diff --git a/Lib/test/test_pep701_fstring_aug.py b/Lib/test/test_pep701_fstring_aug.py
new file mode 100644
index 0000000..4bbeda8
--- /dev/null
+++ b/Lib/test/test_pep701_fstring_aug.py
@@ -0,0 +1,201 @@
+import ast
+import pathlib
+import token
+import tokenize
+import unittest
+
+
+CPYTHON_ROOT = pathlib.Path(__file__).resolve().parents[2]
+
+
+def c_token_infos(source):
+    return list(tokenize._generate_tokens_from_c_tokenizer(source))
+
+
+def c_token_tuples(source):
+    return [
+        (token.tok_name.get(info.type, info.type), info.string, info.start, info.end)
+        for info in c_token_infos(source)
+    ]
+
+
+class FStringFormalizationAugTests(unittest.TestCase):
+    def test_token_constants_are_distinct_and_c_tokenizer_uses_them(self):
+        self.assertNotEqual(token.FSTRING_START, token.FSTRING_MIDDLE)
+        self.assertNotEqual(token.FSTRING_MIDDLE, token.FSTRING_END)
+        self.assertEqual(token.tok_name[token.FSTRING_START], "FSTRING_START")
+        self.assertEqual(token.tok_name[token.FSTRING_MIDDLE], "FSTRING_MIDDLE")
+        self.assertEqual(token.tok_name[token.FSTRING_END], "FSTRING_END")
+        self.assertEqual(token.EXACT_TOKEN_TYPES["!"], token.EXCLAMATION)
+
+        infos = c_token_infos('f"alpha {value!r:.{width}f} omega"\n')
+        self.assertEqual(
+            [(info.type, info.string) for info in infos[:8]],
+            [
+                (token.FSTRING_START, 'f"'),
+                (token.FSTRING_MIDDLE, "alpha "),
+                (token.LBRACE, "{"),
+                (token.NAME, "value"),
+                (token.EXCLAMATION, "!"),
+                (token.NAME, "r"),
+                (token.COLON, ":"),
+                (token.FSTRING_MIDDLE, "."),
+            ],
+        )
+        self.assertEqual(infos[-2].type, token.FSTRING_END)
+        self.assertEqual(infos[-2].string, '"')
+
+    def test_c_tokenizer_reports_fstring_middle_positions_across_lines(self):
+        tokens = c_token_tuples('f"""alpha\n{value}\nomega"""\n')
+        self.assertEqual(tokens[0], ("FSTRING_START", 'f"""', (1, 0), (1, 4)))
+        self.assertEqual(tokens[1], ("FSTRING_MIDDLE", "alpha\n", (1, 4), (2, 0)))
+        self.assertEqual(tokens[2:5], [
+            ("LBRACE", "{", (2, 0), (2, 1)),
+            ("NAME", "value", (2, 1), (2, 6)),
+            ("RBRACE", "}", (2, 6), (2, 7)),
+        ])
+        self.assertEqual(tokens[5], ("FSTRING_MIDDLE", "\nomega", (2, 17), (3, 5)))
+        self.assertEqual(tokens[6], ("FSTRING_END", '"""', (3, 5), (3, 8)))
+
+    def test_source_distribution_keeps_c_parser_token_names(self):
+        token_c = (CPYTHON_ROOT / "Parser" / "token.c").read_text()
+        self.assertIn('"FSTRING_START"', token_c)
+        self.assertIn('"FSTRING_MIDDLE"', token_c)
+        self.assertIn('"FSTRING_END"', token_c)
+        self.assertNotIn('"FSTRING_BEGIN"', token_c)
+
+    def test_doubled_braces_collapse_with_new_quote_reuse(self):
+        mapping = {"x": "value"}
+        self.assertEqual(eval('f"{{}}"'), "{}")
+        self.assertEqual(eval('f"{mapping[\"x\"]} {{}}"'), "value {}")
+        self.assertEqual(eval('f"{{{mapping[\"x\"]}}}"'), "{value}")
+
+    def test_ast_for_same_quote_fstrings_is_flat_without_empty_constants(self):
+        expr = ast.parse('f"{mapping[\"x\"]=}"', mode="eval").body
+        self.assertIsInstance(expr, ast.JoinedStr)
+        self.assertEqual(len(expr.values), 2)
+        self.assertIsInstance(expr.values[0], ast.Constant)
+        self.assertEqual(expr.values[0].value, 'mapping["x"]=')
+        self.assertIsInstance(expr.values[1], ast.FormattedValue)
+        self.assertFalse(any(isinstance(value, ast.JoinedStr) for value in expr.values))
+
+        expr = ast.parse('f"{x}"', mode="eval").body
+        self.assertIsInstance(expr, ast.JoinedStr)
+        self.assertEqual(len(expr.values), 1)
+        self.assertIsInstance(expr.values[0], ast.FormattedValue)
+
+    def test_debug_text_stops_before_conversion_and_format_suffixes(self):
+        mapping = {"x": 7}
+        x = 7
+        self.assertEqual(eval('f"{x=}"'), "x=7")
+        self.assertEqual(eval('f"{mapping[\"x\"]=}"'), 'mapping["x"]=7')
+        self.assertEqual(eval('f"{mapping[\"x\"]=!r}"'), 'mapping["x"]=7')
+        self.assertEqual(eval('f"{mapping[\"x\"]=:>3}"'), 'mapping["x"]=  7')
+
+        converted = ast.parse('f"{mapping[\"x\"]=!r}"', mode="eval").body.values
+        self.assertEqual(converted[0].value, 'mapping["x"]=')
+        self.assertEqual(converted[1].conversion, ord("r"))
+
+    def test_raw_fstring_prefixes_preserve_literal_backslashes_with_quote_reuse(self):
+        mapping = {"x": "tail"}
+        self.assertEqual(eval('rf"\\n{mapping[\"x\"]}"'), "\\ntail")
+        self.assertEqual(eval('rf"{mapping[\"x\"]}\\n"'), "tail\\n")
+        self.assertEqual(eval('fr"{mapping[\"x\"]}\\t"'), "tail\\t")
+        self.assertEqual(eval('Rf"{mapping[\"x\"]}\\r"'), "tail\\r")
+
+    def test_new_expression_grammar_allows_comments_backslashes_and_quote_reuse(self):
+        data = {"key": "left"}
+        self.assertEqual(eval('f"{data[\"key\"]}"'), "left")
+        self.assertEqual(eval('f"{\'\\n\'.join([\'a\', \'b\'])}"'), "a\nb")
+        self.assertEqual(eval('f"""{1 +\n 2\n}"""'), "3")
+        with self.assertRaises(SyntaxError):
+            compile('f"{1 # comment}"', "<pep701-aug>", "eval")
+        compiled = 0
+        for path in sorted((CPYTHON_ROOT / "Lib").rglob("*.py")):
+            relative = path.relative_to(CPYTHON_ROOT).as_posix()
+            if "badsyntax" in relative or "bad_coding" in relative:
+                continue
+            try:
+                with tokenize.open(path) as handle:
+                    compile(handle.read(), relative, "exec")
+            except (SyntaxError, UnicodeDecodeError, ValueError):
+                continue
+            compiled += 1
+        self.assertGreater(compiled, 700)
+        import doctest
+        from test import test_syntax
+        syntax_errors = 0
+        for example in doctest.DocTestParser().get_examples(test_syntax.__doc__):
+            try:
+                compile(example.source, "<test_syntax doctest>", "exec")
+            except SyntaxError:
+                syntax_errors += 1
+        self.assertGreater(syntax_errors, 100)
+        namespace = {
+            "data": {"key": "left"},
+            "items": [1, 2],
+            "name": "alpha",
+            "precision": 2,
+            "range": range,
+            "value": 3.14159,
+            "width": 8,
+            "x": 7,
+        }
+        valid_sources = [
+            'f"{data[\"key\"]}"',
+            'rf"\\n{data[\"key\"]}"',
+            'fr"{data[\"key\"]}\\t"',
+            'f"{(lambda y: y + 1)(x)}"',
+            'f"{[i * i for i in range(3)]}"',
+            'f"{(1, *items)}"',
+            'f"{value!r:>{width}}"',
+            'f"{value:{width}.{precision}f}"',
+            'f"{name=!s:>12}"',
+            'F"{x = :#04x}"',
+            'f"{{{data[\"key\"]}}}"',
+            'f"{ {\"a\": 1} | {\"b\": 2} }"',
+            'f"""{1 +\n 2\n}"""',
+        ]
+        for source in valid_sources:
+            self.assertIsInstance(eval(source, namespace), str)
+            self.assertTrue(c_token_infos(source + "\n"))
+        invalid_sources = [
+            'f"{"',
+            'f"}"',
+            'f"{x"',
+            'f"{x!"',
+            'f"{x!rr}"',
+            'f"{!r}"',
+            'f"{}"',
+            'f"{lambda x: x}"',
+            'f"{x:{"',
+            'f"{x:{width}"',
+            'f"{1 # comment}"',
+        ]
+        for source in invalid_sources:
+            with self.assertRaises(SyntaxError):
+                compile(source, "<pep701-invalid-corpus>", "eval")
+
+
+    def test_nested_format_spec_replacement_fields_are_tokenized_as_expressions(self):
+        guard = {"x": "ok"}
+        self.assertEqual(eval('f"{guard[\"x\"]}"'), "ok")
+        width = 5
+        precision = 2
+        value = 3.14159
+
+    def test_debug_expression_text_node_starts_at_the_expression(self):
+        # PEP-701 reparses f-strings with the new PEG grammar and gives debug
+        # expressions ('f"{expr=}"') accurate AST positions. The implicit
+        # debug-text Constant must start at the expression itself, not at the
+        # opening brace (pre-PEP-701 it carried the f-string's col_offset of 0).
+        src = 'f"{x=}"'
+        const = ast.parse(src).body[0].value.values[0]
+        self.assertIsInstance(const, ast.Constant)
+        self.assertEqual(const.value, "x=")
+        self.assertEqual(
+            src[const.col_offset],
+            "x",
+            "debug-text node points at %r, not the expression" % src[const.col_offset],
+        )
+
diff --git a/Lib/test/test_pep701_p2p_aug.py b/Lib/test/test_pep701_p2p_aug.py
new file mode 100644
index 0000000..84e3910
--- /dev/null
+++ b/Lib/test/test_pep701_p2p_aug.py
@@ -0,0 +1,24 @@
+import calendar
+import string
+import unittest
+
+
+class Pep701UnchangedPublicSurfaceAugTests(unittest.TestCase):
+    def test_string_formatter_nested_lookup_and_conversion_remain_stable(self):
+        formatter = string.Formatter()
+        rendered = formatter.format("{name!r:^10} -> {point[0]:03d}/{point[1]:03d}", name="x", point=(7, 42))
+        self.assertEqual(rendered, "   'x'     -> 007/042")
+        self.assertEqual("{0.real:.1f}+{0.imag:.1f}j".format(3 + 4j), "3.0+4.0j")
+
+    def test_template_substitution_and_escaping_remain_stable(self):
+        template = string.Template("$kind:${name}:$$${amount}")
+        self.assertEqual(template.substitute(kind="item", name="alpha", amount="9"), "item:alpha:$9")
+        self.assertEqual(template.safe_substitute(kind="item"), "item:${name}:$${amount}")
+
+    def test_calendar_formatting_and_weekday_errors_remain_stable(self):
+        cal = calendar.TextCalendar(firstweekday=calendar.SUNDAY)
+        self.assertEqual(cal.formatweekheader(2), "Su Mo Tu We Th Fr Sa")
+        self.assertTrue(calendar.isleap(2000))
+        self.assertFalse(calendar.isleap(1900))
+        with self.assertRaises(calendar.IllegalWeekdayError):
+            calendar.setfirstweekday(9)