Vertex AI Search Datastores (Pass-through)

Call the Vertex AI Discovery Engine Search API through LiteLLM, using Google's native request and response shapes.

Provider Doc: https://cloud.google.com/generative-ai-app-builder/docs/reference/rest/v1/projects.locations.dataStores.servingConfigs/search

Want the unified API instead?

This page is the raw Google API through the proxy. If you want to query the datastore through the OpenAI-compatible POST /v1/vector_stores/{id}/search endpoint, or use it for RAG in /chat/completions, register it as a managed vector store (provider vertex_ai/search_api).

What you get

• The full Discovery Engine API surface, unchanged.
• Configure credentials once on the proxy, use everywhere.
• If the datastore id in the URL is registered as a managed vector store, LiteLLM resolves its project and credentials from the registration automatically.

Quick Start

Step 1. Set credentials

export DEFAULT_VERTEXAI_PROJECT="your-project-id"
export DEFAULT_VERTEXAI_LOCATION="us-central1"
export DEFAULT_GOOGLE_APPLICATION_CREDENTIALS="/path/to/credentials.json"

Step 2. Start proxy

litellm

Step 3. Search your datastore

curl -X POST \
  "http://localhost:4000/vertex_ai/discovery/v1/projects/my-project/locations/global/collections/default_collection/dataStores/my-datastore/servingConfigs/default_config:search" \
  -H "Content-Type: application/json" \
  -H "x-litellm-api-key: Bearer sk-1234" \
  -d '{
    "query": "How do I authenticate?",
    "pageSize": 10
  }'

Endpoint

{PROXY_BASE_URL}/vertex_ai/discovery/{endpoint:path}

Routes to https://discoveryengine.googleapis.com

Examples

Search with Filters

curl -X POST \
  "http://localhost:4000/vertex_ai/discovery/v1/projects/my-project/locations/global/collections/default_collection/dataStores/my-datastore/servingConfigs/default_config:search" \
  -H "Content-Type: application/json" \
  -H "x-litellm-api-key: Bearer sk-1234" \
  -d '{
    "query": "tutorials",
    "pageSize": 20,
    "filter": "category = \"beginner\"",
    "spellCorrectionSpec": {"mode": "AUTO"}
  }'

Python

import requests

url = "http://localhost:4000/vertex_ai/discovery/v1/projects/my-project/locations/global/collections/default_collection/dataStores/my-datastore/servingConfigs/default_config:search"

response = requests.post(url, 
    headers={
        "Content-Type": "application/json",
        "x-litellm-api-key": "Bearer sk-1234"
    },
    json={"query": "pricing", "pageSize": 10}
)

for result in response.json().get("results", []):
    data = result["document"]["derivedStructData"]
    print(f"{data['title']}: {data['link']}")