Add filter with metadata using restricts

README.md

@@ -6,7 +6,24 @@ An MCP (Model Context Protocol) server that exposes a `knowledge_search` tool fo
 
 1. A natural-language query is embedded using a Gemini embedding model.
 2. The embedding is sent to a Vertex AI Matching Engine index endpoint to find nearest neighbors.
-3. The matched document contents are fetched from a GCS bucket and returned to the caller.
+3. Optional filters (restricts) can be applied to search only specific source folders.
+4. The matched document contents are fetched from a GCS bucket and returned to the caller.
+
+## Filtering by Source Folder
+
+The `knowledge_search` tool supports filtering results by source folder:
+
+```python
+# Search all folders
+knowledge_search(query="what is a savings account?")
+
+# Search only in specific folders
+knowledge_search(
+    query="what is a savings account?",
+    source_folders=["Educacion Financiera", "Productos y Servicios"]
+)
+```
+
 
 ## Prerequisites
 

agent.py

@@ -57,9 +57,20 @@ async def async_main() -> None:
         model="gemini-2.0-flash",
         name="knowledge_agent",
         instruction=(
-            "You are a helpful assistant with access to a knowledge base. "
-            "Use the knowledge_search tool to find relevant information "
-            "when the user asks questions. Summarize the results clearly."
+            "You are a helpful assistant with access to a knowledge base organized by folders. "
+            "Use the knowledge_search tool to find relevant information when the user asks questions.\n\n"
+            "Available folders in the knowledge base:\n"
+            "- 'Educacion Financiera': Educational content about finance, savings, investments, financial concepts\n"
+            "- 'Funcionalidades de la App Movil': Mobile app features, functionality, usage instructions\n"
+            "- 'Productos y Servicios': Bank products and services, accounts, procedures\n\n"
+            "IMPORTANT: When the user asks about a specific topic, analyze which folders are relevant "
+            "and use the source_folders parameter to filter results for more precise answers.\n\n"
+            "Examples:\n"
+            "- User asks about 'cuenta de ahorros' → Use source_folders=['Educacion Financiera', 'Productos y Servicios']\n"
+            "- User asks about 'cómo usar la app móvil' → Use source_folders=['Funcionalidades de App Movil']\n"
+            "- User asks about 'transferencias en la app' → Use source_folders=['Funcionalidades de App Movil', 'Productos y Servicios']\n"
+            "- User asks general question → Don't use source_folders (search all)\n\n"
+            "Summarize the results clearly in Spanish."
         ),
         tools=[toolset],
     )

main.py

@@ -1,8 +1,11 @@
 # ruff: noqa: INP001
 """Async helpers for querying Vertex AI vector search via MCP."""
 
+import argparse
 import asyncio
 import io
+import logging
+import os
 from collections.abc import AsyncIterator, Sequence
 from contextlib import asynccontextmanager
 from dataclasses import dataclass
@@ -14,8 +17,9 @@ from gcloud.aio.storage import Storage
 from google import genai
 from google.genai import types as genai_types
 from mcp.server.fastmcp import Context, FastMCP
+from pydantic_settings import BaseSettings, PydanticBaseSettingsSource, YamlConfigSettingsSource
 
-from .utils import Settings, _args, log_structured_entry
+logger = logging.getLogger(__name__)
 
 HTTP_TOO_MANY_REQUESTS = 429
 HTTP_SERVER_ERROR = 500
@@ -87,9 +91,12 @@ class GoogleCloudFileStorage:
                 file_stream.name = file_name
             except TimeoutError as exc:
                 last_exception = exc
-                log_structured_entry(
-                    f"Timeout downloading gs://{self.bucket_name}/{file_name} (attempt {attempt + 1}/{max_retries})"
-                    "WARNING"
+                logger.warning(
+                    "Timeout downloading gs://%s/%s (attempt %d/%d)",
+                    self.bucket_name,
+                    file_name,
+                    attempt + 1,
+                    max_retries,
                 )
             except aiohttp.ClientResponseError as exc:
                 last_exception = exc
@@ -97,9 +104,13 @@ class GoogleCloudFileStorage:
                     exc.status == HTTP_TOO_MANY_REQUESTS
                     or exc.status >= HTTP_SERVER_ERROR
                 ):
-                     log_structured_entry(
-                        f"HTTP {exc.status} downloading gs://{self.bucket_name}/{file_name} (attempt {attempt + 1}/{max_retries})"
-                        "WARNING"
+                    logger.warning(
+                        "HTTP %d downloading gs://%s/%s (attempt %d/%d)",
+                        exc.status,
+                        self.bucket_name,
+                        file_name,
+                        attempt + 1,
+                        max_retries,
                     )
                 else:
                     raise
@@ -193,6 +204,7 @@ class GoogleCloudVectorSearch:
         deployed_index_id: str,
         query: Sequence[float],
         limit: int,
+        restricts: list[dict[str, list[str]]] | None = None,
     ) -> list[SearchResult]:
         """Run an async similarity search via the REST API.
 
@@ -218,14 +230,18 @@ class GoogleCloudVectorSearch:
             f"/locations/{self.location}"
             f"/indexEndpoints/{endpoint_id}:findNeighbors"
         )
+        query_payload = {
+            "datapoint": {"feature_vector": list(query)},
+            "neighbor_count": limit,
+        }
+
+        # Add restricts if provided
+        if restricts:
+            query_payload["restricts"] = restricts
+
         payload = {
             "deployed_index_id": deployed_index_id,
-            "queries": [
-                {
-                    "datapoint": {"feature_vector": list(query)},
-                    "neighbor_count": limit,
-                },
-            ],
+            "queries": [query_payload],
         }
 
         headers = await self._async_get_auth_headers()
@@ -272,6 +288,58 @@ class GoogleCloudVectorSearch:
 # ---------------------------------------------------------------------------
 
 
+def _parse_args() -> argparse.Namespace:
+    parser = argparse.ArgumentParser()
+    parser.add_argument(
+        "--transport",
+        choices=["stdio", "sse"],
+        default="stdio",
+    )
+    parser.add_argument("--host", default="0.0.0.0")
+    parser.add_argument("--port", type=int, default=8080)
+    parser.add_argument(
+        "--config",
+        default=os.environ.get("CONFIG_FILE", "config.yaml"),
+    )
+    return parser.parse_args()
+
+
+_args = _parse_args()
+
+
+class Settings(BaseSettings):
+    """Server configuration populated from env vars and a YAML config file."""
+
+    model_config = {"env_file": ".env", "yaml_file": _args.config}
+
+    project_id: str
+    location: str
+    bucket: str
+    index_name: str
+    deployed_index_id: str
+    endpoint_name: str
+    endpoint_domain: str
+    embedding_model: str = "gemini-embedding-001"
+    search_limit: int = 10
+
+    @classmethod
+    def settings_customise_sources(
+        cls,
+        settings_cls: type[BaseSettings],
+        init_settings: PydanticBaseSettingsSource,
+        env_settings: PydanticBaseSettingsSource,
+        dotenv_settings: PydanticBaseSettingsSource,
+        file_secret_settings: PydanticBaseSettingsSource,
+    ) -> tuple[PydanticBaseSettingsSource, ...]:
+        return (
+            init_settings,
+            env_settings,
+            dotenv_settings,
+            YamlConfigSettingsSource(settings_cls),
+            file_secret_settings,
+        )
+
+
 @dataclass
 class AppContext:
     """Shared resources initialised once at server startup."""
@@ -322,12 +390,16 @@ mcp = FastMCP(
 async def knowledge_search(
     query: str,
     ctx: Context,
+    source_folders: list[str] | None = None,
 ) -> str:
     """Search a knowledge base using a natural-language query.
 
     Args:
         query: The text query to search for.
         ctx: MCP request context (injected automatically).
+        source_folders: Optional list of source folder paths to filter results.
+                       If provided, only documents from these folders will be returned.
+                       Example: ["Educacion Financiera", "Productos y Servicios"]
 
     Returns:
         A formatted string containing matched documents with id and content.
@@ -350,13 +422,31 @@ async def knowledge_search(
     embedding = response.embeddings[0].values
     t_embed = time.perf_counter()
 
+    # Build restricts for source folder filtering if provided
+    restricts = None
+    if source_folders:
+        restricts = [
+            {
+                "namespace": "source_folder",
+                "allow": source_folders,
+            }
+        ]
+        logger.info(f"Filtering by source_folders: {source_folders}")
+    else:
+        logger.info("No filtering - searching all folders")
+
     search_results = await app.vector_search.async_run_query(
         deployed_index_id=app.settings.deployed_index_id,
         query=embedding,
         limit=app.settings.search_limit,
+        restricts=restricts,
     )
     t_search = time.perf_counter()
 
+    # Log raw results from Vertex AI before similarity filtering
+    logger.info(f"Raw results from Vertex AI (before similarity filter): {len(search_results)} chunks")
+    logger.info(f"Raw chunk IDs: {[s['id'] for s in search_results]}")
+
     # Apply similarity filtering
     if search_results:
         max_sim = max(r["distance"] for r in search_results)
@@ -366,16 +456,13 @@ async def knowledge_search(
             for s in search_results
             if s["distance"] > cutoff and s["distance"] > min_sim
         ]
-    
-    log_structured_entry(
-        "knowledge_search timing",
-        "INFO",
-        {
-            "embedding": f"{round((t_embed - t0) * 1000, 1)}ms",
-            "vector_serach": f"{round((t_search - t_embed) * 1000, 1)}ms",
-            "total": f"{round((t_search - t0) * 1000, 1)}ms",
-            "chunks": {[s["id"] for s in search_results]}
-        }
+
+    logger.info(
+        "knowledge_search timing: embedding=%sms, vector_search=%sms, total=%sms, chunks=%s",
+        round((t_embed - t0) * 1000, 1),
+        round((t_search - t_embed) * 1000, 1),
+        round((t_search - t0) * 1000, 1),
+        [s["id"] for s in search_results],
     )
 
     # Format results as XML-like documents

utils/__init__.py

@@ -1,4 +0,0 @@
-from .config import Settings, _args
-from .logging_setup import log_structured_entry
-
-__all__ = ['Settings', '_args', 'log_structured_entry']

utils/config.py

@@ -1,54 +0,0 @@
-import os
-import argparse
-from pydantic_settings import BaseSettings, PydanticBaseSettingsSource, YamlConfigSettingsSource
-
-
-def _parse_args() -> argparse.Namespace:
-    parser = argparse.ArgumentParser()
-    parser.add_argument(
-        "--transport",
-        choices=["stdio", "sse"],
-        default="stdio",
-    )
-    parser.add_argument("--host", default="0.0.0.0")
-    parser.add_argument("--port", type=int, default=8080)
-    parser.add_argument(
-        "--config",
-        default=os.environ.get("CONFIG_FILE", "config.yaml"),
-    )
-    return parser.parse_args()
-
-
-_args = _parse_args()
-
-class Settings(BaseSettings):
-    """Server configuration populated from env vars and a YAML config file."""
-
-    model_config = {"env_file": ".env", "yaml_file": _args.config}
-
-    project_id: str
-    location: str
-    bucket: str
-    index_name: str
-    deployed_index_id: str
-    endpoint_name: str
-    endpoint_domain: str
-    embedding_model: str = "gemini-embedding-001"
-    search_limit: int = 10
-
-    @classmethod
-    def settings_customise_sources(
-        cls,
-        settings_cls: type[BaseSettings],
-        init_settings: PydanticBaseSettingsSource,
-        env_settings: PydanticBaseSettingsSource,
-        dotenv_settings: PydanticBaseSettingsSource,
-        file_secret_settings: PydanticBaseSettingsSource,
-    ) -> tuple[PydanticBaseSettingsSource, ...]:
-        return (
-            init_settings,
-            env_settings,
-            dotenv_settings,
-            YamlConfigSettingsSource(settings_cls),
-            file_secret_settings,
-        )

utils/logging_setup.py

@@ -1,50 +0,0 @@
-"""
-Centralized Cloud Logging setup.
-Uses CloudLoggingHandler (background thread) so logging does not add latency
-"""
-
-import logging
-from typing import Optional, Dict, Literal
-
-import google.cloud.logging
-from google.cloud.logging.handlers import CloudLoggingHandler
-
-from .config import Settings
-
-
-def _setup_logger() -> logging.Logger:
-    """Create or return the singleton evaluation logger."""
-    log_name = "va_agent-evaluation-logs"
-    logger = logging.getLogger(log_name)
-    cfg = Settings.model_validate({})
-    if any(isinstance(h, CloudLoggingHandler) for h in logger.handlers):
-        return logger
-
-    try:
-        client = google.cloud.logging.Client(project=cfg.project_id)
-        handler = CloudLoggingHandler(client, name=log_name)  # async transport
-        logger.addHandler(handler)
-        logger.setLevel(logging.INFO)
-    except Exception as e:
-        # Fallback to console if Cloud Logging is unavailable (local dev)
-        logging.basicConfig(level=logging.INFO)
-        logger = logging.getLogger(log_name)
-        logger.warning("Cloud Logging setup failed; using console. Error: %s", e)
-
-    return logger
-
-
-_eval_log = _setup_logger()
-
-
-def log_structured_entry(message: str, severity: Literal["INFO", "WARNING", "ERROR"], custom_log: Optional[Dict] = None) -> None:
-    """
-    Emit a JSON-structured log row.
-
-    Args:
-        message: Short label for the row (e.g., "Final agent turn").
-        severity: "INFO" | "WARNING" | "ERROR" etc.
-        custom_log: A dict with your structured payload.
-    """
-    level = getattr(logging, severity.upper(), logging.INFO)
-    _eval_log.log(level, message, extra={"json_fields": {"message": message, "custom": custom_log or {}}})