diff --git a/.gitignore b/.gitignore
index ffa747e..67eaeb6 100644
--- a/.gitignore
+++ b/.gitignore
@@ -8,3 +8,5 @@ pre-edited-cs/Profile*
 pre-edited-cs/window\.rect
 
 *Copy/
+
+venv/
diff --git a/caver/patcher.py b/caver/patcher.py
new file mode 100644
index 0000000..aa9d08f
--- /dev/null
+++ b/caver/patcher.py
@@ -0,0 +1,60 @@
+from pathlib import Path
+from typing import Optional
+from lupa import LuaRuntime
+import logging
+import shutil
+pre_edited_cs = __import__("pre-edited-cs")
+
+
+CSVERSION = 3
+
+def patch_files(patch_data: dict, output_dir: Path):
+    ensure_base_files_exist(output_dir)
+
+    TscFile = LuaRuntime().eval(Path(__file__).parent.joinpath("tsc_file.lua").read_text())
+    for mapname, mapdata in patch_data["maps"].items():
+        patch_map(mapname, mapdata, TscFile, output_dir)
+    
+    patch_mychar(patch_data["mychar"], output_dir)
+
+    patch_hash(patch_data["hash"], output_dir)
+
+def ensure_base_files_exist(output_dir: Path):
+    internal_copy = pre_edited_cs.get_path()
+
+    version = output_dir.joinpath("data", "Stage", "_version.txt")
+    keep_existing_files = version.exists() and int(version.read_text()) >= CSVERSION
+
+    def should_ignore(path: Path, names: list[str]):
+        if not keep_existing_files:
+            return []
+        return [path.joinpath(name) for name in names if path.joinpath(name).exists() and path.joinpath(name).is_file()]
+    
+    shutil.copytree(internal_copy, output_dir, ignore=should_ignore)
+
+def patch_map(mapname: str, mapdata: dict[str, dict], TscFile, output_dir: Path):
+    mappath = output_dir.joinpath("data", "Stage", f"{mapname}.tsc")
+    tsc_file = TscFile.new({}, mappath.read_bytes(), logging.getLogger("caver"))
+
+    for event, script in mapdata["pickups"].items():
+        TscFile.placeItemAtLocation(tsc_file, script, event, mapname)
+    
+    for event, song in mapdata["music"].items():
+        TscFile.placeSongAtCue(tsc_file, song["song_id"], event, song["original_id"], mapname)
+    
+    for event, script in mapdata["entrances"].items():
+        TscFile.placeTraAtEntrance(tsc_file, script, event, mapname)
+
+    mappath.write_bytes(TscFile.getText(tsc_file))
+    output_dir.joinpath("data", "Plaintext", f"{mapname}.txt")
+
+def patch_mychar(mychar: Optional[str], output_dir: Path):
+    if mychar is None:
+        return
+    mychar_img = Path(mychar).read_bytes()
+    output_dir.joinpath("data", "MyChar.bmp").write_bytes(mychar_img)
+
+def patch_hash(hash: list[int], output_dir: Path):
+    hash_strings = [f"{num:04d}" for num in hash]
+    hash_string = ",".join(hash_strings)
+    output_dir.joinpath("data", "hash.txt").write_text(hash_string)
\ No newline at end of file
diff --git a/caver/tsc_file.lua b/caver/tsc_file.lua
index 2213f51..cc40944 100644
--- a/caver/tsc_file.lua
+++ b/caver/tsc_file.lua
@@ -1,49 +1,33 @@
-local C = Class:extend()
+local TscFile = {}
 
--- local ITEM_DATA = require 'database.items'
-
-local OPTIONAL_REPLACES = {
-  'Max health increased by ',
-  'Max life increased by ',
-  '<ACH0041', -- Cave Story+ only, trigger achievement.
-}
-
-function C:new(path)
-  logInfo('reading TSC: ' .. path)
-
-  local file = lf.newFile(path)
-  assert(file:open('r'))
-
-  local contents, size = file:read()
+function TscFile:new(contents, py_logging)
+  self.log = py_logging
   self._text = self:_codec(contents, 'decode')
-
-  assert(file:close())
-  assert(file:release())
 end
 
-function C:hasUnreplacedItems()
-  return #self._unreplaced >= 1
-end
-
-function C:placeItemAtLocation(item, location)
+function TscFile:placeItemAtLocation(script, event, mapname)
   local wasChanged
-  self._text, wasChanged = self:_stringReplace(self._text, "<EVE....", item.script, location.event)
+  self._text, wasChanged = self:_stringReplace(self._text, "<EVE....", script, event)
   if not wasChanged then
-    local template = 'Unable to place [%s] "%s" at "%s".'
-    logError(template:format(location.map, item.name, location.name))
+    local template = 'Unable to place script "%s" at [%s] event "%s".'
+    self.log.error(template:format(script, mapname, event))
   end
 end
 
-function C:placeSongAtCue(songid, event, map, originalid)
+function TscFile:placeSongAtCue(songid, event, originalid, mapname)
   local wasChanged
   self._text, wasChanged = self:_stringReplace(self._text, "<CMU" .. originalid, "<CMU" .. songid, event, {"<CMU0015", "<CMU0000"})
   if not wasChanged then
     local template = "Unable to replace [%s] event #%s's music cue with %q."
-    logWarning(template:format(map, event, songid))
+    self.log.warning(template:format(mapname, event, songid))
   end
 end
 
-function C:_stringReplace(text, needle, replacement, label, overrides)
+function TscFile:placeTraAtEntrance(script, event, mapname)
+  return -- TODO for entrance rando
+end
+
+function TscFile:_stringReplace(text, needle, replacement, label, overrides)
   overrides = overrides or {}
   local pStart, pEnd = self:_getLabelPositionRange(label)
 
@@ -53,11 +37,11 @@ function C:_stringReplace(text, needle, replacement, label, overrides)
     i = text:find(needle, pStart)
 
     if i == nil then
-      logDebug(('Unable to replace "%s" with "%s"'):format(needle, replacement))
+      self.log.debug(('Unable to replace "%s" with "%s"'):format(needle, replacement))
       return text, false
     elseif i > pEnd then
       -- This is totally normal and can be ignored.
-      logDebug(('Found "%s", but was outside of label.'):format(needle, replacement))
+      self.log.debug(('Found "%s", but was outside of label.'):format(needle, replacement))
       return text, false
     end
 
@@ -88,7 +72,7 @@ function C:_stringReplace(text, needle, replacement, label, overrides)
   return a .. replacement .. b, true
 end
 
-function C:_getLabelPositionRange(label)
+function TscFile:_getLabelPositionRange(label)
   local labelStart, labelEnd
 
   -- Recursive shit for when label is a table...
@@ -128,7 +112,7 @@ function C:_getLabelPositionRange(label)
   end
 
   if labelStart == nil then
-    logError(("%s: Could not find label: %s"):format(self.mapName, label))
+    self.log.error(("%s: Could not find label: %s"):format(self.mapName, label))
     labelStart = 1
   end
 
@@ -139,18 +123,15 @@ function C:_getLabelPositionRange(label)
   return labelStart, labelEnd
 end
 
-function C:writePlaintextTo(path)
-  logInfo('writing Plaintext TSC to: ' .. path)
-  U.writeFile(path, self._text)
+function TscFile:getPlaintext()
+  return self._text
 end
 
-function C:writeTo(path)
-  logInfo('writing TSC to: ' .. path)
-  local encoded = self:_codec(self._text, 'encode')
-  U.writeFile(path, encoded)
+function TscFile:getText()
+  return self:_codec(self._text, 'encode')
 end
 
-function C:_codec(text, mode)
+function TscFile:_codec(text, mode)
   -- Create array of chars.
   local chars = {}
   text:gsub(".", function(c) table.insert(chars, c) end)
@@ -166,9 +147,9 @@ function C:_codec(text, mode)
     error('Unknown codec mode: ' .. tostring(mode))
   end
 
-  logDebug("  filesize", #chars)
-  logDebug("  encoding char:", encodingChar)
-  logDebug("  encoding char position:", encodingCharPosition)
+  self.log.debug("  filesize", #chars)
+  self.log.debug("  encoding char:", encodingChar)
+  self.log.debug("  encoding char position:", encodingCharPosition)
 
   -- Encode or decode.
   for pos, char in ipairs(chars) do
@@ -182,4 +163,4 @@ function C:_codec(text, mode)
   return decoded
 end
 
-return C
+return TscFile
diff --git a/pre-edited-cs/__init__.py b/pre-edited-cs/__init__.py
index e69de29..25ba3ac 100644
--- a/pre-edited-cs/__init__.py
+++ b/pre-edited-cs/__init__.py
@@ -0,0 +1,5 @@
+from pathlib import Path
+
+
+def get_path():
+    return Path(__file__).parent