Claude Official Skill: claude-api

What it is

The claude-api skill is an official Claude Code skill maintained by Anthropic. It activates automatically when your code imports anthropic, @anthropic-ai/sdk, or claude_agent_sdk, and provides Claude Code with the knowledge to build LLM-powered applications correctly. The skill covers prompt caching, streaming, tool use, vision, and the managed agents API.

This skill targets developers building production applications on the Claude API who want Claude Code to generate correct, idiomatic SDK code rather than guessing at API shapes.

How it saves time or tokens

Without this skill, Claude Code may generate outdated or incorrect API calls for Anthropic-specific features like prompt caching or extended thinking. The skill injects current API patterns so generated code works on first run. It also teaches Claude Code to use prompt caching by default, which can reduce token costs by up to 90% for repeated prefixes.

How to use

1. Install the skill in Claude Code:

claude skill install anthropics/skills/claude-api

1. Or manually place the skill file:

mkdir -p .claude/skills/claude-api
# Copy SKILL.md content to .claude/skills/claude-api/SKILL.md

1. Start coding with the Claude API -- the skill activates automatically:

import anthropic

client = anthropic.Anthropic()
message = client.messages.create(
    model='claude-sonnet-4-20250514',
    max_tokens=1024,
    messages=[{'role': 'user', 'content': 'Hello'}]
)
print(message.content[0].text)

Example

import anthropic

client = anthropic.Anthropic()

# Streaming with tool use
with client.messages.stream(
    model='claude-sonnet-4-20250514',
    max_tokens=1024,
    tools=[{
        'name': 'get_weather',
        'description': 'Get current weather for a city',
        'input_schema': {
            'type': 'object',
            'properties': {
                'city': {'type': 'string'}
            },
            'required': ['city']
        }
    }],
    messages=[{'role': 'user', 'content': 'Weather in Tokyo?'}]
) as stream:
    for text in stream.text_stream:
        print(text, end='', flush=True)

Related on TokRepo

• AI tools for coding -- Other developer tools and coding assistants
• Prompt library -- Curated prompts and skill files for AI coding tools

Common pitfalls

• Forgetting to set the ANTHROPIC_API_KEY environment variable before running -- the SDK throws a generic error that does not clearly indicate the missing key
• Using an outdated model identifier; always check the current model names in the Anthropic docs as they change with new releases
• Not enabling prompt caching for repeated system prompts, which wastes tokens on every request