diff --git a/scripts/python/check_prerequisites.py b/scripts/python/check_prerequisites.py
new file mode 100644
index 0000000000..50c31cb513
--- /dev/null
+++ b/scripts/python/check_prerequisites.py
@@ -0,0 +1,207 @@
+#!/usr/bin/env python3
+"""Consolidated prerequisite checking script."""
+
+from __future__ import annotations
+
+import json
+import sys
+from dataclasses import dataclass
+from pathlib import Path
+
+try:
+    from common import FeaturePaths, format_speckit_command, get_feature_paths
+except ImportError:  # pragma: no cover - direct execution from unusual cwd
+    sys.path.insert(0, str(Path(__file__).resolve().parent))
+    from common import FeaturePaths, format_speckit_command, get_feature_paths
+
+
+def _json_line(payload: object) -> str:
+    return json.dumps(payload, ensure_ascii=False, separators=(",", ":")) + "\n"
+
+
+HELP_TEXT = """Usage: check_prerequisites.py [OPTIONS]
+
+Consolidated prerequisite checking for Spec-Driven Development workflow.
+
+OPTIONS:
+  --json              Output in JSON format
+  --require-tasks     Require tasks.md to exist (for implementation phase)
+  --include-tasks     Include tasks.md in AVAILABLE_DOCS list
+  --paths-only        Only output path variables (no prerequisite validation)
+  --help, -h          Show this help message
+
+EXAMPLES:
+  # Check task prerequisites (plan.md required)
+  ./check_prerequisites.py --json
+
+  # Check implementation prerequisites (plan.md + tasks.md required)
+  ./check_prerequisites.py --json --require-tasks --include-tasks
+
+  # Get feature paths only (no validation)
+  ./check_prerequisites.py --paths-only
+
+"""
+
+
+@dataclass(frozen=True)
+class Args:
+    json_mode: bool = False
+    require_tasks: bool = False
+    include_tasks: bool = False
+    paths_only: bool = False
+
+
+def _parse_args(argv: list[str]) -> Args:
+    json_mode = False
+    require_tasks = False
+    include_tasks = False
+    paths_only = False
+
+    for arg in argv:
+        if arg == "--json":
+            json_mode = True
+        elif arg == "--require-tasks":
+            require_tasks = True
+        elif arg == "--include-tasks":
+            include_tasks = True
+        elif arg == "--paths-only":
+            paths_only = True
+        elif arg in {"--help", "-h"}:
+            sys.stdout.write(HELP_TEXT)
+            raise SystemExit(0)
+        else:
+            print(
+                f"ERROR: Unknown option '{arg}'. Use --help for usage information.",
+                file=sys.stderr,
+            )
+            raise SystemExit(1)
+
+    return Args(
+        json_mode=json_mode,
+        require_tasks=require_tasks,
+        include_tasks=include_tasks,
+        paths_only=paths_only,
+    )
+
+
+def _dir_has_entries(path: Path) -> bool:
+    try:
+        return path.is_dir() and any(path.iterdir())
+    except OSError:
+        return False
+
+
+def _available_docs(paths: FeaturePaths, include_tasks: bool) -> list[str]:
+    docs: list[str] = []
+    if paths.research.is_file():
+        docs.append("research.md")
+    if paths.data_model.is_file():
+        docs.append("data-model.md")
+    if _dir_has_entries(paths.contracts_dir):
+        docs.append("contracts/")
+    if paths.quickstart.is_file():
+        docs.append("quickstart.md")
+    if include_tasks and paths.tasks.is_file():
+        docs.append("tasks.md")
+    return docs
+
+
+def _print_paths_only(paths: FeaturePaths, json_mode: bool) -> None:
+    if json_mode:
+        sys.stdout.write(
+            _json_line(
+                {
+                    "REPO_ROOT": str(paths.repo_root),
+                    "BRANCH": paths.current_branch,
+                    "FEATURE_DIR": str(paths.feature_dir),
+                    "FEATURE_SPEC": str(paths.feature_spec),
+                    "IMPL_PLAN": str(paths.impl_plan),
+                    "TASKS": str(paths.tasks),
+                }
+            )
+        )
+        return
+
+    print(f"REPO_ROOT: {paths.repo_root}")
+    print(f"BRANCH: {paths.current_branch}")
+    print(f"FEATURE_DIR: {paths.feature_dir}")
+    print(f"FEATURE_SPEC: {paths.feature_spec}")
+    print(f"IMPL_PLAN: {paths.impl_plan}")
+    print(f"TASKS: {paths.tasks}")
+
+
+def _check_file(path: Path, description: str) -> None:
+    marker = "✓" if path.is_file() else "✗"
+    print(f"  {marker} {description}")
+
+
+def _check_dir(path: Path, description: str) -> None:
+    marker = "✓" if _dir_has_entries(path) else "✗"
+    print(f"  {marker} {description}")
+
+
+def _print_text_results(paths: FeaturePaths, include_tasks: bool) -> None:
+    print(f"FEATURE_DIR:{paths.feature_dir}")
+    print("AVAILABLE_DOCS:")
+    _check_file(paths.research, "research.md")
+    _check_file(paths.data_model, "data-model.md")
+    _check_dir(paths.contracts_dir, "contracts/")
+    _check_file(paths.quickstart, "quickstart.md")
+    if include_tasks:
+        _check_file(paths.tasks, "tasks.md")
+
+
+def main(argv: list[str] | None = None) -> int:
+    args = _parse_args(list(argv if argv is not None else sys.argv[1:]))
+
+    try:
+        paths = get_feature_paths(
+            no_persist=args.paths_only,
+            script_file=Path(__file__),
+        )
+    except SystemExit as exc:
+        if exc.code == 0:
+            return 0
+        print("ERROR: Failed to resolve feature paths", file=sys.stderr)
+        return int(exc.code) if isinstance(exc.code, int) else 1
+
+    if args.paths_only:
+        _print_paths_only(paths, args.json_mode)
+        return 0
+
+    if not paths.feature_dir.is_dir():
+        print(f"ERROR: Feature directory not found: {paths.feature_dir}", file=sys.stderr)
+        print(
+            f"Run {format_speckit_command('specify', paths.repo_root)} first to create the feature structure.",
+            file=sys.stderr,
+        )
+        return 1
+
+    if not paths.impl_plan.is_file():
+        print(f"ERROR: plan.md not found in {paths.feature_dir}", file=sys.stderr)
+        print(
+            f"Run {format_speckit_command('plan', paths.repo_root)} first to create the implementation plan.",
+            file=sys.stderr,
+        )
+        return 1
+
+    if args.require_tasks and not paths.tasks.is_file():
+        print(f"ERROR: tasks.md not found in {paths.feature_dir}", file=sys.stderr)
+        print(
+            f"Run {format_speckit_command('tasks', paths.repo_root)} first to create the task list.",
+            file=sys.stderr,
+        )
+        return 1
+
+    docs = _available_docs(paths, args.include_tasks)
+    if args.json_mode:
+        sys.stdout.write(
+            _json_line({"FEATURE_DIR": str(paths.feature_dir), "AVAILABLE_DOCS": docs})
+        )
+    else:
+        _print_text_results(paths, args.include_tasks)
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())
diff --git a/scripts/python/common.py b/scripts/python/common.py
new file mode 100644
index 0000000000..77c13eefbb
--- /dev/null
+++ b/scripts/python/common.py
@@ -0,0 +1,210 @@
+"""Shared helpers for Spec Kit Python scripts."""
+
+from __future__ import annotations
+
+import json
+import os
+import sys
+from dataclasses import dataclass
+from pathlib import Path
+
+
+def _trim_trailing_separators(value: Path) -> str:
+    text = str(value)
+    while len(text) > 1 and text.endswith((os.sep, "/")):
+        text = text[:-1]
+    return text
+
+
+def find_specify_root(start_dir: Path | None = None) -> Path | None:
+    current = (start_dir or Path.cwd()).resolve()
+    while True:
+        if (current / ".specify").is_dir():
+            return current
+        parent = current.parent
+        if parent == current:
+            return None
+        current = parent
+
+
+def resolve_specify_init_dir() -> Path:
+    raw = os.environ.get("SPECIFY_INIT_DIR", "")
+    candidate = Path(raw)
+    if not candidate.is_absolute():
+        candidate = Path.cwd() / candidate
+    try:
+        init_root = candidate.resolve(strict=True)
+    except OSError:
+        print(
+            f"ERROR: SPECIFY_INIT_DIR does not point to an existing directory: {raw}",
+            file=sys.stderr,
+        )
+        raise SystemExit(1)
+    if not init_root.is_dir():
+        print(
+            f"ERROR: SPECIFY_INIT_DIR does not point to an existing directory: {raw}",
+            file=sys.stderr,
+        )
+        raise SystemExit(1)
+    if not (init_root / ".specify").is_dir():
+        print(
+            "ERROR: SPECIFY_INIT_DIR is not a Spec Kit project "
+            f"(no .specify/ directory): {init_root}",
+            file=sys.stderr,
+        )
+        raise SystemExit(1)
+    return init_root
+
+
+def get_repo_root(script_file: Path | None = None) -> Path:
+    if os.environ.get("SPECIFY_INIT_DIR"):
+        return resolve_specify_init_dir()
+
+    specify_root = find_specify_root()
+    if specify_root is not None:
+        return specify_root
+
+    if script_file is not None:
+        script_root = find_specify_root(script_file.resolve().parent)
+        if script_root is not None:
+            return script_root
+
+        # Installed scripts live at .specify/scripts/python/<script>.py.
+        return script_file.resolve().parents[3]
+    return Path.cwd().resolve()
+
+
+def get_current_branch() -> str:
+    return os.environ.get("SPECIFY_FEATURE", "")
+
+
+def read_feature_json_feature_directory(repo_root: Path) -> str:
+    feature_json = repo_root / ".specify" / "feature.json"
+    if not feature_json.is_file():
+        return ""
+    try:
+        data = json.loads(feature_json.read_text(encoding="utf-8"))
+    except (OSError, json.JSONDecodeError):
+        return ""
+    value = data.get("feature_directory") if isinstance(data, dict) else None
+    return value if isinstance(value, str) else ""
+
+
+def _json_dump(data: dict[str, str]) -> str:
+    return json.dumps(data, ensure_ascii=False, separators=(",", ":")) + "\n"
+
+
+def persist_feature_json(repo_root: Path, feature_dir_value: str) -> None:
+    value = feature_dir_value
+    try:
+        relative = Path(value)
+        if relative.is_absolute():
+            try:
+                value = relative.resolve().relative_to(repo_root.resolve()).as_posix()
+            except ValueError:
+                value = str(relative)
+    except OSError:
+        pass
+
+    current = read_feature_json_feature_directory(repo_root)
+    if current == value:
+        return
+
+    specify_dir = repo_root / ".specify"
+    specify_dir.mkdir(parents=True, exist_ok=True)
+    (specify_dir / "feature.json").write_text(
+        _json_dump({"feature_directory": value}),
+        encoding="utf-8",
+    )
+
+
+@dataclass(frozen=True)
+class FeaturePaths:
+    repo_root: Path
+    current_branch: str
+    feature_dir: Path
+    feature_spec: Path
+    impl_plan: Path
+    tasks: Path
+    research: Path
+    data_model: Path
+    quickstart: Path
+    contracts_dir: Path
+
+
+def get_feature_paths(
+    *, no_persist: bool = False, script_file: Path | None = None
+) -> FeaturePaths:
+    repo_root = get_repo_root(script_file)
+    current_branch = get_current_branch()
+
+    feature_dir_raw = os.environ.get("SPECIFY_FEATURE_DIRECTORY", "")
+    if feature_dir_raw:
+        feature_dir = Path(feature_dir_raw)
+        if not feature_dir.is_absolute():
+            feature_dir = repo_root / feature_dir
+        if not no_persist:
+            persist_feature_json(repo_root, feature_dir_raw)
+    elif (repo_root / ".specify" / "feature.json").is_file():
+        stored = read_feature_json_feature_directory(repo_root)
+        if not stored:
+            print(
+                "ERROR: Feature directory not found. Set SPECIFY_FEATURE_DIRECTORY "
+                "or ensure .specify/feature.json contains feature_directory.",
+                file=sys.stderr,
+            )
+            raise SystemExit(1)
+        feature_dir = Path(stored)
+        if not feature_dir.is_absolute():
+            feature_dir = repo_root / feature_dir
+    else:
+        print(
+            "ERROR: Feature directory not found. Set SPECIFY_FEATURE_DIRECTORY "
+            "or run the specify command to create .specify/feature.json.",
+            file=sys.stderr,
+        )
+        raise SystemExit(1)
+
+    if not current_branch:
+        current_branch = Path(_trim_trailing_separators(feature_dir)).name
+
+    return FeaturePaths(
+        repo_root=repo_root,
+        current_branch=current_branch,
+        feature_dir=feature_dir,
+        feature_spec=feature_dir / "spec.md",
+        impl_plan=feature_dir / "plan.md",
+        tasks=feature_dir / "tasks.md",
+        research=feature_dir / "research.md",
+        data_model=feature_dir / "data-model.md",
+        quickstart=feature_dir / "quickstart.md",
+        contracts_dir=feature_dir / "contracts",
+    )
+
+
+def get_invoke_separator(repo_root: Path) -> str:
+    integration_json = repo_root / ".specify" / "integration.json"
+    if not integration_json.is_file():
+        return "."
+    try:
+        state = json.loads(integration_json.read_text(encoding="utf-8"))
+        key = state.get("default_integration") or state.get("integration") or ""
+        settings = state.get("integration_settings")
+        if isinstance(key, str) and isinstance(settings, dict):
+            entry = settings.get(key)
+            if isinstance(entry, dict) and entry.get("invoke_separator") in {".", "-"}:
+                return entry["invoke_separator"]
+    except (OSError, json.JSONDecodeError):
+        pass
+    return "."
+
+
+def format_speckit_command(command_name: str, repo_root: Path) -> str:
+    separator = get_invoke_separator(repo_root)
+    name = command_name.lstrip("/")
+    if name.startswith("speckit."):
+        name = name[len("speckit.") :]
+    elif name.startswith("speckit-"):
+        name = name[len("speckit-") :]
+    name = name.replace(".", separator)
+    return f"/speckit{separator}{name}"
diff --git a/tests/test_check_prerequisites_python_parity.py b/tests/test_check_prerequisites_python_parity.py
new file mode 100644
index 0000000000..72970188df
--- /dev/null
+++ b/tests/test_check_prerequisites_python_parity.py
@@ -0,0 +1,333 @@
+"""Parity tests for the Python check-prerequisites PoC."""
+
+from __future__ import annotations
+
+import json
+import os
+import shutil
+import subprocess
+import sys
+from pathlib import Path
+
+import pytest
+
+from tests.conftest import requires_bash
+
+PROJECT_ROOT = Path(__file__).resolve().parent.parent
+COMMON_SH = PROJECT_ROOT / "scripts" / "bash" / "common.sh"
+CHECK_PREREQS_SH = PROJECT_ROOT / "scripts" / "bash" / "check-prerequisites.sh"
+COMMON_PS = PROJECT_ROOT / "scripts" / "powershell" / "common.ps1"
+CHECK_PREREQS_PS = PROJECT_ROOT / "scripts" / "powershell" / "check-prerequisites.ps1"
+COMMON_PY = PROJECT_ROOT / "scripts" / "python" / "common.py"
+CHECK_PREREQS_PY = PROJECT_ROOT / "scripts" / "python" / "check_prerequisites.py"
+
+HAS_PWSH = shutil.which("pwsh") is not None
+_WINDOWS_POWERSHELL = (
+    shutil.which("powershell.exe") or shutil.which("powershell")
+) if os.name == "nt" else None
+
+
+def _install_scripts(repo: Path) -> None:
+    bash_dir = repo / ".specify" / "scripts" / "bash"
+    bash_dir.mkdir(parents=True, exist_ok=True)
+    shutil.copy(COMMON_SH, bash_dir / "common.sh")
+    shutil.copy(CHECK_PREREQS_SH, bash_dir / "check-prerequisites.sh")
+
+    ps_dir = repo / ".specify" / "scripts" / "powershell"
+    ps_dir.mkdir(parents=True, exist_ok=True)
+    shutil.copy(COMMON_PS, ps_dir / "common.ps1")
+    shutil.copy(CHECK_PREREQS_PS, ps_dir / "check-prerequisites.ps1")
+
+    py_dir = repo / ".specify" / "scripts" / "python"
+    py_dir.mkdir(parents=True, exist_ok=True)
+    shutil.copy(COMMON_PY, py_dir / "common.py")
+    shutil.copy(CHECK_PREREQS_PY, py_dir / "check_prerequisites.py")
+
+
+def _write_feature_json(
+    repo: Path, feature_directory: str = "specs/001-my-feature"
+) -> None:
+    (repo / ".specify" / "feature.json").write_text(
+        json.dumps({"feature_directory": feature_directory}, separators=(",", ":"))
+        + "\n",
+        encoding="utf-8",
+    )
+
+
+def _clean_env() -> dict[str, str]:
+    env = os.environ.copy()
+    for key in list(env):
+        if key.startswith("SPECIFY_"):
+            env.pop(key)
+    return env
+
+
+def _git_init(repo: Path) -> None:
+    subprocess.run(["git", "init", "-q"], cwd=repo, check=True)
+    subprocess.run(
+        ["git", "config", "user.email", "test@example.com"], cwd=repo, check=True
+    )
+    subprocess.run(["git", "config", "user.name", "Test User"], cwd=repo, check=True)
+    subprocess.run(
+        ["git", "commit", "--allow-empty", "-m", "init", "-q"], cwd=repo, check=True
+    )
+
+
+@pytest.fixture
+def prereq_repo(tmp_path: Path) -> Path:
+    repo = tmp_path / "proj"
+    repo.mkdir()
+    _git_init(repo)
+    (repo / ".specify").mkdir()
+    _install_scripts(repo)
+    return repo
+
+
+def _py_cmd(repo: Path, *args: str) -> list[str]:
+    script = repo / ".specify" / "scripts" / "python" / "check_prerequisites.py"
+    return [sys.executable, str(script), *args]
+
+
+def _repo_copy_py_cmd(repo: Path, *args: str) -> list[str]:
+    script = repo / "scripts" / "python" / "check_prerequisites.py"
+    return [sys.executable, str(script), *args]
+
+
+def _bash_cmd(repo: Path, *args: str) -> list[str]:
+    script = repo / ".specify" / "scripts" / "bash" / "check-prerequisites.sh"
+    return ["bash", str(script), *args]
+
+
+def _ps_cmd(repo: Path, *args: str) -> list[str]:
+    script = repo / ".specify" / "scripts" / "powershell" / "check-prerequisites.ps1"
+    exe = "pwsh" if HAS_PWSH else _WINDOWS_POWERSHELL
+    return [exe, "-NoProfile", "-File", str(script), *args]
+
+
+def _run(
+    cmd: list[str], repo: Path, env: dict[str, str] | None = None
+) -> subprocess.CompletedProcess[str]:
+    return subprocess.run(
+        cmd,
+        cwd=repo,
+        capture_output=True,
+        text=True,
+        check=False,
+        env=env or _clean_env(),
+    )
+
+
+def _json_stdout(result: subprocess.CompletedProcess[str]) -> object:
+    return json.loads(result.stdout)
+
+
+def _normalize_status_text(text: str) -> str:
+    return (
+        text.replace("  ✓ ", "  [OK] ")
+        .replace("  ✗ ", "  [FAIL] ")
+        .replace("\r\n", "\n")
+    )
+
+
+def _normalize_help_text(text: str) -> str:
+    normalized = text.replace("\r\n", "\n").replace(
+        "check-prerequisites.sh", "check_prerequisites.py"
+    )
+    return "\n".join("" if not line.strip() else line for line in normalized.split("\n"))
+
+
+@requires_bash
+@pytest.mark.parametrize(
+    "args",
+    [
+        ("--json",),
+        ("--json", "--include-tasks"),
+        ("--json", "--require-tasks", "--include-tasks"),
+        ("--json", "--paths-only"),
+    ],
+)
+def test_python_json_output_matches_bash(prereq_repo: Path, args: tuple[str, ...]) -> None:
+    feat = prereq_repo / "specs" / "001-my-feature"
+    feat.mkdir(parents=True)
+    (feat / "plan.md").write_text("# plan\n", encoding="utf-8")
+    (feat / "tasks.md").write_text("# tasks\n", encoding="utf-8")
+    (feat / "research.md").write_text("# research\n", encoding="utf-8")
+    (feat / "data-model.md").write_text("# model\n", encoding="utf-8")
+    (feat / "quickstart.md").write_text("# quickstart\n", encoding="utf-8")
+    (feat / "contracts" / "v1").mkdir(parents=True)
+    _write_feature_json(prereq_repo)
+
+    bash = _run(_bash_cmd(prereq_repo, *args), prereq_repo)
+    py = _run(_py_cmd(prereq_repo, *args), prereq_repo)
+
+    assert py.returncode == bash.returncode == 0
+    assert py.stderr == bash.stderr == ""
+    assert _json_stdout(py) == _json_stdout(bash)
+
+
+@requires_bash
+def test_python_text_output_matches_bash(prereq_repo: Path) -> None:
+    feat = prereq_repo / "specs" / "001-my-feature"
+    feat.mkdir(parents=True)
+    (feat / "plan.md").write_text("# plan\n", encoding="utf-8")
+    (feat / "contracts").mkdir()
+    _write_feature_json(prereq_repo)
+
+    bash = _run(_bash_cmd(prereq_repo, "--include-tasks"), prereq_repo)
+    py = _run(_py_cmd(prereq_repo, "--include-tasks"), prereq_repo)
+
+    assert py.returncode == bash.returncode == 0
+    assert py.stderr == bash.stderr == ""
+    assert _normalize_status_text(py.stdout) == _normalize_status_text(bash.stdout)
+
+
+@requires_bash
+def test_python_help_output_matches_bash(prereq_repo: Path) -> None:
+    bash = _run(_bash_cmd(prereq_repo, "--help"), prereq_repo)
+    py = _run(_py_cmd(prereq_repo, "--help"), prereq_repo)
+
+    assert py.returncode == bash.returncode == 0
+    assert py.stderr == bash.stderr == ""
+    assert _normalize_help_text(py.stdout) == _normalize_help_text(bash.stdout)
+
+
+@requires_bash
+def test_python_unknown_option_matches_bash_error_shape(prereq_repo: Path) -> None:
+    bash = _run(_bash_cmd(prereq_repo, "--bogus"), prereq_repo)
+    py = _run(_py_cmd(prereq_repo, "--bogus"), prereq_repo)
+
+    assert py.returncode == bash.returncode == 1
+    assert py.stdout == bash.stdout == ""
+    assert py.stderr == bash.stderr
+
+
+@pytest.mark.skipif(not (HAS_PWSH or _WINDOWS_POWERSHELL), reason="no PowerShell available")
+@pytest.mark.parametrize(
+    ("py_args", "ps_args"),
+    [
+        (("--json",), ("-Json",)),
+        (("--json", "--include-tasks"), ("-Json", "-IncludeTasks")),
+        (
+            ("--json", "--require-tasks", "--include-tasks"),
+            ("-Json", "-RequireTasks", "-IncludeTasks"),
+        ),
+        (("--json", "--paths-only"), ("-Json", "-PathsOnly")),
+    ],
+)
+def test_python_json_output_matches_powershell(
+    prereq_repo: Path, py_args: tuple[str, ...], ps_args: tuple[str, ...]
+) -> None:
+    feat = prereq_repo / "specs" / "001-my-feature"
+    feat.mkdir(parents=True)
+    (feat / "plan.md").write_text("# plan\n", encoding="utf-8")
+    (feat / "tasks.md").write_text("# tasks\n", encoding="utf-8")
+    (feat / "research.md").write_text("# research\n", encoding="utf-8")
+    (feat / "data-model.md").write_text("# model\n", encoding="utf-8")
+    (feat / "quickstart.md").write_text("# quickstart\n", encoding="utf-8")
+    (feat / "contracts" / "v1").mkdir(parents=True)
+    _write_feature_json(prereq_repo)
+
+    ps = _run(_ps_cmd(prereq_repo, *ps_args), prereq_repo)
+    py = _run(_py_cmd(prereq_repo, *py_args), prereq_repo)
+
+    assert py.returncode == ps.returncode == 0
+    assert py.stderr == ps.stderr == ""
+    assert _json_stdout(py) == _json_stdout(ps)
+
+
+def test_python_repo_copy_script_file_fallback_finds_repo_root(tmp_path: Path) -> None:
+    repo = tmp_path / "proj"
+    outside = tmp_path / "outside"
+    repo.mkdir()
+    outside.mkdir()
+    _git_init(repo)
+    (repo / ".specify").mkdir()
+    _write_feature_json(repo)
+    (repo / "specs" / "001-my-feature").mkdir(parents=True)
+
+    py_dir = repo / "scripts" / "python"
+    py_dir.mkdir(parents=True)
+    shutil.copy(COMMON_PY, py_dir / "common.py")
+    shutil.copy(CHECK_PREREQS_PY, py_dir / "check_prerequisites.py")
+
+    py = _run(_repo_copy_py_cmd(repo, "--json", "--paths-only"), outside)
+
+    assert py.returncode == 0, py.stderr
+    assert Path(_json_stdout(py)["REPO_ROOT"]) == repo
+
+
+def test_python_paths_only_does_not_persist_feature_json(prereq_repo: Path) -> None:
+    (prereq_repo / "specs" / "001-my-feature").mkdir(parents=True)
+    (prereq_repo / "specs" / "002-other").mkdir(parents=True)
+    _write_feature_json(prereq_repo, "specs/001-my-feature")
+    feature_json = prereq_repo / ".specify" / "feature.json"
+    before = feature_json.read_text(encoding="utf-8")
+    env = _clean_env()
+    env["SPECIFY_FEATURE_DIRECTORY"] = "specs/002-other"
+
+    py = _run(_py_cmd(prereq_repo, "--json", "--paths-only"), prereq_repo, env=env)
+
+    assert py.returncode == 0, py.stderr
+    assert "002-other" in _json_stdout(py)["FEATURE_DIR"]
+    assert feature_json.read_text(encoding="utf-8") == before
+
+
+def test_python_normal_mode_persists_feature_json(prereq_repo: Path) -> None:
+    (prereq_repo / "specs" / "001-my-feature").mkdir(parents=True)
+    feat = prereq_repo / "specs" / "002-other"
+    feat.mkdir(parents=True)
+    (feat / "plan.md").write_text("# plan\n", encoding="utf-8")
+    _write_feature_json(prereq_repo, "specs/001-my-feature")
+    env = _clean_env()
+    env["SPECIFY_FEATURE_DIRECTORY"] = "specs/002-other"
+
+    py = _run(_py_cmd(prereq_repo, "--json"), prereq_repo, env=env)
+
+    assert py.returncode == 0, py.stderr
+    data = json.loads(
+        (prereq_repo / ".specify" / "feature.json").read_text(encoding="utf-8")
+    )
+    assert data["feature_directory"] == "specs/002-other"
+
+
+@pytest.mark.parametrize(
+    ("args", "expected"),
+    [
+        (("--json",), "Feature directory not found"),
+        (("--json",), "plan.md not found"),
+        (("--json", "--require-tasks"), "tasks.md not found"),
+    ],
+    ids=["missing_feature_context", "missing_plan", "missing_tasks"],
+)
+def test_python_negative_errors_are_stderr_only(
+    tmp_path: Path, args: tuple[str, ...], expected: str
+) -> None:
+    repo = tmp_path / "proj"
+    repo.mkdir()
+    _git_init(repo)
+    (repo / ".specify").mkdir()
+    _install_scripts(repo)
+
+    if expected in {"plan.md not found", "tasks.md not found"}:
+        feat = repo / "specs" / "001-my-feature"
+        feat.mkdir(parents=True)
+        _write_feature_json(repo)
+        if expected == "tasks.md not found":
+            (feat / "plan.md").write_text("# plan\n", encoding="utf-8")
+
+    py = _run(_py_cmd(repo, *args), repo)
+
+    assert py.returncode != 0
+    assert expected in py.stderr
+    assert expected not in py.stdout
+    assert py.stdout.strip() == ""
+
+
+def test_python_branch_falls_back_to_feature_dir_basename(prereq_repo: Path) -> None:
+    (prereq_repo / "specs" / "001-my-feature").mkdir(parents=True)
+    _write_feature_json(prereq_repo)
+
+    py = _run(_py_cmd(prereq_repo, "--json", "--paths-only"), prereq_repo)
+
+    assert py.returncode == 0, py.stderr
+    assert _json_stdout(py)["BRANCH"] == "001-my-feature"