diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
new file mode 100644
index 0000000..8bb3555
--- /dev/null
+++ b/.pre-commit-config.yaml
@@ -0,0 +1,18 @@
+# See https://pre-commit.com for more information
+# See https://pre-commit.com/hooks.html for more hooks
+
+repos:
+-   repo: https://github.com/astral-sh/ruff-pre-commit
+    # Ruff version.
+    rev: v0.2.2
+    hooks:
+      - id: ruff
+        args: [ --fix, --exit-non-zero-on-fix ]
+      - id: ruff-format
+
+-   repo: https://github.com/henriquegemignani/jsonschema-to-typeddict
+    rev: v1.1.1
+    hooks:
+    -   id: jsonschema-to-typeddict
+        files: caver/schema/schema.json
+        args: [ --output-path, caver/schema/types.py, --root-name, CaverData ]
diff --git a/caver/patcher.py b/caver/patcher.py
index 5a7f4dc..b5731ce 100644
--- a/caver/patcher.py
+++ b/caver/patcher.py
@@ -1,26 +1,46 @@
+from __future__ import annotations
+
+import json
+import logging
+import platform as pl
+import shutil
+import sys
+import textwrap
+import typing
 from enum import Enum
 from pathlib import Path
-from typing import Callable, Optional
-from randovania_lupa import LuaRuntime # type: ignore
-import logging
-import shutil
-import textwrap
-import sys
-import platform as pl
+from uuid import UUID
 
 import pre_edited_cs
+from randovania_lupa import LuaRuntime  # type: ignore
 
+from caver.schema.validator_with_default import DefaultValidatingDraft7Validator
 
+LuaFile = typing.Any
+
+if typing.TYPE_CHECKING:
+    from collections.abc import Callable
+
+    from caver.schema import (
+        CaverData,
+        CaverdataMaps,
+        CaverdataOtherTsc,
+        EventNumber,
+        MapName,
+    )
 
 CSVERSION = 5
 
+
 class CaverException(Exception):
     pass
 
+
 class CSPlatform(Enum):
     FREEWARE = "freeware"
     TWEAKED = "tweaked"
 
+
 def get_path() -> Path:
     if getattr(sys, "frozen", False):
         file_dir = Path(getattr(sys, "_MEIPASS"))
@@ -28,34 +48,46 @@ def get_path() -> Path:
         file_dir = Path(__file__).parent.parent
     return file_dir.joinpath("caver")
 
-def patch_files(patch_data: dict, output_dir: Path, platform: CSPlatform, progress_update: Callable[[str, float], None]):
+
+def validate(patch_data: dict) -> None:
+    with Path(__file__).parent.joinpath("schema/schema.json").open() as f:
+        schema = json.load(f)
+    DefaultValidatingDraft7Validator(schema).validate(patch_data)
+
+
+def patch_files(
+    patch_data: CaverData, output_dir: Path, platform: CSPlatform, progress_update: Callable[[str, float], None]
+) -> None:
+    progress_update("Validating schema...", -1)
+    validate(typing.cast(dict, patch_data))
+
     progress_update("Copying base files...", -1)
     ensure_base_files_exist(platform, output_dir)
 
     total = len(patch_data["maps"].keys()) + len(patch_data["other_tsc"].keys()) + 3
 
     lua_file = get_path().joinpath("tsc_file.lua").read_text()
-    TscFile = LuaRuntime().execute(lua_file)
+    TscFile = typing.cast(LuaFile, LuaRuntime().execute(lua_file))
 
     for i, (mapname, mapdata) in enumerate(patch_data["maps"].items()):
-        progress_update(f"Patching {mapname}...", i/total)
+        progress_update(f"Patching {mapname}...", i / total)
         patch_map(mapname, mapdata, TscFile, output_dir)
 
     for filename, scripts in patch_data["other_tsc"].items():
         i += 1
-        progress_update(f"Patching {filename}.tsc...", i/total)
+        progress_update(f"Patching {filename}.tsc...", i / total)
         patch_other(filename, scripts, TscFile, output_dir)
 
     i += 1
-    progress_update("Copying MyChar...", i/total)
+    progress_update("Copying MyChar...", i / total)
     patch_mychar(patch_data["mychar"], output_dir, platform is CSPlatform.TWEAKED)
 
     i += 1
-    progress_update("Copying hash...", i/total)
+    progress_update("Copying hash...", i / total)
     patch_hash(patch_data["hash"], output_dir)
 
     i += 1
-    progress_update("Copying UUID...", i/total)
+    progress_update("Copying UUID...", i / total)
     patch_uuid(patch_data["uuid"], output_dir)
 
     if platform == CSPlatform.TWEAKED:
@@ -64,27 +96,35 @@ def patch_files(patch_data: dict, output_dir: Path, platform: CSPlatform, progre
         else:
             output_dir.joinpath("CSTweaked").unlink()
 
-def ensure_base_files_exist(platform: CSPlatform, output_dir: Path):
+
+def ensure_base_files_exist(platform: CSPlatform, output_dir: Path) -> None:
     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: str, names: list[str]):
+    def should_ignore(path: str, names: list[str]) -> list[str]:
         base = ["__init__.py", "__pycache__", "ScriptSource", "__pyinstaller"]
         if keep_existing_files:
             p = Path(path)
-            base.extend([str(p.joinpath(name)) for name in names if p.joinpath(name).exists() and p.joinpath(name).is_file()])
+            base.extend(
+                [str(p.joinpath(name)) for name in names if p.joinpath(name).exists() and p.joinpath(name).is_file()]
+            )
         return base
 
     try:
         shutil.copytree(internal_copy.joinpath(platform.value), output_dir, ignore=should_ignore, dirs_exist_ok=True)
-        shutil.copytree(internal_copy.joinpath("data"), output_dir.joinpath("data"), ignore=should_ignore, dirs_exist_ok=True)
+        shutil.copytree(
+            internal_copy.joinpath("data"), output_dir.joinpath("data"), ignore=should_ignore, dirs_exist_ok=True
+        )
     except shutil.Error:
-        raise CaverException("Error copying base files. Ensure the directory is not read-only, and that Doukutsu.exe is closed")
+        raise CaverException(
+            "Error copying base files. Ensure the directory is not read-only, and that Doukutsu.exe is closed"
+        )
     output_dir.joinpath("data", "Plaintext").mkdir(exist_ok=True)
 
-def patch_map(mapname: str, mapdata: dict[str, dict], TscFile, output_dir: Path):
+
+def patch_map(mapname: MapName, mapdata: CaverdataMaps, TscFile: LuaFile, output_dir: Path) -> None:
     mappath = output_dir.joinpath("data", "Stage", f"{mapname}.tsc")
     tsc_file = TscFile.new(TscFile, mappath.read_bytes(), logging.getLogger("caver"))
 
@@ -95,7 +135,7 @@ def patch_map(mapname: str, mapdata: dict[str, dict], TscFile, output_dir: Path)
         TscFile.placeSongAtCue(tsc_file, song["song_id"], event, song["original_id"], mapname)
 
     for event, script in mapdata["entrances"].items():
-        needle = "<EVE...." # TODO: create a proper pattern
+        needle = "<EVE...."  # TODO: create a proper pattern
         TscFile.placeScriptAtEvent(tsc_file, script, event, mapname, needle)
 
     for event, hint in mapdata["hints"].items():
@@ -106,7 +146,10 @@ def patch_map(mapname: str, mapdata: dict[str, dict], TscFile, output_dir: Path)
     mappath.write_bytes(bytes(chars))
     output_dir.joinpath("data", "Plaintext", f"{mapname}.txt").write_text(TscFile.getPlaintext(tsc_file))
 
-def patch_other(filename: str, scripts: dict[str, dict[str, str]], TscFile, output_dir: Path):
+
+def patch_other(
+    filename: MapName, scripts: dict[EventNumber, CaverdataOtherTsc], TscFile: LuaFile, output_dir: Path
+) -> None:
     filepath = output_dir.joinpath("data", f"{filename}.tsc")
     tsc_file = TscFile.new(TscFile, filepath.read_bytes(), logging.getLogger("caver"))
 
@@ -117,7 +160,8 @@ def patch_other(filename: str, scripts: dict[str, dict[str, str]], TscFile, outp
     filepath.write_bytes(bytes(chars))
     output_dir.joinpath("data", "Plaintext", f"{filename}.txt").write_text(TscFile.getPlaintext(tsc_file))
 
-def patch_mychar(mychar: Optional[str], output_dir: Path, add_upscale: bool):
+
+def patch_mychar(mychar: str | None, output_dir: Path, add_upscale: bool) -> None:
     if mychar is None:
         return
     mychar_img = Path(mychar).read_bytes()
@@ -129,15 +173,18 @@ def patch_mychar(mychar: Optional[str], output_dir: Path, add_upscale: bool):
         output_dir.joinpath("data", "sprites_up", "MyChar.bmp").write_bytes(mychar_up_img)
 
 
-def patch_hash(hash: list[int], output_dir: Path):
+def patch_hash(hash: list[int], output_dir: Path) -> None:
     hash_strings = [f"{num:04d}" for num in hash]
     hash_string = ",".join(hash_strings)
     output_dir.joinpath("data", "hash.txt").write_text(hash_string)
 
-def patch_uuid(uuid: str, output_dir: Path):
+
+def patch_uuid(uuid: str, output_dir: Path) -> None:
+    uuid = f"{{{UUID(uuid)}}}"
     output_dir.joinpath("data", "uuid.txt").write_text(uuid)
 
-def wrap_msg_text(text: str, facepic: bool, *, ending: str = "<NOD", max_text_boxes: Optional[int] = 1) -> str:
+
+def wrap_msg_text(text: str, facepic: bool, *, ending: str = "<NOD", max_text_boxes: int | None = 1) -> str:
     hard_limit = 35
     msgbox_limit = 26 if facepic else hard_limit
 
@@ -145,19 +192,21 @@ def wrap_msg_text(text: str, facepic: bool, *, ending: str = "<NOD", max_text_bo
     lines = textwrap.wrap(text, width=msgbox_limit, max_lines=max_lines)
 
     text = ""
-    for i, l in enumerate(lines):
-        text += l
-        if i < len(lines)-1:
+    for i, line in enumerate(lines):
+        text += line
+        if i < len(lines) - 1:
             if i % 3 == 2:
                 text += "<NOD"
-            if len(l) != hard_limit:
+            if len(line) != hard_limit:
                 text += "\r\n"
     text += ending
 
     return text
 
+
 def create_hint_script(text: str, facepic: bool, ending: str) -> str:
     """
-    A desperate attempt to generate valid <MSG text. Fills one text box (up to three lines). Attempts to wrap words elegantly.
+    A desperate attempt to generate valid <MSG text.
+    Fills one text box (up to three lines). Attempts to wrap words elegantly.
     """
     return f"<PRI<MSG<TUR{wrap_msg_text(text, facepic, ending=ending)}"
diff --git a/caver/schema/__init__.py b/caver/schema/__init__.py
new file mode 100644
index 0000000..1722609
--- /dev/null
+++ b/caver/schema/__init__.py
@@ -0,0 +1,23 @@
+from caver.schema.types import (
+    CaverData,
+    CaverdataMaps,
+    CaverdataMapsHints,
+    CaverdataMapsMusic,
+    CaverdataOtherTsc,
+    EventNumber,
+    MapName,
+    TscScript,
+    TscValue,
+)
+
+__all__ = [
+    "CaverData",
+    "TscValue",
+    "EventNumber",
+    "MapName",
+    "TscScript",
+    "CaverdataMapsHints",
+    "CaverdataMapsMusic",
+    "CaverdataMaps",
+    "CaverdataOtherTsc",
+]
diff --git a/caver/schema/schema.json b/caver/schema/schema.json
new file mode 100644
index 0000000..df059bd
--- /dev/null
+++ b/caver/schema/schema.json
@@ -0,0 +1,195 @@
+{
+    "$schema": "http://json-schema.org/draft-07/schema#",
+    "type": "object",
+    "properties": {
+        "$schema": {
+            "type": "string",
+            "format": "uri"
+        },
+        "maps": {
+            "type": "object", 
+            "propertyNames": {
+                "$ref": "#/$defs/map_name"
+            },
+            "additionalProperties": {
+                "type": "object",
+                "properties": {
+                    "pickups": {
+                        "type": "object",
+                        "propertyNames": {
+                            "$ref": "#/$defs/event_number"
+                        },
+                        "additionalProperties": {
+                            "$ref": "#/$defs/tsc_script"
+                        },
+                        "default": {}
+                    },
+                    "hints": {
+                        "type": "object",
+                        "propertyNames": {
+                            "$ref": "#/$defs/event_number"
+                        },
+                        "additionalProperties": {
+                            "type": "object",
+                            "properties": {
+                                "text": {
+                                    "type": "string"
+                                },
+                                "facepic": {
+                                    "$ref": "#/$defs/tsc_value",
+                                    "default": "0000"
+                                },
+                                "ending": {
+                                    "$ref": "#/$defs/tsc_script",
+                                    "default": "<END"
+                                }
+                            },
+                            "required": [
+                                "text",
+                                "facepic",
+                                "ending"
+                            ],
+                            "additionalProperties": false
+                        },
+                        "default": {}
+                    },
+                    "music": {
+                        "type": "object",
+                        "propertyNames": {
+                            "$ref": "#/$defs/event_number"
+                        },
+                        "additionalProperties": {
+                            "type": "object",
+                            "properties": {
+                                "original_id": {
+                                    "$ref": "#/$defs/tsc_value"
+                                },
+                                "song_id": {
+                                    "$ref": "#/$defs/tsc_value"
+                                }
+                            },
+                            "required": [
+                                "original_id",
+                                "song_id"
+                            ],
+                            "additionalProperties": false
+                        },
+                        "default": {}
+                    },
+                    "entrances": {
+                        "type": "object",
+                        "propertyNames": {
+                            "$ref": "#/$defs/event_number"
+                        },
+                        "additionalProperties": {
+                            "$ref": "#/$defs/tsc_script"
+                        },
+                        "default": {}
+                    }
+                },
+                "additionalProperties": false,
+                "required": [
+                    "pickups",
+                    "hints",
+                    "music",
+                    "entrances"
+                ]
+            },
+            "default": {}
+        },
+        "other_tsc": {
+            "type": "object",
+            "propertyNames": {
+                "$ref": "#/$defs/map_name"
+            },
+            "additionalProperties": {
+                "type": "object",
+                "propertyNames": {
+                    "$ref": "#/$defs/event_number"
+                },
+                "additionalProperties": {
+                    "type": "object",
+                    "properties": {
+                        "needle": {
+                            "type": "string",
+                            "description": "Lua pattern to search for and replace within the event"
+                        },
+                        "script": {
+                            "$ref": "#/$defs/tsc_script"
+                        }
+                    },
+                    "required": [
+                        "needle",
+                        "script"
+                    ],
+                    "additionalProperties": false
+                }
+            },
+            "default": {}
+        },
+        "mychar": {
+            "description": "A path to the mychar.bmp file to use (Optional)",
+            "anyOf": [
+                {
+                    "type": "null"
+                },
+                {
+                    "type": "string",
+                    "pattern": "^*.bmp$"
+                }
+            ],
+            "default": null
+        },
+        "hash": {
+            "description": "An array of five item IDs to display on the title screen, within [1, 39]",
+            "type": "array",
+            "items": {
+                "type": "integer",
+                "minimum": 1,
+                "maximum": 39
+            },
+            "minItems": 5,
+            "maxItems": 5,
+            "default": [1,1,1,1,1]
+        },
+        "uuid": {
+            "description": "The UUID for the world in a multiworld session, or the empty UUID if single player.",
+            "type": "string",
+            "pattern": "^\\{[a-fA-F0-9]{8}-[a-fA-F0-9]{4}-[a-fA-F0-9]{4}-[a-fA-F0-9]{4}-[a-fA-F0-9]{12}\\}$",
+            "default": "{00000000-0000-0000-0000-000000000000}"
+        },
+        "platform": {
+            "description": "Which supported platform to export to.",
+            "$comment": "Not actually used by the patcher.",
+            "type": "string",
+            "enum": [
+                "freeware",
+                "tweaked"
+            ]
+        }
+    },
+    "required": [
+        "maps",
+        "other_tsc",
+        "mychar",
+        "hash",
+        "uuid"
+    ],
+    "additionalProperties": false,
+    "$defs": {
+        "tsc_value": {
+            "type": "string",
+            "pattern": "^[ -~]{4}$"
+        },
+        "event_number": {
+            "$ref": "#/$defs/tsc_value",
+            "$comment": "Semantic alias for tsc_value"
+        },
+        "map_name": {
+            "type": "string"
+        },
+        "tsc_script": {
+            "type": "string"
+        }
+    }
+}
\ No newline at end of file
diff --git a/caver/schema/types.py b/caver/schema/types.py
new file mode 100644
index 0000000..df9073c
--- /dev/null
+++ b/caver/schema/types.py
@@ -0,0 +1,54 @@
+# This file is generated. Manual changes will be lost
+# fmt: off
+# ruff: noqa
+from __future__ import annotations
+
+import typing_extensions as typ
+
+
+# Definitions
+TscValue: typ.TypeAlias = str
+EventNumber: typ.TypeAlias = TscValue
+MapName: typ.TypeAlias = str
+TscScript: typ.TypeAlias = str
+
+
+# Schema entries
+@typ.final
+class CaverdataMapsHints(typ.TypedDict):
+    text: str
+    facepic: TscValue
+    ending: TscScript
+
+
+@typ.final
+class CaverdataMapsMusic(typ.TypedDict):
+    original_id: TscValue
+    song_id: TscValue
+
+
+@typ.final
+class CaverdataMaps(typ.TypedDict):
+    pickups: dict[EventNumber, TscScript]
+    hints: dict[EventNumber, CaverdataMapsHints]
+    music: dict[EventNumber, CaverdataMapsMusic]
+    entrances: dict[EventNumber, TscScript]
+
+
+@typ.final
+class CaverdataOtherTsc(typ.TypedDict):
+    needle: str
+    script: TscScript
+
+
+
+@typ.final
+class Caverdata(typ.TypedDict):
+    maps: dict[MapName, CaverdataMaps]
+    other_tsc: dict[MapName, dict[EventNumber, CaverdataOtherTsc]]
+    mychar: None | str
+    hash: list[int]
+    uuid: str
+    platform: typ.NotRequired[str]
+
+CaverData: typ.TypeAlias = Caverdata
diff --git a/caver/schema/validator_with_default.py b/caver/schema/validator_with_default.py
new file mode 100644
index 0000000..c65ce8c
--- /dev/null
+++ b/caver/schema/validator_with_default.py
@@ -0,0 +1,25 @@
+from jsonschema import Draft7Validator, validators
+
+
+def extend_with_default(validator_class):
+    validate_properties = validator_class.VALIDATORS["properties"]
+
+    def set_defaults(validator, properties, instance, schema):
+        for property, subschema in properties.items():
+            if "default" in subschema:
+                instance.setdefault(property, subschema["default"])
+
+        yield from validate_properties(
+            validator,
+            properties,
+            instance,
+            schema,
+        )
+
+    return validators.extend(
+        validator_class,
+        {"properties": set_defaults},
+    )
+
+
+DefaultValidatingDraft7Validator = extend_with_default(Draft7Validator)
diff --git a/pyproject.toml b/pyproject.toml
index fa7d672..3b1c7f9 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -5,3 +5,18 @@ build-backend = "setuptools.build_meta"
 [tool.setuptools_scm]
 local_scheme = "no-local-version"
 write_to = "caver/version.py"
+
+[tool.ruff]
+line-length = 120
+lint.select = ["E", "F", "W", "C90", "I", "UP"]
+src = ["src"]
+
+# Version to target for generated code.
+target-version = "py310"
+
+[tool.mypy]
+files = [
+    "caver/patcher.py",
+]
+follow_imports = "silent"
+disallow_untyped_defs = true
\ No newline at end of file
diff --git a/setup.cfg b/setup.cfg
index 4aff3a2..73a2e8a 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -10,17 +10,18 @@ classifiers =
     License :: OSI Approved :: zlib/libpng License
     Development Status :: 5 - Production/Stable
     Intended Audience :: Developers
-    Programming Language :: Python :: 3.9
+    Programming Language :: Python :: 3.10
     Programming Language :: Other Scripting Engines
 
 [options]
 packages = find:
 install_requires =
     randovania-lupa>=1.10
+    jsonschema>=4.0.0
 
 include_package_data = True
 zip_safe = False
-python_requires = >=3.9
+python_requires = >=3.10
 
 #
 # Entry Points for PyInstaller