diff --git a/pyxdsm/XDSM.pyi b/pyxdsm/XDSM.pyi
new file mode 100644
index 0000000..c15c6a5
--- /dev/null
+++ b/pyxdsm/XDSM.pyi
@@ -0,0 +1,143 @@
+from typing import Iterator, NamedTuple, Literal, Sequence
+
+OPT: str
+SUBOPT: str
+SOLVER: str
+DOE: str
+IFUNC: str
+FUNC: str
+GROUP: str
+IGROUP: str
+METAMODEL: str
+LEFT: str
+RIGHT: str
+
+tikzpicture_template: str
+tex_template: str
+
+def chunk_label(label: str, n_chunks: int) -> Iterator[str]: ...
+def _parse_label(
+    label: str | list[str] | tuple[str, ...], label_width: int | None = ...
+) -> str: ...
+def _label_to_spec(label: str | list[str], spec: set[str]) -> None: ...
+
+class System(NamedTuple):
+    node_name: str
+    style: str
+    label: str | list[str]
+    stack: bool
+    faded: bool
+    label_width: int | None
+    spec_name: str
+
+class Input(NamedTuple):
+    node_name: str
+    label: str | list[str]
+    label_width: int | None
+    style: str
+    stack: bool
+    faded: bool
+
+class Output(NamedTuple):
+    node_name: str
+    label: str | list[str]
+    label_width: int | None
+    style: str
+    stack: bool
+    faded: bool
+    side: Literal["left", "right"]
+
+class Connection(NamedTuple):
+    src: str
+    target: str
+    label: str | list[str]
+    label_width: int | None
+    style: str
+    stack: bool
+    faded: bool
+    src_faded: bool
+    target_faded: bool
+
+class Process(NamedTuple):
+    systems: list[str]
+    arrow: str
+    faded: bool
+
+class XDSM:
+    systems: list[System]
+    connections: list[Connection]
+    left_outs: dict[str, Output]
+    right_outs: dict[str, Output]
+    ins: dict[str, Input]
+    processes: list[Process]
+    use_sfmath: bool
+    optional_packages: list[str]
+    auto_fade: dict[str, str]
+
+    def __init__(
+        self,
+        use_sfmath: bool = ...,
+        optional_latex_packages: str | list[str] | None = ...,
+        auto_fade: dict[str, str] | None = ...,
+    ) -> None: ...
+    def add_system(
+        self,
+        node_name: str,
+        style: str,
+        label: str | list[str] | tuple[str, ...],
+        stack: bool = ...,
+        faded: bool = ...,
+        label_width: int | None = ...,
+        spec_name: str | None = ...,
+    ) -> None: ...
+    def add_input(
+        self,
+        name: str,
+        label: str | list[str] | tuple[str, ...],
+        label_width: int | None = None,
+        style: str = "DataIO",
+        stack: bool = False,
+        faded: bool = False,
+    ) -> None: ...
+    def add_output(
+        self,
+        name: str,
+        label: str | list[str] | tuple[str, ...],
+        label_width: int | None = None,
+        style: str = "DataIO",
+        stack: bool = False,
+        faded: bool = False,
+        side: Literal["left", "right"] = "left",
+    ) -> None: ...
+    def connect(
+        self,
+        src: str,
+        target: str,
+        label: str | list[str] | tuple[str, ...],
+        label_width: int | None = None,
+        style: str = "DataInter",
+        stack: bool = False,
+        faded: bool = False,
+    ) -> None: ...
+    def add_process(
+        self,
+        systems: Sequence[str],
+        arrow: bool = True,
+        faded: bool = False,
+    ) -> None: ...
+    # def _build_node_grid(self) -> str: ...
+    # def _build_edges(self) -> str: ...
+    # def _build_process_chain(self) -> str: ...
+    # def _compose_optional_package_list(self) -> str: ...
+    def write(
+        self,
+        file_name: str,
+        build: bool = True,
+        cleanup: bool = True,
+        quiet: bool = False,
+        outdir: str = ".",
+    ) -> None: ...
+    def write_sys_specs(
+        self,
+        folder_name: str,
+    ) -> None: ...