diff --git a/strands_robots/tools/gr00t_inference.py b/strands_robots/tools/gr00t_inference.py
index 4921e64..10c23cd 100644
--- a/strands_robots/tools/gr00t_inference.py
+++ b/strands_robots/tools/gr00t_inference.py
@@ -7,6 +7,7 @@
 """
 
 import os
+import re
 import socket
 import subprocess
 import time
@@ -14,6 +15,82 @@
 
 from strands import tool
 
+# ─────────────────────────────────────────────────────────────────────
+# Input validation helpers
+# ─────────────────────────────────────────────────────────────────────
+
+# Characters that must never appear in values interpolated into commands.
+_SHELL_META = re.compile(r"[;&|`$(){}\[\]!<>\\'\"\n\r\x00]")
+
+# Strict patterns for enumerable parameters.
+_DATA_CONFIG_RE = re.compile(r"^[a-z][a-z0-9_]{0,63}$")
+_EMBODIMENT_TAG_RE = re.compile(r"^[a-z][a-z0-9_]{0,31}$")
+_CONTAINER_NAME_RE = re.compile(r"^[a-zA-Z0-9][a-zA-Z0-9._-]{0,127}$")
+
+# Allowlists for TensorRT dtype parameters.
+_VALID_VIT_DTYPES = {"fp16", "fp8"}
+_VALID_LLM_DTYPES = {"fp16", "nvfp4", "fp8"}
+_VALID_DIT_DTYPES = {"fp16", "fp8"}
+
+
+def _validate_path(value: str, label: str) -> None:
+    """Reject paths containing shell metacharacters, null bytes, or traversal sequences."""
+    if "\x00" in value:
+        raise ValueError(f"{label} must not contain null bytes")
+    if ".." in value.split("/"):
+        raise ValueError(f"{label} must not contain '..' path traversal components")
+    if _SHELL_META.search(value):
+        raise ValueError(f"{label} contains disallowed characters: {value!r}")
+
+
+def validate_inputs(
+    *,
+    data_config: str,
+    embodiment_tag: str,
+    port: int,
+    vit_dtype: str,
+    llm_dtype: str,
+    dit_dtype: str,
+    checkpoint_path: str | None = None,
+    trt_engine_path: str = "gr00t_engine",
+    container_name: str | None = None,
+) -> None:
+    """Validate all user-supplied parameters in one place.
+
+    Raises ValueError for any invalid input. This centralises validation so
+    that the main tool function stays focused on orchestration and each
+    check is independently testable via this single entry-point.
+    """
+    # Enumerable string parameters
+    if not _DATA_CONFIG_RE.match(data_config):
+        raise ValueError(
+            f"data_config must be lowercase alphanumeric/underscore (got {data_config!r}). "
+            f"See the tool docstring for the full list of accepted configs."
+        )
+    if not _EMBODIMENT_TAG_RE.match(embodiment_tag):
+        raise ValueError(f"embodiment_tag must be lowercase alphanumeric/underscore (got {embodiment_tag!r})")
+
+    # Docker container name
+    if container_name is not None and not _CONTAINER_NAME_RE.match(container_name):
+        raise ValueError(f"container_name must match Docker naming rules (got {container_name!r})")
+
+    # Filesystem paths — reject shell metacharacters and traversal
+    if checkpoint_path is not None:
+        _validate_path(checkpoint_path, "checkpoint_path")
+    _validate_path(trt_engine_path, "trt_engine_path")
+
+    # TensorRT dtype allowlists
+    if vit_dtype not in _VALID_VIT_DTYPES:
+        raise ValueError(f"vit_dtype must be one of {_VALID_VIT_DTYPES}, got {vit_dtype!r}")
+    if llm_dtype not in _VALID_LLM_DTYPES:
+        raise ValueError(f"llm_dtype must be one of {_VALID_LLM_DTYPES}, got {llm_dtype!r}")
+    if dit_dtype not in _VALID_DIT_DTYPES:
+        raise ValueError(f"dit_dtype must be one of {_VALID_DIT_DTYPES}, got {dit_dtype!r}")
+
+    # Port range
+    if not (1 <= port <= 65535):
+        raise ValueError(f"port must be between 1 and 65535, got {port}")
+
 
 @tool
 def gr00t_inference(
@@ -24,7 +101,7 @@ def gr00t_inference(
     data_config: str = "fourier_gr1_arms_only",
     embodiment_tag: str = "gr1",
     denoising_steps: int = 4,
-    host: str = "0.0.0.0",
+    host: str = "127.0.0.1",
     container_name: str | None = None,
     timeout: int = 60,
     use_tensorrt: bool = False,
@@ -112,7 +189,7 @@ def gr00t_inference(
         data_config: Embodiment data config name (see Data configs above).
         embodiment_tag: Embodiment tag for the model (e.g., ``gr1``, ``so100``).
         denoising_steps: Number of denoising steps for action generation (default: 4).
-        host: Host address to bind the service to (default: ``0.0.0.0``).
+        host: Host address to bind the service to (default: ``127.0.0.1``).
         container_name: Specific Docker container name. Auto-detected if omitted.
         timeout: Seconds to wait for service startup (default: 60).
         use_tensorrt: Enable TensorRT acceleration (default: False).
@@ -180,6 +257,19 @@ def gr00t_inference(
     if api_token is None:
         api_token = os.environ.get("GROOT_API_TOKEN")
 
+    # ── Validate all inputs in one call ───────────────────────────────
+    validate_inputs(
+        data_config=data_config,
+        embodiment_tag=embodiment_tag,
+        port=port,
+        vit_dtype=vit_dtype,
+        llm_dtype=llm_dtype,
+        dit_dtype=dit_dtype,
+        checkpoint_path=checkpoint_path,
+        trt_engine_path=trt_engine_path,
+        container_name=container_name,
+    )
+
     if action == "find_containers":
         return _find_gr00t_containers()
     elif action == "list":
@@ -314,6 +404,27 @@ def _check_service_status(port: int) -> dict[str, Any]:
         }
 
 
+def _is_gr00t_process(container_name: str, pid: str) -> bool:
+    """Verify that a PID inside a container belongs to a GR00T inference process.
+
+    This prevents accidentally killing unrelated processes that happen to
+    be listening on the same port.
+    """
+    try:
+        result = subprocess.run(
+            ["docker", "exec", container_name, "cat", f"/proc/{pid}/cmdline"],
+            capture_output=True,
+            text=True,
+            check=False,
+        )
+        if result.returncode == 0:
+            cmdline = result.stdout.replace("\x00", " ")
+            return "inference_service" in cmdline or "gr00t" in cmdline.lower()
+    except Exception:
+        pass
+    return False
+
+
 def _stop_service(port: int) -> dict[str, Any]:
     """Stop GR00T inference service running on specific port."""
     try:
@@ -334,13 +445,21 @@ def _stop_service(port: int) -> dict[str, Any]:
                     if result.returncode == 0 and result.stdout.strip():
                         pids = result.stdout.strip().split("\n")
                         for pid in pids:
-                            if pid:
+                            pid = pid.strip()
+                            if pid and _is_gr00t_process(container_name, pid):
                                 subprocess.run(["docker", "exec", container_name, "kill", "-TERM", pid], check=True)
 
                         time.sleep(2)
 
                         result = subprocess.run(
-                            ["docker", "exec", container_name, "pgrep", "-f", f"inference_service.py.*--port {port}"],
+                            [
+                                "docker",
+                                "exec",
+                                container_name,
+                                "pgrep",
+                                "-f",
+                                f"inference_service.py.*--port {port}",
+                            ],
                             capture_output=True,
                             text=True,
                             check=False,
@@ -349,7 +468,8 @@ def _stop_service(port: int) -> dict[str, Any]:
                         if result.returncode == 0 and result.stdout.strip():
                             pids = result.stdout.strip().split("\n")
                             for pid in pids:
-                                if pid:
+                                pid = pid.strip()
+                                if pid and _is_gr00t_process(container_name, pid):
                                     subprocess.run(["docker", "exec", container_name, "kill", "-KILL", pid], check=True)
 
                         return {
@@ -362,22 +482,32 @@ def _stop_service(port: int) -> dict[str, Any]:
                 except subprocess.CalledProcessError:
                     continue
 
-        # Fallback: try host system
-        result = subprocess.run(["lsof", "-t", f"-i:{port}"], capture_output=True, text=True)
+        # Fallback: try host system — only kill processes that match inference_service
+        result = subprocess.run(
+            ["pgrep", "-f", f"inference_service.py.*--port {port}"],
+            capture_output=True,
+            text=True,
+        )
 
         if result.returncode == 0:
             pids = result.stdout.strip().split("\n")
             for pid in pids:
+                pid = pid.strip()
                 if pid:
                     subprocess.run(["kill", "-TERM", pid], check=True)
 
             time.sleep(2)
 
-            result = subprocess.run(["lsof", "-t", f"-i:{port}"], capture_output=True, text=True)
+            result = subprocess.run(
+                ["pgrep", "-f", f"inference_service.py.*--port {port}"],
+                capture_output=True,
+                text=True,
+            )
 
             if result.returncode == 0:
                 pids = result.stdout.strip().split("\n")
                 for pid in pids:
+                    pid = pid.strip()
                     if pid:
                         subprocess.run(["kill", "-KILL", pid], check=True)
 
diff --git a/tests/groot/test_gr00t_inference_validation.py b/tests/groot/test_gr00t_inference_validation.py
new file mode 100644
index 0000000..f059ce6
--- /dev/null
+++ b/tests/groot/test_gr00t_inference_validation.py
@@ -0,0 +1,194 @@
+"""Tests for gr00t_inference input validation."""
+
+import pytest
+
+from strands_robots.tools.gr00t_inference import validate_inputs
+
+
+class TestValidateInputs:
+    """Test the centralised validate_inputs() function."""
+
+    def test_valid_defaults(self):
+        """Default parameter values must pass validation."""
+        validate_inputs(
+            data_config="fourier_gr1_arms_only",
+            embodiment_tag="gr1",
+            port=5555,
+            vit_dtype="fp8",
+            llm_dtype="nvfp4",
+            dit_dtype="fp8",
+        )
+
+    def test_valid_with_all_optional(self):
+        """All optional parameters provided with valid values."""
+        validate_inputs(
+            data_config="so100_dualcam",
+            embodiment_tag="so100",
+            port=8000,
+            vit_dtype="fp16",
+            llm_dtype="fp16",
+            dit_dtype="fp16",
+            checkpoint_path="/data/checkpoints/model",
+            trt_engine_path="my_engine",
+            container_name="isaac-gr00t-1",
+        )
+
+    # ── data_config ──────────────────────────────────────────────────
+
+    def test_invalid_data_config_uppercase(self):
+        with pytest.raises(ValueError, match="data_config"):
+            validate_inputs(
+                data_config="UPPER",
+                embodiment_tag="gr1",
+                port=5555,
+                vit_dtype="fp8",
+                llm_dtype="nvfp4",
+                dit_dtype="fp8",
+            )
+
+    def test_invalid_data_config_shell_chars(self):
+        with pytest.raises(ValueError, match="data_config"):
+            validate_inputs(
+                data_config="config;rm -rf /",
+                embodiment_tag="gr1",
+                port=5555,
+                vit_dtype="fp8",
+                llm_dtype="nvfp4",
+                dit_dtype="fp8",
+            )
+
+    # ── embodiment_tag ───────────────────────────────────────────────
+
+    def test_invalid_embodiment_tag(self):
+        with pytest.raises(ValueError, match="embodiment_tag"):
+            validate_inputs(
+                data_config="so100",
+                embodiment_tag="BAD TAG!",
+                port=5555,
+                vit_dtype="fp8",
+                llm_dtype="nvfp4",
+                dit_dtype="fp8",
+            )
+
+    # ── port ─────────────────────────────────────────────────────────
+
+    def test_port_zero(self):
+        with pytest.raises(ValueError, match="port"):
+            validate_inputs(
+                data_config="so100",
+                embodiment_tag="so100",
+                port=0,
+                vit_dtype="fp8",
+                llm_dtype="nvfp4",
+                dit_dtype="fp8",
+            )
+
+    def test_port_too_high(self):
+        with pytest.raises(ValueError, match="port"):
+            validate_inputs(
+                data_config="so100",
+                embodiment_tag="so100",
+                port=70000,
+                vit_dtype="fp8",
+                llm_dtype="nvfp4",
+                dit_dtype="fp8",
+            )
+
+    # ── dtype allowlists ─────────────────────────────────────────────
+
+    def test_invalid_vit_dtype(self):
+        with pytest.raises(ValueError, match="vit_dtype"):
+            validate_inputs(
+                data_config="so100",
+                embodiment_tag="so100",
+                port=5555,
+                vit_dtype="int8",
+                llm_dtype="nvfp4",
+                dit_dtype="fp8",
+            )
+
+    def test_invalid_llm_dtype(self):
+        with pytest.raises(ValueError, match="llm_dtype"):
+            validate_inputs(
+                data_config="so100",
+                embodiment_tag="so100",
+                port=5555,
+                vit_dtype="fp8",
+                llm_dtype="bf16",
+                dit_dtype="fp8",
+            )
+
+    def test_invalid_dit_dtype(self):
+        with pytest.raises(ValueError, match="dit_dtype"):
+            validate_inputs(
+                data_config="so100",
+                embodiment_tag="so100",
+                port=5555,
+                vit_dtype="fp8",
+                llm_dtype="nvfp4",
+                dit_dtype="nvfp4",
+            )
+
+    # ── path validation ──────────────────────────────────────────────
+
+    def test_checkpoint_path_traversal(self):
+        with pytest.raises(ValueError, match="checkpoint_path"):
+            validate_inputs(
+                data_config="so100",
+                embodiment_tag="so100",
+                port=5555,
+                vit_dtype="fp8",
+                llm_dtype="nvfp4",
+                dit_dtype="fp8",
+                checkpoint_path="/data/../../../etc/passwd",
+            )
+
+    def test_checkpoint_path_null_byte(self):
+        with pytest.raises(ValueError, match="checkpoint_path"):
+            validate_inputs(
+                data_config="so100",
+                embodiment_tag="so100",
+                port=5555,
+                vit_dtype="fp8",
+                llm_dtype="nvfp4",
+                dit_dtype="fp8",
+                checkpoint_path="/data/model\x00.bin",
+            )
+
+    def test_trt_engine_path_shell_injection(self):
+        with pytest.raises(ValueError, match="trt_engine_path"):
+            validate_inputs(
+                data_config="so100",
+                embodiment_tag="so100",
+                port=5555,
+                vit_dtype="fp8",
+                llm_dtype="nvfp4",
+                dit_dtype="fp8",
+                trt_engine_path="engine; rm -rf /",
+            )
+
+    # ── container_name ───────────────────────────────────────────────
+
+    def test_invalid_container_name(self):
+        with pytest.raises(ValueError, match="container_name"):
+            validate_inputs(
+                data_config="so100",
+                embodiment_tag="so100",
+                port=5555,
+                vit_dtype="fp8",
+                llm_dtype="nvfp4",
+                dit_dtype="fp8",
+                container_name="-invalid",
+            )
+
+    def test_container_name_none_is_ok(self):
+        """container_name=None should pass (auto-detect)."""
+        validate_inputs(
+            data_config="so100",
+            embodiment_tag="so100",
+            port=5555,
+            vit_dtype="fp8",
+            llm_dtype="nvfp4",
+            dit_dtype="fp8",
+            container_name=None,
+        )