diff --git a/scripts/cxx-api/parser/__main__.py b/scripts/cxx-api/parser/__main__.py
index 84dbb9a57cbd..00f5d219356b 100644
--- a/scripts/cxx-api/parser/__main__.py
+++ b/scripts/cxx-api/parser/__main__.py
@@ -193,22 +193,20 @@ def build_snapshots(
                     failed_views = ", ".join(name for name, _ in errors)
                     raise RuntimeError(f"Failed to generate snapshots: {failed_views}")
     else:
-        with tempfile.TemporaryDirectory(prefix="cxx-api-test-") as work_dir:
-            snapshot = build_snapshot_for_view(
-                api_view="Test",
-                react_native_dir=react_native_dir,
-                include_directories=[],
-                exclude_patterns=[],
-                definitions={},
-                output_dir=output_dir,
-                codegen_platform=None,
-                verbose=verbose,
-                input_filter=input_filter,
-                work_dir=work_dir,
-            )
-
-            if verbose:
-                print(snapshot)
+        snapshot = build_snapshot_for_view(
+            api_view="Test",
+            react_native_dir=react_native_dir,
+            include_directories=[],
+            exclude_patterns=[],
+            definitions={},
+            output_dir=output_dir,
+            codegen_platform=None,
+            verbose=verbose,
+            input_filter=input_filter,
+        )
+
+        if verbose:
+            print(snapshot)
 
 
 def get_default_snapshot_dir() -> str:
diff --git a/scripts/cxx-api/parser/builders.py b/scripts/cxx-api/parser/builders.py
index c595183d86c1..03e0d1bc6a3e 100644
--- a/scripts/cxx-api/parser/builders.py
+++ b/scripts/cxx-api/parser/builders.py
@@ -41,7 +41,12 @@
     resolve_linked_text_name,
     split_specialization,
 )
-from .utils.argument_parsing import _find_matching_angle, _split_arguments
+from .utils.argument_parsing import (
+    _find_matching_angle,
+    _split_arguments,
+    format_parsed_type,
+    parse_type_with_argstrings,
+)
 
 
 @dataclass
@@ -161,8 +166,14 @@ def get_base_classes(
 ) -> list:
     """
     Get the base classes of a compound object.
+
+    Deduplicates base classes by name. Doxygen can emit duplicate
+    ``basecompoundref`` entries when a class inherits constructors via
+    ``using Base::Base;`` — the using-declaration is incorrectly reported
+    as an additional base class reference.
     """
     base_classes = []
+    seen_names: set[str] = set()
     if compound_object.basecompoundref:
         for base in compound_object.basecompoundref:
             # base is a compoundRefType with:
@@ -179,6 +190,10 @@ def get_base_classes(
                 # Ignore private base classes
                 continue
 
+            if base_name in seen_names:
+                continue
+            seen_names.add(base_name)
+
             base_classes.append(
                 base_class(
                     base_name,
@@ -307,6 +322,16 @@ def get_doxygen_params(
             if param.get_type()
             else ""
         )
+
+        # Doxygen may incorrectly cross-reference parameter names inside
+        # inline function pointer types to member variables of the enclosing
+        # class, producing qualified paths like "const void*
+        # ns::Class::data" instead of "const void* data".  Re-parse the
+        # type through parse_type_with_argstrings which delegates to
+        # _parse_single_argument — that already strips "::" from names.
+        segments = parse_type_with_argstrings(param_type)
+        if len(segments) > 1:
+            param_type = format_parsed_type(segments)
         param_name = param.declname or param.defname or None
         param_default = (
             resolve_linked_text_name(param.defval)[0].strip() if param.defval else None
@@ -333,6 +358,8 @@ def get_doxygen_params(
                     + param_array
                 )
                 param_name = None
+            elif param_name:
+                param_name += param_array
             else:
                 param_type += param_array
 
@@ -350,6 +377,29 @@ def get_doxygen_params(
                     param_type[:insert_pos] + param_name + param_type[insert_pos:]
                 )
                 param_name = None
+        else:
+            # Doxygen bug: for pointer-to-member-function params with
+            # ref-qualifiers (& or &&), Doxygen incorrectly embeds the
+            # parameter name in the type string between cv-qualifiers
+            # and the ref-qualifier, and omits <declname> entirely:
+            #   <type>R(ns::*)() const asFoo &amp;</type>
+            # Detect this pattern and reconstruct the correct type:
+            #   R(ns::*asFoo)() const &
+            m = re.search(
+                r"(\([^)]*::\*\))"  # group 1: ptr-to-member declarator
+                r"(.+?)"  # group 2: param list + cv-qualifiers
+                r"\s+([a-zA-Z_]\w*)"  # group 3: misplaced identifier
+                r"\s*(&{1,2})\s*$",  # group 4: ref-qualifier
+                param_type,
+            )
+            if m:
+                param_type = (
+                    param_type[: m.end(1) - 1]  # up to ')' of (ns::*)
+                    + m.group(3)  # insert extracted name
+                    + param_type[m.end(1) - 1 : m.end(2)]  # ')' + params + cv-quals
+                    + " "
+                    + m.group(4)  # ref-qualifier
+                )
 
         qualifiers, core_type = extract_qualifiers(param_type)
         arguments.append((qualifiers, core_type, param_name, param_default))
diff --git a/scripts/cxx-api/parser/member/variable_member.py b/scripts/cxx-api/parser/member/variable_member.py
index 8c456f6c1e17..403af09eae45 100644
--- a/scripts/cxx-api/parser/member/variable_member.py
+++ b/scripts/cxx-api/parser/member/variable_member.py
@@ -111,6 +111,8 @@ def to_string(
                 result += f"{qualified_type} (*{name})({formatted_args})"
         else:
             result += f"{format_parsed_type(self._parsed_type)} {name}"
+            if self.argstring:
+                result += self.argstring
 
         if STORE_INITIALIZERS_IN_SNAPSHOT and self.value is not None:
             if self.is_brace_initializer:
diff --git a/scripts/cxx-api/parser/scope/base_scope_kind.py b/scripts/cxx-api/parser/scope/base_scope_kind.py
index 02aa9720687b..ae27e0a583c4 100644
--- a/scripts/cxx-api/parser/scope/base_scope_kind.py
+++ b/scripts/cxx-api/parser/scope/base_scope_kind.py
@@ -34,7 +34,12 @@ def _format_scope_body(self, scope: Scope, member_suffix: str = "") -> str:
         stringified_members = [
             member.to_string(2) + member_suffix for member in scope.get_members()
         ]
+
         stringified_members = natsorted(stringified_members)
+        # Deduplicate members that produce identical signatures (e.g.
+        # constructors inherited from multiple bases).
+        stringified_members = list(dict.fromkeys(stringified_members))
+
         result = "{"
         if stringified_members:
             result += "\n" + "\n".join(stringified_members)
diff --git a/scripts/cxx-api/parser/scope/namespace_scope_kind.py b/scripts/cxx-api/parser/scope/namespace_scope_kind.py
index 0d7444be5473..57aaae3df7a9 100644
--- a/scripts/cxx-api/parser/scope/namespace_scope_kind.py
+++ b/scripts/cxx-api/parser/scope/namespace_scope_kind.py
@@ -35,6 +35,8 @@ def to_string(self, scope: Scope) -> str:
         result = []
         for kind in MemberKind:
             sorted_group = natsorted(groups[kind])
+            # Deduplicate members with identical signatures.
+            sorted_group = list(dict.fromkeys(sorted_group))
             result.extend(sorted_group)
 
         return "\n".join(result)
diff --git a/scripts/cxx-api/parser/utils/argument_parsing.py b/scripts/cxx-api/parser/utils/argument_parsing.py
index e9bcfb010eeb..1449f46bac30 100644
--- a/scripts/cxx-api/parser/utils/argument_parsing.py
+++ b/scripts/cxx-api/parser/utils/argument_parsing.py
@@ -530,6 +530,14 @@ def parse_type_with_argstrings(
                 i = close + 1
                 continue
 
+            # Complex declarator starting with * or &, e.g. *(*fp)(int)
+            # in "int(*(*fp)(int))(double)".  Argument lists never start
+            # with pointer/reference characters.
+            if stripped and stripped[0] in ("*", "&"):
+                current_text.append(type_str[i : close + 1])
+                i = close + 1
+                continue
+
             # Try to parse as a function argument list
             args: list[Argument] = []
             if stripped:
diff --git a/scripts/cxx-api/tests/snapshots/should_deduplicate_base_classes_with_using_constructor/snapshot.api b/scripts/cxx-api/tests/snapshots/should_deduplicate_base_classes_with_using_constructor/snapshot.api
new file mode 100644
index 000000000000..068fda219250
--- /dev/null
+++ b/scripts/cxx-api/tests/snapshots/should_deduplicate_base_classes_with_using_constructor/snapshot.api
@@ -0,0 +1,12 @@
+struct test::Converter<int> : public test::ConverterBase<int> {
+  public void doSomething();
+}
+
+template <typename T>
+struct test::Converter {
+}
+
+template <typename T>
+struct test::ConverterBase {
+  public ConverterBase() = default;
+}
diff --git a/scripts/cxx-api/tests/snapshots/should_deduplicate_base_classes_with_using_constructor/test.h b/scripts/cxx-api/tests/snapshots/should_deduplicate_base_classes_with_using_constructor/test.h
new file mode 100644
index 000000000000..c0e82719c055
--- /dev/null
+++ b/scripts/cxx-api/tests/snapshots/should_deduplicate_base_classes_with_using_constructor/test.h
@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#pragma once
+
+namespace test {
+
+template <typename T>
+struct ConverterBase {
+  ConverterBase() = default;
+};
+
+template <typename T>
+struct Converter {};
+
+template <>
+struct Converter<int> : public ConverterBase<int> {
+  using ConverterBase<int>::ConverterBase;
+  void doSomething();
+};
+
+} // namespace test
diff --git a/scripts/cxx-api/tests/snapshots/should_handle_array_syntax_correctly/snapshot.api b/scripts/cxx-api/tests/snapshots/should_handle_array_syntax_correctly/snapshot.api
new file mode 100644
index 000000000000..d0f9dd2bf878
--- /dev/null
+++ b/scripts/cxx-api/tests/snapshots/should_handle_array_syntax_correctly/snapshot.api
@@ -0,0 +1,3 @@
+void test::arrayParam(const char name[]);
+void test::arrayParamSized(int values[10]);
+void test::arrayParamUnnamed(const char[]);
diff --git a/scripts/cxx-api/tests/snapshots/should_handle_array_syntax_correctly/test.h b/scripts/cxx-api/tests/snapshots/should_handle_array_syntax_correctly/test.h
new file mode 100644
index 000000000000..43240dd86f06
--- /dev/null
+++ b/scripts/cxx-api/tests/snapshots/should_handle_array_syntax_correctly/test.h
@@ -0,0 +1,16 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#pragma once
+
+namespace test {
+
+void arrayParam(const char name[]);
+void arrayParamSized(int values[10]);
+void arrayParamUnnamed(const char[]);
+
+} // namespace test
diff --git a/scripts/cxx-api/tests/snapshots/should_handle_array_variable/snapshot.api b/scripts/cxx-api/tests/snapshots/should_handle_array_variable/snapshot.api
new file mode 100644
index 000000000000..fd3f119e9564
--- /dev/null
+++ b/scripts/cxx-api/tests/snapshots/should_handle_array_variable/snapshot.api
@@ -0,0 +1 @@
+const char test::ViewComponentName[];
diff --git a/scripts/cxx-api/tests/snapshots/should_handle_array_variable/test.h b/scripts/cxx-api/tests/snapshots/should_handle_array_variable/test.h
new file mode 100644
index 000000000000..cf1624f6b919
--- /dev/null
+++ b/scripts/cxx-api/tests/snapshots/should_handle_array_variable/test.h
@@ -0,0 +1,14 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#pragma once
+
+namespace test {
+
+const char ViewComponentName[] = "View";
+
+} // namespace test
diff --git a/scripts/cxx-api/tests/snapshots/should_handle_multiple_inherited_constructors/snapshot.api b/scripts/cxx-api/tests/snapshots/should_handle_multiple_inherited_constructors/snapshot.api
new file mode 100644
index 000000000000..4b008a74d180
--- /dev/null
+++ b/scripts/cxx-api/tests/snapshots/should_handle_multiple_inherited_constructors/snapshot.api
@@ -0,0 +1,27 @@
+class test::BaseTextShadowNode : public test::ShadowNode {
+  public BaseTextShadowNode(const test::ShadowNode& source, const test::ShadowNode::Fragment& fragment);
+  public BaseTextShadowNode(const test::ShadowNode::Fragment& fragment, const test::ShadowNode::Shared& family, test::ShadowNode::Traits traits);
+}
+
+class test::ConcreteViewShadowNode : public test::ShadowNode {
+  public ConcreteViewShadowNode(const test::ShadowNode& source, const test::ShadowNode::Fragment& fragment);
+  public ConcreteViewShadowNode(const test::ShadowNode::Fragment& fragment, const test::ShadowNode::Shared& family, test::ShadowNode::Traits traits);
+}
+
+class test::ParagraphShadowNode : public test::ConcreteViewShadowNode, public test::BaseTextShadowNode {
+  public ParagraphShadowNode(const test::ShadowNode& source, const test::ShadowNode::Fragment& fragment);
+  public ParagraphShadowNode(const test::ShadowNode::Fragment& fragment, const test::ShadowNode::Shared& family, test::ShadowNode::Traits traits);
+}
+
+class test::ShadowNode {
+}
+
+enum test::ShadowNode::Traits {
+  None,
+}
+
+struct test::ShadowNode::Fragment {
+}
+
+struct test::ShadowNode::Shared {
+}
diff --git a/scripts/cxx-api/tests/snapshots/should_handle_multiple_inherited_constructors/test.h b/scripts/cxx-api/tests/snapshots/should_handle_multiple_inherited_constructors/test.h
new file mode 100644
index 000000000000..2d19852e49cc
--- /dev/null
+++ b/scripts/cxx-api/tests/snapshots/should_handle_multiple_inherited_constructors/test.h
@@ -0,0 +1,37 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#pragma once
+
+namespace test {
+
+class ShadowNode {
+ public:
+  struct Fragment {};
+  struct Shared {};
+  enum class Traits { None };
+};
+
+class ConcreteViewShadowNode : public ShadowNode {
+ public:
+  ConcreteViewShadowNode(const ShadowNode &source, const Fragment &fragment);
+  ConcreteViewShadowNode(const Fragment &fragment, const Shared &family, Traits traits);
+};
+
+class BaseTextShadowNode : public ShadowNode {
+ public:
+  BaseTextShadowNode(const ShadowNode &source, const Fragment &fragment);
+  BaseTextShadowNode(const Fragment &fragment, const Shared &family, Traits traits);
+};
+
+class ParagraphShadowNode : public ConcreteViewShadowNode, public BaseTextShadowNode {
+ public:
+  using BaseTextShadowNode::BaseTextShadowNode;
+  using ConcreteViewShadowNode::ConcreteViewShadowNode;
+};
+
+} // namespace test
diff --git a/scripts/cxx-api/tests/snapshots/should_handle_pointer_to_member_function_param_with_ref_qualifier/snapshot.api b/scripts/cxx-api/tests/snapshots/should_handle_pointer_to_member_function_param_with_ref_qualifier/snapshot.api
new file mode 100644
index 000000000000..1906db310c8f
--- /dev/null
+++ b/scripts/cxx-api/tests/snapshots/should_handle_pointer_to_member_function_param_with_ref_qualifier/snapshot.api
@@ -0,0 +1,8 @@
+struct folly::dynamic {
+}
+
+
+template <typename R, typename... T>
+R test::jsArg(const folly::dynamic& arg, R(folly::dynamic::*asFoo)() const &, const T &... desc);
+template <typename R, typename... T>
+R test::jsArg(const folly::dynamic& arg, R(folly::dynamic::*asFoo)() const, const T &... desc);
diff --git a/scripts/cxx-api/tests/snapshots/should_handle_pointer_to_member_function_param_with_ref_qualifier/test.h b/scripts/cxx-api/tests/snapshots/should_handle_pointer_to_member_function_param_with_ref_qualifier/test.h
new file mode 100644
index 000000000000..fcdb31e047a7
--- /dev/null
+++ b/scripts/cxx-api/tests/snapshots/should_handle_pointer_to_member_function_param_with_ref_qualifier/test.h
@@ -0,0 +1,23 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#pragma once
+
+namespace folly {
+
+struct dynamic {};
+
+} // namespace folly
+
+namespace test {
+
+template <typename R, typename... T>
+R jsArg(const folly::dynamic &arg, R (folly::dynamic::*asFoo)() const, const T &...desc);
+template <typename R, typename... T>
+R jsArg(const folly::dynamic &arg, R (folly::dynamic::*asFoo)() const &, const T &...desc);
+
+} // namespace test
diff --git a/scripts/cxx-api/tests/snapshots/should_not_qualify_function_pointer_param_args_to_outer_class/snapshot.api b/scripts/cxx-api/tests/snapshots/should_not_qualify_function_pointer_param_args_to_outer_class/snapshot.api
new file mode 100644
index 000000000000..85ed57b79540
--- /dev/null
+++ b/scripts/cxx-api/tests/snapshots/should_not_qualify_function_pointer_param_args_to_outer_class/snapshot.api
@@ -0,0 +1,4 @@
+class test::Runtime {
+  public int data;
+  public virtual void getStringData(void* ctx, void(*)(void* ctx, bool ascii, const void* data, size_t num) cb);
+}
diff --git a/scripts/cxx-api/tests/snapshots/should_not_qualify_function_pointer_param_args_to_outer_class/test.h b/scripts/cxx-api/tests/snapshots/should_not_qualify_function_pointer_param_args_to_outer_class/test.h
new file mode 100644
index 000000000000..0b0c7299f77f
--- /dev/null
+++ b/scripts/cxx-api/tests/snapshots/should_not_qualify_function_pointer_param_args_to_outer_class/test.h
@@ -0,0 +1,20 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#pragma once
+
+namespace test {
+
+class Runtime {
+ public:
+  int data;
+  virtual void getStringData(
+      void* ctx,
+      void (*cb)(void* ctx, bool ascii, const void* data, size_t num));
+};
+
+} // namespace test