> ## Documentation Index
> Fetch the complete documentation index at: https://docs.upsonic.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# WebFetchTool

> A built-in tool that allows models to access and read contents from URLs

## Overview

A built-in tool that allows models to fetch and read content directly from URLs. This is the recommended replacement for the deprecated `UrlContextTool`.

## Usage

```python theme={null}
from upsonic import Agent, Task
from upsonic.tools.builtin_tools import WebFetchTool
from upsonic.models.anthropic import AnthropicModel

# Create model with Anthropic
model = AnthropicModel(
    model_name="claude-sonnet-4-5",
    provider="anthropic"
)

# Basic web fetch tool
web_fetch = WebFetchTool()

# Create task
task = Task(
    description="Fetch the content from https://docs.python.org and summarize the key features of Python",
    tools=[web_fetch]
)

# Create agent
agent = Agent(model=model, name="Web Fetch Agent")

# Execute
result = agent.print_do(task)
print("Result:", result)
```

## Advanced Configuration

```python theme={null}
from upsonic.tools.builtin_tools import WebFetchTool
from upsonic import Agent, Task
from upsonic.models.anthropic import AnthropicModel

model = AnthropicModel(
    model_name="claude-sonnet-4-5",
    provider="anthropic"
)

# Advanced web fetch with domain filtering and citations
advanced_fetch = WebFetchTool(
    max_uses=5,
    allowed_domains=["docs.python.org", "wiki.python.org"],
    enable_citations=True,
    max_content_tokens=2000
)

task = Task(
    description="""
    Fetch and analyze the following Python documentation pages:
    1. https://docs.python.org/3/tutorial/
    2. https://docs.python.org/3/library/functions.html

    Provide a structured summary of what each page covers.
    """,
    tools=[advanced_fetch]
)

agent = Agent(model=model, name="Documentation Reader Agent")
result = agent.print_do(task)
print("Result:", result)
```

## Parameters

* `max_uses` (int, optional): Maximum number of URL fetches allowed
  * Supported by: Anthropic
* `allowed_domains` (List\[str], optional): Only fetch from these domains
  * Supported by: Anthropic
  * Note: Cannot use both `allowed_domains` and `blocked_domains` with Anthropic
* `blocked_domains` (List\[str], optional): Never fetch from these domains
  * Supported by: Anthropic
  * Note: Cannot use both `blocked_domains` and `allowed_domains` with Anthropic
* `enable_citations` (bool): Enable citations for fetched content (default: False)
  * Supported by: Anthropic
* `max_content_tokens` (int, optional): Maximum content length in tokens for fetched content
  * Supported by: Anthropic

## Provider Support

* Anthropic: ✅ Full support
* Google: ✅ Full support
* OpenAI Responses: ❌ Not supported