diff --git a/reference/python/.gitignore b/reference/python/.gitignore
index 45c9cf22c4..d7b81a9377 100644
--- a/reference/python/.gitignore
+++ b/reference/python/.gitignore
@@ -1,3 +1,4 @@
 site/
 .cache
 pyproject.prod.toml  # Backup file created by switch-config.sh
+mkdocs.subset.yml
diff --git a/reference/python/serve_subset.py b/reference/python/serve_subset.py
new file mode 100644
index 0000000000..93f76aa2cf
--- /dev/null
+++ b/reference/python/serve_subset.py
@@ -0,0 +1,167 @@
+import argparse
+import os
+import subprocess
+import sys
+
+import yaml
+
+# --- Custom YAML handling to preserve tags ---
+
+
+class EnvTag:
+    def __init__(self, value):
+        self.value = value
+
+    def __repr__(self):
+        return f"EnvTag({self.value})"
+
+
+class PythonNameTag:
+    def __init__(self, suffix):
+        self.suffix = suffix
+
+    def __repr__(self):
+        return f"PythonNameTag({self.suffix})"
+
+
+def env_constructor(loader, node):
+    if isinstance(node, yaml.SequenceNode):
+        value = loader.construct_sequence(node)
+    else:
+        value = loader.construct_scalar(node)
+    return EnvTag(value)
+
+
+def env_representer(dumper, data):
+    if isinstance(data.value, list):
+        return dumper.represent_sequence("!ENV", data.value)
+    return dumper.represent_scalar("!ENV", str(data.value))
+
+
+def python_name_multi_constructor(loader, tag_suffix, node):
+    return PythonNameTag(tag_suffix)
+
+
+def python_name_representer(dumper, data):
+    return dumper.represent_scalar(f"tag:yaml.org,2002:python/name:{data.suffix}", "")
+
+
+# Register with SafeLoader
+yaml.SafeLoader.add_constructor("!ENV", env_constructor)
+yaml.SafeLoader.add_multi_constructor(
+    "tag:yaml.org,2002:python/name:", python_name_multi_constructor
+)
+
+
+# Custom Dumper
+class CustomDumper(yaml.SafeDumper):
+    pass
+
+
+CustomDumper.add_representer(EnvTag, env_representer)
+CustomDumper.add_representer(PythonNameTag, python_name_representer)
+
+# --- End Custom YAML handling ---
+
+
+def main():
+    parser = argparse.ArgumentParser(description="Serve a subset of the documentation.")
+    parser.add_argument(
+        "section",
+        help="The section of the nav to include (e.g., 'LangGraph', 'Integrations'). Case-insensitive.",
+    )
+    parser.add_argument(
+        "--config", default="mkdocs.yml", help="Path to the input mkdocs.yml file."
+    )
+    parser.add_argument(
+        "--out",
+        default="mkdocs.subset.yml",
+        help="Path to the output temporary config file.",
+    )
+    parser.add_argument(
+        "--clean", action="store_true", help="Build a clean version (no dirty reload)."
+    )
+
+    args = parser.parse_args()
+
+    try:
+        with open(args.config) as f:
+            config = yaml.load(f, Loader=yaml.SafeLoader)
+    except FileNotFoundError:
+        print(f"Error: Could not find {args.config}")
+        sys.exit(1)
+    except yaml.YAMLError as e:
+        print(f"Error parsing YAML: {e}")
+        sys.exit(1)
+
+    if "nav" not in config:
+        print("Error: 'nav' section not found in mkdocs.yml")
+        sys.exit(1)
+
+    original_nav = config["nav"]
+    new_nav = []
+
+    target = args.section.lower()
+    found = False
+
+    for item in original_nav:
+        # Item is usually a dict { "Name": "path" } or { "Name": [...] }
+        if isinstance(item, dict):
+            key = list(item.keys())[0]
+            value = item[key]
+
+            # Always keep "Get started" or root index to ensure site builds
+            if "get started" in key.lower() or (
+                isinstance(value, str) and value == "index.md"
+            ):
+                new_nav.append(item)
+                continue
+
+            # Check if this is the requested section
+            if target in key.lower():
+                new_nav.append(item)
+                found = True
+        elif isinstance(item, str):
+            # String item
+            if target in item.lower():
+                new_nav.append(item)
+                found = True
+
+    if not found:
+        print(f"Error: No section matching '{args.section}' found in nav.")
+        print("Available top-level sections:")
+        for item in original_nav:
+            if isinstance(item, dict):
+                print(f" - {list(item.keys())[0]}")
+            else:
+                print(f" - {item}")
+        sys.exit(1)
+
+    config["nav"] = new_nav
+
+    # Write the new config
+    with open(args.out, "w") as f:
+        yaml.dump(config, f, Dumper=CustomDumper, sort_keys=False)
+
+    print(
+        f"Generated {args.out} with sections: {[list(i.keys())[0] for i in new_nav if isinstance(i, dict)]}"
+    )
+
+    # Run mkdocs serve
+    cmd = ["uv", "run", "--no-sync", "python", "-m", "mkdocs", "serve", "-f", args.out]
+    if not args.clean:
+        cmd.append("--dirty")
+
+    print(f"Running: {' '.join(cmd)}")
+    try:
+        subprocess.run(cmd, check=True)
+    except KeyboardInterrupt:
+        print("\nStopping server...")
+    finally:
+        if os.path.exists(args.out):
+            os.remove(args.out)
+            print(f"Removed {args.out}")
+
+
+if __name__ == "__main__":
+    main()