claude

Claude

Claude (by Anthropic) is OpenAI's main competitor. It is famous for its large context window (200k+), low hallucination rates, and "Artifacts" UI.

When to Use

• Advanced Reasoning & Complex Analysis: Claude 3.5 Sonnet / Opus for intricate coding, mathematics, and logic.
• Prompt Caching on Large Contexts: Slashing latency and cost by up to 90% for repeated documentation, codebases, and books.
• Reliable Tool & Function Calling: Multi-turn agentic workflows invoking APIs and external tools with strict schema adherence.
• Vision & Document Intelligence: Transcribing, analyzing, and extracting data from charts, screenshots, and PDFs.

Quick Start

import anthropic

client = anthropic.Anthropic()

message = client.messages.create(
    model="claude-3-5-sonnet-20241022",
    max_tokens=1024,
    system="You are an expert software architect.",
    messages=[
        {"role": "user", "content": "Explain event sourcing in 2 sentences."}
    ]
)

print(message.content[0].text)

Core Concepts

Tool Use (Function Calling) with Anthropic SDK

Exposing structured tools to Claude for agentic execution:

import os
from anthropic import Anthropic

client = Anthropic(api_key=os.environ.get("ANTHROPIC_API_KEY"))

tools = [
    {
        "name": "lookup_user_balance",
        "description": "Retrieve current account balance and active currency for a customer.",
        "input_schema": {
            "type": "object",
            "properties": {
                "customer_id": {"type": "string", "description": "The unique customer UUID"},
            },
            "required": ["customer_id"],
        },
    }
]

response = client.messages.create(
    model="claude-3-5-sonnet-20241022",
    max_tokens=1024,
    tools=tools,
    messages=[
        {"role": "user", "content": "What is the balance for customer cust_98234?"}
    ]
)

# Inspect tool use request
for content in response.content:
    if content.type == "tool_use":
        print(f"Tool Requested: {content.name}")
        print(f"Arguments: {content.input}")