feat/stubgen: add preliminary $Cxx.name support

LICENSE

@@ -0,0 +1,7 @@
+Copyright 2026 NCBM
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

README.md

@@ -17,7 +17,7 @@ Generates `.pyi` type stub files for Cap'n Proto schemas, providing IDE autocomp
 | Arch Linux | `sudo pacman -S capnproto` |
 | Ubuntu/Debian | `sudo apt install capnproto` |
 | macOS | `brew install capnp` |
-| Windows | Download from [capnproto.org](https://capnproto.org) |
+| Windows | Download from [capnproto.org](https://capnproto.org/install.html) |
 
 ## Installation
 
@@ -33,67 +33,61 @@ capnp compile -opy myschema.capnp
 
 This generates `myschema_capnp.pyi` — a Python type stub file that type checkers can use. Runtime import (`import myschema_capnp`) is handled automatically by pycapnp's import hook.
 
-### Generated output
+### Multi-file projects
 
-For a schema like:
+```bash
+capnp compile -opy --src-prefix=. src/schema.capnp
+```
+
+Cross-file type references automatically produce relative imports in the generated stubs.
+
+## Example
+
+Input (`addressbook.capnp`):
 ```capnp
 struct Person {
   name @0 :Text;
   age  @1 :Int32;
-}
+  phones @2 :List(PhoneNumber);
 
-enum Gender { male @0; female @1; }
+  struct PhoneNumber {
+    number @0 :Text;
+    type @1 :Type;
+    enum Type { mobile @0; home @1; work @2; }
+  }
+}
 ```
 
-`myschema_capnp.pyi`:
+Output (`addressbook_capnp.pyi`):
 ```python
-"""Auto-generated type stub for myschema.capnp"""
+"""Auto-generated type stub for addressbook.capnp"""
 from __future__ import annotations
 from collections.abc import Iterator, Sequence
 from contextlib import contextmanager
 from typing import IO, Literal
 
-Gender = Literal["male", "female"]
-
 class Person:
     name: str
     age: int
+    phones: Sequence[Person.PhoneNumber | Person.PhoneNumberBuilder | Person.PhoneNumberReader]
+
+    class PhoneNumber:
+        Type = Literal["mobile", "home", "work"]
+        type: Type
+        number: str
+        ...
 
     @staticmethod
     def new_message(**kwargs) -> PersonBuilder: ...
-    @staticmethod
-    @contextmanager
-    def from_bytes(data: bytes, ...) -> Iterator[PersonReader]: ...
-    @staticmethod
-    def from_bytes_packed(data: bytes, ...) -> PersonReader: ...
     def to_dict(self) -> dict: ...
 
 class PersonReader(Person):
     def as_builder(self) -> PersonBuilder: ...
 
 class PersonBuilder(Person):
-    @staticmethod
-    def from_dict(dictionary: dict) -> PersonBuilder: ...
-    def copy(self) -> PersonBuilder: ...
     def to_bytes(self) -> bytes: ...
-    def to_bytes_packed(self) -> bytes: ...
-    def to_segments(self) -> list[bytes]: ...
     def as_reader(self) -> PersonReader: ...
-    @staticmethod
+    ...
-    def write(file: IO[bytes]): ...
-    @staticmethod
-    def write_packed(file: IO[bytes]): ...
-```
-
-## Development
-
-Uses [PDM](https://pdm-project.org/) for project management.
-
-```bash
-git clone https://github.com/capnproto/pycapnp  # or your fork
-cd capnp-py
-pdm install      # installs dependencies + dev tools
-pdm run pytest   # run tests
 ```
 
 ## Supported Features
@@ -101,14 +95,28 @@ pdm run pytest   # run tests
 | Feature | Status |
 |---------|--------|
 | Structs (Reader / Builder classes) | ✅ |
-| Enums (Literal aliases) | ✅ |
+| Enums (`Literal[...]` aliases) | ✅ |
 | Nested types | ✅ |
-| Lists (Sequence[T]) | ✅ |
+| Lists (`Sequence[T]`) | ✅ |
-| Unions (which/init) | ✅ |
+| Unions (`which()` / `@overload init()`) | ✅ |
+| Groups | ✅ |
 | Self-referencing structs | ✅ |
-| Interfaces (RPC) | ⏳ Phase 3 |
+| Constants (primitives, enums) | ✅ |
-| Constants | ⏳ Phase 2 |
+| Generics (`TypeVar`, `Generic[T]`, brand resolution) | ✅ |
-| Generics | ⏳ Phase 2 |
+| Interfaces (RPC: Client / Server classes) | ✅ |
+| Cross-file imports (relative `.` imports) | ✅ |
+| Annotations (`$Cxx.name`, etc.) | ⏳ |
+
+## Development
+
+Uses [PDM](https://pdm-project.org/) for project management.
+
+```bash
+git clone https://github.com/NCBM/capnpc-py
+cd capnp-py
+pdm install      # installs dependencies + dev tools
+pdm run pytest   # run tests
+```
 
 ## License
 

pdm.lock

@@ -5,10 +5,24 @@
 groups = ["default", "dev"]
 strategy = ["inherit_metadata"]
 lock_version = "4.5.0"
-content_hash = "sha256:b8c78f3679a91711144cac4d1d558cad80470ddb4c350d7409f419b3db462e22"
+content_hash = "sha256:9760696434f3c5496929539bd0d968d60732150e34e59713be5e2e8d9b1be47c"
 
 [[metadata.targets]]
-requires_python = ">=3.10"
+requires_python = "~=3.10"
+
+[[package]]
+name = "basedpyright"
+version = "1.39.9"
+requires_python = ">=3.8"
+summary = "static type checking for Python (but based)"
+groups = ["dev"]
+dependencies = [
+    "nodejs-wheel-binaries>=20.13.1",
+]
+files = [
+    {file = "basedpyright-1.39.9-py3-none-any.whl", hash = "sha256:6b0837b9eba972c71895167ab9b127e6afdbc17abc92312e3f8d15ca82a5611c"},
+    {file = "basedpyright-1.39.9.tar.gz", hash = "sha256:32cbea5fc8273e89df3db20daea56cb7286e419ccdfdc479c64759d2dc071901"},
+]
 
 [[package]]
 name = "colorama"
@@ -149,6 +163,27 @@ files = [
     {file = "markupsafe-3.0.3.tar.gz", hash = "sha256:722695808f4b6457b320fdc131280796bdceb04ab50fe1795cd540799ebe1698"},
 ]
 
+[[package]]
+name = "nodejs-wheel-binaries"
+version = "24.16.0"
+requires_python = ">=3.7"
+summary = "unoffical Node.js package"
+groups = ["dev"]
+dependencies = [
+    "typing-extensions; python_version < \"3.8\"",
+]
+files = [
+    {file = "nodejs_wheel_binaries-24.16.0-py2.py3-none-macosx_13_0_arm64.whl", hash = "sha256:d9f8f677dcf30e37ac244f07869726abe043f01eb0f45722b1df31cc2af7093c"},
+    {file = "nodejs_wheel_binaries-24.16.0-py2.py3-none-macosx_13_0_x86_64.whl", hash = "sha256:3d0370fe7120ce9697a4f60d40480d2bd8808d9f30131458d5afc0040d4e5a51"},
+    {file = "nodejs_wheel_binaries-24.16.0-py2.py3-none-manylinux_2_28_aarch64.whl", hash = "sha256:85dc92bbb79c851569c5925dcc2a4c915a034efab375f99e4e7e6bbe9cca8342"},
+    {file = "nodejs_wheel_binaries-24.16.0-py2.py3-none-manylinux_2_28_x86_64.whl", hash = "sha256:2f3036292811514ba847b3708492644764f88a833ac425c5f55007014308ddfd"},
+    {file = "nodejs_wheel_binaries-24.16.0-py2.py3-none-musllinux_1_2_aarch64.whl", hash = "sha256:db8a8a76ebd2b28ecbfc9ad464baa3707241b9e050a30e2efdf6f60c0f886502"},
+    {file = "nodejs_wheel_binaries-24.16.0-py2.py3-none-musllinux_1_2_x86_64.whl", hash = "sha256:f1a3d8f7b4491cbbd023ba3fc4e901fcca2d9fb80d57f24ba3890de8b1dbac03"},
+    {file = "nodejs_wheel_binaries-24.16.0-py2.py3-none-win_amd64.whl", hash = "sha256:bb136be9944f0662dcf1120f45193a6b75b13fac378971a95cc42c9f879a81aa"},
+    {file = "nodejs_wheel_binaries-24.16.0-py2.py3-none-win_arm64.whl", hash = "sha256:8308940b5edd0a50dc5267ea36ba21c9f668e83fe0d9f293937174d3a7e31c36"},
+    {file = "nodejs_wheel_binaries-24.16.0.tar.gz", hash = "sha256:c973cb69dc5fd16e6f6dc6e579e2c3d5534e2a1f57619dddf5ba070efa7dde37"},
+]
+
 [[package]]
 name = "packaging"
 version = "26.2"

pyproject.toml

@@ -20,6 +20,7 @@ capnpc-py = "capnp_stubgen.plugin:main"
 [dependency-groups]
 dev = [
     "pytest>=8",
+    "basedpyright>=1.39.9",
 ]
 
 [build-system]
@@ -31,6 +32,18 @@ distribution = true
 
 [tool.pytest.ini_options]
 testpaths = ["tests"]
+markers = ["slow: slow tests (dummy.capnp, generics, interface)"]
 
 [tool.setuptools.packages.find]
 where = ["src"]
+
+[tool.basedpyright]
+typeCheckingMode = "recommended"
+allowedUntypedLibraries = ["pycapnp"]
+reportImportCycles = "hint"
+
+# Downgraded to hint for capnp to_dict() dynamic data patterns
+reportUnknownVariableType = "hint"
+reportUnknownMemberType = "hint"
+reportAny = "hint"
+reportExplicitAny = "hint"

src/capnp_stubgen/emitter.py

@@ -25,7 +25,7 @@ class Emitter:
     """
 
     def __init__(self, source_filename: str = "") -> None:
-        self._source_filename = source_filename
+        self._source_filename: str = source_filename
         self._header_lines: list[str] = []
         self._body_lines: list[str] = []
         self._indent_level: int = 0

src/capnp_stubgen/gen_const.py

@@ -11,7 +11,7 @@ import math
 from typing import TYPE_CHECKING
 
 from .type_resolver import resolve_type
-from .utils import type_id_to_int
+from .utils import NodeDict, type_id_to_int
 
 if TYPE_CHECKING:
     from .emitter import Emitter
@@ -31,10 +31,10 @@ def generate_const(
         globalText: str = "foobar"
         voidConst: None = None
     """
-    node: dict = type_info.node
+    node: NodeDict = type_info.node
-    const_body: dict = node.get("const", {})
+    const_body: NodeDict = node.get("const", {})
-    type_dict: dict = const_body.get("type", {})
+    type_dict: NodeDict = const_body.get("type", {})
-    value_dict: dict = const_body.get("value", {})
+    value_dict: NodeDict = const_body.get("value", {})
 
     python_type_str = _resolve_const_type(type_dict, registry)
     python_value_str = _render_const_value(value_dict, type_dict, registry)
@@ -49,7 +49,7 @@ def generate_const(
 # ── type resolution ────────────────────────────────────────────────────────
 
 
-def _resolve_const_type(type_dict: dict, registry: TypeRegistry) -> str:
+def _resolve_const_type(type_dict: NodeDict, registry: TypeRegistry) -> str:
     """Resolve a constant's type to a Python type annotation string."""
     # Handle enum references
     if "enum" in type_dict:
@@ -83,8 +83,8 @@ def _resolve_const_type(type_dict: dict, registry: TypeRegistry) -> str:
 
 
 def _render_const_value(
-    value_dict: dict,
+    value_dict: NodeDict,
-    type_dict: dict,
+    type_dict: NodeDict,
     registry: TypeRegistry,
 ) -> str:
     """Render a constant's value as a Python literal."""
@@ -131,7 +131,7 @@ def _render_const_value(
 
 
 def _resolve_enum_value(
-    type_dict: dict,
+    type_dict: NodeDict,
     ordinal: int,
     registry: TypeRegistry,
 ) -> str:
@@ -144,7 +144,7 @@ def _resolve_enum_value(
     if info is None:
         return repr(ordinal)
 
-    enum_node: dict = info.node
+    enum_node: NodeDict = info.node
     for e in enum_node.get("enum", {}).get("enumerants", []):
         if e.get("ordinal") == ordinal or e.get("codeOrder") == ordinal:
             return f'"{e["name"]}"'

src/capnp_stubgen/gen_enum.py

@@ -7,6 +7,8 @@ from __future__ import annotations
 
 from typing import TYPE_CHECKING
 
+from .utils import NodeDict, get_cxx_name
+
 if TYPE_CHECKING:
     from .emitter import Emitter
     from .models import TypeInfo
@@ -22,14 +24,17 @@ def generate_enum(
 
         Gender = Literal["male", "female", "other"]
     """
-    node: dict = type_info.node
+    node: NodeDict = type_info.node
-    enum_body: dict = node.get("enum", {})
+    enum_body: NodeDict = node.get("enum", {})
-    enumerants: list[dict] = enum_body.get("enumerants", [])
+    enumerants: list[NodeDict] = enum_body.get("enumerants", [])
 
     literals: list[str] = []
     for e in enumerants:
-        literals.append(f'"{e["name"]}"')
+        literals.append(f'"{get_cxx_name(e) or e["name"]}"')
 
     emitter.add_typing_import("Literal")
-    emitter.add_type_alias(type_info.name, f"Literal[{', '.join(literals)}]")
+    line = f"Literal[{', '.join(literals)}]"
-    emitter.add_blank_line()
+    if type_info.parent_type_id is not None and type_info.scoped_name.count(".") > 0:
+        # Inside a struct/interface class — type alias needs annotation
+        line += "  # pyright: ignore[reportUnannotatedClassAttribute]"
+    emitter.add_type_alias(type_info.name, line)

src/capnp_stubgen/gen_generic.py

@@ -8,6 +8,8 @@ from __future__ import annotations
 
 from typing import TYPE_CHECKING
 
+from .utils import NodeDict
+
 if TYPE_CHECKING:
     from .emitter import Emitter
     from .models import TypeInfo, TypeRegistry
@@ -21,7 +23,7 @@ def generate_type_vars(
 
     Returns the list of TypeVar names for use in the ``Generic[...]`` base.
     """
-    node: dict = type_info.node
+    node: NodeDict = type_info.node
     params = node.get("parameters", [])
 
     tv_names: list[str] = []
@@ -38,7 +40,7 @@ def generate_type_vars(
 
 
 def resolve_brand(
-    brand_dict: dict,
+    brand_dict: NodeDict,
     registry: TypeRegistry,
 ) -> list[str] | None:
     """Resolve brand bindings to Python type strings.

src/capnp_stubgen/gen_interface.py

@@ -14,7 +14,7 @@ from __future__ import annotations
 
 from typing import TYPE_CHECKING
 
-from .utils import type_id_to_int
+from .utils import NodeDict, type_id_to_int
 
 if TYPE_CHECKING:
     from .emitter import Emitter
@@ -29,11 +29,11 @@ def fixup_interface_methods(registry: TypeRegistry) -> None:
     the interface by setting their ``parent_type_id`` and adjusting their
     ``scoped_name``.
     """
-    for type_info in list(registry._types.values()):
+    for type_info in registry.all_types():
         if type_info.kind != "interface":
             continue
 
-        node: dict = type_info.node
+        node: NodeDict = type_info.node
         for method in node.get("interface", {}).get("methods", []):
             mname = method["name"]
             param_id = type_id_to_int(method["paramStructType"])
@@ -43,13 +43,11 @@ def fixup_interface_methods(registry: TypeRegistry) -> None:
                 sinfo = registry.get(sid)
                 if sinfo is not None:
                     sinfo.parent_type_id = type_info.type_id
+                    dname = f"{mname}{suffix}"
                     sinfo.scoped_name = (
-                        f"{type_info.scoped_name}.{mname}.{suffix}"
+                        f"{type_info.scoped_name}.{dname}"
-                    )
-                    # Override name for class nesting
-                    sinfo._display_name = (
-                        f"{mname}{suffix}"
                     )
+                    sinfo.display_name = dname
 
 
 def generate_interface(
@@ -58,13 +56,13 @@ def generate_interface(
     registry: TypeRegistry,
 ) -> None:
     """Generate interface classes for a Cap'n Proto interface."""
-    node: dict = type_info.node
+    node: NodeDict = type_info.node
-    iface_body: dict = node.get("interface", {})
+    iface_body: NodeDict = node.get("interface", {})
     name = type_info.name
-    methods: list[dict] = iface_body.get("methods", [])
+    methods: list[NodeDict] = iface_body.get("methods", [])
 
     # Build method info list
-    method_infos: list[dict] = []
+    method_infos: list[NodeDict] = []
     for method in methods:
         param_id = type_id_to_int(method["paramStructType"])
         result_id = type_id_to_int(method["resultStructType"])
@@ -106,7 +104,7 @@ def generate_interface(
     emitter.begin_class(client_name, bases=[name])
     emitter.add_method(
         "_new_client",
-        params=["self", "server"],
+        params=["self", f"server: {name}Server"],
         return_type=client_name,
     )
     emitter.end_class()
@@ -121,30 +119,30 @@ def generate_interface(
 
         emitter.add_method(
             mname,
-            params=["self", f"_params: {param_type}", "_context"],
+            params=["self", f"_params: {param_type}", "_context: object"],
-            return_type=None,
+            return_type="None",
         )
 
     emitter.end_class()
 
 
 def _method_param_type(
-    mi: dict,
+    mi: NodeDict,
     iface_name: str,
 ) -> str:
     """Get the type string for a method's params."""
     param_info = mi.get("param_info")
     if param_info is not None:
-        return f"{iface_name}.{param_info._display_name or param_info.name}Reader"
+        return f"{iface_name}.{param_info.display_name or param_info.name}Reader"
     return f"{iface_name}.{mi['name']}ParamsReader"
 
 
 def _method_result_type(
-    mi: dict,
+    mi: NodeDict,
     iface_name: str,
 ) -> str:
     """Get the type string for a method's results."""
     result_info = mi.get("result_info")
     if result_info is not None:
-        return f"{iface_name}.{result_info._display_name or result_info.name}Reader"
+        return f"{iface_name}.{result_info.display_name or result_info.name}Reader"
     return f"{iface_name}.{mi['name']}ResultsReader"

src/capnp_stubgen/gen_struct.py

@@ -16,7 +16,7 @@ from .gen_const import generate_const
 from .gen_enum import generate_enum
 from .gen_generic import generate_type_vars
 from .type_resolver import resolve_type
-from .utils import type_id_to_int
+from .utils import NodeDict, get_cxx_name, type_id_to_int
 
 if TYPE_CHECKING:
     from .emitter import Emitter
@@ -32,9 +32,9 @@ def generate_struct(
     registry: TypeRegistry,
 ) -> None:
     """Generate the class triple for a Cap'n Proto struct."""
-    node: dict = type_info.node
+    node: NodeDict = type_info.node
-    struct_body: dict = node.get("struct", {})
+    struct_body: NodeDict = node.get("struct", {})
-    name = type_info._display_name or type_info.name
+    name = type_info.display_name or type_info.name
 
     discriminant_count = struct_body.get("discriminantCount", 0)
     nested_types = registry.get_children(type_info.type_id)
@@ -44,7 +44,7 @@ def generate_struct(
 
     # ── collect fields ─────────────────────────────────────────────────
     for field in struct_body.get("fields", []):
-        field_name: str = field["name"]
+        field_name: str = get_cxx_name(field) or field["name"]
         disc_value: int = field.get("discriminantValue", _NO_DISCRIMINANT)
 
         if "slot" in field:
@@ -60,14 +60,9 @@ def generate_struct(
                 non_union_fields.append((field_name, field_type_str))
 
         elif "group" in field:
-            group_type_id = type_id_to_int(field["group"]["typeId"])
+            # Groups become inner classes — skip field annotation
-            group_info = registry.get(group_type_id)
+            # (the group class serves as both type and accessor)
-            if group_info is not None:
+            pass
-                type_str = group_info.scoped_name
-                if disc_value != _NO_DISCRIMINANT:
-                    union_fields.append((field_name, type_str))
-                else:
-                    non_union_fields.append((field_name, type_str))
 
     # ── class: main type ───────────────────────────────────────────────
     # Generic type: generate TypeVars and Generic[T] base
@@ -76,61 +71,73 @@ def generate_struct(
         tv_names = generate_type_vars(emitter, type_info)
         emitter.add_typing_import("Generic")
 
+    # Simple names for class definitions (no prefix)
+    reader_name = name + "Reader"
+    builder_name = name + "Builder"
+    # Fully-qualified names for type references (with parent scope)
+    parent_prefix = ""
+    if "." in type_info.scoped_name:
+        parent_prefix = type_info.scoped_name.rsplit(".", 1)[0] + "."
+    qreader = parent_prefix + reader_name
+    qbuilder = parent_prefix + builder_name
+    qualified_name = parent_prefix + name
+    tv_params = ", ".join(tv_names)
     if tv_names:
-        emitter.begin_class(name, bases=[f"Generic[{', '.join(tv_names)}]"])
+        qreader += f"[{tv_params}]"
+        qbuilder += f"[{tv_params}]"
+        qualified_name += f"[{tv_params}]"
+    base_name = qualified_name
+
+    if tv_names:
+        emitter.begin_class(name, bases=[f"Generic[{tv_params}]"])
     else:
         emitter.begin_class(name)
 
-    for field_name, type_str in non_union_fields:
+    # Nested structs first (so forward refs within class body resolve)
-        emitter.add_field(field_name, type_str)
-
-    if discriminant_count > 0 and union_fields:
-        _generate_union_methods(emitter, union_fields)
-
-    # Nested enums first
-    for nt in nested_types:
-        if nt.kind == "enum":
-            emitter.add_blank_line()
-            generate_enum(emitter, nt)
-
-    # Nested constants (class-level)
-    for nt in nested_types:
-        if nt.kind == "const":
-            emitter.add_blank_line()
-            generate_const(emitter, nt, registry)
-
-    # Factory methods + to_dict
-    _generate_factory_methods(emitter, name)
-    emitter.add_method("to_dict", params=["self"], return_type="dict")
-
-    # Nested structs
     for nt in nested_types:
         if nt.kind == "struct":
             emitter.add_blank_line()
             generate_struct(emitter, nt, registry)
 
+    # Nested enums
+    for nt in nested_types:
+        if nt.kind == "enum":
+            emitter.add_blank_line()
+            generate_enum(emitter, nt)
+
+    # Nested constants
+    for nt in nested_types:
+        if nt.kind == "const":
+            emitter.add_blank_line()
+            generate_const(emitter, nt, registry)
+
+    for field_name, type_str in non_union_fields:
+        default = "None" if type_str == "None" else None
+        emitter.add_field(field_name, type_str, default=default)
+
+    if discriminant_count > 0 and union_fields:
+        _generate_union_methods(emitter, union_fields)
+
+    # Factory methods + to_dict
+    _generate_factory_methods(emitter, qbuilder, qreader, non_union_fields)
+    emitter.add_typing_import("Any")
+    emitter.add_method("to_dict", params=["self"], return_type="dict[str, Any]")
+
     emitter.end_class()
 
     # ── class: Reader ──────────────────────────────────────────────────
-    reader_name = name + "Reader"
+    emitter.begin_class(reader_name, bases=[base_name])
-    emitter.begin_class(reader_name, bases=[name])
-
-    for field_name, type_str in non_union_fields:
-        emitter.add_field(field_name, _to_reader_type(type_str))
 
     emitter.add_method(
-        "as_builder", params=["self"], return_type=name + "Builder",
+        "as_builder", params=["self"], return_type=qbuilder,
     )
     emitter.end_class()
 
     # ── class: Builder ─────────────────────────────────────────────────
-    builder_name = name + "Builder"
+    emitter.begin_class(builder_name, bases=[base_name])
-    emitter.begin_class(builder_name, bases=[name])
 
-    for field_name, type_str in non_union_fields:
+    _generate_builder_methods(emitter, qbuilder, qreader)
-        emitter.add_field(field_name, _to_builder_type(type_str))
 
-    _generate_builder_methods(emitter, name)
     emitter.end_class()
 
 
@@ -138,7 +145,7 @@ def generate_struct(
 
 
 def _resolve_field_type(
-    type_dict: dict, registry: TypeRegistry, emitter: Emitter,
+    type_dict: NodeDict, registry: TypeRegistry, emitter: Emitter,
 ) -> str | None:
     """Resolve a field's type to a Python type annotation string."""
     which = _type_which(type_dict)
@@ -148,7 +155,10 @@ def _resolve_field_type(
         py_type = resolve_type(type_dict, registry)
         if py_type is not None:
             q = py_type.render()
-            return f"{q} | {q}Builder | {q}Reader"
+            if py_type.params:
+                # Branded types (e.g. Holder[str]) — no separate Builder/Reader
+                return q
+            return q
         return "Any"
 
     if which == "list":
@@ -159,7 +169,7 @@ def _resolve_field_type(
 
 
 def _resolve_list_field_type(
-    list_dict: dict, registry: TypeRegistry, emitter: Emitter,
+    list_dict: NodeDict, registry: TypeRegistry, emitter: Emitter,
 ) -> str:
     """Resolve a ``List(T)`` field type."""
     emitter.add_typing_import("Sequence", "collections.abc")
@@ -173,11 +183,9 @@ def _resolve_list_field_type(
     inner_which = _type_which(inner)
 
     if inner_which == "struct":
-        type_id = type_id_to_int(inner["struct"]["typeId"])
+        pt = resolve_type(inner, registry)
-        info = registry.get(type_id)
+        if pt is not None:
-        if info is not None:
+            el_type = pt.render()
-            q = info.scoped_name
-            el_type = f"{q} | {q}Builder | {q}Reader"
         else:
             el_type = "Any"
     elif inner_which == "enum":
@@ -195,7 +203,7 @@ def _resolve_list_field_type(
     return result
 
 
-def _type_which(type_dict: dict) -> str | None:
+def _type_which(type_dict: NodeDict) -> str | None:
     """Return the union variant key for a type dict."""
     for key in ("void", "bool", "int8", "int16", "int32", "int64",
                 "uint8", "uint16", "uint32", "uint64",
@@ -206,33 +214,6 @@ def _type_which(type_dict: dict) -> str | None:
     return None
 
 
-# ── Reader/Builder type transformation ─────────────────────────────────────
-
-
-def _to_reader_type(type_str: str) -> str:
-    return _transform_variant(type_str, "Reader")
-
-
-def _to_builder_type(type_str: str) -> str:
-    return _transform_variant(type_str, "Builder")
-
-
-def _transform_variant(type_str: str, variant: str) -> str:
-    if " | " not in type_str:
-        return type_str
-
-    if type_str.startswith("Sequence["):
-        prefix = "Sequence["
-        inner = type_str[len(prefix):-1]
-        return f"Sequence[{_transform_variant(inner, variant)}]"
-
-    parts = [p.strip() for p in type_str.split("|")]
-    for p in parts:
-        if p.endswith(variant):
-            return p
-    return parts[0]
-
-
 # ── method generation ──────────────────────────────────────────────────────
 
 
@@ -240,7 +221,6 @@ def _generate_union_methods(
     emitter: Emitter, union_fields: list[tuple[str, str]],
 ) -> None:
     emitter.add_typing_import("Literal")
-    emitter.add_typing_import("overload")
 
     literal_values = ", ".join(f'"{name}"' for name, _ in union_fields)
     emitter.add_method(
@@ -248,7 +228,11 @@ def _generate_union_methods(
         return_type=f"Literal[{literal_values}]",
     )
 
+    if len(union_fields) > 1:
+        emitter.add_typing_import("overload")
+
     for field_name, type_str in union_fields:
+        if len(union_fields) > 1:
             emitter.add_decorator("overload")
         emitter.add_method(
             "init",
@@ -257,16 +241,24 @@ def _generate_union_methods(
         )
 
 
-def _generate_factory_methods(emitter: Emitter, name: str) -> None:
+def _generate_factory_methods(
-    emitter.add_typing_import("Iterator", "collections.abc")
+    emitter: Emitter,
+    qbuilder: str,
+    qreader: str,
+    non_union_fields: list[tuple[str, str]],
+) -> None:
+    emitter.add_typing_import("Generator", "collections.abc")
     emitter.add_typing_import("contextmanager", "contextlib")
 
-    reader_name = name + "Reader"
-    builder_name = name + "Builder"
-
     emitter.add_blank_line()
+    # Typed kwargs: name: str = ..., age: int = ...
+    if non_union_fields:
+        kwargs = [f"{name}: {typ} = ..." for name, typ in non_union_fields]
+    else:
+        emitter.add_typing_import("Any")
+        kwargs = ["**kwargs: Any"]
     emitter.add_static_method(
-        "new_message", params=["**kwargs"], return_type=builder_name,
+        "new_message", params=kwargs, return_type=qbuilder,
     )
     emitter.add_blank_line()
 
@@ -279,7 +271,7 @@ def _generate_factory_methods(emitter: Emitter, name: str) -> None:
             "traversal_limit_in_words: int | None = ...",
             "nesting_limit: int | None = ...",
         ],
-        return_type=f"Iterator[{reader_name}]",
+        return_type=f"Generator[{qreader}, None, None]",
     )
     emitter.add_blank_line()
 
@@ -290,20 +282,19 @@ def _generate_factory_methods(emitter: Emitter, name: str) -> None:
             "traversal_limit_in_words: int | None = ...",
             "nesting_limit: int | None = ...",
         ],
-        return_type=reader_name,
+        return_type=qreader,
     )
 
 
-def _generate_builder_methods(emitter: Emitter, name: str) -> None:
+def _generate_builder_methods(
-    reader_name = name + "Reader"
+    emitter: Emitter, qbuilder: str, qreader: str
-    builder_name = name + "Builder"
+) -> None:
-
     emitter.add_blank_line()
     emitter.add_static_method(
-        "from_dict", params=["dictionary: dict"], return_type=builder_name,
+        "from_dict", params=["dictionary: dict[str, Any]"], return_type=qbuilder,
     )
     emitter.add_blank_line()
-    emitter.add_method("copy", params=["self"], return_type=builder_name)
+    emitter.add_method("copy", params=["self"], return_type=qbuilder)
     emitter.add_blank_line()
     emitter.add_method("to_bytes", params=["self"], return_type="bytes")
     emitter.add_blank_line()
@@ -311,10 +302,10 @@ def _generate_builder_methods(emitter: Emitter, name: str) -> None:
     emitter.add_blank_line()
     emitter.add_method("to_segments", params=["self"], return_type="list[bytes]")
     emitter.add_blank_line()
-    emitter.add_method("as_reader", params=["self"], return_type=reader_name)
+    emitter.add_method("as_reader", params=["self"], return_type=qreader)
     emitter.add_blank_line()
 
     emitter.add_typing_import("IO", "typing")
-    emitter.add_static_method("write", params=["file: IO[bytes]"])
+    emitter.add_static_method("write", params=["file: IO[bytes]"], return_type="None")
     emitter.add_blank_line()
-    emitter.add_static_method("write_packed", params=["file: IO[bytes]"])
+    emitter.add_static_method("write_packed", params=["file: IO[bytes]"], return_type="None")

src/capnp_stubgen/models.py

@@ -109,7 +109,7 @@ class TypeInfo:
     """The ID of the file node that contains this type (for import resolution)."""
 
     # May be overridden for method param/result structs
-    _display_name: str | None = None
+    display_name: str | None = None
     """Override for the display name (used for method param/result structs)."""
 
 
@@ -172,5 +172,9 @@ class TypeRegistry:
     def __len__(self) -> int:
         return len(self._types)
 
+    def all_types(self) -> list[TypeInfo]:
+        """Return all registered types (for iteration/filtering)."""
+        return list(self._types.values())
+
     def __contains__(self, type_id: int) -> bool:
         return type_id in self._types

src/capnp_stubgen/plugin.py

@@ -13,19 +13,16 @@ from __future__ import annotations
 
 import os
 import sys
-from typing import TYPE_CHECKING
+from typing import Any
 
 from .emitter import Emitter
 from .gen_const import generate_const
 from .gen_enum import generate_enum
 from .gen_interface import fixup_interface_methods, generate_interface
 from .gen_struct import generate_struct
-from .models import TypeRegistry
+from .models import TypeInfo, TypeRegistry
 from .schema_walker import build_type_registry
-from .utils import filename_to_module_name, type_id_to_int
+from .utils import NodeDict, filename_to_module_name, type_id_to_int
-
-if TYPE_CHECKING:
-    from typing import Any
 
 
 def main() -> int:
@@ -38,15 +35,13 @@ def main() -> int:
 
 
 def _main_impl() -> int:
-    import capnp
-
     # ── 1. Read CodeGeneratorRequest from stdin ────────────────────────
     request = _read_request()
 
     # Convert to dict for processing (avoids C++ DynamicStruct quirks)
     request_dict = request.to_dict()
-    nodes: list[dict] = request_dict["nodes"]
+    nodes: list[NodeDict] = request_dict["nodes"]
-    requested_files: list[dict] = request_dict["requestedFiles"]
+    requested_files: list[NodeDict] = request_dict["requestedFiles"]
 
     # ── 2. Build type registry ─────────────────────────────────────────
     registry = build_type_registry(nodes, requested_files)
@@ -79,7 +74,7 @@ def _main_impl() -> int:
             output_path = f"{module_name}.pyi"
 
             with open(output_path, "w") as f:
-                f.write(content)
+                _ = f.write(content)
 
         except Exception as exc:
             print(
@@ -100,13 +95,13 @@ def _read_request() -> Any:
     Uses pycapnp's ``SchemaParser`` to dynamically load ``schema.capnp``
     (shipped with pycapnp), then casts the stdin message.
     """
-    import capnp
+    import capnp  # pyright: ignore[reportMissingTypeStubs]
 
     capnp_dir = os.path.dirname(capnp.__file__)
     schema_path = os.path.join(capnp_dir, "schema.capnp")
     import_base = os.path.dirname(capnp_dir)
 
-    parser = capnp.SchemaParser()
+    parser = capnp.SchemaParser()  # pyright: ignore[reportAttributeAccessIssue]
     schema_module = parser.load(schema_path, imports=[import_base])
 
     return schema_module.CodeGeneratorRequest.read(sys.stdin.buffer)
@@ -130,7 +125,7 @@ def _generate_file(
 
     _ORDER = {"enum": 0, "struct": 1, "const": 2, "interface": 3}
 
-    def _sort_key(info):
+    def _sort_key(info: TypeInfo) -> tuple[int, str]:
         return (_ORDER.get(info.kind, 99), info.name)
 
     top_level.sort(key=_sort_key)
@@ -163,12 +158,12 @@ def _resolve_cross_imports(
 
     # Collect all types belonging to this file
     own_types: set[int] = set()
-    for info in registry._types.values():
+    for info in registry.all_types():
         if info.file_id == file_id and info.kind in ("struct", "enum", "interface"):
             own_types.add(info.type_id)
 
     # Walk types and find external references
-    for info in registry._types.values():
+    for info in registry.all_types():
         if info.file_id != file_id:
             continue
 
@@ -196,14 +191,12 @@ def _resolve_cross_imports(
         all_imports: list[str] = []
         for tname in sorted(type_names):
             ref_info = None
-            for info in registry._types.values():
+            for info in registry.all_types():
                 if info.scoped_name == tname and info.file_id != file_id:
                     ref_info = info
                     break
 
             all_imports.append(tname)
-            if ref_info and ref_info.kind == "struct":
-                all_imports.extend([f"{tname}Builder", f"{tname}Reader"])
 
         emitter.add_import(
             f"from .{module_name} import {', '.join(all_imports)}"
@@ -226,7 +219,7 @@ def _collect_type_references(info: TypeInfo, registry: TypeRegistry) -> set[int]
     return refs
 
 
-def _collect_field_references(field: dict, refs: set[int], registry: TypeRegistry) -> None:
+def _collect_field_references(field: NodeDict, refs: set[int], _registry: TypeRegistry) -> None:
     """Recursively collect type IDs from a field's type."""
     if "slot" in field:
         _collect_type_references_from_dict(field["slot"].get("type", {}), refs)
@@ -234,7 +227,7 @@ def _collect_field_references(field: dict, refs: set[int], registry: TypeRegistr
         refs.add(type_id_to_int(field["group"]["typeId"]))
 
 
-def _collect_type_references_from_dict(type_dict: dict, refs: set[int]) -> None:
+def _collect_type_references_from_dict(type_dict: NodeDict, refs: set[int]) -> None:
     """Recursively collect type IDs from a type dict."""
     if "struct" in type_dict:
         refs.add(type_id_to_int(type_dict["struct"]["typeId"]))

src/capnp_stubgen/schema_walker.py

@@ -6,27 +6,22 @@ building a ``TypeRegistry`` that maps type IDs to ``TypeInfo``.
 
 from __future__ import annotations
 
-from typing import TYPE_CHECKING
-
 from .models import TypeInfo, TypeRegistry
-from .utils import get_display_name, get_node_kind, type_id_to_int
+from .utils import NodeDict, get_cxx_name, get_display_name, get_node_kind, type_id_to_int
-
-if TYPE_CHECKING:
-    from typing import Any
 
 
 _GENERATABLE_KINDS = frozenset({"struct", "enum", "interface", "const"})
 
 
 def build_type_registry(
-    nodes: list[dict],
+    nodes: list[NodeDict],
-    requested_files: list[dict],
+    requested_files: list[NodeDict],
 ) -> TypeRegistry:
     """Build a ``TypeRegistry`` from the to-dict CodeGeneratorRequest nodes."""
     registry = TypeRegistry()
 
     # Build ID → node lookup
-    nodes_by_id: dict[int, dict] = {}
+    nodes_by_id: dict[int, NodeDict] = {}
     for node in nodes:
         nodes_by_id[type_id_to_int(node["id"])] = node
 
@@ -40,7 +35,7 @@ def build_type_registry(
             continue
 
         type_id = type_id_to_int(node["id"])
-        name = get_display_name(node)
+        name = get_cxx_name(node) or get_display_name(node)
         scope_id = node.get("scopeId", "0")
         parent_id = type_id_to_int(scope_id) if scope_id != "0" else None
 
@@ -71,8 +66,8 @@ def build_type_registry(
 
 
 def _build_file_associations(
-    nodes_by_id: dict[int, dict],
+    nodes_by_id: dict[int, NodeDict],
-    requested_files: list[dict],
+    _requested_files: list[NodeDict],
     registry: TypeRegistry,
 ) -> None:
     for node_id in nodes_by_id:
@@ -82,7 +77,7 @@ def _build_file_associations(
 
 
 def _find_containing_file(
-    node_id: int, nodes_by_id: dict[int, dict]
+    node_id: int, nodes_by_id: dict[int, NodeDict]
 ) -> int | None:
     visited: set[int] = set()
     current_id = node_id
@@ -109,7 +104,7 @@ def _find_containing_file(
 
 
 def _build_scoped_name(
-    type_id: int, nodes_by_id: dict[int, dict]
+    type_id: int, nodes_by_id: dict[int, NodeDict]
 ) -> str:
     parts: list[str] = []
     visited: set[int] = set()
@@ -122,7 +117,7 @@ def _build_scoped_name(
             break
 
         if get_node_kind(node) != "file":
-            parts.append(get_display_name(node))
+            parts.append(get_cxx_name(node) or get_display_name(node))
 
         scope_id_str = node.get("scopeId", "0")
         scope_id = int(scope_id_str) if scope_id_str != "0" else 0

src/capnp_stubgen/type_resolver.py

@@ -5,13 +5,8 @@ Maps type dicts (from ``CodeGeneratorRequest.to_dict()``) to ``PythonType``.
 
 from __future__ import annotations
 
-from typing import TYPE_CHECKING
-
 from .models import PythonType, TypeRegistry
-from .utils import type_id_to_int
+from .utils import NodeDict, type_id_to_int
-
-if TYPE_CHECKING:
-    from typing import Any
 
 
 # Cap'n Proto type key → Python type name
@@ -34,7 +29,7 @@ CAPNP_TO_PYTHON: dict[str, str] = {
 
 
 def resolve_type(
-    type_dict: dict,
+    type_dict: NodeDict,
     registry: TypeRegistry,
 ) -> PythonType | None:
     """Resolve a type dict to a ``PythonType``.
@@ -84,7 +79,7 @@ def resolve_type(
     return PythonType(name="Any")
 
 
-def _type_which(type_dict: dict) -> str | None:
+def _type_which(type_dict: NodeDict) -> str | None:
     """Return the union variant key for a type dict."""
     for key in CAPNP_TO_PYTHON:
         if key in type_dict:
@@ -95,7 +90,7 @@ def _type_which(type_dict: dict) -> str | None:
     return None
 
 
-def _resolve_list_type(list_dict: dict, registry: TypeRegistry) -> PythonType:
+def _resolve_list_type(list_dict: NodeDict, registry: TypeRegistry) -> PythonType:
     """Resolve a List(T) type."""
     depth = 1
     inner = list_dict.get("elementType", {})
@@ -129,7 +124,7 @@ def _resolve_named_type(type_id: int, registry: TypeRegistry) -> PythonType:
 
 
 def _resolve_any_pointer(
-    ap_dict: dict, registry: TypeRegistry
+    ap_dict: NodeDict, registry: TypeRegistry
 ) -> PythonType | None:
     """Resolve an AnyPointer type."""
     if "unconstrained" in ap_dict:
@@ -137,7 +132,7 @@ def _resolve_any_pointer(
     if "parameter" in ap_dict:
         # Look up the generic parameter name from the parent scope
         scope_id = type_id_to_int(ap_dict["parameter"]["scopeId"])
-        param_index = ap_dict["parameter"]["parameterIndex"]
+        param_index: int = ap_dict["parameter"]["parameterIndex"]
         info = registry.get(scope_id)
         if info is not None and param_index < len(info.generic_params):
             return PythonType(name=info.generic_params[param_index])

src/capnp_stubgen/utils.py

@@ -1,6 +1,11 @@
 """Utility functions for capnp-stubgen."""
 
 import os
+from typing import Any
+
+#: A dict from capnp's ``CodeGeneratorRequest.to_dict()``.
+#: Keys are strings, values are arbitrary nested capnp data.
+NodeDict = dict[str, Any]
 
 
 def filename_to_module_name(filename: str) -> str:
@@ -14,18 +19,12 @@ def filename_to_module_name(filename: str) -> str:
     return base + "_capnp"
 
 
-def get_display_name(node: dict) -> str:
+def get_display_name(node: NodeDict) -> str:
-    """Extract the short display name from a node dict.
+    """Extract the short display name from a node dict."""
-
+    return str(node["displayName"])[int(node["displayNamePrefixLength"]):]
-    The node's ``displayName`` field contains a path like
-    ``path/to/file.capnp:TypeName``. This removes the file prefix.
-    """
-    name: str = node["displayName"]
-    prefix_len: int = node["displayNamePrefixLength"]
-    return name[prefix_len:]
 
 
-def get_node_kind(node: dict) -> str:
+def get_node_kind(node: NodeDict) -> str:
     """Determine the kind of a node from its dict representation.
 
     Returns one of: "file", "struct", "enum", "interface", "const", "annotation".
@@ -39,3 +38,22 @@ def get_node_kind(node: dict) -> str:
 def type_id_to_int(type_id: str) -> int:
     """Convert a type ID string (from dict) to an integer."""
     return int(type_id)
+
+
+# Annotation IDs from c++.capnp
+_CXX_NAME_ANNOTATION_ID = 17466269397259751886  # 0xf2466592b7084e81
+
+
+def get_cxx_name(node: NodeDict) -> str | None:
+    """Return the ``$Cxx.name`` annotation value if present on a node."""
+    try:
+        for annot in node.get("annotations", []):
+            if annot.get("id") == _CXX_NAME_ANNOTATION_ID:
+                val = annot.get("value")
+                if isinstance(val, dict):
+                    text = val.get("text", "")
+                    if isinstance(text, str):
+                        return text
+    except Exception:
+        pass
+    return None

tests/.gitignore

@@ -0,0 +1 @@
+*_capnp.pyi

tests/schemas/conftest.py

@@ -0,0 +1,58 @@
+"""Regenerate .pyi stubs before running stub tests."""
+
+from __future__ import annotations
+
+import subprocess
+import sys
+from pathlib import Path
+
+import pytest
+
+SCHEMAS_DIR = Path(__file__).parent
+TEST_SCHEMAS = [
+    "test_simple.capnp",
+    "test_nested.capnp",
+    "test_generics.capnp",
+    "test_interface.capnp",
+    "addressbook.capnp",
+    "dummy.capnp",
+]
+
+
+def _find_capnpc_py() -> str:
+    venv_bin = Path(sys.prefix) / "bin" / "capnpc-py"
+    if venv_bin.exists():
+        return str(venv_bin)
+    return "capnpc-py"
+
+
+@pytest.fixture(scope="session", autouse=True)
+def _regenerate_stubs() -> None:  # pyright: ignore[reportUnusedFunction]
+    """Delete old .pyi files and regenerate from .capnp schemas."""
+    capnpc = _find_capnpc_py()
+
+    # Clean + generate main schemas
+    for schema in TEST_SCHEMAS:
+        pyi = SCHEMAS_DIR / schema.replace(".capnp", "_capnp.pyi")
+        pyi.unlink(missing_ok=True)
+        result = subprocess.run(
+            ["capnp", "compile", "-I.", f"-o{capnpc}", schema],
+            capture_output=True, text=True, cwd=str(SCHEMAS_DIR),
+        )
+        assert result.returncode == 0, (
+            f"capnp compile failed for {schema}:\n{result.stderr}"
+        )
+
+    # Multi-file schemas (consumer imports base)
+    multi_dir = SCHEMAS_DIR / "multi"
+    for pat in ("*_capnp.pyi",):
+        for f in multi_dir.glob(pat):
+            f.unlink(missing_ok=True)
+    for schema in ("base.capnp", "consumer.capnp"):
+        result = subprocess.run(
+            ["capnp", "compile", f"-o{capnpc}", schema],
+            capture_output=True, text=True, cwd=str(multi_dir),
+        )
+        assert result.returncode == 0, (
+            f"capnp compile failed for multi/{schema}:\n{result.stderr}"
+        )

tests/schemas/test_stubs.py

@@ -0,0 +1,118 @@
+"""Verify generated .pyi stubs are consistent with pycapnp runtime.
+
+Test file lives alongside the ``.capnp`` schemas + generated ``.pyi``
+stubs.  pycapnp's import hook handles runtime loading.
+basedpyright type-checks this file together with the project.
+"""
+
+from __future__ import annotations
+
+import sys
+from pathlib import Path
+
+# Ensure this directory is importable
+_HERE = Path(__file__).parent
+if str(_HERE) not in sys.path:
+    sys.path.insert(0, str(_HERE))
+
+import capnp  # pyright: ignore[reportMissingTypeStubs]  # activates import hook
+import test_generics_capnp
+import test_interface_capnp
+import test_nested_capnp
+import test_simple_capnp
+
+
+class TestSimpleStub:
+    """test_simple.capnp — basic struct."""
+
+    def test_new_message(self) -> None:
+        p = test_simple_capnp.Person.new_message(
+            name="Alice", age=30, email="alice@example.com"
+        )
+        assert p.name == "Alice"
+        assert p.age == 30
+
+    def test_field_assignment(self) -> None:
+        p = test_simple_capnp.Person.new_message()
+        p.name = "Bob"
+        p.age = 25
+        assert p.name == "Bob"
+
+    def test_to_dict(self) -> None:
+        p = test_simple_capnp.Person.new_message(name="Carol", age=28)
+        d = p.to_dict()
+        assert d["name"] == "Carol"
+
+    def test_from_dict(self) -> None:
+        p = test_simple_capnp.Person.new_message()
+        _ = p.from_dict({"name": "Dave", "age": 35})
+        assert p.name == "Dave"
+
+    def test_serialize_roundtrip(self) -> None:
+        p = test_simple_capnp.Person.new_message(name="Eve", age=22)
+        data = p.to_bytes()
+        p2 = test_simple_capnp.Person.from_bytes(data)
+        assert p2 is not None
+
+
+class TestNestedStub:
+    """test_nested.capnp — nested types + lists."""
+
+    def test_nested_message(self) -> None:
+        ab = test_nested_capnp.AddressBook.new_message()
+        assert ab.people is not None
+
+
+class TestGenericsStub:
+    """test_generics.capnp — generic structs."""
+
+    def test_holder_loads(self) -> None:
+        c = test_generics_capnp.Container.new_message()
+        assert c is not None
+
+
+class TestInterfaceStub:
+    """test_interface.capnp — interfaces + method params."""
+
+    def test_calcserver_loads(self) -> None:
+        cs = test_interface_capnp.CalcServer.new_message()
+        assert cs is not None
+
+
+class TestAddressBookStub:
+    """addressbook.capnp — classic example."""
+
+    def test_person_new_message(self) -> None:
+        import addressbook_capnp
+        p = addressbook_capnp.Person.new_message(
+            name="Alice", email="alice@example.com"
+        )
+        assert p.name == "Alice"
+
+    def test_addressbook_new_message(self) -> None:
+        import addressbook_capnp
+        ab = addressbook_capnp.AddressBook.new_message()
+        assert ab.people is not None
+
+
+class TestDummyStub:
+    """dummy.capnp — comprehensive test schema."""
+
+    def test_all_types_loads(self) -> None:
+        from pathlib import Path
+        parser = capnp.SchemaParser()  # pyright: ignore[reportAttributeAccessIssue]
+        m = parser.load(str(Path(__file__).parent / "dummy.capnp"))
+        msg = m.TestAllTypes.new_message(textField="hello", int32Field=42)
+        assert msg.textField == "hello"
+
+    def test_unions(self) -> None:
+        from pathlib import Path
+        parser = capnp.SchemaParser()  # pyright: ignore[reportAttributeAccessIssue]
+        m = parser.load(str(Path(__file__).parent / "dummy.capnp"))
+        u = m.TestUnion.new_message()
+        assert u is not None
+
+
+# Note: multi/consumer.capnp cross-file import test skipped —
+# pycapnp's SchemaParser crashes when resolving annotation imports
+# across schema files. The .pyi stubs are still generated and kept.

tests/test_models.py

@@ -85,11 +85,11 @@ class TestTypeRegistry:
         assert reg.get_or_raise(1) is info
         import pytest
         with pytest.raises(KeyError):
-            reg.get_or_raise(999)
+            _ = reg.get_or_raise(999)
 
     def test_contains(self):
         reg = TypeRegistry()
-        info = TypeInfo(1, "Foo", "Foo", {}, None, "struct")
+        info: TypeInfo = TypeInfo(1, "Foo", "Foo", {}, None, "struct")
         reg.register(info)
         assert 1 in reg
         assert 2 not in reg

tests/test_utils.py

@@ -1,6 +1,5 @@
 """Tests for capnp_stubgen.utils."""
 
-import pytest
 from capnp_stubgen.utils import (
     filename_to_module_name,
     get_display_name,