python: deepseek-harness SDK and runtime carrier packages

python/sdk-runtime/src/deepseek_harness_runtime/__init__.py

@@ -0,0 +1,151 @@
+"""Locate the bundled DeepSeek Harness SDK runtime shipped with this package.
+
+Two runtime carriers coexist under ``runtime/``, both injected by the repo's
+``scripts/build-exe-for-python-sdk.ts`` build (neither is checked into git):
+
+- **exe (production)**: single-file executables named
+  ``dsh-jsonrpc-agent-pkg-<platform>-<arch>`` (platform in {linux, macos}, arch in
+  {x64, arm64}); the target machine needs no Node installation.
+- **node (dev-only)**: the full deploy closure under ``runtime/node/``
+  (``package.json`` + ``node_modules/``), executed as ``node
+  runtime/node/node_modules/@deepseek-ai/dsh-jsonrpc-agent/lib/bin.js`` on a
+  system Node >= 22.19. It is the current checkout's source build, never
+  selected automatically, and excluded from wheel/sdist distributions.
+
+``runtime/cordis.yml`` IS checked in: it is the default agent configuration
+the client SDK injects via ``$DSH_CORDIS_CONFIG`` for zero-config runs — the
+runtime itself always requires an explicit config and has no built-in
+fallback.
+"""
+
+from __future__ import annotations
+
+import os
+import platform
+import shutil
+import sys
+from pathlib import Path
+
+PACKAGE_METADATA_FILENAME = "deepseek-harness-runtime.json"
+
+RUNTIME_MODE_ENV_VAR = "DSH_RUNTIME_MODE"
+
+_PLATFORM_TAGS = {"linux": "linux", "darwin": "macos"}
+_ARCH_TAGS = {"x86_64": "x64", "amd64": "x64", "arm64": "arm64", "aarch64": "arm64"}
+
+_EXE_ACQUISITION_HINT = (
+    "Two ways to get the executable: run `scripts/build-exe-for-python-sdk.ts` (via tsx) in a "
+    "deepseek-harness checkout, or download the platform artifact of the `build-exe-for-python-sdk` "
+    "CI workflow; place the file in this package's runtime/ directory. For local development "
+    "against a repo source build, explicitly select the dev-only node carrier with "
+    f"{RUNTIME_MODE_ENV_VAR}=node (or resolve_bundled_launch_args('node'))."
+)
+
+
+def bundled_package_dir() -> Path:
+    """Root directory of the installed runtime package data (the directory of this module)."""
+    root = Path(__file__).resolve().parent
+    metadata = root / PACKAGE_METADATA_FILENAME
+    if not metadata.is_file():
+        raise FileNotFoundError(f"deepseek-harness-runtime-bin is missing {metadata}")
+    return root
+
+
+def bundled_default_config_path() -> Path:
+    """Path of the checked-in default runtime configuration (``runtime/cordis.yml``).
+
+    The client SDK injects this path via ``$DSH_CORDIS_CONFIG`` when the caller
+    supplies no config and the launch resolves to the bundled runtime — the
+    runtime binary itself always demands an explicit config.
+    """
+    path = bundled_package_dir() / "runtime" / "cordis.yml"
+    if not path.is_file():
+        raise FileNotFoundError(
+            f"deepseek-harness-runtime-bin is missing the default runtime config at {path}"
+        )
+    return path
+
+
+def bundled_runtime_path() -> Path:
+    """Absolute path of the bundled single-file runtime executable for the current platform.
+
+    Raises FileNotFoundError when the platform is unsupported or the executable
+    has not been placed into this package; the message names the acquisition
+    routes (acquisition strategy is deliberately separate from this lookup
+    interface, so an on-demand download can replace it without touching
+    callers).
+    """
+    tag = _current_platform_tag()
+    path = bundled_package_dir() / "runtime" / f"dsh-jsonrpc-agent-pkg-{tag}"
+    if not path.is_file():
+        raise FileNotFoundError(
+            f"deepseek-harness-runtime-bin is missing the runtime executable at {path}. "
+            + _EXE_ACQUISITION_HINT
+        )
+    return path
+
+
+def resolve_bundled_launch_args(mode: str | None = None) -> tuple[str, ...]:
+    """The argv tuple that launches the bundled runtime.
+
+    Mode selection: the explicit ``mode`` argument wins, then the
+    ``DSH_RUNTIME_MODE`` environment variable (``exe`` | ``node``), then
+    automatic resolution. Automatic resolution finds the production exe ONLY —
+    the dev-only node carrier must be selected explicitly so a production
+    deployment can never silently ride on a source build. Returns
+    ``(exe_path,)`` in exe mode and ``(node_path, bin_js_path)`` in node mode;
+    raises FileNotFoundError when the selected carrier is unavailable and
+    ValueError for an unknown mode value.
+    """
+    selected = mode if mode is not None else os.environ.get(RUNTIME_MODE_ENV_VAR)
+    if selected is None or selected == "exe":
+        return (str(bundled_runtime_path()),)
+    if selected == "node":
+        return _node_launch_args()
+    raise ValueError(
+        f"unsupported DeepSeek Harness runtime mode {selected!r}: expected 'exe' or 'node' "
+        f"(explicit argument or ${RUNTIME_MODE_ENV_VAR})"
+    )
+
+
+def _current_platform_tag() -> str:
+    plat = _PLATFORM_TAGS.get(sys.platform)
+    arch = _ARCH_TAGS.get(platform.machine().lower())
+    if plat is None or arch is None:
+        raise FileNotFoundError(
+            "no bundled dsh-jsonrpc-agent executable exists for this platform "
+            f"(sys.platform={sys.platform!r}, machine={platform.machine()!r}); supported: "
+            "linux/macos on x64/arm64. " + _EXE_ACQUISITION_HINT
+        )
+    return f"{plat}-{arch}"
+
+
+def _node_launch_args() -> tuple[str, str]:
+    node_root = bundled_package_dir() / "runtime" / "node"
+    bin_js = (
+        node_root / "node_modules" / "@deepseek-ai" / "dsh-jsonrpc-agent" / "lib" / "bin.js"
+    )
+    if not bin_js.is_file():
+        raise FileNotFoundError(
+            f"the dev-only node runtime closure is missing at {node_root} "
+            f"(no {bin_js}); run `scripts/build-exe-for-python-sdk.ts` in a deepseek-harness "
+            "checkout, which builds and copies the deploy closure here. The node carrier "
+            "is for repo-local development only — production uses the single-file exe."
+        )
+    node = shutil.which("node")
+    if node is None:
+        raise FileNotFoundError(
+            "the node runtime mode needs a system `node` (>=22.19) on PATH; "
+            "install Node.js or use the exe mode"
+        )
+    return (node, str(bin_js))
+
+
+__all__ = [
+    "PACKAGE_METADATA_FILENAME",
+    "RUNTIME_MODE_ENV_VAR",
+    "bundled_default_config_path",
+    "bundled_package_dir",
+    "bundled_runtime_path",
+    "resolve_bundled_launch_args",
+]