Search Operators

Use the following search operators with the Search API:

Operator	Description	Example
site	Searches for webpages from a particular domain (including subdomains)	`site:uscourts.gov`
filetype	Searches for webpages that are of the specified file type	`filetype:pdf`
lang	Searches for webpages that are in a particular language (ISO 639-1 format)	`lang:es`
+	Searches for webpages that contain the exact term after the `+`	`+GAAP`
-	Searches for webpages that do not contain the exact term after the `-`	`-prs`
AND	Logical operator to combine expressions	`guitar AND Fender`
OR	Logical operator to combine expressions	`guitar OR drum`
NOT	Negation of expressions	`NOT site:uscourts.gov`

How To Use Search Operators

Suppose you want to make search on the MCP protocol. If your query is what ic MCP? the API will return relevant results from different websites. In the case you want to retrieve the content only from the Model Context Protocol official website, your query must be What is MCP? site:modelcontextprotocol.io. The snippets below show you how to do so in cURL and Python:

cURL
Python

curl --request GET \
    --url 'https://ydc-index.io/v1/search?query=What%20is%20MCP%3F%20site%3Amodelcontextprotocol.io' \
    --header 'X-API-Key: YOUR_API_KEY'

# Create and activate a virtual environment
# pip install requests
import requests
import json

# Define the API endpoint and the headers
url = "https://ydc-index.io/v1/search"
headers = {
    "X-API-Key": "YOUR_API_KEY" 
}

# Define the search query parameters
params = {
    "query": "What is MCP? site:modelcontextprotocol.io"
}

# Make the GET request
response = requests.get(url, headers=headers, params=params)

# Print the JSON response, formatted for readability
print(json.dumps(response.json(), indent=2))

Below is the result you will obtain:

{
  "results": {
    "web": [
      {
        "url": "https://modelcontextprotocol.io/",
        "title": "What is the Model Context Protocol (MCP)? - Model Context Protocol",
        "description": "MCP (Model Context Protocol) is an open-source standard for connecting AI applications to external systems. Using MCP, AI applications like Claude or ChatGPT can connect to data sources (e.g. local files, databases), tools (e.g. search engines, calculators) and workflows (e.g.",
        "snippets": [
          "Just as USB-C provides a standardized way to connect electronic devices, MCP provides a standardized way to connect AI applications to external systems.",
          "Depending on where you sit in the ecosystem, MCP can have a range of benefits.",
          "Developers: MCP reduces development time and complexity when building, or integrating with, an AI application or agent.",
          "AI applications or agents: MCP provides access to an ecosystem of data sources, tools and apps which will enhance capabilities and improve the end-user experience."
        ],
        "thumbnail_url": "https://raw.githubusercontent.com/modelcontextprotocol/docs/2eb6171ddbfeefde349dc3b8d5e2b87414c26250/images/og-image.png",
        "favicon_url": "https://you.com/favicon?domain=modelcontextprotocol.io&size=128"
      },
      {
        "url": "https://modelcontextprotocol.io/specification/2025-06-18",
        "title": "Specification - Model Context Protocol",
        "description": "Model Context Protocol (MCP) is an open protocol that enables seamless integration between LLM applications and external data sources and tools. Whether you’re building an AI-powered IDE, enhancing a chat interface, or creating custom AI workflows, MCP provides a standardized way to connect ...",
        "snippets": [
          "Model Context Protocol (MCP) is an open protocol that enables seamless integration between LLM applications and external data sources and tools. Whether you’re building an AI-powered IDE, enhancing a chat interface, or creating custom AI workflows, MCP provides a standardized way to connect LLMs with the context they need.",
          "Servers: Services that provide context and capabilities MCP takes some inspiration from the Language Server Protocol, which standardizes how to add support for programming languages across a whole ecosystem of development tools.",
          "In a similar way, MCP standardizes how to integrate additional context and tools into the ecosystem of AI applications.",
          "MCP provides a standardized way for applications to:"
        ],
        "thumbnail_url": "https://raw.githubusercontent.com/modelcontextprotocol/docs/2eb6171ddbfeefde349dc3b8d5e2b87414c26250/images/og-image.png",
        "favicon_url": "https://you.com/favicon?domain=modelcontextprotocol.io&size=128"
      },
                  
      // Content omitted for brevity

    ]
  },
  "metadata": {
    "query": "What is MCP? site:modelcontextprotocol.io",
    "search_uuid": "7139420b-d86c-4a83-82b4-08d778f0b01a",
    "latency": 0.7904746532440186
  }
}

Tutorials

Errors

How To Use Search Operators

​How To Use Search Operators

How To Use Search Operators