = {
diff --git a/lib/default.nix b/lib/default.nix
index 53e701e22..b609eeb1f 100644
--- a/lib/default.nix
+++ b/lib/default.nix
@@ -30,6 +30,6 @@ lib.fix (clanLib: {
   # Plain imports.
   values = import ./introspection { inherit lib; };
   jsonschema = import ./jsonschema { inherit lib; };
-  select = import select/default.nix;
+  select = self.inputs.nix-select.lib;
   facts = import ./facts.nix { inherit lib; };
 })
diff --git a/lib/flake-module.nix b/lib/flake-module.nix
index 19c093391..bb4e91c99 100644
--- a/lib/flake-module.nix
+++ b/lib/flake-module.nix
@@ -11,7 +11,6 @@ rec {
     ./introspection/flake-module.nix
     ./inventory/flake-module.nix
     ./jsonschema/flake-module.nix
-    ./select/flake-module.nix
   ];
   flake.clanLib = import ./default.nix {
     inherit lib inputs self;
diff --git a/lib/select/default.nix b/lib/select/default.nix
deleted file mode 100644
index d291f50d0..000000000
--- a/lib/select/default.nix
+++ /dev/null
@@ -1,68 +0,0 @@
-let
-  recursiveSelect =
-    selectorIndex: selectorList: target:
-    let
-      selector = builtins.elemAt selectorList selectorIndex;
-    in
-
-    # selector is empty, we are done
-    if selectorIndex + 1 > builtins.length selectorList then
-      target
-
-    else if builtins.isList target then
-      # support bla.* for lists and recurse into all elements
-      if selector == "*" then
-        builtins.map (v: recursiveSelect (selectorIndex + 1) selectorList v) target
-      # support bla.3 for lists and recurse into the 4th element
-      else if (builtins.match "[[:digit:]]*" selector) == [ ] then
-        recursiveSelect (selectorIndex + 1) selectorList (
-          builtins.elemAt target (builtins.fromJSON selector)
-        )
-      else
-        throw "only * or a number is allowed in list selector"
-
-    else if builtins.isAttrs target then
-      # handle the case bla.x.*.z where x is an attrset and we recurse into all elements
-      if selector == "*" then
-        builtins.mapAttrs (_: v: recursiveSelect (selectorIndex + 1) selectorList v) target
-      # support bla.{x,y,z}.world where we get world from each of x, y and z
-      else if (builtins.match ''^\{([^}]*)}$'' selector) != null then
-        let
-          attrsAsList = (
-            builtins.filter (x: !builtins.isList x) (
-              builtins.split "," (builtins.head (builtins.match ''^\{([^}]*)}$'' selector))
-            )
-          );
-          dummyAttrSet = builtins.listToAttrs (
-            map (x: {
-              name = x;
-              value = null;
-            }) attrsAsList
-          );
-          filteredAttrs = builtins.intersectAttrs dummyAttrSet target;
-        in
-        builtins.mapAttrs (_: v: recursiveSelect (selectorIndex + 1) selectorList v) filteredAttrs
-      else
-        recursiveSelect (selectorIndex + 1) selectorList (builtins.getAttr selector target)
-    else
-      throw "Expected a list or an attrset";
-
-  parseSelector =
-    selector:
-    let
-      splitByQuote = x: builtins.filter (x: !builtins.isList x) (builtins.split ''"'' x);
-      splitByDot =
-        x:
-        builtins.filter (x: x != "") (
-          map (builtins.replaceStrings [ "." ] [ "" ]) (
-            builtins.filter (x: !builtins.isList x) (builtins.split ''\.'' x)
-          )
-        );
-      handleQuoted =
-        x: if x == [ ] then [ ] else [ (builtins.head x) ] ++ handleUnquoted (builtins.tail x);
-      handleUnquoted =
-        x: if x == [ ] then [ ] else splitByDot (builtins.head x) ++ handleQuoted (builtins.tail x);
-    in
-    handleUnquoted (splitByQuote selector);
-in
-selector: target: recursiveSelect 0 (parseSelector selector) target
diff --git a/lib/select/flake-module.nix b/lib/select/flake-module.nix
deleted file mode 100644
index 915a60f25..000000000
--- a/lib/select/flake-module.nix
+++ /dev/null
@@ -1,45 +0,0 @@
-{ self, inputs, ... }:
-let
-  inputOverrides = builtins.concatStringsSep " " (
-    builtins.map (input: " --override-input ${input} ${inputs.${input}}") (builtins.attrNames inputs)
-  );
-in
-{
-  perSystem =
-    {
-      pkgs,
-      lib,
-      system,
-      ...
-    }:
-    {
-      # Run: nix-unit --extra-experimental-features flakes --flake .#legacyPackages.x86_64-linux.evalTests
-      legacyPackages.evalTests-select = import ./tests.nix {
-        inherit lib;
-        inherit (self) clanLib;
-      };
-
-      checks = {
-        lib-select-eval = pkgs.runCommand "tests" { nativeBuildInputs = [ pkgs.nix-unit ]; } ''
-          export HOME="$(realpath .)"
-          export NIX_ABORT_ON_WARN=1
-          nix-unit --eval-store "$HOME" \
-            --extra-experimental-features flakes \
-            --show-trace \
-            ${inputOverrides} \
-            --flake ${
-              self.filter {
-                include = [
-                  "flakeModules"
-                  "lib"
-                  "clanModules/flake-module.nix"
-                  "clanModules/borgbackup"
-                ];
-              }
-            }#legacyPackages.${system}.evalTests-select
-
-          touch $out
-        '';
-      };
-    };
-}
diff --git a/lib/select/tests.nix b/lib/select/tests.nix
deleted file mode 100644
index c5e0e5cb7..000000000
--- a/lib/select/tests.nix
+++ /dev/null
@@ -1,10 +0,0 @@
-{ clanLib, ... }:
-let
-  inherit (clanLib) select;
-in
-{
-  test_simple_1 = {
-    expr = select "a" { a = 1; };
-    expected = 1;
-  };
-}
diff --git a/pkgs/clan-cli/clan_cli/backups/restore.py b/pkgs/clan-cli/clan_cli/backups/restore.py
index 49902dc4b..d9746b32e 100644
--- a/pkgs/clan-cli/clan_cli/backups/restore.py
+++ b/pkgs/clan-cli/clan_cli/backups/restore.py
@@ -18,10 +18,7 @@ def restore_service(machine: Machine, name: str, provider: str, service: str) ->
         msg = f"Service {service} not found in configuration. Available services are: {', '.join(backup_folders.keys())}"
         raise ClanError(msg)
 
-    folders = backup_folders[service]["folders"].values()
-    assert all(isinstance(f, str) for f in folders), (
-        f"folders must be a list of strings instead of {folders}"
-    )
+    folders = backup_folders[service]["folders"]
     env = {}
     env["NAME"] = name
     # FIXME: If we have too many folder this might overflow the stack.
diff --git a/pkgs/clan-cli/clan_cli/flake.py b/pkgs/clan-cli/clan_cli/flake.py
index 25a59dd29..065edc1e6 100644
--- a/pkgs/clan-cli/clan_cli/flake.py
+++ b/pkgs/clan-cli/clan_cli/flake.py
@@ -1,11 +1,11 @@
 import json
 import logging
-import re
-from dataclasses import dataclass
+from dataclasses import asdict, dataclass, field
+from enum import Enum
 from hashlib import sha1
 from pathlib import Path
 from tempfile import NamedTemporaryFile
-from typing import Any, cast
+from typing import Any
 
 from clan_cli.cmd import Log, RunOpts, run
 from clan_cli.dirs import user_cache_dir
@@ -21,42 +21,212 @@ from clan_cli.nix import (
 log = logging.getLogger(__name__)
 
 
-class AllSelector:
-    pass
+class SetSelectorType(str, Enum):
+    """
+    enum for the type of selector in a set.
+    For now this is either a string or a maybe selector.
+    """
+
+    STR = "str"
+    MAYBE = "maybe"
 
 
-Selector = str | int | AllSelector | set[int] | set[str]
+@dataclass
+class SetSelector:
+    """
+    This class represents a selector used in a set.
+    type: SetSelectorType = SetSelectorType.STR
+    value: str = ""
+
+    a set looks like this:
+    {key1,key2}
+    """
+
+    type: SetSelectorType = SetSelectorType.STR
+    value: str = ""
 
 
-def split_selector(selector: str) -> list[Selector]:
+class SelectorType(str, Enum):
+    """
+    enum for the type of a selector
+    this can be all, string, set or maybe
+    """
+
+    ALL = "all"
+    STR = "str"
+    SET = "set"
+    MAYBE = "maybe"
+
+
+@dataclass
+class Selector:
+    """
+    A class to represent a selector, which selects nix elements one level down.
+    consists of a SelectorType and a value.
+
+    if the type is all, no value is needed, since it selects all elements.
+    if the type is str, the value is a string, which is the key in a dict.
+    if the type is maybe the value is a string, which is the key in a dict.
+    if the type is set, the value is a list of SetSelector objects.
+    """
+
+    type: SelectorType = SelectorType.STR
+    value: str | list[SetSelector] | None = None
+
+    def as_dict(self) -> dict[str, Any]:
+        if self.type == SelectorType.SET:
+            assert isinstance(self.value, list)
+            return {
+                "type": self.type.value,
+                "value": [asdict(selector) for selector in self.value],
+            }
+        if self.type == SelectorType.ALL:
+            return {"type": self.type.value}
+        if self.type == SelectorType.STR:
+            assert isinstance(self.value, str)
+            return {"type": self.type.value, "value": self.value}
+        if self.type == SelectorType.MAYBE:
+            assert isinstance(self.value, str)
+            return {"type": self.type.value, "value": self.value}
+        msg = f"Invalid selector type: {self.type}"
+        raise ValueError(msg)
+
+
+def selectors_as_dict(selectors: list[Selector]) -> list[dict[str, Any]]:
+    return [selector.as_dict() for selector in selectors]
+
+
+def selectors_as_json(selectors: list[Selector]) -> str:
+    return json.dumps(selectors_as_dict(selectors))
+
+
+def parse_selector(selector: str) -> list[Selector]:
     """
     takes a string and returns a list of selectors.
 
     a selector can be:
     - a string, which is a key in a dict
     - an integer, which is an index in a list
-    - a set of strings, which are keys in a dict
-    - a set of integers, which are indices in a list
-    - a quoted string, which is a key in a dict
+    - a set of strings or integers, which are keys in a dict or indices in a list.
     - the string "*", which selects all elements in a list or dict
     """
-    pattern = r'"[^"]*"|[^.]+'
-    matches = re.findall(pattern, selector)
-
-    # Extract the matched groups (either quoted or unquoted parts)
+    stack: list[str] = []
     selectors: list[Selector] = []
-    for selector in matches:
-        if selector == "*":
-            selectors.append(AllSelector())
-        elif selector.isdigit():
-            selectors.append({int(selector)})
-        elif selector.startswith("{") and selector.endswith("}"):
-            sub_selectors = set(selector[1:-1].split(","))
-            selectors.append(sub_selectors)
-        elif selector.startswith('"') and selector.endswith('"'):
-            selectors.append(selector[1:-1])
+    acc_str: str = ""
+
+    # only used by set for now
+    submode = ""
+    acc_selectors: list[SetSelector] = []
+
+    for i in range(len(selector)):
+        c = selector[i]
+        if stack == []:
+            mode = "start"
         else:
-            selectors.append(selector)
+            mode = stack[-1]
+
+        if mode == "end":
+            if c == ".":
+                stack.pop()
+                if stack != []:
+                    msg = "expected empy stack, but got {stack}"
+                    raise ValueError(msg)
+            else:
+                msg = "expected ., but got {c}"
+                raise ValueError(msg)
+
+        elif mode == "start":
+            if c == "*":
+                stack.append("end")
+                selectors.append(Selector(type=SelectorType.ALL))
+            elif c == "?":
+                stack.append("maybe")
+            elif c == '"':
+                stack += ["str", "quote"]
+            elif c == "{":
+                stack.append("set")
+            elif c == ".":
+                selectors.append(Selector(type=SelectorType.STR, value=acc_str))
+            else:
+                stack.append("str")
+                acc_str += c
+
+        elif mode == "set":
+            if submode == "" and c == "?":
+                submode = "maybe"
+            elif c == "\\":
+                stack.append("escape")
+                if submode == "":
+                    submode = "str"
+            elif c == '"':
+                stack.append("quote")
+                if submode == "":
+                    submode = "str"
+            elif c == ",":
+                if submode == "maybe":
+                    set_select_type = SetSelectorType.MAYBE
+                else:
+                    set_select_type = SetSelectorType.STR
+                acc_selectors.append(SetSelector(type=set_select_type, value=acc_str))
+                submode = ""
+                acc_str = ""
+            elif c == "}":
+                if submode == "maybe":
+                    set_select_type = SetSelectorType.MAYBE
+                else:
+                    set_select_type = SetSelectorType.STR
+                acc_selectors.append(SetSelector(type=set_select_type, value=acc_str))
+                selectors.append(Selector(type=SelectorType.SET, value=acc_selectors))
+
+                submode = ""
+                acc_selectors = []
+
+                acc_str = ""
+                stack.pop()
+                stack.append("end")
+            else:
+                acc_str += c
+                if submode == "":
+                    submode = "str"
+
+        elif mode == "quote":
+            if c == '"':
+                stack.pop()
+            elif c == "\\":
+                stack.append("escape")
+            else:
+                acc_str += c
+
+        elif mode == "escape":
+            stack.pop()
+            acc_str += c
+
+        elif mode == "str" or mode == "maybe":
+            if c == ".":
+                stack.pop()
+                if mode == "maybe":
+                    select_type = SelectorType.MAYBE
+                else:
+                    select_type = SelectorType.STR
+                selectors.append(Selector(type=select_type, value=acc_str))
+                acc_str = ""
+            elif c == "\\":
+                stack.append("escape")
+            else:
+                acc_str += c
+
+    if stack != []:
+        if stack[-1] == "str" or stack[-1] == "maybe":
+            if stack[-1] == "maybe":
+                select_type = SelectorType.MAYBE
+            else:
+                select_type = SelectorType.STR
+            selectors.append(Selector(type=select_type, value=acc_str))
+        elif stack[-1] == "end":
+            pass
+        else:
+            msg = f"expected empty stack, but got {stack}"
+            raise ValueError(msg)
 
     return selectors
 
@@ -64,94 +234,18 @@ def split_selector(selector: str) -> list[Selector]:
 @dataclass
 class FlakeCacheEntry:
     """
-    a recursive structure to store the cache, with a value and a selector
+    a recursive structure to store the cache.
+    consists of a dict with the keys being the selectors and the values being FlakeCacheEntry objects.
+
+    is_list is used to check if the value is a list.
+    exists is used to check if the value exists, which can be false if it was selected via maybe.
+    fetched_all is used to check if we have all keys on the current level.
     """
 
-    def __init__(
-        self,
-        value: str | float | dict[str, Any] | list[Any] | None,
-        selectors: list[Selector],
-        is_out_path: bool = False,
-    ) -> None:
-        self.value: str | float | int | None | dict[str | int, FlakeCacheEntry]
-        self.selector: set[int] | set[str] | AllSelector
-        selector: Selector = AllSelector()
-
-        if selectors == []:
-            self.selector = AllSelector()
-        elif isinstance(selectors[0], set):
-            self.selector = selectors[0]
-            selector = selectors[0]
-        elif isinstance(selectors[0], int):
-            self.selector = {int(selectors[0])}
-            selector = int(selectors[0])
-        elif isinstance(selectors[0], str):
-            self.selector = {selectors[0]}
-            selector = selectors[0]
-        elif isinstance(selectors[0], AllSelector):
-            self.selector = AllSelector()
-
-        if is_out_path:
-            if selectors != []:
-                msg = "Cannot index outPath"
-                raise ValueError(msg)
-            if not isinstance(value, str):
-                msg = "outPath must be a string"
-                raise ValueError(msg)
-            self.value = value
-
-        elif isinstance(selector, str):
-            self.value = {selector: FlakeCacheEntry(value, selectors[1:])}
-
-        elif isinstance(value, dict):
-            if isinstance(self.selector, set):
-                if not all(isinstance(v, str) for v in self.selector):
-                    msg = "Cannot index dict with non-str set"
-                    raise ValueError(msg)
-            self.value = {}
-            for key, value_ in value.items():
-                if key == "outPath":
-                    self.value[key] = FlakeCacheEntry(
-                        value_, selectors[1:], is_out_path=True
-                    )
-                else:
-                    self.value[key] = FlakeCacheEntry(value_, selectors[1:])
-
-        elif isinstance(value, list):
-            if isinstance(selector, int):
-                if len(value) != 1:
-                    msg = "Cannot index list with int selector when value is not singleton"
-                    raise ValueError(msg)
-                self.value = {
-                    int(selector): FlakeCacheEntry(value[0], selectors[1:]),
-                }
-            if isinstance(selector, set):
-                if all(isinstance(v, int) for v in selector):
-                    self.value = {}
-                    for i, v in enumerate([selector]):
-                        assert isinstance(v, int)
-                        self.value[int(v)] = FlakeCacheEntry(value[i], selectors[1:])
-                else:
-                    msg = "Cannot index list with non-int set"
-                    raise ValueError(msg)
-            elif isinstance(self.selector, AllSelector):
-                self.value = {}
-                for i, v in enumerate(value):
-                    if isinstance(v, dict | list | str | float | int):
-                        self.value[i] = FlakeCacheEntry(v, selectors[1:])
-            else:
-                msg = f"expected integer selector or all for type list, but got {type(selector)}"
-                raise TypeError(msg)
-
-        elif isinstance(value, str) and value.startswith("/nix/store/"):
-            self.value = {}
-            self.selector = self.selector = {"outPath"}
-            self.value["outPath"] = FlakeCacheEntry(
-                value, selectors[1:], is_out_path=True
-            )
-
-        elif isinstance(value, (str | float | int | None)):
-            self.value = value
+    value: str | float | dict[str, Any] | None = field(default_factory=dict)
+    is_list: bool = False
+    exists: bool = True
+    fetched_all: bool = False
 
     def insert(
         self,
@@ -159,175 +253,236 @@ class FlakeCacheEntry:
         selectors: list[Selector],
     ) -> None:
         selector: Selector
+        # if we have no more selectors, it means we select all keys from now one and futher down
         if selectors == []:
-            selector = AllSelector()
+            selector = Selector(type=SelectorType.ALL)
         else:
             selector = selectors[0]
 
-        if isinstance(selector, str):
-            if isinstance(self.value, dict):
-                if selector in self.value:
-                    self.value[selector].insert(value, selectors[1:])
-                else:
-                    self.value[selector] = FlakeCacheEntry(value, selectors[1:])
-                return
-            msg = f"Cannot insert {selector} into non dict value"
-            raise TypeError(msg)
+        # first we find out if we have all subkeys already
 
-        if isinstance(selector, AllSelector):
-            self.selector = AllSelector()
-        elif isinstance(self.selector, set) and isinstance(selector, set):
-            if all(isinstance(v, str) for v in self.selector) and all(
-                isinstance(v, str) for v in selector
-            ):
-                selector = cast(set[str], selector)
-                self.selector = cast(set[str], self.selector)
-                self.selector = self.selector.union(selector)
-            elif all(isinstance(v, int) for v in self.selector) and all(
-                isinstance(v, int) for v in selector
-            ):
-                selector = cast(set[int], selector)
-                self.selector = cast(set[int], self.selector)
-                self.selector = self.selector.union(selector)
-            else:
-                msg = "Cannot union set of different types"
-                raise ValueError(msg)
-        elif isinstance(self.selector, set) and isinstance(selector, int):
-            if all(isinstance(v, int) for v in self.selector):
-                self.selector = cast(set[int], self.selector)
-                self.selector.add(selector)
+        if self.fetched_all:
+            pass
+        elif selector.type == SelectorType.ALL:
+            self.fetched_all = True
 
-        elif isinstance(self.selector, set) and isinstance(selector, str):
-            if all(isinstance(v, str) for v in self.selector):
-                self.selector = cast(set[str], self.selector)
-                self.selector.add(selector)
+        # if we have a string selector, that means we are usually on a dict or a list, since we cannot walk down scalar values
+        # so we passthrough the value to the next level
+        if selector.type == SelectorType.STR:
+            assert isinstance(selector.value, str)
+            assert isinstance(self.value, dict)
+            if selector.value not in self.value:
+                self.value[selector.value] = FlakeCacheEntry()
+            self.value[selector.value].insert(value, selectors[1:])
 
-        else:
-            msg = f"Cannot insert {selector} into {self.selector}"
-            raise TypeError(msg)
+        # if we get a MAYBE, check if the selector is in the output, if not we create a entry with exists = False
+        # otherwise we just insert the value into the current dict
+        # we can skip creating the non existing entry if we already fetched all keys
+        elif selector.type == SelectorType.MAYBE:
+            assert isinstance(self.value, dict)
+            assert isinstance(value, dict)
+            assert isinstance(selector.value, str)
+            if selector.value in value:
+                if selector.value not in self.value:
+                    self.value[selector.value] = FlakeCacheEntry()
+                self.value[selector.value].insert(value[selector.value], selectors[1:])
+            elif not self.fetched_all:
+                if selector.value not in self.value:
+                    self.value[selector.value] = FlakeCacheEntry()
+                self.value[selector.value].exists = False
 
-        if isinstance(self.value, dict) and isinstance(value, dict):
+        # insert a dict is pretty straight forward
+        elif isinstance(value, dict):
+            assert isinstance(self.value, dict)
             for key, value_ in value.items():
-                if key in self.value:
-                    self.value[key].insert(value_, selectors[1:])
-                else:
-                    self.value[key] = FlakeCacheEntry(value_, selectors[1:])
+                if key not in self.value:
+                    self.value[key] = FlakeCacheEntry()
+                self.value[key].insert(value_, selectors[1:])
 
-        elif isinstance(self.value, dict) and isinstance(value, list):
-            if isinstance(selector, set):
-                if not all(isinstance(v, int) for v in selector):
-                    msg = "Cannot list with non-int set"
-                    raise ValueError(msg)
-                for realindex, requested_index in enumerate(selector):
-                    assert isinstance(requested_index, int)
-                    if requested_index in self.value:
-                        self.value[requested_index].insert(
-                            value[realindex], selectors[1:]
-                        )
-            elif isinstance(selector, AllSelector):
-                for index, v in enumerate(value):
-                    if index in self.value:
-                        self.value[index].insert(v, selectors[1:])
-                    else:
-                        self.value[index] = FlakeCacheEntry(v, selectors[1:])
-            elif isinstance(selector, int):
-                if selector in self.value:
-                    self.value[selector].insert(value[0], selectors[1:])
-                else:
-                    self.value[selector] = FlakeCacheEntry(value[0], selectors[1:])
+        # to store a list we also use a dict, so we know which indices we have
+        elif isinstance(value, list):
+            self.is_list = True
+            fetched_indices: list[str] = []
+            # if we are in a set, we take all the selectors
+            if selector.type == SelectorType.SET:
+                assert isinstance(selector.value, list)
+                for subselector in selector.value:
+                    fetched_indices.append(subselector.value)
+            # if it's just a str, that is the index
+            elif selector.type == SelectorType.STR:
+                assert isinstance(selector.value, str)
+                fetched_indices = [selector.value]
+            # otherwise we just take all the indices, which is the length of the list
+            elif selector.type == SelectorType.ALL:
+                fetched_indices = list(map(str, range(len(value))))
+
+            # insert is the same is insert a dict
+            assert isinstance(self.value, dict)
+            for i, requested_index in enumerate(fetched_indices):
+                assert isinstance(requested_index, str)
+                if requested_index not in self.value:
+                    self.value[requested_index] = FlakeCacheEntry()
+                self.value[requested_index].insert(value[i], selectors[1:])
+
+        # strings need to be checked if they are store paths
+        # if they are, we store them as a dict with the outPath key
+        # this is to mirror nix behavior, where the outPath of an attrset is used if no further key is specified
         elif isinstance(value, str) and value.startswith("/nix/store/"):
-            self.value = {}
-            self.value["outPath"] = FlakeCacheEntry(
-                value, selectors[1:], is_out_path=True
-            )
+            assert selectors == []
+            if value.startswith("/nix/store/"):
+                self.value = {"outPath": FlakeCacheEntry(value)}
 
-        elif isinstance(value, (str | float | int)):
-            if self.value:
-                if self.value != value:
-                    msg = "value mismatch in cache, something is fishy"
-                    raise TypeError(msg)
-
-        elif value is None:
-            if self.value is not None:
-                msg = "value mismatch in cache, something is fishy"
+        # if we have a normal scalar, we check if it conflicts with a maybe already store value
+        # since an empty attrset is the default value, we cannot check that, so we just set it to the value
+        elif isinstance(value, float | int | str) or value is None:
+            assert selectors == []
+            if self.value == {}:
+                self.value = value
+            elif self.value != value:
+                msg = f"Cannot insert {value} into cache, already have {self.value}"
                 raise TypeError(msg)
 
-        else:
-            msg = f"Cannot insert value of type {type(value)} into cache"
-            raise TypeError(msg)
-
     def is_cached(self, selectors: list[Selector]) -> bool:
         selector: Selector
         if selectors == []:
-            selector = AllSelector()
-        else:
-            selector = selectors[0]
+            return self.fetched_all
+        selector = selectors[0]
 
+        # for store paths we have to check if they still exist, otherwise they have to be rebuild and are thus not cached
         if isinstance(self.value, str) and self.value.startswith("/nix/store/"):
             return Path(self.value).exists()
+
+        # if self.value is not dict but we request more selectors, we assume we are cached and an error will be thrown in the select function
         if isinstance(self.value, str | float | int | None):
-            return selectors == []
-        if isinstance(selector, AllSelector):
-            if isinstance(self.selector, AllSelector):
+            return True
+
+        # we just fetch all subkeys, so we need to check of we inserted all keys at this level before
+        if selector.type == SelectorType.ALL:
+            assert isinstance(self.value, dict)
+            if self.fetched_all:
                 result = all(
                     self.value[sel].is_cached(selectors[1:]) for sel in self.value
                 )
                 return result
-            # TODO: check if we already have all the keys anyway?
             return False
         if (
-            isinstance(selector, set)
-            and isinstance(self.selector, set)
+            selector.type == SelectorType.SET
+            and isinstance(selector.value, list)
             and isinstance(self.value, dict)
         ):
-            if not selector.issubset(self.selector):
-                return False
+            for requested_selector in selector.value:
+                val = requested_selector.value
+                if val not in self.value:
+                    # if we fetched all keys and we are not in the dict, we can assume we are cached
+                    return self.fetched_all
+                # if a key does not exist from a previous fetch, we can assume it is cached
+                if self.value[val].exists is False:
+                    return True
+                if not self.value[val].is_cached(selectors[1:]):
+                    return False
 
-            result = all(
-                self.value[sel].is_cached(selectors[1:]) if sel in self.value else True
-                for sel in selector
-            )
+            return True
 
-            return result
-        if isinstance(selector, str | int) and isinstance(self.value, dict):
-            if selector in self.value:
-                result = self.value[selector].is_cached(selectors[1:])
-                return result
-            return False
+        # string and maybe work the same for cache checking
+        if (
+            selector.type == SelectorType.STR or selector.type == SelectorType.MAYBE
+        ) and isinstance(self.value, dict):
+            assert isinstance(selector.value, str)
+            val = selector.value
+            if val not in self.value:
+                # if we fetched all keys and we are not in there, refetching won't help, so we can assume we are cached
+                return self.fetched_all
+            if self.value[val].exists is False:
+                return True
+            return self.value[val].is_cached(selectors[1:])
 
         return False
 
     def select(self, selectors: list[Selector]) -> Any:
         selector: Selector
         if selectors == []:
-            selector = AllSelector()
+            selector = Selector(type=SelectorType.ALL)
         else:
             selector = selectors[0]
 
+        # mirror nix behavior where we return outPath if no further selector is specified
         if selectors == [] and isinstance(self.value, dict) and "outPath" in self.value:
             return self.value["outPath"].value
 
-        if isinstance(self.value, str | float | int | None):
+        # if we are at the end of the selector chain, we return the value
+        if selectors == [] and isinstance(self.value, str | float | int | None):
             return self.value
+
+        # if we fetch a specific key, we return the recurse into that value in the dict
+        if selector.type == SelectorType.STR and isinstance(self.value, dict):
+            assert isinstance(selector.value, str)
+            return self.value[selector.value].select(selectors[1:])
+
+        # if we are a MAYBE selector, we check if the key exists in the dict
+        if selector.type == SelectorType.MAYBE and isinstance(self.value, dict):
+            assert isinstance(selector.value, str)
+            if selector.value in self.value:
+                if self.value[selector.value].exists:
+                    return {
+                        selector.value: self.value[selector.value].select(selectors[1:])
+                    }
+                return {}
+            if self.fetched_all:
+                return {}
+
+        # otherwise we return a list or a dict
         if isinstance(self.value, dict):
-            if isinstance(selector, AllSelector):
-                return {k: v.select(selectors[1:]) for k, v in self.value.items()}
-            if isinstance(selector, set):
-                return {
-                    k: v.select(selectors[1:])
-                    for k, v in self.value.items()
-                    if k in selector
-                }
-            if isinstance(selector, str | int):
-                return self.value[selector].select(selectors[1:])
-        msg = f"Cannot select {selector} from type {type(self.value)}"
-        raise TypeError(msg)
+            keys_to_select: list[str] = []
+            # if we want to select all keys, we take all existing sub elements
+            if selector.type == SelectorType.ALL:
+                for key in self.value:
+                    if self.value[key].exists:
+                        keys_to_select.append(key)
+
+            # if we want to select a set of keys, we take the keys from the selector
+            if selector.type == SelectorType.SET:
+                assert isinstance(selector.value, list)
+                for subselector in selector.value:
+                    # make sure the keys actually exist if we have a maybe selector
+                    if subselector.type == SetSelectorType.MAYBE:
+                        if (
+                            subselector.value in self.value
+                            and self.value[subselector.value].exists
+                        ):
+                            keys_to_select.append(subselector.value)
+                    else:
+                        keys_to_select.append(subselector.value)
+
+            # if we are a list, return a list
+            if self.is_list:
+                result = []
+                for index in keys_to_select:
+                    result.append(self.value[index].select(selectors[1:]))
+                    return result
+
+            # otherwise return a dict
+            return {k: self.value[k].select(selectors[1:]) for k in keys_to_select}
+
+        # return a KeyError if we cannot fetch the key
+        str_selector: str
+        if selector.type == SelectorType.ALL:
+            str_selector = "*"
+        elif selector.type == SelectorType.SET:
+            subselectors: list[str] = []
+            assert isinstance(selector.value, list)
+            for subselector in selector.value:
+                subselectors.append(subselector.value)
+            str_selector = "{" + ",".join(subselectors) + "}"
+        else:
+            assert isinstance(selector.value, str)
+            str_selector = selector.value
+
+        raise KeyError(str_selector)
 
     def __getitem__(self, name: str) -> "FlakeCacheEntry":
         if isinstance(self.value, dict):
             return self.value[name]
-        msg = f"value is a {type(self.value)}, so cannot subscribe"
-        raise TypeError(msg)
+        raise KeyError(name)
 
     def as_json(self) -> dict[str, Any]:
         json_data: Any = {}
@@ -338,21 +493,13 @@ class FlakeCacheEntry:
         else:  # == str | float | None
             json_data["value"] = self.value
 
-        if isinstance(self.selector, AllSelector):
-            json_data["selector"] = "all-selector"
-        else:  # == set[int] | set[str]
-            json_data["selector"] = list(self.selector)
+        json_data["is_list"] = self.is_list
+        json_data["exists"] = self.exists
+        json_data["fetched_all"] = self.fetched_all
         return json_data
 
     @staticmethod
     def from_json(json_data: dict[str, Any]) -> "FlakeCacheEntry":
-        raw_selector = json_data.get("selector")
-        if raw_selector == "all-selector":
-            selector: Any = AllSelector()
-        else:  # == set[int] | set[str]
-            assert isinstance(raw_selector, list)
-            selector = set(raw_selector)
-
         raw_value = json_data.get("value")
         if isinstance(raw_value, dict):
             value: Any = {}
@@ -361,9 +508,13 @@ class FlakeCacheEntry:
         else:  # == str | float | None
             value = raw_value
 
-        entry = FlakeCacheEntry(None, [], is_out_path=False)
-        entry.selector = selector
-        entry.value = value
+        is_list = json_data.get("is_list", False)
+        exists = json_data.get("exists", True)
+        fetched_all = json_data.get("fetched_all", False)
+
+        entry = FlakeCacheEntry(
+            value=value, is_list=is_list, exists=exists, fetched_all=fetched_all
+        )
         return entry
 
     def __repr__(self) -> str:
@@ -379,22 +530,22 @@ class FlakeCache:
     """
 
     def __init__(self) -> None:
-        self.cache: FlakeCacheEntry = FlakeCacheEntry({}, [])
+        self.cache: FlakeCacheEntry = FlakeCacheEntry()
 
     def insert(self, data: dict[str, Any], selector_str: str) -> None:
         if selector_str:
-            selectors = split_selector(selector_str)
+            selectors = parse_selector(selector_str)
         else:
             selectors = []
 
         self.cache.insert(data, selectors)
 
     def select(self, selector_str: str) -> Any:
-        selectors = split_selector(selector_str)
+        selectors = parse_selector(selector_str)
         return self.cache.select(selectors)
 
     def is_cached(self, selector_str: str) -> bool:
-        selectors = split_selector(selector_str)
+        selectors = parse_selector(selector_str)
         return self.cache.is_cached(selectors)
 
     def save_to_file(self, path: Path) -> None:
@@ -544,13 +695,17 @@ class Flake:
         if nix_options is None:
             nix_options = []
 
+        str_selectors: list[str] = []
+        for selector in selectors:
+            str_selectors.append(selectors_as_json(parse_selector(selector)))
+
         config = nix_config()
         nix_code = f"""
             let
               flake = builtins.getFlake("path:{self.store_path}?narHash={self.hash}");
             in
               flake.inputs.nixpkgs.legacyPackages.{config["system"]}.writeText "clan-flake-select" (
-                builtins.toJSON [ {" ".join([f"(flake.clanInternals.clanLib.select ''{attr}'' flake)" for attr in selectors])} ]
+                builtins.toJSON [ {" ".join([f"(flake.clanInternals.clanLib.select.applySelectors (builtins.fromJSON ''{attr}'') flake)" for attr in str_selectors])} ]
               )
         """
         if tmp_store := nix_test_store():
diff --git a/pkgs/clan-cli/clan_cli/templates.py b/pkgs/clan-cli/clan_cli/templates.py
index d3f632ec9..956e2f1dd 100644
--- a/pkgs/clan-cli/clan_cli/templates.py
+++ b/pkgs/clan-cli/clan_cli/templates.py
@@ -95,10 +95,10 @@ def get_clan_nix_attrset(clan_dir: Flake | None = None) -> ClanExports:
 
     raw_clan_exports: dict[str, Any] = {"self": {"clan": {}}, "inputs": {"clan": {}}}
 
-    try:
-        raw_clan_exports["self"] = clan_dir.select("clan.{templates}")
-    except ClanCmdError as ex:
-        log.debug(ex)
+    maybe_templates = clan_dir.select("?clan.?templates")
+    if "clan" in maybe_templates:
+        raw_clan_exports["self"] = maybe_templates["clan"]
+    else:
         log.info("Current flake does not export the 'clan' attribute")
 
     # FIXME: flake.select destroys lazy evaluation
@@ -112,7 +112,7 @@ def get_clan_nix_attrset(clan_dir: Flake | None = None) -> ClanExports:
         # of import statements.
         # This needs to be fixed in clan.select
         # For now always define clan.templates or no clan attribute at all
-        temp = clan_dir.select("inputs.*.{clan}.templates")
+        temp = clan_dir.select("inputs.*.?clan.templates")
 
         # FIXME: We need this because clan.select removes the templates attribute
         # but not the clan and other attributes leading up to templates
diff --git a/pkgs/clan-cli/clan_cli/tests/test_flake_caching.py b/pkgs/clan-cli/clan_cli/tests/test_flake_caching.py
index d50d37160..7c5cd1b35 100644
--- a/pkgs/clan-cli/clan_cli/tests/test_flake_caching.py
+++ b/pkgs/clan-cli/clan_cli/tests/test_flake_caching.py
@@ -1,35 +1,282 @@
 import logging
 
 import pytest
-from clan_cli.flake import Flake, FlakeCache, FlakeCacheEntry
+from clan_cli.flake import (
+    Flake,
+    FlakeCache,
+    FlakeCacheEntry,
+    parse_selector,
+    selectors_as_dict,
+)
 from clan_cli.tests.fixtures_flakes import ClanFlake
 
 log = logging.getLogger(__name__)
 
 
+def test_parse_selector() -> None:
+    selectors = parse_selector("x")
+    assert selectors_as_dict(selectors) == [
+        {"type": "str", "value": "x"},
+    ]
+    selectors = parse_selector("?x")
+    assert selectors_as_dict(selectors) == [
+        {"type": "maybe", "value": "x"},
+    ]
+    selectors = parse_selector('"x"')
+    assert selectors_as_dict(selectors) == [
+        {"type": "str", "value": "x"},
+    ]
+    selectors = parse_selector("*")
+    assert selectors_as_dict(selectors) == [
+        {"type": "all"},
+    ]
+    selectors = parse_selector("{x}")
+    assert selectors_as_dict(selectors) == [
+        {
+            "type": "set",
+            "value": [
+                {"type": "str", "value": "x"},
+            ],
+        },
+    ]
+    selectors = parse_selector("{x}.y")
+    assert selectors_as_dict(selectors) == [
+        {
+            "type": "set",
+            "value": [
+                {"type": "str", "value": "x"},
+            ],
+        },
+        {"type": "str", "value": "y"},
+    ]
+    selectors = parse_selector("x.y.z")
+    assert selectors_as_dict(selectors) == [
+        {"type": "str", "value": "x"},
+        {"type": "str", "value": "y"},
+        {"type": "str", "value": "z"},
+    ]
+    selectors = parse_selector("x.*")
+    assert selectors_as_dict(selectors) == [
+        {"type": "str", "value": "x"},
+        {"type": "all"},
+    ]
+    selectors = parse_selector("*.x")
+    assert selectors_as_dict(selectors) == [
+        {"type": "all"},
+        {"type": "str", "value": "x"},
+    ]
+    selectors = parse_selector("x.*.z")
+    assert selectors_as_dict(selectors) == [
+        {"type": "str", "value": "x"},
+        {"type": "all"},
+        {"type": "str", "value": "z"},
+    ]
+    selectors = parse_selector("x.{y,z}")
+    assert selectors_as_dict(selectors) == [
+        {"type": "str", "value": "x"},
+        {
+            "type": "set",
+            "value": [
+                {"type": "str", "value": "y"},
+                {"type": "str", "value": "z"},
+            ],
+        },
+    ]
+    selectors = parse_selector("x.?zzz.{y,?z,x,*}")
+    assert selectors_as_dict(selectors) == [
+        {"type": "str", "value": "x"},
+        {"type": "maybe", "value": "zzz"},
+        {
+            "type": "set",
+            "value": [
+                {"type": "str", "value": "y"},
+                {"type": "maybe", "value": "z"},
+                {"type": "str", "value": "x"},
+                {"type": "str", "value": "*"},
+            ],
+        },
+    ]
+
+    selectors = parse_selector('x."?zzz".?zzz\\.asd..{y,\\?z,"x,",*}')
+    assert selectors_as_dict(selectors) == [
+        {"type": "str", "value": "x"},
+        {"type": "str", "value": "?zzz"},
+        {"type": "maybe", "value": "zzz.asd"},
+        {"type": "str", "value": ""},
+        {
+            "type": "set",
+            "value": [
+                {"type": "str", "value": "y"},
+                {"type": "str", "value": "?z"},
+                {"type": "str", "value": "x,"},
+                {"type": "str", "value": "*"},
+            ],
+        },
+    ]
+
+
+def test_insert_and_iscached() -> None:
+    test_cache = FlakeCacheEntry()
+    selectors = parse_selector("x.y.z")
+    test_cache.insert("x", selectors)
+    assert test_cache["x"]["y"]["z"].value == "x"
+    assert test_cache.is_cached(selectors)
+    assert not test_cache.is_cached(parse_selector("x.y"))
+    assert test_cache.is_cached(parse_selector("x.y.z.1"))
+    assert not test_cache.is_cached(parse_selector("x.*.z"))
+    assert test_cache.is_cached(parse_selector("x.{y}.z"))
+    assert test_cache.is_cached(parse_selector("x.?y.z"))
+    assert not test_cache.is_cached(parse_selector("x.?z.z"))
+
+    test_cache = FlakeCacheEntry()
+    selectors = parse_selector("x.*.z")
+    test_cache.insert({"y": "x"}, selectors)
+    assert test_cache["x"]["y"]["z"].value == "x"
+    assert test_cache.is_cached(selectors)
+    assert not test_cache.is_cached(parse_selector("x.y"))
+    assert not test_cache.is_cached(parse_selector("x.y.x"))
+    assert test_cache.is_cached(parse_selector("x.y.z.1"))
+    assert test_cache.is_cached(parse_selector("x.{y}.z"))
+    assert test_cache.is_cached(parse_selector("x.{y,z}.z"))
+    assert test_cache.is_cached(parse_selector("x.{y,?z}.z"))
+    assert test_cache.is_cached(parse_selector("x.?y.z"))
+    assert test_cache.is_cached(parse_selector("x.?z.z"))
+
+    test_cache = FlakeCacheEntry()
+    selectors = parse_selector("x.{y}.z")
+    test_cache.insert({"y": "x"}, selectors)
+    assert test_cache["x"]["y"]["z"].value == "x"
+    assert test_cache.is_cached(selectors)
+    assert not test_cache.is_cached(parse_selector("x.y"))
+    assert test_cache.is_cached(parse_selector("x.y.z.1"))
+    assert not test_cache.is_cached(parse_selector("x.*.z"))
+    assert test_cache.is_cached(parse_selector("x.{y}.z"))
+    assert test_cache.is_cached(parse_selector("x.?y.z"))
+    assert not test_cache.is_cached(parse_selector("x.?z.z"))
+
+    test_cache = FlakeCacheEntry()
+    selectors = parse_selector("x.?y.z")
+    test_cache.insert({"y": "x"}, selectors)
+    assert test_cache["x"]["y"]["z"].value == "x"
+    assert test_cache.is_cached(selectors)
+    assert not test_cache.is_cached(parse_selector("x.y"))
+    assert test_cache.is_cached(parse_selector("x.y.z.1"))
+    assert not test_cache.is_cached(parse_selector("x.*.z"))
+    assert test_cache.is_cached(parse_selector("x.{y}.z"))
+    assert test_cache.is_cached(parse_selector("x.?y.z"))
+    assert not test_cache.is_cached(parse_selector("x.?z.z"))
+
+    test_cache = FlakeCacheEntry()
+    selectors = parse_selector("x.?y.z")
+    test_cache.insert({}, selectors)
+    assert test_cache["x"]["y"].exists is False
+    assert test_cache.is_cached(selectors)
+    assert test_cache.is_cached(parse_selector("x.y"))
+    assert test_cache.is_cached(parse_selector("x.y.z.1"))
+    assert test_cache.is_cached(parse_selector("x.?y.z.1"))
+    assert not test_cache.is_cached(parse_selector("x.*.z"))
+    assert test_cache.is_cached(parse_selector("x.{y}.z"))
+    assert test_cache.is_cached(parse_selector("x.?y.abc"))
+    assert not test_cache.is_cached(parse_selector("x.?z.z"))
+
+    test_cache = FlakeCacheEntry()
+    selectors = parse_selector("x.{y,z}.z")
+    test_cache.insert({"y": 1, "z": 2}, selectors)
+    assert test_cache["x"]["y"]["z"].value == 1
+    assert test_cache["x"]["z"]["z"].value == 2
+    assert test_cache.is_cached(selectors)
+    assert not test_cache.is_cached(parse_selector("x.y"))
+    assert test_cache.is_cached(parse_selector("x.y.z.1"))
+    assert not test_cache.is_cached(parse_selector("x.*.z"))
+    assert test_cache.is_cached(parse_selector("x.{y}.z"))
+    assert not test_cache.is_cached(parse_selector("x.?y.abc"))
+    assert test_cache.is_cached(parse_selector("x.?z.z"))
+
+    test_cache = FlakeCacheEntry()
+    selectors = parse_selector("x.y")
+    test_cache.insert(1, selectors)
+    selectors = parse_selector("x.z")
+    test_cache.insert(2, selectors)
+    assert test_cache["x"]["y"].value == 1
+    assert test_cache["x"]["z"].value == 2
+    assert test_cache.is_cached(parse_selector("x.y"))
+    assert test_cache.is_cached(parse_selector("x.y.z.1"))
+    assert not test_cache.is_cached(parse_selector("x.*.z"))
+    assert test_cache.is_cached(parse_selector("x.{y}.z"))
+    assert test_cache.is_cached(parse_selector("x.?y.abc"))
+    assert test_cache.is_cached(parse_selector("x.?z.z"))
+    assert not test_cache.is_cached(parse_selector("x.?x.z"))
+
+    test_cache = FlakeCacheEntry()
+    selectors = parse_selector("x.y.z")
+    test_cache.insert({"a": {"b": {"c": 1}}}, selectors)
+    assert test_cache.is_cached(selectors)
+    assert test_cache.is_cached(parse_selector("x.y.z.a.b.c"))
+    assert test_cache.is_cached(parse_selector("x.y.z.a.b"))
+    assert test_cache.is_cached(parse_selector("x.y.z.a"))
+    assert test_cache.is_cached(parse_selector("x.y.z"))
+    assert not test_cache.is_cached(parse_selector("x.y"))
+    assert not test_cache.is_cached(parse_selector("x"))
+    assert test_cache.is_cached(parse_selector("x.y.z.xxx"))
+
+    test_cache = FlakeCacheEntry()
+    selectors = parse_selector("x.y")
+    test_cache.insert(1, selectors)
+    with pytest.raises(TypeError):
+        test_cache.insert(2, selectors)
+    assert test_cache["x"]["y"].value == 1
+
+
 def test_select() -> None:
+    test_cache = FlakeCacheEntry()
+
+    test_cache.insert("bla", parse_selector("a.b.c"))
+    assert test_cache.select(parse_selector("a.b.c")) == "bla"
+    assert test_cache.select(parse_selector("a.b")) == {"c": "bla"}
+    assert test_cache.select(parse_selector("a")) == {"b": {"c": "bla"}}
+    assert test_cache.select(parse_selector("a.b.?c")) == {"c": "bla"}
+    assert test_cache.select(parse_selector("a.?b.?c")) == {"b": {"c": "bla"}}
+    assert test_cache.select(parse_selector("a.?c")) == {}
+    assert test_cache.select(parse_selector("a.?x.c")) == {}
+    assert test_cache.select(parse_selector("a.*")) == {"b": {"c": "bla"}}
+    assert test_cache.select(parse_selector("a.*.*")) == {"b": {"c": "bla"}}
+    assert test_cache.select(parse_selector("a.*.c")) == {"b": "bla"}
+    assert test_cache.select(parse_selector("a.b.*")) == {"c": "bla"}
+    assert test_cache.select(parse_selector("a.{b}.c")) == {"b": "bla"}
+    assert test_cache.select(parse_selector("a.{b}.{c}")) == {"b": {"c": "bla"}}
+    assert test_cache.select(parse_selector("a.b.{c}")) == {"c": "bla"}
+    assert test_cache.select(parse_selector("a.{?b}.c")) == {"b": "bla"}
+    assert test_cache.select(parse_selector("a.{?b,?x}.c")) == {"b": "bla"}
+    with pytest.raises(KeyError):
+        test_cache.select(parse_selector("a.b.x"))
+    with pytest.raises(KeyError):
+        test_cache.select(parse_selector("a.b.c.x"))
+    with pytest.raises(KeyError):
+        test_cache.select(parse_selector("a.{b,x}.c"))
+
     testdict = {"x": {"y": [123, 345, 456], "z": "bla"}}
-    test_cache = FlakeCacheEntry(testdict, [])
-    assert test_cache["x"]["z"].value == "bla"
-    assert test_cache.is_cached(["x", "z"])
-    assert not test_cache.is_cached(["x", "y", "z"])
-    assert test_cache.select(["x", "y", 0]) == 123
-    assert not test_cache.is_cached(["x", "z", 1])
-
-
-def test_insert() -> None:
-    test_cache = FlakeCacheEntry({}, [])
-    # Inserting the same thing twice should succeed
-    test_cache.insert(None, ["nix"])
-    test_cache.insert(None, ["nix"])
-    assert test_cache.select(["nix"]) is None
+    test_cache.insert(testdict, parse_selector("testdict"))
+    assert test_cache["testdict"]["x"]["z"].value == "bla"
+    selectors = parse_selector("testdict.x.z")
+    assert test_cache.select(selectors) == "bla"
+    selectors = parse_selector("testdict.x.z.z")
+    with pytest.raises(KeyError):
+        test_cache.select(selectors)
+    selectors = parse_selector("testdict.x.y.0")
+    assert test_cache.select(selectors) == 123
+    selectors = parse_selector("testdict.x.z.1")
+    with pytest.raises(KeyError):
+        test_cache.select(selectors)
 
 
 def test_out_path() -> None:
     testdict = {"x": {"y": [123, 345, 456], "z": "/nix/store/bla"}}
-    test_cache = FlakeCacheEntry(testdict, [])
-    assert test_cache.select(["x", "z"]) == "/nix/store/bla"
-    assert test_cache.select(["x", "z", "outPath"]) == "/nix/store/bla"
+    test_cache = FlakeCacheEntry()
+    test_cache.insert(testdict, [])
+    selectors = parse_selector("x.z")
+    assert test_cache.select(selectors) == "/nix/store/bla"
+    selectors = parse_selector("x.z.outPath")
+    assert test_cache.select(selectors) == "/nix/store/bla"
 
 
 @pytest.mark.with_core
@@ -85,10 +332,10 @@ def test_conditional_all_selector(flake: ClanFlake) -> None:
     assert isinstance(flake1._cache, FlakeCache)  # noqa: SLF001
     assert isinstance(flake2._cache, FlakeCache)  # noqa: SLF001
     log.info("First select")
-    res1 = flake1.select("inputs.*.{clan,missing}")
+    res1 = flake1.select("inputs.*.{?clan,?missing}")
 
     log.info("Second (cached) select")
-    res2 = flake1.select("inputs.*.{clan,missing}")
+    res2 = flake1.select("inputs.*.{?clan,?missing}")
 
     assert res1 == res2
     assert res1["clan-core"].get("clan") is not None
diff --git a/pkgs/clan-cli/flake-module.nix b/pkgs/clan-cli/flake-module.nix
index ce736765c..2a34bfc6e 100644
--- a/pkgs/clan-cli/flake-module.nix
+++ b/pkgs/clan-cli/flake-module.nix
@@ -86,8 +86,8 @@
       # only adding clanCoreWithVendoredDeps to the nix store is not enough
       templateDerivation = pkgs.closureInfo {
         rootPaths =
-          builtins.attrValues (self.clanLib.select "clan.templates.clan.*.path" self)
-          ++ builtins.attrValues (self.clanLib.select "clan.templates.machine.*.path" self);
+          builtins.attrValues (self.clanLib.select.select "clan.templates.clan.*.path" self)
+          ++ builtins.attrValues (self.clanLib.select.select "clan.templates.machine.*.path" self);
       };
 
       clanCoreWithVendoredDeps =