diff --git a/.github/workflows/docs.yml b/.github/workflows/docs.yml
index 4b8f892..5e41df8 100644
--- a/.github/workflows/docs.yml
+++ b/.github/workflows/docs.yml
@@ -14,7 +14,8 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - run: cp src/swydd/__init__.py docs/swydd.py
+      - name: build docs
+        run: ./tasks.py docs
 
       - name: Upload artifact
         uses: actions/upload-pages-artifact@latest
diff --git a/docs/swydd.py b/docs/swydd.py
new file mode 100644
index 0000000..3ae3934
--- /dev/null
+++ b/docs/swydd.py
@@ -0,0 +1,452 @@
+import argparse
+import inspect
+import os
+import shlex
+import subprocess
+import sys
+from argparse import (
+    Action,
+    ArgumentParser,
+    RawDescriptionHelpFormatter,
+    _SubParsersAction,
+)
+from functools import wraps
+from inspect import Parameter
+from pathlib import Path
+from typing import Any, Callable, Dict, List, Optional, Tuple
+
+__version__ = "0.1.0"
+
+
+class SubcommandHelpFormatter(RawDescriptionHelpFormatter):
+    """custom help formatter to remove bracketed list of subparsers"""
+
+    def _format_action(self, action: Action) -> str:
+        # TODO: actually modify the real "format_action for better control"
+        parts = super(RawDescriptionHelpFormatter, self)._format_action(action)
+        if action.nargs == argparse.PARSER:
+            lines = parts.split("\n")[1:]
+            tasks, targets = [], []
+            for line in lines:
+                if len(line) > 0 and line.strip().split()[0] in ctx.targets:
+                    targets.append(line)
+                else:
+                    tasks.append(line)
+            parts = "\n".join(tasks)
+            if len(targets) > 0 and ctx.show_targets:
+                parts += "\n".join(("\ntargets:", *targets))
+
+        return parts
+
+
+def _id_from_func(f: Callable[..., Any]):
+    return str(id(wrapped) if (wrapped := getattr(f, "__wrapped__", None)) else id(f))
+
+
+class Task:
+    def __init__(
+        self, func=Callable[..., Any], name: Optional[str] = None, show: bool = False
+    ) -> None:
+        self.show = show
+        self.id = _id_from_func(func)
+        self.name = name if name else func.__name__
+        self.func = func
+        self.targets = []
+        self.needs = []
+        self._process_signature()
+
+    def _process_signature(self) -> None:
+        self.signature = inspect.signature(self.func)
+        self.params = {}
+        for name, param in self.signature.parameters.items():
+            self.params[name] = {"Parameter": param}
+
+    def _update_option(self, name: str, help: str, **kwargs) -> None:
+        self.params[name] = {
+            **self.params.get(name, {}),
+            "help": help,
+            "kwargs": kwargs,
+        }
+
+    def _mark(self) -> None:
+        self.show = True
+
+
+class Graph:
+    def __init__(self) -> None:
+        self.nodes = {}
+        self.edges = {}
+
+    def add_nodes(self, task, node1, node2):
+        if node1 not in self.nodes:
+            self.nodes[node1] = []
+        if node2 not in self.nodes:
+            self.nodes[node2] = []
+
+        self.edges[node1] = task
+        if node2:
+            self.nodes[node1].append(node2)
+
+
+class Context:
+    def __init__(self) -> None:
+        self._env: Dict[str, str] = {}
+        self._tasks: Dict[str, Any] = {}
+        self.targets: Dict[str, Any] = {}
+        self.data: Any = None
+        self.flags: Dict[str, Any] = {}
+        self._flag_defs: List[Tuple[Tuple[str, ...], Any]] = []
+        self.show_targets = True
+        self._graph = Graph()
+
+        # global flags
+        self.dry = False
+        self.dag = False
+        self.verbose = False
+        self.force = False
+
+    def _add_task(self, func: Callable[..., Any], show: bool = False) -> str:
+        if (id_ := _id_from_func(func)) not in self._tasks:
+            self._tasks[id_] = Task(func)
+        if show:
+            self._tasks[id_]._mark()
+        return id_
+
+    def _update_option(self, func: Callable[..., Any], name: str, help: str, **kwargs):
+        if (id_ := _id_from_func(func)) not in self._tasks:
+            raise ValueError
+        self._tasks[id_]._update_option(name, help, **kwargs)
+
+    def _add_target(self, func: Callable[..., Any], target: str) -> None:
+        self._add_task(func)
+        id_ = _id_from_func(func)
+        self._tasks[id_].targets.append(target)
+
+    def _add_need(self, func: Callable[..., Any], need: str) -> None:
+        self._add_task(func)
+        id_ = _id_from_func(func)
+        self._tasks[id_].needs.append(need)
+
+    def _generate_graph(self) -> None:
+        for task in self._tasks.values():
+            if not task.targets:
+                continue
+
+            for target in task.targets:
+                if not task.needs:
+                    self._graph.add_nodes(task, target, None)
+                else:
+                    for need in task.needs:
+                        self._graph.add_nodes(task, target, need)
+
+    def add_flag(self, *args: str, **kwargs: Any) -> None:
+        name = max(args, key=len).split("-")[-1]
+        self.flags[name] = None
+        self._flag_defs.append((args, kwargs))
+
+
+ctx = Context()
+
+
+def define_env(key: str, value: str) -> None:
+    ctx._env.update({key: value})
+
+
+class Exec:
+    def __init__(
+        self, cmd: str, shell: bool = False, output: bool = False, **kwargs: Any
+    ) -> None:
+        self.shell = shell
+        self.cmd = cmd
+        if shell:
+            self._cmd = cmd
+        else:
+            self._cmd = shlex.split(cmd)
+        self.output = output
+        self.cmd_kwargs = kwargs
+
+    def _build_kwargs(self) -> Dict[str, Any]:
+        sub_kwargs: Dict[str, Any] = dict(env={**os.environ, **ctx._env})
+
+        if self.shell:
+            sub_kwargs["shell"] = True
+
+        if self.output:
+            sub_kwargs["text"] = True  # assume text is the desired output
+            sub_kwargs["capture_output"] = True
+
+        sub_kwargs.update(**self.cmd_kwargs)
+        return sub_kwargs
+
+    def execute(self) -> subprocess.CompletedProcess:
+        if ctx.verbose:
+            sys.stdout.write(f"swydd exec | {self.cmd}\n")
+
+        return subprocess.run(self._cmd, **self._build_kwargs())
+
+    def get(self):
+        p = self.execute()
+        if p.returncode != 0:
+            sys.stderr.write("non-zero exit status in Exec().get()\n")
+            sys.stderr.write(f"  cmd: {self.cmd}\n")
+            sys.stderr.write(f"  stdout: {p.stdout}\n")
+            sys.stderr.write(f"  stderr: {p.stderr}\n")
+            sys.exit(p.returncode)
+        return p
+
+
+def sh(cmd: str, shell: bool = False, **kwargs: Any) -> subprocess.CompletedProcess:
+    return Exec(cmd, shell=shell, **kwargs).execute()
+
+
+def task(func: Callable[..., Any]) -> Callable[..., None]:
+    ctx._add_task(func, show=True)
+
+    def wrap(*args: Any, **kwargs: Any) -> None:
+        return func(*args, **kwargs)
+
+    return wrap
+
+
+def inspect_wrapper(place, func):
+    if wrapped := getattr(func, "__wrapped__", None):
+        print(place, "wrapped->", id(wrapped))
+
+    print(
+        place,
+        id(func),
+    )
+
+
+def task2(
+    hidden: bool = False,
+) -> Callable[[Callable[..., Any]], Callable[..., Callable[..., None]]]:
+    def wrapper(func: Callable[..., Any]) -> Callable[..., Callable[..., None]]:
+        ctx._add_task(func, show=True)
+
+        inspect_wrapper("task", func)
+
+        @wraps(func)
+        def inner(*args: Any, **kwargs: Any) -> Callable[..., None]:
+            return func(*args, **kwargs)
+
+        return inner
+
+    return wrapper
+
+
+def targets(
+    *args: str,
+) -> Callable[[Callable[..., Any]], Callable[..., Callable[..., None]]]:
+    def wrapper(func: Callable[..., Any]) -> Callable[..., Callable[..., None]]:
+        inspect_wrapper("targets", func)
+        ctx._add_task(func)
+        for arg in args:
+            ctx._add_target(func, arg)
+            ctx.targets[arg] = _id_from_func(func)
+
+        @wraps(func)
+        def inner(*args: Any, **kwargs: Any) -> Callable[..., None]:
+            return func(*args, **kwargs)
+
+        return inner
+
+    return wrapper
+
+
+def needs(
+    *args: str,
+) -> Callable[[Callable[..., Any]], Callable[..., Callable[..., None]]]:
+    def wrapper(func: Callable[..., Any]) -> Callable[..., Callable[..., None]]:
+        for arg in args:
+            ctx._add_need(func, arg)
+
+        @wraps(func)
+        def inner(*args: Any, **kwargs: Any) -> Callable[..., None]:
+            return func(*args, **kwargs)
+
+        return inner
+
+    return wrapper
+
+
+def option(
+    name: str,
+    help: str,
+    **help_kwargs: str,
+) -> Callable[[Callable[..., Any]], Callable[..., Callable[..., None]]]:
+    def wrapper(func: Callable[..., Any]) -> Callable[..., Callable[..., None]]:
+        ctx._add_task(func)
+        ctx._update_option(func, name.replace("-", "_"), help, **help_kwargs)
+
+        @wraps(func)
+        def inner(*args: Any, **kwargs: Any) -> Callable[..., None]:
+            return func(*args, **kwargs)
+
+        return inner
+
+    return wrapper
+
+
+def manage(version: bool = False) -> None:
+    """manage self"""
+    print("self management stuff")
+    if version:
+        print("current version", __version__)
+
+
+def noop(*args, **kwargs) -> Any:
+    pass
+
+
+def target_generator(
+    target: str,
+    needs: List[str] | None = None,
+) -> Callable[[Callable[..., Any]], Callable[..., Callable[..., None]]]:
+    def wrapper(func: Callable[..., Any]) -> Callable[..., Callable[..., None]]:
+        @wraps(func)
+        def inner(*args: Any, **kwargs: Any) -> Callable[..., None]:
+            if not (target_path := Path(target)).is_file():
+                return func(*args, **kwargs)
+            elif not needs:
+                sys.stderr.write(f"{target} already exists\n")
+            else:
+                target_stats = target_path.stat()
+                needs_stats = [Path(need).stat() for need in needs]
+                if any((stat.st_mtime > target_stats.st_mtime for stat in needs_stats)):
+                    return func(*args, **kwargs)
+                else:
+                    sys.stderr.write("doing nothing\n")
+
+            return noop(*args, **kwargs)
+
+        return inner
+
+    return wrapper
+
+
+def generate_task_subparser(
+    shared: ArgumentParser,
+    subparsers: _SubParsersAction,
+    task: Task,
+    target: Optional[str] = None,
+) -> Optional[ArgumentParser]:
+    if not task.show and not target:
+        return
+
+    prog = os.path.basename(sys.argv[0])
+    name = task.name if not target else target
+    doc = task.func.__doc__.splitlines()[0] if task.func.__doc__ else ""
+    subparser = subparsers.add_parser(
+        name,
+        help=doc,
+        description=task.func.__doc__,
+        parents=[shared],
+        usage=f"%(prog)s {name} [opts]",
+        prog=prog,
+    )
+    for name, info in task.params.items():
+        param = info.get("Parameter")  # must check signature for args?
+
+        args = (f"--{name.replace('_','-')}",)
+        kwargs = {"help": info.get("help", "")}
+
+        if param.annotation is bool:
+            kwargs.update({"default": False, "action": "store_true"})
+        elif param.annotation != Parameter.empty:
+            kwargs.update({"type": param.annotation})
+        kwargs.update(
+            {"required": True}
+            if param.default == Parameter.empty
+            else {"default": param.default}
+        )
+
+        kwargs.update(info.get("kwargs", {}))
+        subparser.add_argument(*args, **kwargs)
+
+    f = (
+        target_generator(target, ctx._graph.nodes[target])(task.func)
+        if target
+        else task.func
+    )
+    subparser.set_defaults(func=f)
+    return subparser
+
+
+def add_targets(
+    shared: ArgumentParser, subparsers: _SubParsersAction, ctx: Context
+) -> None:
+    for target, id_ in ctx.targets.items():
+        subp = generate_task_subparser(shared, subparsers, ctx._tasks[id_], str(target))
+
+        if subp:
+            subp.add_argument("--dag", help="show target dag", action="store_true")
+            subp.add_argument("--force", help="force execution", action="store_true")
+
+
+def cli() -> None:
+    ctx._generate_graph()
+
+    parser = ArgumentParser(
+        formatter_class=SubcommandHelpFormatter, usage="%(prog)s <task/target> [opts]"
+    )
+    shared = ArgumentParser(add_help=False)
+
+    for flag_args, flag_kwargs in ctx._flag_defs:
+        shared.add_argument(*flag_args, **flag_kwargs)
+
+    shared.add_argument(
+        "-v", "--verbose", help="use verbose output", action="store_true"
+    )
+    shared.add_argument(
+        "-n", "--dry-run", help="don't execute tasks", action="store_true"
+    )
+
+    subparsers = parser.add_subparsers(
+        title="tasks", required=True, dest="pos-arg", metavar="<task/target>"
+    )
+
+    if len(sys.argv) > 1 and sys.argv[1] == "self":
+        generate_task_subparser(
+            shared, subparsers, Task(manage, name="self", show=True)
+        )
+
+    add_targets(shared, subparsers, ctx)
+
+    for task in ctx._tasks.values():
+        generate_task_subparser(shared, subparsers, task)
+
+    args = vars(parser.parse_args())
+    _ = args.pop("pos-arg", None)
+    ctx.verbose = args.pop("verbose", False)
+    ctx.dry = args.pop("dry_run", False)
+    ctx.dag = args.pop("dag", False)
+    ctx.force = args.pop("force", False)
+    for name in ctx.flags:
+        ctx.flags[name] = args.pop(name)
+
+    if f := args.pop("func", None):
+        if ctx.dry:
+            sys.stderr.write("dry run >>>\n" f"  args: {args}\n")
+            sys.stderr.write(
+                (
+                    "\n".join(
+                        f"  {line}"
+                        for line in inspect.getsource(f).splitlines()
+                        if not line.startswith("@")
+                    )
+                    + "\n"
+                )
+            )
+        elif ctx.dag:
+            sys.stderr.write(
+                "currently --dag is a noop\n"
+                "future versions will generate a dag for specified target\n"
+            )
+        else:
+            f(**args)
+
+
+if __name__ == "__main__":
+    sys.stderr.write("this module should not be invoked directly\n")
+    sys.exit(1)
diff --git a/docs/v0.1.0/swydd.py b/docs/v0.1.0/swydd.py
new file mode 100644
index 0000000..5917a0e
--- /dev/null
+++ b/docs/v0.1.0/swydd.py
@@ -0,0 +1,337 @@
+import argparse
+import inspect
+import os
+import shlex
+import subprocess
+import sys
+from argparse import (
+    Action,
+    ArgumentParser,
+    RawDescriptionHelpFormatter,
+    _SubParsersAction,
+)
+from functools import wraps
+from inspect import Parameter
+from typing import Any, Callable, Dict, List, Optional, Tuple
+
+__version__ = "0.1.0"
+
+
+class SubcommandHelpFormatter(RawDescriptionHelpFormatter):
+    """custom help formatter to remove bracketed list of subparsers"""
+
+    def _format_action(self, action: Action) -> str:
+        # TODO: actually modify the real "format_action for better control"
+        print(action)
+        parts = super(RawDescriptionHelpFormatter, self)._format_action(action)
+        if action.nargs == argparse.PARSER:
+            lines = parts.split("\n")[1:]
+            tasks, targets = [], []
+            for line in lines:
+                if len(line) > 0 and line.strip().split()[0] in ctx.targets:
+                    targets.append(line)
+                else:
+                    tasks.append(line)
+            parts = "\n".join(tasks)
+            if len(targets) > 0 and ctx.show_targets:
+                parts += "\n".join(("\ntargets:", *targets))
+
+        return parts
+
+
+def _id_from_func(f: Callable[..., Any]):
+    return str(id(wrapped) if (wrapped := getattr(f, "__wrapped__", None)) else id(f))
+
+
+class Task:
+    def __init__(self, func=Callable[..., Any]) -> None:
+        self.show = False
+        self.id = _id_from_func(func)
+        self.name = func.__name__
+        self.func = func
+        self.targets = []
+
+        self._process_signature()
+
+    def _process_signature(self) -> None:
+        self.signature = inspect.signature(self.func)
+        self.params = {}
+        for name, param in self.signature.parameters.items():
+            self.params[name] = {"Parameter": param}
+
+    def _update_option(self, name: str, help: str, **kwargs) -> None:
+        self.params[name] = {
+            **self.params.get(name, {}),
+            "help": help,
+            "kwargs": kwargs,
+        }
+
+    def _mark(self) -> None:
+        self.show = True
+
+
+class Context:
+    def __init__(self) -> None:
+        self._tasks: Dict[str, Any] = {}
+        self.targets: Dict[str, Any] = {}
+        self.data: Any = None
+        self.flags: Dict[str, Any] = {}
+        self._flag_defs: List[Tuple[Tuple[str, ...], Any]] = []
+        self.show_targets = True
+
+        # global flags
+        self.dry = False
+        self.dag = False
+        self.verbose = False
+
+    def _add_task(self, func: Callable[..., Any], show: bool = False) -> None:
+        if (id_ := _id_from_func(func)) not in self._tasks:
+            self._tasks[id_] = Task(func)
+        if show:
+            self._tasks[id_]._mark()
+
+    def _update_option(self, func: Callable[..., Any], name: str, help: str, **kwargs):
+        if (id_ := _id_from_func(func)) not in self._tasks:
+            raise ValueError
+        self._tasks[id_]._update_option(name, help, **kwargs)
+
+    def add_flag(self, *args: str, **kwargs: Any) -> None:
+        name = max(args, key=len).split("-")[-1]
+        self.flags[name] = None
+        self._flag_defs.append((args, kwargs))
+
+
+ctx = Context()
+
+
+class Exec:
+    def __init__(self, cmd: str, shell: bool = False) -> None:
+        self.shell = shell
+        self.cmd = cmd
+
+    def execute(self) -> int:
+        if ctx.verbose:
+            sys.stdout.write(f"exec: {self.cmd}\n")
+        if self.shell:
+            return subprocess.run(self.cmd, shell=True).returncode
+        else:
+            return subprocess.run(shlex.split(self.cmd)).returncode
+
+
+def sh(cmd: str, shell: bool = False) -> int:
+    return Exec(cmd, shell=shell).execute()
+
+
+# decorators
+
+
+def task(func: Callable[..., Any]) -> Callable[..., None]:
+    ctx._add_task(func, show=True)
+
+    def wrap(*args: Any, **kwargs: Any) -> None:
+        return func(*args, **kwargs)
+
+    return wrap
+
+
+# def inspect_wrapper(place, func):
+#     if wrapped := getattr(func, "__wrapped__", None):
+#         print(place, "wrapped->", id(wrapped))
+#
+#     print(
+#         place,
+#         id(func),
+#     )
+#
+
+
+def targets(
+    *args: str,
+) -> Callable[[Callable[..., Any]], Callable[..., Callable[..., None]]]:
+    def wrapper(func: Callable[..., Any]) -> Callable[..., Callable[..., None]]:
+        ctx._add_task(func)
+        for arg in args:
+            ctx.targets[arg] = _id_from_func(func)
+
+        @wraps(func)
+        def inner(*args: Any, **kwargs: Any) -> Callable[..., None]:
+            return func(*args, **kwargs)
+
+        return inner
+
+    return wrapper
+
+
+def option(
+    name: str,
+    help: str,
+    **help_kwargs: str,
+) -> Callable[[Callable[..., Any]], Callable[..., Callable[..., None]]]:
+    def wrapper(func: Callable[..., Any]) -> Callable[..., Callable[..., None]]:
+        ctx._add_task(func)
+        ctx._update_option(func, name, help, **help_kwargs)
+
+        @wraps(func)
+        def inner(*args: Any, **kwargs: Any) -> Callable[..., None]:
+            return func(*args, **kwargs)
+
+        return inner
+
+    return wrapper
+
+
+def manage(version: bool = False) -> None:
+    """manage self"""
+    print("self management stuff")
+    if version:
+        print("current version", __version__)
+
+
+def generate_task_subparser(
+    shared: ArgumentParser,
+    subparsers: _SubParsersAction,
+    task: Task,
+    target: Optional[str] = None,
+) -> Optional[ArgumentParser]:
+    if not task.show and not target:
+        return
+
+    prog = os.path.basename(sys.argv[0])
+    name = task.name if not target else target
+    doc = task.func.__doc__.splitlines()[0] if task.func.__doc__ else ""
+    subparser = subparsers.add_parser(
+        name,
+        help=doc,
+        description=task.func.__doc__,
+        parents=[shared],
+        usage=f"%(prog)s {name} [opts]",
+        prog=prog,
+    )
+    for name, info in task.params.items():
+        param = info.get("Parameter")  # must check signature for args?
+        args = (f"--{name}",)
+        kwargs = {"help": info.get("help", "")}
+
+        if param.annotation == bool:
+            kwargs.update({"default": False, "action": "store_true"})
+        elif param.annotation != Parameter.empty:
+            kwargs.update({"type": param.annotation})
+        kwargs.update(
+            {"required": True}
+            if param.default == Parameter.empty
+            else {"default": param.default}
+        )
+
+        kwargs.update(info.get("kwargs", {}))
+        subparser.add_argument(*args, **kwargs)
+    subparser.set_defaults(func=task.func)
+    return subparser
+
+
+def generate_subparser(
+    shared: ArgumentParser,
+    subparsers: _SubParsersAction,
+    name: str,
+    info: Dict[str, Any],
+) -> ArgumentParser:
+    func = info["func"]
+    signature = info["signature"]
+    help = info.get("help")
+    doc = func.__doc__.splitlines()[0] if func.__doc__ else ""
+    subparser = subparsers.add_parser(
+        name, help=doc, description=func.__doc__, parents=[shared]
+    )
+    for name, param in signature.parameters.items():
+        args = (f"--{name}",)
+        kwargs = {"help": help.get(name, "")} if help else {}
+
+        if param.annotation == bool:
+            kwargs.update({"default": False, "action": "store_true"})
+        elif param.annotation != Parameter.empty:
+            kwargs.update({"type": param.annotation})
+        kwargs.update(
+            {"required": True}
+            if param.default == Parameter.empty
+            else {"default": param.default}
+        )
+
+        subparser.add_argument(*args, **kwargs)
+    subparser.set_defaults(func=func)
+    return subparser
+
+
+def add_targets(
+    shared: ArgumentParser, subparsers: _SubParsersAction, ctx: Context
+) -> None:
+    for target, id_ in ctx.targets.items():
+        subp = generate_task_subparser(shared, subparsers, ctx._tasks[id_], str(target))
+        if subp:
+            subp.add_argument("--dag", help="show target dag", action="store_true")
+
+
+def cli() -> None:
+    parser = ArgumentParser(
+        formatter_class=SubcommandHelpFormatter, usage="%(prog)s <task/target> [opts]"
+    )
+    shared = ArgumentParser(add_help=False)
+
+    for flag_args, flag_kwargs in ctx._flag_defs:
+        shared.add_argument(*flag_args, **flag_kwargs)
+
+    shared.add_argument(
+        "-v", "--verbose", help="use verbose output", action="store_true"
+    )
+    shared.add_argument(
+        "-n", "--dry-run", help="don't execute tasks", action="store_true"
+    )
+
+    subparsers = parser.add_subparsers(
+        title="tasks",
+        required=True,
+    )
+
+    if len(sys.argv) > 1 and sys.argv[1] == "self":
+        generate_subparser(
+            shared,
+            subparsers,
+            "self",
+            dict(func=manage, signature=inspect.signature(manage)),
+        )
+
+    add_targets(shared, subparsers, ctx)
+
+    for _, task in ctx._tasks.items():
+        generate_task_subparser(shared, subparsers, task)
+
+    args = vars(parser.parse_args())
+    ctx.verbose = args.pop("verbose", False)
+    ctx.dry = args.pop("dry_run", False)
+    ctx.dag = args.pop("dag", False)
+    for name in ctx.flags:
+        ctx.flags[name] = args.pop(name)
+
+    if f := args.pop("func", None):
+        if ctx.dry:
+            sys.stderr.write("dry run >>>\n" f"  args: {args}\n")
+            sys.stderr.write(
+                (
+                    "\n".join(
+                        f"  {line}"
+                        for line in inspect.getsource(f).splitlines()
+                        if not line.startswith("@")
+                    )
+                    + "\n"
+                )
+            )
+        elif ctx.dag:
+            sys.stderr.write(
+                "currently --dag is a noop\n"
+                "future versions will generate a dag for specified target\n"
+            )
+        else:
+            f(**args)
+
+
+if __name__ == "__main__":
+    sys.stderr.write("this module should not be invoked directly\n")
+    sys.exit(1)
diff --git a/src/swydd/__init__.py b/src/swydd/__init__.py
index 414c25d..3ae3934 100644
--- a/src/swydd/__init__.py
+++ b/src/swydd/__init__.py
@@ -153,25 +153,50 @@ def define_env(key: str, value: str) -> None:
 
 
 class Exec:
-    def __init__(self, cmd: str, shell: bool = False) -> None:
+    def __init__(
+        self, cmd: str, shell: bool = False, output: bool = False, **kwargs: Any
+    ) -> None:
         self.shell = shell
         self.cmd = cmd
+        if shell:
+            self._cmd = cmd
+        else:
+            self._cmd = shlex.split(cmd)
+        self.output = output
+        self.cmd_kwargs = kwargs
 
-    def execute(self) -> int:
+    def _build_kwargs(self) -> Dict[str, Any]:
+        sub_kwargs: Dict[str, Any] = dict(env={**os.environ, **ctx._env})
+
+        if self.shell:
+            sub_kwargs["shell"] = True
+
+        if self.output:
+            sub_kwargs["text"] = True  # assume text is the desired output
+            sub_kwargs["capture_output"] = True
+
+        sub_kwargs.update(**self.cmd_kwargs)
+        return sub_kwargs
+
+    def execute(self) -> subprocess.CompletedProcess:
         if ctx.verbose:
             sys.stdout.write(f"swydd exec | {self.cmd}\n")
-        if self.shell:
-            return subprocess.run(
-                self.cmd, shell=True, env={**os.environ, **ctx._env}
-            ).returncode
-        else:
-            return subprocess.run(
-                shlex.split(self.cmd), env={**os.environ, **ctx._env}
-            ).returncode
+
+        return subprocess.run(self._cmd, **self._build_kwargs())
+
+    def get(self):
+        p = self.execute()
+        if p.returncode != 0:
+            sys.stderr.write("non-zero exit status in Exec().get()\n")
+            sys.stderr.write(f"  cmd: {self.cmd}\n")
+            sys.stderr.write(f"  stdout: {p.stdout}\n")
+            sys.stderr.write(f"  stderr: {p.stderr}\n")
+            sys.exit(p.returncode)
+        return p
 
 
-def sh(cmd: str, shell: bool = False) -> int:
-    return Exec(cmd, shell=shell).execute()
+def sh(cmd: str, shell: bool = False, **kwargs: Any) -> subprocess.CompletedProcess:
+    return Exec(cmd, shell=shell, **kwargs).execute()
 
 
 def task(func: Callable[..., Any]) -> Callable[..., None]:
diff --git a/tasks.py b/tasks.py
index 1934794..25a54c7 100755
--- a/tasks.py
+++ b/tasks.py
@@ -4,6 +4,7 @@ __import__("sys").path.append("src")  # noqa
 
 import shutil
 import sys
+from pathlib import Path
 
 import swydd as s
 
@@ -26,4 +27,23 @@ def check(no_mypy: bool = False):
         s.sh("mypy src/")
 
 
+def write_docs_src(tag):
+    src_text = s.Exec(f"git show {tag}:src/swydd/__init__.py", output=True).get().stdout
+    (verdir := (Path(__file__).parent / "docs" / tag)).mkdir(exist_ok=True)
+    (verdir / "swydd.py").write_text(src_text)
+
+
+@s.task
+def docs():
+    """build docs"""
+    p = s.Exec("git tag --list", output=True).get()
+    versions = [line for line in p.stdout.splitlines() if line.startswith("v")]
+    for ver in versions:
+        write_docs_src(ver)
+    shutil.copyfile(
+        Path(__file__).parent / "src" / "swydd" / "__init__.py",
+        Path(__file__).parent / "docs" / "swydd.py",
+    )
+
+
 s.cli()