chore: migration 1

libs/cli/langgraph_cli/__main__.py

@@ -1,4 +1,4 @@
-from .cli import cli
+from .entrypoint import main
 
 if __name__ == "__main__":
-    cli()
+    main()

libs/cli/langgraph_cli/entrypoint.py

@@ -0,0 +1,74 @@
+"""User-facing entrypoint for the LangGraph CLI."""
+
+from __future__ import annotations
+
+import os
+import pathlib
+import sys
+from collections.abc import Sequence
+
+import click
+
+from .cli import cli
+
+_GO_CLI_FLAG = "LANGGRAPH_USE_GO_CLI"
+_GO_CLI_PATH_ENV = "LANGGRAPH_GO_CLI_PATH"
+_CALLING_PYTHON_ENV = "LANGGRAPH_CALLING_PYTHON"
+
+_TRUE_VALUES = frozenset({"1", "true", "yes", "on"})
+
+
+def _legacy_cli(argv: Sequence[str] | None = None) -> None:
+    cli.main(args=list(argv) if argv is not None else None, prog_name="langgraph")
+
+
+def _should_use_go_cli() -> bool:
+    value = os.environ.get(_GO_CLI_FLAG, "")
+    return value.strip().lower() in _TRUE_VALUES
+
+
+def _bundled_go_cli_path() -> pathlib.Path:
+    binary_name = "langgraph.exe" if os.name == "nt" else "langgraph"
+    return pathlib.Path(__file__).resolve().parent / "bin" / binary_name
+
+
+def _resolve_go_cli_path() -> pathlib.Path | None:
+    override = os.environ.get(_GO_CLI_PATH_ENV)
+    if override:
+        path = pathlib.Path(override).expanduser()
+        return path.resolve()
+
+    bundled = _bundled_go_cli_path()
+    if bundled.is_file():
+        return bundled
+
+    return None
+
+
+def _exec_go_cli(argv: Sequence[str]) -> None:
+    path = _resolve_go_cli_path()
+    if path is None:
+        raise click.ClickException(
+            "Go CLI requested via LANGGRAPH_USE_GO_CLI, but no langgraph binary was "
+            "found. Set LANGGRAPH_GO_CLI_PATH or install a wheel that bundles the "
+            "binary."
+        )
+    if not path.is_file():
+        raise click.ClickException(
+            f"LANGGRAPH_GO_CLI_PATH points to a missing file: {path}"
+        )
+
+    env = os.environ.copy()
+    env.setdefault(_CALLING_PYTHON_ENV, sys.executable)
+    os.execvpe(str(path), [str(path), *argv], env)
+
+
+def main(argv: Sequence[str] | None = None) -> None:
+    args = list(sys.argv[1:] if argv is None else argv)
+    try:
+        if _should_use_go_cli():
+            _exec_go_cli(args)
+        _legacy_cli(args)
+    except click.ClickException as exc:
+        exc.show()
+        raise SystemExit(exc.exit_code) from exc