### Configure Web Fetch Tool Request

Source: https://platform.claude.com/docs/en/agents-and-tools/tool-use/web-fetch-tool

Example of initializing a request with the web_fetch tool definition.

```json
  max_tokens: 1024,
  messages: [
    { role: "user", content: "Please analyze the content at https://example.com/article" }
  ],
  tools: [{
    type: "web_fetch_20250910",
    name: "web_fetch",
    max_uses: 5
  }]
)
puts message
```

--------------------------------

### Install Anthropic and MCP SDKs

Source: https://platform.claude.com/docs/en/agents-and-tools/mcp-connector

Install both the Anthropic SDK and the MCP SDK using npm to utilize the client-side helpers.

```bash
npm install @anthropic-ai/sdk @modelcontextprotocol/sdk
```

--------------------------------

### Multi-step Automation Workflow

Source: https://platform.claude.com/docs/en/agents-and-tools/tool-use/bash-tool

Demonstration of chaining multiple commands to install dependencies, create files, and execute scripts within a persistent session.

```text
User request:
"Install the requests library and create a simple Python script that
fetches a joke from an API, then run it."

Claude's tool uses:
1. Install package
   {"command": "pip install requests"}

2. Create script
   {"command": "cat > fetch_joke.py << 'EOF'\nimport requests\nresponse = requests.get('https://official-joke-api.appspot.com/random_joke')\njoke = response.json()\nprint(f\"Setup: {joke['setup']}\")\nprint(f\"Punchline: {joke['punchline']}\")\nEOF"}

3. Run script
   {"command": "python fetch_joke.py"}
```

--------------------------------

### Deferred Tools with TypeScript SDK

Source: https://platform.claude.com/docs/en/agents-and-tools/tool-use/tool-search-tool

This TypeScript example shows how to configure deferred tools when creating a message using the Anthropic SDK. Make sure to install the SDK (`npm install @anthropic-ai/sdk`).

```TypeScript
import Anthropic from "@anthropic-ai/sdk";

const client = new Anthropic();

async function main() {
  const response = await client.messages.create({
    model: "claude-opus-4-7",
    max_tokens: 2048,
    messages: [
      {
        role: "user",
        content: "What is the weather in San Francisco?"
      }
    ],
    tools: [
      {
        type: "tool_search_tool_regex_20251119",
        name: "tool_search_tool_regex"
      },
      {
        name: "get_weather",
        description: "Get the weather at a specific location",
        input_schema: {
          type: "object" as const,
          properties: {
            location: { type: "string" },
            unit: {
              type: "string",
              enum: ["celsius", "fahrenheit"]
            }
          },
          required: ["location"]
        },
        defer_loading: true
      },
      {
        name: "search_files",
        description: "Search through files in the workspace",
        input_schema: {
          type: "object" as const,
          properties: {
            query: { type: "string" },
            file_types: {
              type: "array" as const,
              items: { type: "string" }
            }
          },
          required: ["query"]
        },
        defer_loading: true
      }
    ]
  });

  console.log(response);
}

main();
```

--------------------------------

### Create Message with MCP Server and Toolset (Ruby)

Source: https://platform.claude.com/docs/en/agents-and-tools/mcp-connector

This Ruby example shows how to configure and send a message with an MCP server and toolset using the Anthropic Ruby client. Ensure the gem is installed.

```ruby
require "anthropic"

client = Anthropic::Client.new

response = client.beta.messages.create(
  model: "claude-opus-4-7",
  max_tokens: 1000,
  messages: [
    { role: "user", content: "What tools do you have available?" }
  ],
  mcp_servers: [
    {
      type: "url",
      url: "https://example-server.modelcontextprotocol.io/sse",
      name: "example-mcp",
      authorization_token: "YOUR_TOKEN"
    }
  ],
  tools: [
    {
      type: "mcp_toolset",
      mcp_server_name: "example-mcp"
    }
  ],
  betas: ["mcp-client-2025-11-20"]
)

puts response

```

--------------------------------

### Example File Content Output

Source: https://platform.claude.com/docs/en/agents-and-tools/tool-use/memory-tool

Illustrates the formatted output for file content with line numbers.

```text
Here's the content of /memories/notes.txt with line numbers:
     1	Hello World
     2	This is line two
    10	Line ten
   100	Line one hundred
```

--------------------------------

### Use Web Fetch Tool with PHP SDK

Source: https://platform.claude.com/docs/en/agents-and-tools/tool-use/web-fetch-tool

Analyze web content in PHP by incorporating the web_fetch_20250910 tool. This example assumes the Anthropic PHP SDK is installed and the API key is set.

```php
<?php

use Anthropic\Client;

$client = new Client(apiKey: getenv("ANTHROPIC_API_KEY"));

$message = $client->messages->create(
    maxTokens: 1024,
    messages: [
        ['role' => 'user', 'content' => 'Please analyze the content at https://example.com/article']
    ],
    model: 'claude-opus-4-7',
    tools: [[
        'type' => 'web_fetch_20250910',
        'name' => 'web_fetch',
        'max_uses' => 5,
    ]],
);
echo $message;
```

--------------------------------

### Implement Deferred Tool Loading

Source: https://platform.claude.com/docs/en/agents-and-tools/tool-use/tool-search-tool

Example of a tool definition with defer_loading enabled to allow on-demand loading.

```json
{
  "name": "get_weather",
  "description": "Get current weather for a location",
  "input_schema": {
    "type": "object",
    "properties": {
      "location": { "type": "string" },
      "unit": { "type": "string", "enum": ["celsius", "fahrenheit"] }
    },
    "required": ["location"]
  },
  "defer_loading": true
}
```

--------------------------------

### Initialize Anthropic Client in Java

Source: https://platform.claude.com/docs/en/agents-and-tools/tool-use/code-execution-tool

Setup the Anthropic client using environment variables for subsequent API interactions.

```java
public class ContainerReuse {
    public static void main(String[] args) {
        AnthropicClient client = AnthropicOkHttpClient.fromEnv();
```

--------------------------------

### Streaming Code Execution Events

Source: https://platform.claude.com/docs/en/agents-and-tools/tool-use/code-execution-tool

This example shows how to receive code execution events as they occur, including start, delta, and result streams.

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

// Code execution streamed
event: content_block_delta
data: {"type": "content_block_delta", "index": 1, "delta": {"type": "input_json_delta", "partial_json": "{\"code\":\"import pandas as pd\ndf = pd.read_csv('data.csv')\nprint(df.head())\"}"}}

// Pause while code executes

// Execution results streamed
event: content_block_start
data: {"type": "content_block_start", "index": 2, "content_block": {"type": "code_execution_tool_result", "tool_use_id": "srvtoolu_xyz789", "content": {"stdout": "   A  B  C\n0  1  2  3\n1  4  5  6", "stderr": ""}}}
```

--------------------------------

### Install Claude API Skill as a Plugin

Source: https://platform.claude.com/docs/en/agents-and-tools/agent-skills/claude-api-skill

Install the Claude API skill as a plugin within Claude Code.

```bash
/plugin marketplace add anthropics/skills
/plugin install claude-api@anthropic-agent-skills
```

--------------------------------

### Enable MCP Tools via API and CLI

Source: https://platform.claude.com/docs/en/agents-and-tools/mcp-connector

Examples showing how to configure an MCP server connection using cURL and the Anthropic CLI.

```bash
curl https://api.anthropic.com/v1/messages \
  -H "Content-Type: application/json" \
  -H "X-API-Key: $ANTHROPIC_API_KEY" \
  -H "anthropic-version: 2023-06-01" \
  -H "anthropic-beta: mcp-client-2025-11-20" \
  -d '{
    "model": "claude-opus-4-7",
    "max_tokens": 1000,
    "messages": [{"role": "user", "content": "What tools do you have available?"}],
    "mcp_servers": [
      {
        "type": "url",
        "url": "https://example-server.modelcontextprotocol.io/sse",
        "name": "example-mcp",
        "authorization_token": "YOUR_TOKEN"
      }
    ],
    "tools": [
      {
        "type": "mcp_toolset",
        "mcp_server_name": "example-mcp"
      }
    ]
  }'
```

```bash
ant beta:messages create --beta mcp-client-2025-11-20 <<'YAML'
model: claude-opus-4-7
max_tokens: 1000
messages:
  - role: user
    content: What tools do you have available?
mcp_servers:
  - type: url
    url: https://example-server.modelcontextprotocol.io/sse
    name: example-mcp
    authorization_token: YOUR_TOKEN
tools:
  - type: mcp_toolset
    mcp_server_name: example-mcp
YAML
```

--------------------------------

### CLI Example for Container Creation

Source: https://platform.claude.com/docs/en/agents-and-tools/tool-use/code-execution-tool

This CLI command demonstrates the initial request to create a container and write a file. The container ID is captured for subsequent reuse.

```bash
# First request: Create a file with a random number
CONTAINER_ID=$(ant messages create \
  --transform container.id --format yaml \
    --model claude-opus-4-7 \
    --max-tokens 4096 \
    --message '{role: user, content: Write a file with a random number and save it to "/tmp/number.txt"}' \
    --tool '{type: code_execution_20250825, name: code_execution}'
)
```

--------------------------------

### Migrate an existing project

Source: https://platform.claude.com/docs/en/agents-and-tools/agent-skills/claude-api-skill

Example task for migrating a codebase to a specific model version.

```text
/claude-api migrate this codebase to claude-opus-4-7 and re-tune effort
```

--------------------------------

### Define deferred tool

Source: https://platform.claude.com/docs/en/agents-and-tools/tool-use/tool-search-tool

Example of a tool definition with defer_loading enabled.

```json
{
  "name": "my_tool",
  "description": "Full description here",
  "input_schema": {
    // complete schema
  },
  "defer_loading": true
}
```

--------------------------------

### Memory Tool Interaction Examples

Source: https://platform.claude.com/docs/en/agents-and-tools/tool-use/memory-tool

Demonstrates the sequence of tool calls and results for checking directories and reading file contents during a memory-enabled session.

```json
{
  "type": "tool_use",
  "id": "toolu_01C4D5E6F7G8H9I0J1K2L3M4",
  "name": "memory",
  "input": {
    "command": "view",
    "path": "/memories"
  }
}
```

```json
{
  "type": "tool_result",
  "tool_use_id": "toolu_01C4D5E6F7G8H9I0J1K2L3M4",
  "content": "Here're the files and directories up to 2 levels deep in /memories, excluding hidden items and node_modules:\n4.0K\t/memories\n1.5K\t/memories/customer_service_guidelines.xml\n2.0K\t/memories/refund_policies.xml"
}
```

```json
{
  "type": "tool_use",
  "id": "toolu_01D5E6F7G8H9I0J1K2L3M4N5",
  "name": "memory",
  "input": {
    "command": "view",
    "path": "/memories/customer_service_guidelines.xml"
  }
}
```

```json
{
  "type": "tool_result",
  "tool_use_id": "toolu_01D5E6F7G8H9I0J1K2L3M4N5",
  "content": "Here's the content of /memories/customer_service_guidelines.xml with line numbers:\n     1\t<guidelines>\n     2\t<addressing_customers>\n     3\t- Always address customers by their first name\n     4\t- Use empathetic language\n..."
}
```

--------------------------------

### Install Claude API Skill using npx

Source: https://platform.claude.com/docs/en/agents-and-tools/agent-skills/claude-api-skill

Install the Claude API skill from the Anthropic skills repository using the npx command.

```bash
npx skills add https://github.com/anthropics/skills --skill claude-api
```

--------------------------------

### Initialize Bash Tool

Source: https://platform.claude.com/docs/en/agents-and-tools/tool-use/bash-tool

Examples of how to enable the bash tool when calling the Anthropic API via cURL, CLI, or the Python SDK.

```bash
curl https://api.anthropic.com/v1/messages \
  -H "content-type: application/json" \
  -H "x-api-key: $ANTHROPIC_API_KEY" \
  -H "anthropic-version: 2023-06-01" \
  -d '{
    "model": "claude-opus-4-7",
    "max_tokens": 1024,
    "tools": [
      {
        "type": "bash_20250124",
        "name": "bash"
      }
    ],
    "messages": [
      {
        "role": "user",
        "content": "List all Python files in the current directory."
      }
    ]
  }'
```

```bash
ant messages create \
  --model claude-opus-4-7 \
  --max-tokens 1024 \
  --tool '{type: bash_20250124, name: bash}' \
  --message '{role: user, content: List all Python files in the current directory.}'
```

```python
import anthropic

client = anthropic.Anthropic()

response = client.messages.create(
    model="claude-opus-4-7",
    max_tokens=1024,
    tools=[{"type": "bash_20250124", "name": "bash"}],
    messages=[
        {"role": "user", "content": "List all Python files in the current directory."}
    ],
)

print(response)
```

--------------------------------

### Scaffold a Managed Agent

Source: https://platform.claude.com/docs/en/agents-and-tools/agent-skills/claude-api-skill

Initializes the Managed Agent setup process through an interactive interview.

```text
/claude-api managed-agents-onboard
```

--------------------------------

### Skill Directory Structure Example

Source: https://platform.claude.com/docs/en/agents-and-tools/agent-skills/overview

Illustrates the typical file organization within a Skill directory, including markdown instructions and Python scripts.

```text
pdf-skill/
├── SKILL.md (main instructions)
├── FORMS.md (form-filling guide)
├── REFERENCE.md (detailed API reference)
└── scripts/
    └── fill_form.py (utility script)
```

--------------------------------

### Handle Bash Command Response

Source: https://platform.claude.com/docs/en/agents-and-tools/tool-use/code-execution-tool

Example of the tool use and result format for bash command execution.

```json
[
  {
    "type": "server_tool_use",
    "id": "srvtoolu_01B3C4D5E6F7G8H9I0J1K2L3",
    "name": "bash_code_execution",
    "input": {
      "command": "ls -la | head -5"
    }
  },
  {
    "type": "bash_code_execution_tool_result",
    "tool_use_id": "srvtoolu_01B3C4D5E6F7G8H9I0J1K2L3",
    "content": {
      "type": "bash_code_execution_result",
      "stdout": "total 24\ndrwxr-xr-x 2 user user 4096 Jan 1 12:00 .\ndrwxr-xr-x 3 user user 4096 Jan 1 11:00 ..\n-rw-r--r-- 1 user user  220 Jan 1 12:00 data.csv\n-rw-r--r-- 1 user user  180 Jan 1 12:00 config.json",
      "stderr": "",
      "return_code": 0
    }
  }
]
```

--------------------------------

### Skill Metadata Example

Source: https://platform.claude.com/docs/en/agents-and-tools/agent-skills/overview

YAML frontmatter for a Skill, providing discovery information like name and description. This metadata is always loaded.

```yaml
---
name: pdf-processing
description: Extract text and tables from PDF files, fill forms, merge documents. Use when working with PDF files or when the user mentions PDFs, forms, or document extraction.
---
```

--------------------------------

### Handle File Operation Responses

Source: https://platform.claude.com/docs/en/agents-and-tools/tool-use/code-execution-tool

Examples of tool use and result formats for viewing, creating, and editing files.

```json
[
  {
    "type": "server_tool_use",
    "id": "srvtoolu_01C4D5E6F7G8H9I0J1K2L3M4",
    "name": "text_editor_code_execution",
    "input": {
      "command": "view",
      "path": "config.json"
    }
  },
  {
    "type": "text_editor_code_execution_tool_result",
    "tool_use_id": "srvtoolu_01C4D5E6F7G8H9I0J1K2L3M4",
    "content": {
      "type": "text_editor_code_execution_result",
      "file_type": "text",
      "content": "{\n  \"setting\": \"value\",\n  \"debug\": true\n}",
      "numLines": 4,
      "startLine": 1,
      "totalLines": 4
    }
  }
]
```

```json
[
  {
    "type": "server_tool_use",
    "id": "srvtoolu_01D5E6F7G8H9I0J1K2L3M4N5",
    "name": "text_editor_code_execution",
    "input": {
      "command": "create",
      "path": "new_file.txt",
      "file_text": "Hello, World!"
    }
  },
  {
    "type": "text_editor_code_execution_tool_result",
    "tool_use_id": "srvtoolu_01D5E6F7G8H9I0J1K2L3M4N5",
    "content": {
      "type": "text_editor_code_execution_result",
      "is_file_update": false
    }
  }
]
```

```json
[
  {
    "type": "server_tool_use",
    "id": "srvtoolu_01E6F7G8H9I0J1K2L3M4N5O6",
    "name": "text_editor_code_execution",
    "input": {
      "command": "str_replace",
      "path": "config.json",
      "old_str": "\"debug\": true",
      "new_str": "\"debug\": false"
    }
  },
  {
    "type": "text_editor_code_execution_tool_result",
    "tool_use_id": "srvtoolu_01E6F7G8H9I0J1K2L3M4N5O6",
    "content": {
      "type": "text_editor_code_execution_result",
      "oldStart": 3,
      "oldLines": 1,
      "newStart": 3,
      "newLines": 1,
      "lines": ["-  \"debug\": true", "+  \"debug\": false"]
    }
  }
]
```

--------------------------------

### Invoke a server tool

Source: https://platform.claude.com/docs/en/agents-and-tools/tool-use/overview

Examples of using the web_search server tool via various interfaces. Server tools are executed on Anthropic's infrastructure.

```bash
curl https://api.anthropic.com/v1/messages \
  -H "x-api-key: $ANTHROPIC_API_KEY" \
  -H "anthropic-version: 2023-06-01" \
  -H "content-type: application/json" \
  -d '{
    "model": "claude-opus-4-7",
    "max_tokens": 1024,
    "tools": [{"type": "web_search_20260209", "name": "web_search"}],
    "messages": [{"role": "user", "content": "What's the latest on the Mars rover?"}]
  }'
```

```bash
ant messages create --transform content --format yaml \
  --model claude-opus-4-7 \
  --max-tokens 1024 \
  --tool '{type: web_search_20260209, name: web_search}' \
  --message '{role: user, content: "What is the latest on the Mars rover?"}'
```

```python
import anthropic

client = anthropic.Anthropic()
response = client.messages.create(
    model="claude-opus-4-7",
    max_tokens=1024,
    tools=[{"type": "web_search_20260209", "name": "web_search"}],
    messages=[{"role": "user", "content": "What's the latest on the Mars rover?"}],
)
print(response.content)
```

```typescript
import Anthropic from "@anthropic-ai/sdk";

const client = new Anthropic();
const response = await client.messages.create({
  model: "claude-opus-4-7",
  max_tokens: 1024,
  tools: [{ type: "web_search_20260209", name: "web_search" }],
  messages: [{ role: "user", content: "What's the latest on the Mars rover?" }]
});
console.log(response.content);
```

--------------------------------

### TypeScript SDK for Computer Use

Source: https://platform.claude.com/docs/en/agents-and-tools/tool-use/computer-use-tool

This TypeScript example shows how to use the Anthropic SDK to enable computer use features in messages.

```TypeScript
import Anthropic from "@anthropic-ai/sdk";

const client = new Anthropic();

const response = await client.beta.messages.create({
  model: "claude-opus-4-7",
  max_tokens: 1024,
  tools: [
    {
      type: "computer_20251124",
      name: "computer",
      display_width_px: 1024,
      display_height_px: 768,
      display_number: 1
    },
    {
      type: "text_editor_20250728",
      name: "str_replace_based_edit_tool"
    },
    {
      type: "bash_20250124",
      name: "bash"
    }
  ],
  messages: [{ role: "user", content: "Save a picture of a cat to my desktop." }],
  betas: ["computer-use-2025-11-24"]
});

console.log(response);
```

--------------------------------

### Programmatic Tool Call Example

Source: https://platform.claude.com/docs/en/agents-and-tools/tool-use/programmatic-tool-calling

This JSON shows a programmatic tool call, including the tool's name, input, and caller information.

```json
{
  "type": "tool_use",
  "id": "toolu_abc123",
  "name": "query_database",
  "input": { "sql": "<sql>" },
  "caller": {
    "type": "code_execution_20260120",
    "tool_id": "srvtoolu_xyz789"
  }
}
```

--------------------------------

### Go SDK for Computer Use

Source: https://platform.claude.com/docs/en/agents-and-tools/tool-use/computer-use-tool

This Go example shows how to initialize the Anthropic client and create messages with computer use tools. It includes error handling for the API call.

```Go
package main

import (
	"context"
	"fmt"
	"log"

	"github.com/anthropics/anthropic-sdk-go"
)

func main() {
	client := anthropic.NewClient()

	response, err := client.Beta.Messages.New(context.TODO(), anthropic.BetaMessageNewParams{
		Model:     anthropic.ModelClaudeOpus4_7,
		MaxTokens: 1024,
		Tools: []anthropic.BetaToolUnionParam{
			{OfComputerUseTool20251124: &anthropic.BetaToolComputerUse20251124Param{
				DisplayWidthPx:  1024,
				DisplayHeightPx: 768,
				DisplayNumber:   anthropic.Int(1),
			}},
			{OfTextEditor20250728: &anthropic.BetaToolTextEditor20250728Param{}},
			{OfBashTool20250124: &anthropic.BetaToolBash20250124Param{}},
		},
		Messages: []anthropic.BetaMessageParam{
			anthropic.NewBetaUserMessage(anthropic.NewBetaTextBlock("Save a picture of a cat to my desktop.")),
		},
		Betas: []anthropic.AnthropicBeta{
			anthropic.AnthropicBetaComputerUse2025_11_24,
		},
	})
	if err != nil {
		log.Fatal(err)
	}
	fmt.Println(response)
}
```

--------------------------------

### Tool Use Implementation via CLI and Python

Source: https://platform.claude.com/docs/en/agents-and-tools/tool-use/text-editor-tool

Demonstrates how to implement the tool use flow using the CLI and the Python SDK.

```bash
ant messages create <<'YAML'
model: claude-opus-4-7
max_tokens: 1024
tools:
  - type: text_editor_20250728
    name: str_replace_based_edit_tool
messages:
  # Previous messages...
  - role: assistant
    content:
      - type: text
        text: >-
          I found the syntax error in your primes.py file. In the `get_primes`
          function, there is a missing colon (:) at the end of the for loop
          line. Let me fix that for you.
      - type: tool_use
        id: toolu_01PqRsTuVwXyZAbCdEfGh
        name: str_replace_based_edit_tool
        input:
          command: str_replace
          path: primes.py
          old_str: "    for num in range(2, limit + 1)"
          new_str: "    for num in range(2, limit + 1):"
  - role: user
    content:
      - type: tool_result
        tool_use_id: toolu_01PqRsTuVwXyZAbCdEfGh
        content: Successfully replaced text at exactly one location.
YAML
```

```python
response = client.messages.create(
    model="claude-opus-4-7",
    max_tokens=1024,
    tools=[{"type": "text_editor_20250728", "name": "str_replace_based_edit_tool"}],
    messages=[
        # Previous messages...
        {
            "role": "assistant",
            "content": [
                {
                    "type": "text",
                    "text": "I found the syntax error in your primes.py file. In the `get_primes` function, there is a missing colon (:) at the end of the for loop line. Let me fix that for you.",
                },
                {
                    "type": "tool_use",
                    "id": "toolu_01PqRsTuVwXyZAbCdEfGh",
                    "name": "str_replace_based_edit_tool",
                    "input": {
                        "command": "str_replace",
                        "path": "primes.py",
                        "old_str": "    for num in range(2, limit + 1)",
                        "new_str": "    for num in range(2, limit + 1):",
                    },
                },
            ],
        },
        {
            "role": "user",
            "content": [
                {
                    "type": "tool_result",
                    "tool_use_id": "toolu_01PqRsTuVwXyZAbCdEfGh",

```

--------------------------------

### Stream tool search events

Source: https://platform.claude.com/docs/en/agents-and-tools/tool-use/tool-search-tool

Example of the SSE stream format when tool search is enabled, showing content block start, delta, and result events.

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

// Search query streamed
event: content_block_delta
data: {"type": "content_block_delta", "index": 1, "delta": {"type": "input_json_delta", "partial_json": "{\"query\":\"weather\"}"}}

// Pause while search executes

// Search results streamed
event: content_block_start
data: {"type": "content_block_start", "index": 2, "content_block": {"type": "tool_search_tool_result", "tool_use_id": "srvtoolu_xyz789", "content": {"type": "tool_search_tool_search_result", "tool_references": [{"type": "tool_reference", "tool_name": "get_weather"}]}}}

// Claude continues with discovered tools
```

--------------------------------

### Send a message with tools using Go

Source: https://platform.claude.com/docs/en/agents-and-tools/tool-use/memory-tool

Use the Go SDK to initialize the client and prepare a message request.

```go
package main

import (
	"context"
	"fmt"
	"log"

	"github.com/anthropics/anthropic-sdk-go"
)

func main() {
	client := anthropic.NewClient()

	response, err := client.Beta.Messages.New(context.TODO(), anthropic.BetaMessageNewParams{
		Model:     anthropic.ModelClaudeOpus4_7,
		MaxTokens: 2048,
```

--------------------------------

### Streaming Web Search Events

Source: https://platform.claude.com/docs/en/agents-and-tools/tool-use/web-search-tool

This example shows the Server-Sent Events (SSE) stream for a web search tool interaction, including message starts, tool use decisions, query streaming, pauses for execution, and result streaming.

```sse
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": ""}}

// Claude's decision to search

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

// Search query streamed
event: content_block_delta
data: {"type": "content_block_delta", "index": 1, "delta": {"type": "input_json_delta", "partial_json": "{\"query\":\"latest quantum computing breakthroughs 2025\"}"}}

// Pause while search executes

// Search results streamed
event: content_block_start
data: {"type": "content_block_start", "index": 2, "content_block": {"type": "web_search_tool_result", "tool_use_id": "srvtoolu_xyz789", "content": [{"type": "web_search_result", "title": "Quantum Computing Breakthroughs in 2025", "url": "https://example.com"}]}}

// Claude's response with citations (omitted in this example)
```

--------------------------------

### Create Message with Tool Use (Go)

Source: https://platform.claude.com/docs/en/agents-and-tools/tool-use/programmatic-tool-calling

Example of creating a message that includes tool use definitions for code execution and database queries in Go. This snippet demonstrates setting up the client and constructing the message parameters.

```go
package main

import (
	"context"
	"fmt"
	"log"

	"github.com/anthropics/anthropic-sdk-go"
)

func main() {
	client := anthropic.NewClient()

	response, err := client.Messages.New(context.TODO(), anthropic.MessageNewParams{
		Model:     anthropic.ModelClaudeOpus4_7,
		MaxTokens: 4096,
		Container: anthropic.MessageNewParamsContainerUnion{
			OfString: anthropic.String("container_xyz789"),
		},
		Messages: []anthropic.MessageParam{
			anthropic.NewUserMessage(anthropic.NewTextBlock("Query customer purchase history from the last quarter and identify our top 5 customers by revenue")),
			{
				Role: anthropic.MessageParamRoleAssistant,
				Content: []anthropic.ContentBlockParamUnion{
					anthropic.NewTextBlock("I'll query the purchase history and analyze the results."),
					{OfServerToolUse: &anthropic.ServerToolUseBlockParam{
						ID:    "srvtoolu_abc123",
						Name:  anthropic.ServerToolUseBlockParamNameCodeExecution,
						Input: map[string]any{"code": "..."}},
					},
					{OfToolUse: &anthropic.ToolUseBlockParam{
						ID:    "toolu_def456",
						Name:  "query_database",
						Input: map[string]any{"sql": "<sql>"},
						Caller: anthropic.ServerToolUseBlockParamCallerUnion{
							OfCodeExecution20260120: &anthropic.ServerToolCaller20260120Param{
								ToolID: "srvtoolu_abc123",
							},
						},
					}},
				},
			},
			{
				Role: anthropic.MessageParamRoleUser,
				Content: []anthropic.ContentBlockParamUnion{
					{OfToolResult: &anthropic.ToolResultBlockParam{
						ToolUseID: "toolu_def456",
						Content: []anthropic.ToolResultBlockParamContentUnion{
							{OfText: &anthropic.TextBlockParam{
								Text: `[{"customer_id": "C1", "revenue": 45000}, {"customer_id": "C2", "revenue": 38000}, ...]`}},
						},
					}},
				},
			},
		},
		Tools: []anthropic.ToolUnionParam{
			{OfCodeExecutionTool20260120: &anthropic.CodeExecutionTool20260120Param{}},
		},
	})
	if err != nil {
		log.Fatal(err)
	}
	fmt.Println(response)
}
```

--------------------------------

### Tool Configuration Merging Example

Source: https://platform.claude.com/docs/en/agents-and-tools/mcp-connector

Demonstrates how tool-specific settings, default configurations, and system defaults merge. Tool-specific settings in 'configs' have the highest precedence, followed by 'default_config', and then system defaults.

```json
{
  "type": "mcp_toolset",
  "mcp_server_name": "google-calendar-mcp",
  "default_config": {
    "defer_loading": true
  },
  "configs": {
    "search_events": {
      "enabled": false
    }
  }
}
```

--------------------------------

### Deferred Tools with Python SDK

Source: https://platform.claude.com/docs/en/agents-and-tools/tool-use/tool-search-tool

This Python snippet demonstrates how to use the Anthropic SDK to create a message with deferred tools. Ensure you have the SDK installed (`pip install anthropic`).

```Python
import anthropic

client = anthropic.Anthropic()

response = client.messages.create(
    model="claude-opus-4-7",
    max_tokens=2048,
    messages=[{"role": "user", "content": "What is the weather in San Francisco?"}],
    tools=[
        {"type": "tool_search_tool_regex_20251119", "name": "tool_search_tool_regex"},
        {
            "name": "get_weather",
            "description": "Get the weather at a specific location",
            "input_schema": {
                "type": "object",
                "properties": {
                    "location": {"type": "string"},
                    "unit": {"type": "string", "enum": ["celsius", "fahrenheit"]},
                },
                "required": ["location"],
            },
            "defer_loading": True,
        },
        {
            "name": "search_files",
            "description": "Search through files in the workspace",
            "input_schema": {
                "type": "object",
                "properties": {
                    "query": {"type": "string"},
                    "file_types": {"type": "array", "items": {"type": "string"}},
                },
                "required": ["query"],
            },
            "defer_loading": True,
        },
    ],
)

print(response)
```

--------------------------------

### Execute Code and Read File in PHP

Source: https://platform.claude.com/docs/en/agents-and-tools/tool-use/code-execution-tool

This PHP example shows how to write a file with a random number and then read it to compute its square, utilizing the code execution tool.

```PHP
<?php

use Anthropic\Client;

$client = new Client(apiKey: getenv("ANTHROPIC_API_KEY"));

$response1 = $client->messages->create(
    maxTokens: 4096,
    messages: [
        ['role' => 'user', 'content' => "Write a file with a random number and save it to '/tmp/number.txt'"]
    ],
    model: 'claude-opus-4-7',
    tools: [
        ['type' => 'code_execution_20250825', 'name' => 'code_execution']
    ],
);

$containerId = $response1->container->id;

$response2 = $client->messages->create(
    container: $containerId,
    maxTokens: 4096,
    messages: [
        ['role' => 'user', 'content' => "Read the number from '/tmp/number.txt' and calculate its square"]
    ],
    model: 'claude-opus-4-7',
    tools: [
        ['type' => 'code_execution_20250825', 'name' => 'code_execution']
    ],
);

```

--------------------------------

### Create Message with Memory Tool (Java)

Source: https://platform.claude.com/docs/en/agents-and-tools/tool-use/memory-tool

This Java example demonstrates how to create a message using the memory tool. It utilizes the Anthropic OkHttp client and requires setting up environment variables for authentication.

```java
import com.anthropic.client.AnthropicClient;
import com.anthropic.client.okhttp.AnthropicOkHttpClient;
import com.anthropic.models.messages.MemoryTool20250818;
import com.anthropic.models.messages.Message;
import com.anthropic.models.messages.MessageCreateParams;
import com.anthropic.models.messages.Model;

public class MemoryToolExample {
    public static void main(String[] args) {
        AnthropicClient client = AnthropicOkHttpClient.fromEnv();

        MessageCreateParams params = MessageCreateParams.builder()
            .model(Model.CLAUDE_OPUS_4_7)
            .maxTokens(2048L)
            .addUserMessage("I'm working on a Python web scraper that keeps crashing with a timeout error. Here's the problematic function:\n\n```python\ndef fetch_page(url, retries=3):\n    for i in range(retries):\n        try:\n            response = requests.get(url, timeout=5)\n            return response.text\n        except requests.exceptions.Timeout:\n            if i == retries - 1:\n                raise\n            time.sleep(1)\n```\n\nPlease help me debug this.")
            .addTool(MemoryTool20250818.builder().build())
            .build();

        Message response = client.messages().create(params);
        System.out.println(response);
    }
}
```

--------------------------------

### cURL Example for Container Reuse

Source: https://platform.claude.com/docs/en/agents-and-tools/tool-use/code-execution-tool

This cURL example demonstrates how to reuse a container for sequential API requests. The first request creates a file, and the container ID is extracted to be used in the second request to read and process the file.

```bash
cd "$(mktemp -d)"
# First request: Create a file with a random number
curl https://api.anthropic.com/v1/messages \
    --header "x-api-key: $ANTHROPIC_API_KEY" \
    --header "anthropic-version: 2023-06-01" \
    --header "content-type: application/json" \
    --data '{
        "model": "claude-opus-4-7",
        "max_tokens": 4096,
        "messages": [{"role": "user", "content": "Write a file with a random number and save it to \"/tmp/number.txt\""}],
        "tools": [{"type": "code_execution_20250825", "name": "code_execution"}]
    }' > response1.json

# Extract container ID from the response (using jq)
CONTAINER_ID=$(jq -r '.container.id' response1.json)

# Second request: Reuse the container to read the file
curl https://api.anthropic.com/v1/messages \
    --header "x-api-key: $ANTHROPIC_API_KEY" \
    --header "anthropic-version: 2023-06-01" \
    --header "content-type: application/json" \
    --data '{
        "container": "'$CONTAINER_ID'",
        "model": "claude-opus-4-7",
        "max_tokens": 4096,
        "messages": [{"role": "user", "content": "Read the number from \"/tmp/number.txt\" and calculate its square"}],
        "tools": [{"type": "code_execution_20250825", "name": "code_execution"}]
    }'
```

--------------------------------

### Skill Directory Structure Example

Source: https://platform.claude.com/docs/en/agents-and-tools/agent-skills/best-practices

Illustrates a recommended directory structure for skills, including a main SKILL.md file and a reference directory for additional documentation. This structure supports progressive disclosure by keeping core information in SKILL.md and detailed content in separate files.

```text
bigquery-skill/
├── SKILL.md (overview, points to reference files)
└── reference/
    ├── finance.md (revenue metrics)
    ├── sales.md (pipeline data)
    └── product.md (usage analytics)
```

--------------------------------

### Execute Code and Read File in Java

Source: https://platform.claude.com/docs/en/agents-and-tools/tool-use/code-execution-tool

This Java example demonstrates creating a file with a random number and then reading that file to calculate its square using the code execution tool.

```Java
MessageCreateParams params1 = MessageCreateParams.builder()
            .model(Model.CLAUDE_OPUS_4_7)
            .maxTokens(4096L)
            .addUserMessage("Write a file with a random number and save it to '/tmp/number.txt'")
            .addTool(CodeExecutionTool20250825.builder().build())
            .build();

        Message response1 = client.messages().create(params1);
        String containerId = response1.container().get().id();

        MessageCreateParams params2 = MessageCreateParams.builder()
            .container(containerId)
            .model(Model.CLAUDE_OPUS_4_7)
            .maxTokens(4096L)
            .addUserMessage("Read the number from '/tmp/number.txt' and calculate its square")
            .addTool(CodeExecutionTool20250825.builder().build())
            .build();

        Message response2 = client.messages().create(params2);
        System.out.println(response2);
```

--------------------------------

### Connecting to Multiple MCP Servers

Source: https://platform.claude.com/docs/en/agents-and-tools/mcp-connector

Example configuration for connecting to and utilizing tools from multiple MCP servers simultaneously. Each server requires a definition in 'mcp_servers' and a corresponding 'mcp_toolset' in the 'tools' array.

```json
{
  "model": "claude-opus-4-7",
  "max_tokens": 1000,
  "messages": [
    {
      "role": "user",
      "content": "Use tools from both mcp-server-1 and mcp-server-2 to complete this task"
    }
  ],
  "mcp_servers": [
    {
      "type": "url",
      "url": "https://mcp.example1.com/sse",
      "name": "mcp-server-1",
      "authorization_token": "TOKEN1"
    },
    {
      "type": "url",
      "url": "https://mcp.example2.com/sse",
      "name": "mcp-server-2",
      "authorization_token": "TOKEN2"
    }
  ],
  "tools": [
    {
      "type": "mcp_toolset",
      "mcp_server_name": "mcp-server-1"
    },
    {
      "type": "mcp_toolset",
      "mcp_server_name": "mcp-server-2",
      "default_config": {
        "defer_loading": true
      }
    }
  ]
}
```

--------------------------------

### Usage Iterations JSON Structure

Source: https://platform.claude.com/docs/en/agents-and-tools/tool-use/advisor-tool

Example of the usage object containing iterations for both executor and advisor messages.

```json
{
  "usage": {
    "input_tokens": 412,
    "cache_read_input_tokens": 0,
    "cache_creation_input_tokens": 0,
    "output_tokens": 531,
    "iterations": [
      {
        "type": "message",
        "input_tokens": 412,
        "cache_read_input_tokens": 0,
        "cache_creation_input_tokens": 0,
        "output_tokens": 89
      },
      {
        "type": "advisor_message",
        "model": "claude-opus-4-7",
        "input_tokens": 823,
        "cache_read_input_tokens": 0,
        "cache_creation_input_tokens": 0,
        "output_tokens": 1612
      },
      {
        "type": "message",
        "input_tokens": 1348,
        "cache_read_input_tokens": 412,
        "cache_creation_input_tokens": 0,
        "output_tokens": 442
      }
    ]
  }
}
```

--------------------------------

### Represent a tool use block

Source: https://platform.claude.com/docs/en/agents-and-tools/tool-use/overview

Example of the JSON structure returned by Claude when it decides to invoke a tool.

```json
{
  "type": "tool_use",
  "id": "toolu_01A09q90qw90lq917835lq9",
  "name": "get_weather",
  "input": { "location": "New York, NY", "unit": "fahrenheit" }
}
```

--------------------------------

### Python: Self-Documenting Configuration Constants

Source: https://platform.claude.com/docs/en/agents-and-tools/agent-skills/best-practices

This Python code demonstrates good practice for configuration parameters by using self-documenting constants with comments explaining their justification.

```python
# HTTP requests typically complete within 30 seconds
# Longer timeout accounts for slow connections
REQUEST_TIMEOUT = 30

# Three retries balances reliability vs speed
# Most intermittent failures resolve by the second retry
MAX_RETRIES = 3
```

--------------------------------

### Extract PDF text with pdfplumber

Source: https://platform.claude.com/docs/en/agents-and-tools/agent-skills/best-practices

A concise example demonstrating text extraction from a PDF using the pdfplumber library.

```python
import pdfplumber

with pdfplumber.open("file.pdf") as pdf:
    text = pdf.pages[0].extract_text()
```

--------------------------------

### Enable All Tools with Default Configuration

Source: https://platform.claude.com/docs/en/agents-and-tools/mcp-connector

A simple configuration to enable all tools from a specified server without any specific overrides.

```json
{
  "type": "mcp_toolset",
  "mcp_server_name": "google-calendar-mcp"
}
```

--------------------------------

### Build a streaming chat UI

Source: https://platform.claude.com/docs/en/agents-and-tools/agent-skills/claude-api-skill

Example task for building a chat interface using the Claude API in TypeScript.

```text
Build a streaming chat UI with the Claude API in TypeScript
```

--------------------------------

### Execute Code and Read File in Ruby

Source: https://platform.claude.com/docs/en/agents-and-tools/tool-use/code-execution-tool

This Ruby example demonstrates writing a file with a random number and subsequently reading it to calculate its square using the code execution tool.

```Ruby
require "anthropic"

client = Anthropic::Client.new

response1 = client.messages.create(
  model: "claude-opus-4-7",
  max_tokens: 4096,
  messages: [
    { role: "user", content: "Write a file with a random number and save it to '/tmp/number.txt'" }
  ],
  tools: [
    { type: "code_execution_20250825", name: "code_execution" }
  ]
)

container_id = response1.container.id

response2 = client.messages.create(
  container: container_id,
  model: "claude-opus-4-7",
  max_tokens: 4096,
  messages: [
    { role: "user", content: "Read the number from '/tmp/number.txt' and calculate its square" }
  ],
  tools: [
    { type: "code_execution_20250825", name: "code_execution" }
  ]
)

puts response2.content
```