Web-Fetch-Tool

{
  "type": "web_fetch_20250910",
  "name": "web_fetch",

  // Optional: Begrenzen Sie die Anzahl der Abrufe pro Anfrage
  "max_uses": 10,

  // Optional: Nur von diesen Domänen abrufen
  "allowed_domains": ["example.com", "docs.example.com"],

  // Optional: Niemals von diesen Domänen abrufen
  "blocked_domains": ["private.example.com"],

  // Optional: Zitate für abgerufene Inhalte aktivieren
  "citations": {
    "enabled": true
  },

  // Optional: Maximale Inhaltslänge in Token
  "max_content_tokens": 100000
}

{
  "role": "assistant",
  "content": [
    // 1. Claudes Entscheidung zum Abrufen
    {
      "type": "text",
      "text": "I'll fetch the content from the article to analyze it."
    },
    // 2. Die Abrufanfrage
    {
      "type": "server_tool_use",
      "id": "srvtoolu_01234567890abcdef",
      "name": "web_fetch",
      "input": {
        "url": "https://example.com/article"
      }
    },
    // 3. Abrufergebnisse
    {
      "type": "web_fetch_tool_result",
      "tool_use_id": "srvtoolu_01234567890abcdef",
      "content": {
        "type": "web_fetch_result",
        "url": "https://example.com/article",
        "content": {
          "type": "document",
          "source": {
            "type": "text",
            "media_type": "text/plain",
            "data": "Full text content of the article..."
          },
          "title": "Article Title",
          "citations": {"enabled": true}
        },
        "retrieved_at": "2025-08-25T10:30:00Z"
      }
    },
    // 4. Claudes Analyse mit Zitaten (falls aktiviert)
    {
      "text": "Based on the article, ",
      "type": "text"
    },
    {
      "text": "the main argument presented is that artificial intelligence will transform healthcare",
      "type": "text",
      "citations": [
        {
          "type": "char_location",
          "document_index": 0,
          "document_title": "Article Title",
          "start_char_index": 1234,
          "end_char_index": 1456,
          "cited_text": "Artificial intelligence is poised to revolutionize healthcare delivery..."
        }
      ]
    }
  ],
  "id": "msg_a930390d3a",
  "usage": {
    "input_tokens": 25039,
    "output_tokens": 931,
    "server_tool_use": {
      "web_fetch_requests": 1
    }
  },
  "stop_reason": "end_turn"
}

{
  "type": "web_fetch_tool_result",
  "tool_use_id": "srvtoolu_02",
  "content": {
    "type": "web_fetch_result",
    "url": "https://example.com/paper.pdf",
    "content": {
      "type": "document",
      "source": {
        "type": "base64",
        "media_type": "application/pdf",
        "data": "JVBERi0xLjQKJcOkw7zDtsOfCjIgMCBvYmo..."
      },
      "citations": {"enabled": true}
    },
    "retrieved_at": "2025-08-25T10:30:02Z"
  }
}

{
  "type": "web_fetch_tool_result",
  "tool_use_id": "srvtoolu_a93jad",
  "content": {
    "type": "web_fetch_tool_error",
    "error_code": "url_not_accessible"
  }
}

import anthropic

client = anthropic.Anthropic()

response = client.messages.create(
    model="claude-sonnet-4-5",
    max_tokens=4096,
    messages=[
        {
            "role": "user",
            "content": "Find recent articles about quantum computing and analyze the most relevant one in detail"
        }
    ],
    tools=[
        {
            "type": "web_search_20250305",
            "name": "web_search",
            "max_uses": 3
        },
        {
            "type": "web_fetch_20250910",
            "name": "web_fetch",
            "max_uses": 5,
            "citations": {"enabled": True}
        }
    ],
    extra_headers={
        "anthropic-beta": "web-fetch-2025-09-10"
    }
)

import anthropic

client = anthropic.Anthropic()

# Erste Anfrage mit Web Fetch
messages = [
    {
        "role": "user",
        "content": "Analyze this research paper: https://arxiv.org/abs/2024.12345"
    }
]

response1 = client.messages.create(
    model="claude-sonnet-4-5",
    max_tokens=1024,
    messages=messages,
    tools=[{
        "type": "web_fetch_20250910",
        "name": "web_fetch"
    }],
    extra_headers={
        "anthropic-beta": "web-fetch-2025-09-10"
    }
)

# Fügen Sie Claudes Antwort zum Gespräch hinzu
messages.append({
    "role": "assistant",
    "content": response1.content
})

# Zweite Anfrage mit Cache-Breakpoint
messages.append({
    "role": "user",
    "content": "What methodology does the paper use?",
    "cache_control": {"type": "ephemeral"}
})

response2 = client.messages.create(
    model="claude-sonnet-4-5",
    max_tokens=1024,
    messages=messages,
    tools=[{
        "type": "web_fetch_20250910",
        "name": "web_fetch"
    }],
    extra_headers={
        "anthropic-beta": "web-fetch-2025-09-10"
    }
)

# Die zweite Antwort profitiert von zwischengespeicherten Abrufergebnissen
print(f"Cache read tokens: {response2.usage.get('cache_read_input_tokens', 0)}")

event: message_start
data: {"type": "message_start", "message": {"id": "msg_abc123", "type": "message"}}

event: content_block_start
data: {"type": "content_block_start", "index": 0, "content_block": {"type": "text", "text": ""}}

// Claudes Entscheidung zum Abrufen

event: content_block_start
data: {"type": "content_block_start", "index": 1, "content_block": {"type": "server_tool_use", "id": "srvtoolu_xyz789", "name": "web_fetch"}}

// Abruf-URL gestreamt
event: content_block_delta
data: {"type": "content_block_delta", "index": 1, "delta": {"type": "input_json_delta", "partial_json": "{\"url\":\"https://example.com/article\"}"}}

// Pause während der Abrufausführung

// Abrufergebnisse gestreamt
event: content_block_start
data: {"type": "content_block_start", "index": 2, "content_block": {"type": "web_fetch_tool_result", "tool_use_id": "srvtoolu_xyz789", "content": {"type": "web_fetch_result", "url": "https://example.com/article", "content": {"type": "document", "source": {"type": "text", "media_type": "text/plain", "data": "Article content..."}}}}}

// Claudes Antwort wird fortgesetzt...

"usage": {
  "input_tokens": 25039,
  "output_tokens": 931,
  "cache_read_input_tokens": 0,
  "cache_creation_input_tokens": 0,
  "server_tool_use": {
    "web_fetch_requests": 1
  }
}