Add LangChain vm_run wrapper example

examples/langchain_vm_run.py

@@ -0,0 +1,84 @@
+"""Thin LangChain wrapper over the public vm_run contract.
+
+Requirements:
+- `pip install langchain-core` or `uv add langchain-core`
+
+This example keeps the framework integration intentionally narrow: a single tool
+that delegates straight to `Pyro.run_in_vm(...)`.
+"""
+
+from __future__ import annotations
+
+import json
+from typing import Any, Callable, TypeVar, cast
+
+from pyro_mcp import Pyro
+
+F = TypeVar("F", bound=Callable[..., Any])
+
+
+def run_vm_run_tool(
+    *,
+    profile: str,
+    command: str,
+    vcpu_count: int,
+    mem_mib: int,
+    timeout_seconds: int = 30,
+    ttl_seconds: int = 600,
+    network: bool = False,
+) -> str:
+    pyro = Pyro()
+    result = pyro.run_in_vm(
+        profile=profile,
+        command=command,
+        vcpu_count=vcpu_count,
+        mem_mib=mem_mib,
+        timeout_seconds=timeout_seconds,
+        ttl_seconds=ttl_seconds,
+        network=network,
+    )
+    return json.dumps(result, sort_keys=True)
+
+
+def build_langchain_vm_run_tool() -> Any:
+    try:
+        from langchain_core.tools import tool  # type: ignore[import-not-found]
+    except ImportError as exc:  # pragma: no cover - dependency guard
+        raise RuntimeError(
+            "langchain-core is required for this example. Install it with "
+            "`uv add langchain-core` or `pip install langchain-core`."
+        ) from exc
+
+    decorator = cast(Callable[[F], F], tool("vm_run"))
+
+    @decorator
+    def vm_run(
+        profile: str,
+        command: str,
+        vcpu_count: int,
+        mem_mib: int,
+        timeout_seconds: int = 30,
+        ttl_seconds: int = 600,
+        network: bool = False,
+    ) -> str:
+        """Run one command in an ephemeral Firecracker VM and clean it up."""
+        return run_vm_run_tool(
+            profile=profile,
+            command=command,
+            vcpu_count=vcpu_count,
+            mem_mib=mem_mib,
+            timeout_seconds=timeout_seconds,
+            ttl_seconds=ttl_seconds,
+            network=network,
+        )
+
+    return vm_run
+
+
+def main() -> None:
+    tool = build_langchain_vm_run_tool()
+    print(tool)
+
+
+if __name__ == "__main__":
+    main()