langchain-quercle

Quercle web search, fetch, and extraction tools for LangChain.

Installation

uv add langchain-quercle
# or
pip install langchain-quercle

Setup

Set your API key as an environment variable:

export QUERCLE_API_KEY=qk_...

Get your API key at quercle.dev.

Quick Start

from quercle_langchain import QuercleSearchTool, QuercleFetchTool

search = QuercleSearchTool()
result = search.invoke("latest developments in AI agents")
print(result)

Tools

Direct Tool Usage

Sync

from quercle_langchain import (
    QuercleSearchTool,
    QuercleFetchTool,
    QuercleRawSearchTool,
    QuercleRawFetchTool,
    QuercleExtractTool,
)

# AI-synthesized search
search = QuercleSearchTool()
result = search.invoke("best practices for building AI agents")
print(result)

# Search with domain filtering
result = search.invoke({
    "query": "Python documentation",
    "allowed_domains": ["docs.python.org"],
})

# Fetch and analyze a page with AI
fetch = QuercleFetchTool()
result = fetch.invoke({
    "url": "https://en.wikipedia.org/wiki/Python_(programming_language)",
    "prompt": "Summarize the key features of Python",
})
print(result)

# Raw search results
raw_search = QuercleRawSearchTool()
result = raw_search.invoke({"query": "Python tutorials", "format": "json"})
print(result)

# Raw URL content
raw_fetch = QuercleRawFetchTool()
result = raw_fetch.invoke({"url": "https://example.com", "use_safeguard": True})
print(result)

# Extract relevant content from a URL
extract = QuercleExtractTool()
result = extract.invoke({
    "url": "https://en.wikipedia.org/wiki/Python_(programming_language)",
    "query": "What are Python's main features?",
    "format": "json",
})
print(result)

Async

import asyncio
from quercle_langchain import (
    QuercleSearchTool,
    QuercleFetchTool,
    QuercleRawSearchTool,
    QuercleRawFetchTool,
    QuercleExtractTool,
)

async def main():
    # AI-synthesized search
    search = QuercleSearchTool()
    result = await search.ainvoke("latest AI agent frameworks")
    print(result)

    # Fetch and analyze with AI
    fetch = QuercleFetchTool()
    result = await fetch.ainvoke({
        "url": "https://en.wikipedia.org/wiki/TypeScript",
        "prompt": "What is TypeScript?",
    })
    print(result)

    # Raw search results
    raw_search = QuercleRawSearchTool()
    result = await raw_search.ainvoke({"query": "Python tutorials", "format": "json"})
    print(result)

    # Raw URL content
    raw_fetch = QuercleRawFetchTool()
    result = await raw_fetch.ainvoke({"url": "https://example.com"})
    print(result)

    # Extract relevant content
    extract = QuercleExtractTool()
    result = await extract.ainvoke({
        "url": "https://en.wikipedia.org/wiki/TypeScript",
        "query": "What is TypeScript used for?",
    })
    print(result)

asyncio.run(main())

Custom API Key

search = QuercleSearchTool(api_key="qk_...")
fetch = QuercleFetchTool(api_key="qk_...")
raw_search = QuercleRawSearchTool(api_key="qk_...")
raw_fetch = QuercleRawFetchTool(api_key="qk_...")
extract = QuercleExtractTool(api_key="qk_...")

Agentic Usage

With LangGraph ReAct Agent

from quercle_langchain import (
    QuercleSearchTool,
    QuercleFetchTool,
    QuercleRawSearchTool,
    QuercleRawFetchTool,
    QuercleExtractTool,
)
from langchain_openai import ChatOpenAI
from langgraph.prebuilt import create_react_agent

model = ChatOpenAI(model="gpt-4o")
tools = [
    QuercleSearchTool(),
    QuercleFetchTool(),
    QuercleRawSearchTool(),
    QuercleRawFetchTool(),
    QuercleExtractTool(),
]

agent = create_react_agent(model, tools)

response = agent.invoke({
    "messages": [
        {"role": "user", "content": "Search for the latest AI news and summarize the top story"}
    ]
})

print(response["messages"][-1].content)

Streaming

for chunk in agent.stream(
    {"messages": [{"role": "user", "content": "Research WebAssembly trends"}]},
    stream_mode="values",
):
    print(chunk["messages"][-1].content)

With Anthropic

from langchain_anthropic import ChatAnthropic

model = ChatAnthropic(model="claude-sonnet-4-20250514")
agent = create_react_agent(model, tools)

API Reference

QuercleSearchTool

AI-synthesized web search with citations.

QuercleFetchTool

Fetch a URL and analyze its content with AI.

QuercleRawSearchTool

Raw web search results without AI synthesis.

QuercleRawFetchTool

Raw URL content without AI processing.

QuercleExtractTool

Extract content chunks relevant to a query from a URL.

Configuration

All tools accept these constructor parameters:

License

MIT