@@ -34,6 +34,7 @@ repos:
      args: [--disable-error-code=has-type,--disable-error-code=import-not-found]
      additional_dependencies:
        [
+         "types-jsonschema~=4.21.0",
          "types-mock==5.0.*",
          "types-PyYAML==6.0",
          "types-toml~=0.10",
 
@@ -0,0 +1,11 @@
+import json
+
+import pytest
+import requests
+
+
+@pytest.fixture(scope="module")
+def codetf_schema():
+    schema_path = "https://raw.githubusercontent.com/pixee/codemodder-specs/main/codetf.schema.json"
+    response = requests.get(schema_path)
+    yield json.loads(response.text)
@@ -15,6 +15,7 @@ dependencies = [
     "isort>=5.12,<5.14",
     "libcst>=1.1,<1.3",
     "packaging>=23.2,<25.0",
+    "pydantic~=2.6.0",
     "pylint>=3.0,<3.2",
     "python-json-logger~=2.0.0",
     "PyYAML~=6.0.0",
@@ -50,6 +51,7 @@ test = [
     "coverage>=7.3,<7.5",
     "Flask<4",
     "Jinja2~=3.1.2",
+    "jsonschema~=4.21.0",
     "lxml>=4.9.3,<5.2.0",
     "mock==5.1.*",
     "pre-commit<4",
@@ -59,6 +61,7 @@ test = [
     "pytest-mock~=3.12.0",
     "pytest-randomly==3.*",
     "pytest-xdist==3.*",
+    "requests~=2.31.0",
     "security~=1.2.0",
     "types-mock==5.1.*",
     "django>=4,<6",
 
@@ -11,12 +11,12 @@
 from codemodder.code_directory import match_files
 from codemodder.codemods.api import BaseCodemod
 from codemodder.codemods.semgrep import SemgrepRuleDetector
+from codemodder.codetf import CodeTF
 from codemodder.context import CodemodExecutionContext
 from codemodder.dependency import Dependency
 from codemodder.logging import configure_logger, log_list, log_section, logger
 from codemodder.project_analysis.file_parsers.package_store import PackageStore
 from codemodder.project_analysis.python_repo_manager import PythonRepoManager
-from codemodder.report.codetf_reporter import report_default
 from codemodder.result import ResultSet
 from codemodder.sarifs import detect_sarif_tools
 from codemodder.semgrep import run as run_semgrep
@@ -210,13 +210,17 @@ def run(original_args) -> int:
         files_to_analyze,
     )
 
-    results = context.compile_results(codemods_to_run)
-
     elapsed = datetime.datetime.now() - start
     elapsed_ms = int(elapsed.total_seconds() * 1000)
 
     if argv.output:
-        report_default(elapsed_ms, argv, original_args, results)
+        codetf = CodeTF.build(
+            context,
+            elapsed_ms,
+            original_args,
+            context.compile_results(codemods_to_run),
+        )
+        codetf.write_report(argv.output)
 
     log_report(context, argv, elapsed_ms, files_to_analyze)
     return 0
 
@@ -11,6 +11,7 @@
 from codemodder.code_directory import file_line_patterns
 from codemodder.codemods.base_detector import BaseDetector
 from codemodder.codemods.base_transformer import BaseTransformerPipeline
+from codemodder.codetf import Reference
 from codemodder.context import CodemodExecutionContext
 from codemodder.file_context import FileContext
 from codemodder.logging import logger
@@ -23,18 +24,6 @@ class ReviewGuidance(Enum):
     MERGE_WITHOUT_REVIEW = 3
 
 
-@dataclass
-class Reference:
-    url: str
-    description: str = ""
-
-    def to_json(self):
-        return {
-            "url": self.url,
-            "description": self.description or self.url,
-        }
-
-
 @dataclass
 class Metadata:
     name: str
@@ -124,7 +113,7 @@ def describe(self):
             "codemod": self.id,
             "summary": self.summary,
             "description": self.description,
-            "references": [ref.to_json() for ref in self.references],
+            "references": [ref.model_dump() for ref in self.references],
         }
 
     def _apply(
 
@@ -1,7 +1,7 @@
 from abc import ABCMeta, abstractmethod
 
-from codemodder.change import ChangeSet
 from codemodder.codemods.base_visitor import BaseTransformer
+from codemodder.codetf import ChangeSet
 from codemodder.context import CodemodExecutionContext
 from codemodder.file_context import FileContext
 from codemodder.result import Result
 
@@ -6,9 +6,9 @@
 from libcst.codemod import CodemodContext, VisitorBasedCodemodCommand
 from libcst.metadata import PositionProvider
 
-from codemodder.change import Change
 from codemodder.codemods.base_visitor import UtilsMixin
 from codemodder.codemods.utils_mixin import NameResolutionMixin
+from codemodder.codetf import Change
 from codemodder.file_context import FileContext
 from codemodder.result import Result
 
@@ -75,7 +75,7 @@ def leave_Call(self, original_node: cst.Call, updated_node: cst.Call):
                 and true_name in self.matching_functions
             ):
                 self.changes_in_file.append(
-                    Change(line_number, self.change_description)
+                    Change(lineNumber=line_number, description=self.change_description)
                 )
 
                 new_args = self.updated_args(updated_node.args)
 
@@ -1,15 +1,16 @@
 from collections import namedtuple
+from typing import cast
 
 import libcst as cst
 from libcst import matchers
 from libcst._position import CodeRange
 from libcst.codemod import CodemodContext
 from libcst.codemod.visitors import AddImportsVisitor, RemoveImportsVisitor
 
-from codemodder.change import Change, ChangeSet
 from codemodder.codemods.base_transformer import BaseTransformerPipeline
 from codemodder.codemods.base_visitor import BaseTransformer
 from codemodder.codemods.utils import get_call_name
+from codemodder.codetf import Change, ChangeSet
 from codemodder.context import CodemodExecutionContext
 from codemodder.dependency import Dependency
 from codemodder.diff import create_diff_from_tree
@@ -99,7 +100,7 @@ def leave_ClassDef(
 
     def node_position(self, node):
         # See https://github.com/Instagram/LibCST/blob/main/libcst/_metadata_dependent.py#L112
-        return self.get_metadata(self.METADATA_DEPENDENCIES[0], node)
+        return cast(CodeRange, self.get_metadata(self.METADATA_DEPENDENCIES[0], node))
 
     def add_change(self, node, description: str, start: bool = True):
         position = self.node_position(node)
@@ -125,7 +126,7 @@ def add_dependency(self, dependency: Dependency):
     def report_change(self, original_node):
         line_number = self.lineno_for_node(original_node)
         self.file_context.codemod_changes.append(
-            Change(line_number, self.change_description)
+            Change(lineNumber=line_number, description=self.change_description)
         )
 
     def remove_unused_import(self, original_node):
@@ -275,8 +276,8 @@ def apply(
             return None
 
         change_set = ChangeSet(
-            str(file_context.file_path.relative_to(context.directory)),
-            diff,
+            path=str(file_context.file_path.relative_to(context.directory)),
+            diff=diff,
             changes=file_context.codemod_changes,
         )
 
 
@@ -6,6 +6,7 @@
 from types import ModuleType
 
 import git
+import jsonschema
 
 from codemodder import __version__, registry
 
@@ -99,7 +100,8 @@ def _assert_results_fields(self, results, output_path):
         result = results[0]
         assert result["codemod"] == self.codemod_instance.id
         assert result["references"] == [
-            ref.to_json() for ref in self.codemod_instance.references
+            ref.model_dump(exclude_none=True)
+            for ref in self.codemod_instance.references
         ]
 
         # TODO: once we add description for each url.
@@ -118,15 +120,15 @@ def _assert_results_fields(self, results, output_path):
 
         assert len(change["changes"]) == self.num_changes
         line_change = change["changes"][0]
-        assert line_change["lineNumber"] == str(self.expected_line_change)
+        assert line_change["lineNumber"] == int(self.expected_line_change)
         assert line_change["description"] == self.change_description
-        assert line_change["packageActions"] == []
-        assert line_change["properties"] == {}
 
-    def _assert_codetf_output(self):
+    def _assert_codetf_output(self, codetf_schema):
         with open(self.output_path, "r", encoding="utf-8") as f:
             codetf = json.load(f)
 
+        jsonschema.validate(codetf, codetf_schema)
+
         assert sorted(codetf.keys()) == ["results", "run"]
         run = codetf["run"]
         self._assert_run_fields(run, self.output_path)
@@ -149,7 +151,7 @@ def check_code_after(self) -> ModuleType:
             path=self.code_path, allowed_exceptions=self.allowed_exceptions
         )
 
-    def test_file_rewritten(self):
+    def test_file_rewritten(self, codetf_schema):
         """
         Tests that file is re-written correctly with new code and correct codetf output.
 
@@ -183,7 +185,7 @@ def test_file_rewritten(self):
 
         self.check_code_after()
         self.check_dependencies_after()
-        self._assert_codetf_output()
+        self._assert_codetf_output(codetf_schema)
         pathlib.Path(self.output_path).unlink(missing_ok=True)
         self._run_idempotency_chec(command)
Original file line number	Diff line number	Diff line change
`@@ -34,6 +34,7 @@ repos:`
`34`	`34`	`args: [--disable-error-code=has-type,--disable-error-code=import-not-found]`
`35`	`35`	`additional_dependencies:`
`36`	`36`	`[`
	`37`	`+ "types-jsonschema~=4.21.0",`
`37`	`38`	`"types-mock==5.0.*",`
`38`	`39`	`"types-PyYAML==6.0",`
`39`	`40`	`"types-toml~=0.10",`